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  1. Where may I obtain a copy of the actual report, instead of just a summary?

    [Response: The full report won’t be finalized until April. –eric]

    Comment by cbone — 2 Feb 2007 @ 11:08 AM

  2. Just mentioning another possible environmental disaster linked to global warming and climate change: when the Greenland glaciers finally melt (either slowly or in a big whoosh) tectonic rebound will probably increase the frequency and magnitude of earthquakes around the world. The 30 foot rise in sea level will cause the Antarctic ice shelves to detach making it easier for the Antarctic glaciers to move more quickly into the ocean, causing still more sea level rise, tectonic rebound and earthquakes.

    Nice world we are leaving our grand children. And theirs.

    [Response: I am happy to be able to correct you that tectonic rebound from the Greenland ice sheet won’t have impacts on earthquakes around the world. Big earthquakes are due to processes much deeper in the earth’s crust, and much more localized. It is, on the other hand, rather likely that rising sea levels will help to destabilize the Antarctic ice sheet. On what timescale, however, remains quite uncertain. –eric]

    Comment by catman306 — 2 Feb 2007 @ 11:25 AM

  3. Minor, minor observation:

    even we need time to digest it

    I know it wasn’t the intention, but that comes across as a little arrogant. I know that you are professional climatologists and wicked smart and all, but I would have gone with sometihing like “and we need time to digest it too.”

    Minor point, but tone matters.

    [Response: Fair enough! Of course what was really meant is that virtually all of the science being reported on is stuff that we are already very familiar with. “Digesting it” means making sure that what we think is in it (even before reading it) is actually in the final text, we most of us, like you, have just gotten a chance to start reading. -eric]

    Comment by BCC — 2 Feb 2007 @ 11:27 AM

  4. The direct link to the summary report (that is, what was published today) is here:

    Keep an eye on to see the other sections as they’re released.

    Comment by Mitch Golden — 2 Feb 2007 @ 11:29 AM

  5. The immediate thing that stood out for me about the AR4 SPM is the willingness to talk (again) about “the globally averaged net effect of human activities since 1750”, whereas here and hereabouts, of recent times, there has been more of a “let’s keep it to the last ~50 years” kind of discussion (whether by accident or design).

    I find this encouraging, for the science.

    Comment by P. Lewis — 2 Feb 2007 @ 11:32 AM

  6. You can find the SPM report at:

    Comment by curving3 — 2 Feb 2007 @ 11:37 AM

  7. “Scientists offered Cash to Dispute Climate Study”

    Comment by Anonymous — 2 Feb 2007 @ 11:59 AM

  8. Note that some media have been comparing apples with pears here: they claimed IPCC has reduced its upper sea level limit from 88 to 59 cm, but the former number from the TAR did include this ice dynamics uncertainty, while the latter from the AR4 does not, precisely because this issue is now considered more uncertain and possibly more serious than before

    This is very confusing to the public. The 59 cm is the upper bound in the A1F1 scenario. I quote from AR4 —

    Models used to date do not include uncertainties in climate-carbon cycle feedback nor do they include the full effects of changes in ice sheet flow, because a basis in published literature is lacking. The projections include a contribution due to increased ice flow from Greenland and Antarctica at the rates observed for 1993-2003, but these flow rates could increase or decrease in the future. For example, if this contribution were to grow linearly with global average temperature change, the upper ranges of sea level rise for SRES scenarios shown in Table SPM-2 would increase by 0.1 m to 0.2 m. Larger values cannot be excluded, but understanding of these effects is too limited to assess their likelihood or provide a best estimate or an upper bound for sea level rise.

    Who among us expects a decreasing or linearly growing flow rate from the ice sheets until the year 2100? This would make recent trends anomalous. The public will see a lower number and not understand that the trend is “more serious than before” — and also not understand recent not-included studies that indicate accelerating flow rates in Greenland and W. Antarctica. Already there is considerable confusion in the media. This constitutes a disservice to mankind.

    Comment by Dave Cohen — 2 Feb 2007 @ 12:00 PM

  9. #1, the report can be found here

    Comment by Sean Davis — 2 Feb 2007 @ 12:07 PM

  10. Sorry to nitpick, but it would be nice if, when finalizing a report that is to be read by hundreds of millions of people, the authors could remove unfinished formating suggestions (e.g. [Numbers to be converted to mm per year] on page 5 and [To be changed: Change annotation from cnstant composition to year 2000 constant concentration. Colour central bar in grey bars and lettering to match A2, A1B, B1 curves as appropriate. Drop model numbers and move to caption] on page 21). It makes an otherwise well-crafted report appear unprofessional. Both of the copies report linked from the IPCC site have these formatting errors, at least at the time of posting:

    Comment by Zeke Hausfather — 2 Feb 2007 @ 12:09 PM

  11. I think I already found an error in the SPM! If you sum up the contributions to sea level rise from 1993-2003 in table SPM-O, you get 0.657, not 0.28. I think they screwed up the Greenland and Antarctic values, which they list as 0.21 (each). If you assume they are 0.021 instead, the sum total contribution is indeed 0.28.


    [Response: Well spotted. I noticed this as well and alerted IPCC a few hours ago. -stefan]

    Comment by Sean Davis — 2 Feb 2007 @ 12:11 PM

  12. BBC News24 are announcing it as the end of “the debate” about the reality of climate change.

    So that means the real battle to get individuals to factor this into behaviour is now starting. It seems to me that our only attainable option is to aim to take the edge off the increases by energy efficiency etc. Drop the talk about “Stop Climate Chaos”, implications that we can just stop fall in the face of evidence and reason. Argue for the attainable; piecemeal reduction of emissions. Do what you can. Every little helps.

    But I think it would have been a stronger “coup de grace” had it been presented at the same time as the WG1 Scientific Basis report. Surely as it’s based on the results of WG1 they could have finalised the full Scientific Basis first?

    These are the sort of people who do stuff as cheeky as attempting to model something as complex as climate and pull it off! (e.g. ) As an intellectual also-ran I request RealClimate leaves the ‘even’ in.

    Comment by CobblyWorlds — 2 Feb 2007 @ 12:12 PM

  13. Neal Boortz attempted to criticize the report. Very interesting and ALL flawed. What’s worse is that he uses it to convince listeners, who have no knowledge of the science and believe him.

    Comment by Karan — 2 Feb 2007 @ 12:13 PM

  14. It would be both very good and very useful to have a point by point rebuttal of the charges this fellow makes. Not being a climatologist’s but certainly someone with a great deal of interest in this subject (I am a research scientist in photobiology) who gets called on to comment occasionally on global climate change (stratospheric ozone depletion/UVB impacts) it would help to have some good strong arguments to counter the comments by this person. Good references would be most appreciative as well.

    Comment by E. C. De Fabo — 2 Feb 2007 @ 12:44 PM

  15. A few errors I’ve noted in the media coverage.

    1. Most reports I’ve heard say that the IPCC says it’s 90% likely that etc. Actually their term “very likely” means 90-99% certain.

    2. Most reports talk about temperature rise etc. by 2100. Actually the summary gives the averages expected 2090-2099, a half-decade sooner. Not significant I suppose but annoying.

    3. Most reports I’ve heard mention a 1.5-4 degree C expected rise. These are actually the best estimated central values for different economic-technological scenarios. Fair enough, but the ranges of temperatures the IPCC considers “likely” go from 1.1-2.9 for the most benign emission scenario to 2.4-6.4 for the least benign one (that’s the one with the 4.0 “best estimate”), so the actual “likely-depending-on-what-we-do” range is 1.1-6.4

    [Response: Spencer, your second point is quite relevant for sea level, where leaving off the last 5.5 years (when it rises fastest) and other technicalities are the reason why the new sea level values look a bit lower than the previous model projections. In fact, all else being equal, for any given emission scenario the new (AR4) models give a slightly higher sea level projection than the old models used in the TAR, we were told in Paris. -stefan]

    Comment by Spencer Weart — 2 Feb 2007 @ 12:48 PM

  16. O.K., so if we assume there is a human coponent, how do we know what percentage of global warming is attributable to humans and, even if we were to stop any further increase from the human component, that would slow down or even reverse the process?

    Comment by Jake — 2 Feb 2007 @ 12:53 PM

  17. Also, Spencer: let’s say “very likely” means 99% certain that (human) greenhouse gases have caused most of the observed increase in globally averaged temperatures since the mid-20th century. What does “most” mean in regard to my pending questions? Does that include gases from non-human sources? Keep in mind that the Paris study, looking at all the science of global warming, will only project a “best estimate” that temperatures will rise by 3 Celsius (5.4 Fahrenheit) by 2100 over pre-industrial levels. I doubt that is bad enough for the entire world to stop in its tracks.

    Comment by Jake — 2 Feb 2007 @ 1:19 PM

  18. #16 exactly…… if humans are the culprit…..

    Should you not be calling for reducing the human population on this planet then?

    Should you not be doing a Kyoto on China, India, and Muslims which each have approximately 1.3 billion and growing populations?

    Comment by lars — 2 Feb 2007 @ 1:31 PM

  19. Just want to think RealClimate for its efforts to help non-scientists to understand the new report. I am part of Al Gore’s Climate Project and working very hard to improve my understanding of all this to complement the local presentations of his slide show I am doing. Realclimate makes that much easier!

    Comment by Steven Leibo Ph.D. — 2 Feb 2007 @ 1:35 PM

  20. The SPM predicts 20% drop in precip in subtropics. Do we trust the models enough to beleive the projections for regional shifts in precip?

    Comment by Sashka — 2 Feb 2007 @ 1:38 PM

  21. Release of this new IPCC summary is a profound event and will be covered by every major newspaper in the world, as it should. Scientifically speaking, no other domain benefits from such a magnificent collaboration of investigators, whose task is to summarize the published literature into concise, universally usable reports – imagine if every field of science had the benefit of such review! What a boon to researchers and the public both. But climate-related science especially demands this level of attention – it is a political decision to do this, not merely an intellectual one, for it reflects the importance and urgency of the relevant information, not to mention the widespread lack of action that it suggests is needed.

    To my mind, as a sometime student and scholar of scientific expression past and present, the report is a well-tuned document. It’s authors have clearly learned a thing or two from the last go-around. It is crisp, data-rich, fairly well-organized, and confident in its points. It uses qualitative but explained probabilities (extremely likely, very likely, likely, etc.), discusses (in yellow-highlighted boxes) the significance of the knowledge domain covered by each section, and admits uncertainties. It is not a policy document, per se: it does not recommend or critique specific measures, ideological concepts, weigh risks and benefits, or the like. It has what might be termed a low intimidation factor, meaning that nearly all the scientific points are comprehensible to the educated layperson. There is a pictorial rhetoric, too, that is very effective. The graphics, though placed at the end instead of embedded in the narrative (as in most scientific documents) are improved from the TAR (2001 report). Going through them has a cumulative effect that even supersedes that of the text. Especially interesting and well-done, in visual terms, is the global map showing temperature trends since 1900 for the major continents. The final two pages of figures, a culmination of sorts, showing predicted temperatures and precipitation patterns for the remainder of the century, are visually striking, and thus daunting. There is calculated force here (on the eye and mind), to be sure, but one that is warranted by the results. To claim this as “propaganda” would be absurd and naive: all effective documents employ these sorts of persuasive tools, and have done so since manuals of rhetoric were written in Greek and Roman times (Galileo’s famous little book, Sidereus nuncius, with the first pictures of a rocky moon, is a superb example).

    But here’s another point. It is not just the content of this document that matters with regard to its place in our evolving discussion on climate change, but how it’s represented in the media. This may be obvious, but the reality is a complex affair. Compare, for example, this morning’s coverage by the International Herald Tribune and our favored NYTimes. The former discusses the importance of the report, it’s confirming aspects with regard to the phenomenon of global warming, and implications, with some spicing of comments by authors and reviewers, some rather silly ones (“This is real. This is real. This is real.”) Most important, though, the article emphasizes that the science is not complete but in progress, and that the new report represents a further step in this process. Yes, we all know this, but saying it in these terms is fairly rare in newspaper and tv reports. As for the NYTimes, they decided to beat the drum of controversy: “Even before its release, world climate report is criticized as too optimistic.” It is focused almost entirely on the discussion over predicted sea level rise – the decision of the IPCC not to include potential ice melt, which is largely (as I understand it) due to timing issues of the published material and also uncertainties related to modeling. Moreover, the article ends with a little melody from Fred Singer about the IPCC being the contrarians now. This is indeed poor stuff from our most valued daily paper, but not really surprising.

    The media are able to bring a critical faculty to bear on scientific subjects, but choose to do so on a haphazard and selective basis. Highlighting controversy, or manufacturing it, is not merely a way to attract attention; it is also a means of distinguishing your own reporting from that of other papers. The most basic aspect to climate science – that it is science-in-the-making, always advancing, always partial, always ready to jettison some things and improve others, and therefore any summary of it will be no more than a snapshot of what has already been surpassed – does not make for good news all the time. Reporters serve different masters than scientists, not necessarily kinder and gentler ones. The final truth is that the media are not necessarily well-qualified, on their own, to transmit technical knowledge to the public, but they are what we have. To understand these matters better, I’d recommend reading Dot Neklin’s book “Selling Science,” which remains the more clear-eyed treatment of the subject.

    In the meantime, we will have to grit our teeth, hope, and sometimes smile at the popular treatment of this new, epochal report. Given the momentum that is now building in the U.S., I expect that good things will come out of the IPCC’s work. As I say, we can certainly hope so.

    Comment by Scott L. Montgomery — 2 Feb 2007 @ 1:41 PM

  22. Jake at #16:

    If you look at the SPM, page 16, there is a nice table of the magnitudes of various factors, anthropogenic and natural. The anthropogenic factors total out to a forcing of 1.6 Watts/m^2, while the natural factors are 0.12. Clearly, the human factors are the biggie. The vast majority of the current warming is ‘our fault.’

    There was also discussion of the ‘% attribution’ question here at RealClimate back in October:

    As for how much we have to change our behaviors before we restore our climate to a pre-industrial state, I think it can’t happen. A certain amount of warming is going to be with us for centuries. What we have to do is stop accelerating the process, so that the total warming is smaller than what are are currently heading towards.

    Comment by Mike — 2 Feb 2007 @ 1:44 PM

  23. Scientists and economists have been offered $10,000 each by a lobby group funded by one of the world’s largest oil companies to undermine a major climate change report due to be published today.
    Letters sent by the American Enterprise Institute (AEI), an ExxonMobil-funded thinktank with close links to the Bush administration, offered the payments for articles that emphasise the shortcomings of a report from the UN’s Intergovernmental Panel on Climate Change (IPCC).,,2004399,00.html

    Comment by Sashka — 2 Feb 2007 @ 1:50 PM

  24. Jake, see the name immediately above your question? click on it to read:

    Comment by Hank Roberts — 2 Feb 2007 @ 1:55 PM

  25. The comment taken from the leftist rag the Guardian, “Scientists and economists have been offered $10,000 each by a lobby group funded by one of the world’s largest oil companies to undermine a major climate change report due to be published today”…

    Hmmm, so what did the IPCC pay people who for the most part aren’t scientists to come up with this myth called global warming?

    [Response: Indeed an intellectually brilliant conspiracy theory… But in case anyone seriously wants to know: the 600+ scientists working on the IPCC reports do this for free in their spare time. That involves lots of hours wading through review comments (the report attracted over 30,000 such comments), and evenings and weekends away from the family. A voluntary effort I right now don’t feel like ever doing again, once seems enough for a lifetime… -stefan]

    Comment by juandos — 2 Feb 2007 @ 2:08 PM

  26. I would like to see more discussion of the reasons for the increase in probability regarding man induced climate change and how one goes from a 60 percent probability to a ninety plus probability. It’s not like rolling dice, I presume, so how precise are these probability estimates. Are they similar to the kinds of probabilities we get from noaa when we look up the forecasted weather? Or what?

    The primary reason I bring this up is the fact that Lindzen seemed to make fun of the whole notion of probability the other night on CNN. Yes, I can understand that all this data and analysis makes us more certain, but is it really reasonable to put a number on it?

    Comment by tom street — 2 Feb 2007 @ 2:08 PM

  27. Re: 2

    Could tectonic rebound from ice loss on Greenland and Antarctic result in additional significant increases in sea level?

    For example, if something raised a portion of the bottom area of a lake, the displacement of the water would increase the surface level of the lake (assuming no lake outlets).

    Comment by Pat Neuman — 2 Feb 2007 @ 2:10 PM

  28. Does anyone know of any literature summarizing positive feedback effects. In particular I am interested in boreal permafrost feedbacks such as thawing permafrost, burning boreal forests…do these feedbacks overtake man made emissions scales and were these considered in the report findings such as shrinking sea ice was (hopefully)?

    Comment by Jason Burford — 2 Feb 2007 @ 2:16 PM

  29. First, I totally agree with point 8 – why did they put in a 59cm upper bound that nobody seems to think is likely to be right – it is confusing, misleading and will be seized on by contrarians. At the very least they should have included an apples to apples comparison, as well as the one discounting the effect, especially in the summary, which is all that many folks will ever read.

    Second – Point 13, Neal Boortz discussion – even if he was right, which is unlikely, he still seems to be saying that global warming is happening. Also he says that the IPCC are saying it is futile as we can’t stop it. That does seem to be the impression I get as well.

    It seems to me that we need to start taking the whole issue of what to do about it a lot more seriously – emissions control is not going to be enough, even if it was incredibly aggressive, and the more optimistic models are right.

    We are most likely going to have a sea level rise over the next century that will cause problems, and the rise will continue in the century after that, and possibly for quite a bit longer.

    Either we need to really give up on places like Bangladesh and Venice and Northern Africa and so on, or we need to get some serious research going into putting the genie back in the bottle.

    I know this is not a popular sentiment amongst climate scientists right now but I really don’t see that we have a choice, do we? Either we accept widescale disruption in the next 100-300 years with phenomenal human cost, or get cracking on finding additional techniques as well as the current ‘reduce carbon emissions’.

    Any additional techniques, such as widescale stratospheric aerosols, or iron filings in the ocean or such like are going to take a decade or more to research, do tests with etc. During that time, the accuracy of models will continue to improve, as will our understanding of ice melt behaviour and the other uncertainties.

    My current project is investigating the current set of options we have for attempting to reduce the impact of global warming – there are about a dozen methods at the moment, varying from plausible to blue sky. We need to push research for this sort of work way up the agenda, instead of it being the poor cousin to analysing what is actually happening – they go together – understand how it works and then changing things to improve the situation.

    Please note – I completely believe the current approach of reducing carbon emissions is necessary, so that we can return to a relatively stable climate and avoid having an even bigger problem to face in the future. But while that happens, I think we have to have additional measures in place, or face a huge human cost.

    Contrarians talk about how we will eventually go into the next ice age, as the climate changes no matter what we do. That is very likely true, and when that starts to happen, we are also going to have to deal with it, or accept even more destructive changes to the planet (I don’t want to get into the philosophy here of that issue…). That is not a reason to ignore the current problems. We have built a world that depends on a very stable climate, and until the population drops dramatically or we can easily adjust, we are going to have to try to maintain that stability, against the current warming and a future cooling.

    Comment by Jeremy Kenyon — 2 Feb 2007 @ 2:24 PM

  30. A question regarding sea water rise…
    If seawater would rise … say 10 m … would the seafloor compact a bit, resulting in less than 10 m effetive rise?

    Comment by Mattias Dahlstrom — 2 Feb 2007 @ 2:24 PM

  31. Pat Neuman — Tectonic rebound takes many thousands of years. The rebounding area you suggest is but a tiny fraction of the surface area of the oceans.

    Comment by David B. Benson — 2 Feb 2007 @ 2:26 PM

  32. A few comments:

    RC writes:

    How good have previous IPCC reports been at projecting the future? Actually, over the last 16 years (since the first report in 1990), they’ve been remarkably good for CO2 changes, temperature changes but actually underpredicted sea level changes.

    The AR4 states:

    Since IPCC’s first report in 1990, assessed projections have suggested global averaged temperature increases between about 0.15 and 0.3ºC per decade for 1990 to 2005. The can now be compared with observed values of about 0.2ºC per decade, strengthening confidence in near-term projections.

    Indeed, the observed trend in global temperatures is about 0.2ºC per decade from 1990 to 2006 (or 2006 for that matter). What seems to be forgotten both by the IPCC and Rahmsdorf et al. (or at least swept far under the rug in Rahmsdorf et al.), is that a big volcano went off in 1992 and cooled global temperatures for 2-3 years afterwards (if not a bit longer). A big non-anthropogenic cooling near the beginning of the period of record being compared in one dataset (the observed data) and not in the other (the collection of IPCC model results) doesn’t lend itself to an appropriate comparison. Using a longer period of record, say 1977-2006, shows the observed global warming to be about 0.17ºC per decade, or, alternatively, removing the known volcano-influenced years, say 1992 and 1993, from the 1990-2005 period of record produces a warming rate of about 0.15ºC per decade. Take your pick. But, in either case, the observed warming rate is certainly in the low range of IPCC projections (from any IPCC report) for the period 1990-2005.

    Also, RC comments about sea level rise and the potential contribution from ice sheet dynamics, quoting the IPCC AR4 SPM:

    Dynamical processes related to ice flow not included in current models but suggested by recent observations could increase the vulnerability of the ice sheets to warming, increasing future sea level rise. Understanding of these processes is limited and there is no consensus on their magnitude.

    I would like to add that also found in the IPCC AR4 SPM is the following concerning the role of dynamic ice processes on sea level rise:

    Models used to date do not include uncertainties in climate-carbon cycle feedback nor do they include the full effects of changes in ice sheet flow, because a basis in published literature is lacking. The projections include a contribution due to increased ice flow from Greenland and Antarctica at the rates observed for 1993-2003, but these flow rates could increase or decrease in the future. For example, if this contribution were to grow linearly with global average temperature change, the upper ranges of sea level rise for SRES scenarios shown in Table SPM-2 would increase by 0.1 m to 0.2 m. Larger values cannot be excluded, but understanding of these effects is too limited to assess their likelihood or provide a best estimate or an upper bound for sea level rise.

    Notice the phrase “but these flow rates could increase or decrease in the future” [emphasis mine]. While some commentors may choose to ignore this (e.g. RealClimate) and others may think that it is a “disservice to mankind” (e.g. comment #8), nevertheless, the IPCC authors felt that the current state of the science necessitated its inclusion.

    -Chip Knappenberger
    to some degree, funded by the fossil fuels industry since 1992

    [Response: First, my name is Rahmstorf. Second, I find your accusation that we sweep something under the rug bizarre, since we show all the data since 1973. I invite everyone to see for themselves; to those without subscription, our paper can be accessed through the link on my home page. -stefan]

    Comment by Chip Knappenberger — 2 Feb 2007 @ 2:34 PM

  33. Re: #28. Something else would sink as Greenland rose but the timing would vary and contribute to the natural sloshing around of global sea level. I post this because I’m amazed at our need to totally understand how the earth and everything works. Somewhere, sometime, some comedian needs to do a skit of how we torture ourselves over our need to know every little detail. It kills my wife. Much more to worry about right now, but as an example the U.S.’s Gulf of Mexico coastline is slowly sinking in response to the melting and subsequent rise of the lands once under the laurentide ice sheet (see Gonzales and Tornqvist in Eos, Vol. 87, No. 45, 7 November 2006).

    Comment by Andrew Sipocz — 2 Feb 2007 @ 2:39 PM

  34. Would the moderators consider deleting the ignorant, sneering, hostile, insulting, content-free and completely worthless remarks from the flame troll identifying himself as “juandos”? Such drivel belongs on Free Republic or some other right-wing hangout, not here.

    Comment by SecularAnimist — 2 Feb 2007 @ 2:57 PM

  35. Re 21 [SPM and the media]

    As Scott writes: The media are able to bring a critical faculty to bear on scientific subjects, but choose to do so on a haphazard and selective basis.

    Indeed. Several media venues have a different spin.

    Popular media behavior is shaped by market forces; hence, the need for a hooking headline and topic based on culling and maintaining readership. Akin to what you have said, I submit media choices are the best guess of an editor seeking to satisfy readership, advertisers, and stockholders.

    Meanwhile, I am going to keep my eyes out for the reaction of ecologists–who can try to make sense of what will happen in the oceans–as currents accommodate to new exchanges of energy, and the poles continue to warm so much faster than the rest of the globe.

    Frankly, my guess is one may very well be able to start watching the collapse of ocean food chains on the news eventuallyâ��partly due to pollution, and overexploitationâ��and now overtaxed by new ocean transport current relationships which are sure to emerge–perhaps without specific prediction. While the task of the IPCC does not stipulate exploring the reaction of ecosystems, the crux of our most vexing of problems will be how the Earth as a whole reacts on a granular level to the new phase composite of climate. Sea level rise may rank as the simplest tasks to deal with.

    So far, rather predictably, the reaction to the report seems to resolve around preconceived attitude and how one tends to lens the world. As others have implied in an earlier thread, pure unadulterated science transcends rhetoric. Move to science applied, and politics rears a head. (The Boortz fellows web site left me shaking my head.)

    As an aside, reading the many earlier threads as of late, on real climate, has been quite time consuming�yet worthwhile. To see such discourse, with some well founded scientific explanation and outlinks�I am thankful.

    Comment by Jim Redden — 2 Feb 2007 @ 3:06 PM

  36. Thanks for your comment. I wanted reassurance, with the thaws happening much quicker now vs the thaws in Earth’s history and those which didn’t involve Greenland and Antarctica. I’ve seen photos of the mud flats near near Anchorage, apparently from rebound. I was surprised by the magnitude of the lifting in that area. Maybe there’s more at work near Anchorage than rebound – like the giant quake they had in the 1960s.

    Comment by Pat Neuman — 2 Feb 2007 @ 3:08 PM

  37. Typo police:

    Actually, over the last 16 years (since the first report in 1990), they’ve been remarkably good for CO2 changes, temperature changes but actually undepredicted sea level changes.

    I assume you meant to type underpredicted. Keep up the good work!

    [Response:Thanks! – gavin]

    Comment by LochDhu — 2 Feb 2007 @ 3:31 PM

  38. Does the IPCC address the recent paper by Lyman et al., documenting ocean cooling the past couple years? Or has this work been dated already by more recent data?

    Comment by Mark Zimmerman — 2 Feb 2007 @ 3:39 PM

  39. I do not know if anyone will ever work out the evidence, but this lay reader is assured the contributors of Real Science have been a strong support for the work of hundreds of scientists who have worked to make the report of or to the IPCC the best science can do. This is due to the steadfast centering function RC has performed. Unhappily it will now be needful to prepare for the attacks of a crowd of ideologues who are even worse than the gang that could not count, the economists. I guess someone will come forward, but they will have quite a job to measure up to the standard RC has set. Three cheers and a tiger.

    Comment by garhane — 2 Feb 2007 @ 3:39 PM

  40. Climate change. Maybe man made maybe not! But what does it matter. We obviously will have to make some tough decisions!
    Let me pose a Question?
    Lets say there is a large asteroid discovered on a collision course with earth!
    At that time, we may have many ways of which to stop this catastrophe. But maybe just maybe this is our only oppotunity to reverse the global warming issue by allowing it to strike! Therebye starting a new iceage.
    Are we ready to assume all resposibility for mankind who seems to be more concerned about whats causing global warming then the ultimate effects of sustained ignorance will lead us.

    Some day we will have to decide!
    It may mean that we lose half of the earths population but mankind will endure.Or will we?

    Comment by James Stample — 2 Feb 2007 @ 3:55 PM

  41. #11: data for Greenland and Antarctica are messed up for the 1961-2003 period as well (factor of 10 too high). I guess those data were in mm/year instead of m/century (cf. the editing note above the table that they forgot to remove). Probably American authors, for them mm are units from Mars, like Btu/ft2/h for us Europeans.

    Comment by Ark — 2 Feb 2007 @ 4:08 PM

  42. RE #12, yes, every little bit helps. So print these 21 pages on used paper, if possible, or doubled-sided on recycled paper. I get my used paper at the university library, mainly page separator sheets, and it’s high grade. First REDUCE, second REUSE, third RECYCLE.

    I forgot what the cut-off date was for the journal articles included in AR4. Was it June 2005 or 2006?

    I always take these reports as being on the conservative side of conservative, since they require great consensus, beyond the typical conservative (false-positive avoiding) single scientific studies. I think the cutting edge studies of dangerous predictions would indicate greater harms than what IPCC indicates (though the reports do include ranges, but may excluded the highest ends).

    Another point, each succeeding report not only reveals greater precision in the science, but also that global warming is more potentially dangerous than experts had earlier thought. I might be wrong, but that’s the sense I get.

    Comment by Lynn Vincentnathan — 2 Feb 2007 @ 4:25 PM

  43. Ark, You’re right. They apparently screwed up the Antarctic contribution for 1961-2003 as well in Table SPM-0. Also, if you assume they meant 0.014, the numbers in the 1961-2003 column don’t add up (i.e. .042+.05+.05+.014 = .156, NOT .11 as they have in the table)

    Comment by Sean Davis — 2 Feb 2007 @ 4:40 PM

  44. [[Now that you are one of those who are either ignorant beyond all help or just a pathological liar, do you have any other excuses for being a fear monger?

    Just asking… ]]

    Stay off the sauce when you post. It improves the quality of your prose.

    Comment by Barton Paul Levenson — 2 Feb 2007 @ 4:44 PM

  45. Where is the discussion of natural variability in all this? There is of course the minor contribution of solar irradiance but the changes over the ENSO cycle, over decadal timescales and over longer period don’t rate a mention. The decadal variance in particular is dismissed at Wikapedia as climate noise and addressed on this site as a single paragraph and a blind link. How is this possible?

    The cyclical changes in global temperature and climate more generally over periods of decades – to 1946, 1947 to 1975 and 1975 to 1998 in the instrument record – and, from proxy data, occuring 11 times in the past 400 years with an average duration of 23 years.

    FAR predicts a 0.2 degree C/decade rise in temperature over the next couple of decades. The history of decadal variability suggests that temperatures will decline (since 1998) over the next couple of decades – well before which the entire science community is utterly discredited. Don’t believe me – this is very simple experiment and one that doesn’t require 5000 of the world’s leading scientists.

    Random fluctuation is not much of an explanation for such a persistent and influential phenomenon. I feel like being very rude but will of course refrain. Feel free to claim that the temperature decline since 1998 is random climate noise – pretty much as the CRU did on New Years Day 2007 when claiming, after 2006 came in at the sixth warmest year, that 2007 will surely see the upward trend return. I am not likely to be listening until I see the data.

    Comment by Robert Ellison — 2 Feb 2007 @ 4:45 PM

  46. Says RK Pachauri, DG, The Energy and Resources Institute & Chair IPCC: “A number of scientists say Siachen should be made a protected area, a heritage site of sorts, and that there should be no army presence on either side. For purely ecological reasons, this *might* be a good idea. But I *don’t* see why there would be melting as a result of military presence and activity.” The *s show a vagueness unworthy of an environment leader who ought to ask for withdrawal of all troops immediately’
    Please Cleck to see how indian and Pakistan Army melting Siachen glacier – 58k – – 32k – Cached – Similar pages – 39k – Cached – Similar pages – 21k – Cached – Similar pages

    Comment by Ajit Singh — 2 Feb 2007 @ 4:45 PM

  47. While you can appreciate the representation of scientific knowledge, available late 2006, in this IPCC report, you might wonder how it will affect the political decision-chain. Here in the Netherlands, the rather conservative estimates on sea-level-rise already led to (secondline) features in the national television news show, in which the one-line statement “Holland will not be flooded…” sounded like a sense of relief. But even without accounting for possible dynamic changes in icecaps the consequences stated in the report make clear there is not much relief while reading carefully. My point is that it is not just a question of how much sea-level-rise will occur. Agricultural and land-use change, growing salinity of groundwater and estuaries, re-arranging drinking-water facilities, changing character of rivers etcetera. This will put an ever growing strain on our national budget. Not to mention the help we might want to offer in less fortunate regions in the coming world. It is time to be clever and to accept that it might cost us a considerable amount of our “business as usual” to cope. I just hope the full fourth assessment will contribute to that awareness!

    Comment by Hans Vermeer — 2 Feb 2007 @ 4:46 PM

  48. Any significance to the fact that the report was released on Grounfhog Day? “If the groundhog sees his shadow, there’ll be another six weeks of winter.” (Probably as valid as some of the exquisitately accurate computer modelling with questionable input data.)

    Comment by Lee Morrison — 2 Feb 2007 @ 4:55 PM

  49. Sea stand rise — On another thread, Nigel Williams asked for a 500 year prediction. I offered 7 m for the melting of the Greenland ice sheet and up to 20 m (conservatively high) for the melting of the West Antarctic ice sheet. So minor adjustments due to isostacy and tectonic rebound are just too insignificant to consider when faced with a long-range prediction of 22–27 m.

    Comment by David B. Benson — 2 Feb 2007 @ 5:00 PM

  50. One query concerns precipitation. In a warmer world the oceans will warm, causing more evaporation. The warmer air will be able to hold more water. Therfore one would expect a greenhouse world to be a lot wetter. Yet the report forecasts droughts and reductions in rainfall most places.
    This is odd, especially in the tropics where there will be a lot of extra precpitation looking for somewhere to go. Where will it all end up?

    Comment by David Price — 2 Feb 2007 @ 5:06 PM

  51. #15, thanks, Spencer, for that clarification. I had thought that 1.5-4 degree C range must have been the climate sensitivity range for 2X CO2, because 4 degrees didn’t seem like the worse-case human emissions scenario (at highest sensitivity). And I believe TAR had the upper figure (of worse case scenario) at 5.8 degrees C. So the AR4 figure would be an increase — am I right? But the media have been jumping around these past few months saying AR4 indicates GW will not be so bad, bec they’ve ratcheted down the warming figures.

    #16, Jake, I’m also concerned with natural GHG emissions increasing due to the warming that the human emissions have caused. I do hope AR4 deals with that, even though such positive feedbacks entail a lot of uncertainty.

    So my question then would be, is 6.4 degrees C the upper end only for the worst case of human emissions (at the highest sensitivity), and thus leaves out the positive feedbacks (nature emitting due to the warming, lower albedo from melting ice)? I mean, is there a possibility of even a higher temp when both human emissions and positive feedbacks are considered.

    From what I understand, positive feedbacks (e.g., from melting permafrost & clathrates, & reduced albedo) are not included in the models.

    #17, I do think a 3 degree increase would be pretty disasterous, esp for the poor peoples of the world (& it would make the rich a lot poorer); it’s sort of like the reichter scale – the change from a 6 to a 7 involves a lot more danger & harm than from a 5 to a 6, so a rise from 2 to 3 degrees C with GW would probably entail a lot more harms than a 1 to 2 degree increase, with a 5 to 6 degree increase extremely bad. You don’t want to go there. I’m just waiting to get Mark Lynas’s SIX DEGREES when it comes out in March; in lay language he takes us through each degree increase — 1, 2, 3, 4, 5, 6 degrees — and what each degree increase would mean re effects and harms.

    Comment by Lynn Vincentnathan — 2 Feb 2007 @ 5:09 PM

  52. Just today the opposition ( is claiming that language such as “One final point is that improvements in the clarity of the language from the SPM should be propagated back to the individual chapters in order to remove any superficial ambiguity. The science content will not change.” is simple proof that making the science fit the summary is what is being done. The idea that a negotiated political “summary” should propagate it’s language back to the detailed science is very suspicious to many people for whom global warming as a result of human activity is NOT a clear fact.

    Comment by Oldfart — 2 Feb 2007 @ 5:19 PM

  53. #43: Sean, I’m pretty sure that it’s mm/year in both Greenland and Antarctic ice sheets numbers 1961-2003 (like in 1993-2003 numbers). So in metres/century: 0.042+0.050+0.005+0.014=0.111, or approx 0.11.

    Comment by Ark — 2 Feb 2007 @ 5:20 PM

  54. This is extremely shameless. Steven Milloy at has released the draft of the working group 1. How desperate will these political puppets get?

    Comment by Karan — 2 Feb 2007 @ 5:31 PM

  55. Re #15: Maybe just a typo but the SPM defines “very likely” as 90% to 95% certain, “Extremely likely” covers 95% to 99% certain. Very glad to to see the precise definitions of terms that still carry an effective qualitative message.

    Comment by Ells — 2 Feb 2007 @ 5:49 PM

  56. re 19:

    Will Al Gore adapt his sea level projection for The Netherlands?

    Comment by Hans Erren — 2 Feb 2007 @ 5:49 PM

  57. I personally believe that the biggest issue related appears to be the rate of CO2 increase and hence the time that it takes for 2 C of warming to take place. Currently annual emissions increases are 2 ppmv but recent years have seen 2.6 and 2.5 ppmv increases, if that accelerates to 3 ppmv somehow then we could be out of time as 100 ppmv increase to 480 ppmv which would take 50 years at 2 ppmv will only take 33 years at 3ppmv.

    i wonder what the latest 2006 annual increase rates are and whether this is set to increase?

    Comment by pete best — 2 Feb 2007 @ 5:53 PM

  58. I just put up a new post summarizing what (I noticed) has changed in the IPCC from TAR to AR4.
    IPCC SPM- So What’s New?


    Comment by Sean Davis — 2 Feb 2007 @ 5:56 PM

  59. (If my comment is not suitable for posting, please email me and explain why, thank you.)

    I had asked in the previous blog post (comment was not posted):

    Do we have some sort of numerical representation for the greenhouse effect? In other words, a measurement of total solar energy which reaches the surface, and what percent is direct sunlight versus what percent is the greenhouse effect. Do we have such a number, and have we tracked changes in it (and for how long?

    Thank you.

    Comment by Walt Bennett — 2 Feb 2007 @ 6:01 PM

  60. Off topic, but …

    The American Solar Energy Society today released a 200 page report, “Tackling Climate Change in the US: Potential U.S. Carbon Emissions Reductions from Renewable Energy and Energy Efficiency by 2030” which outlines how the USA can reduce its carbon emissions by 60 to 80 percent by 2030 with improvements in efficiency and deployment of existing clean, renewable energy technologies.

    The 60 to 80 percent reduction is in line with what is needed to keep CO2 concentrations below 450 to 500 ppm, which is what most scientists believe is necessary to prevent the worst effects of global warming.

    Fifty-seven percent of the carbon reductions are from energy efficiency improvements, and forty-three percent are from renewables. No expansion of nuclear power is included in the proposal.

    I know that many frequent contributors to these comment pages are very interested in solutions to the problem of reducing US carbon emissions, and will find this report useful.

    Comment by SecularAnimist — 2 Feb 2007 @ 6:08 PM

  61. Dr Rajendra Pachauri, IPCC chairman and DG, The Energy and Resources Institute & Chair IPCC: “A number of scientists say Siachen should be made a protected area, a heritage site of sorts, and that there should be no army presence on either side. For purely ecological reasons, this *might* be a good idea. But I *don’t* see why there would be melting as a result of military presence and activity.” The *s show a vagueness unworthy of an environment leader who ought to ask for withdrawal of all troops immediately! Click to see the view of chairman IPCC
    So, we should not expect a lot from IPCC, currently head by Dr Rajendra Pachauri, as his biased, unprofessional remarked already appeared in news paper and enough to say that it would be another media hype and noting else.

    Comment by Ajit Singh — 2 Feb 2007 @ 6:14 PM

  62. Walt Bennett wrote: “Do we have some sort of numerical representation for the greenhouse effect? In other words, a measurement of total solar energy which reaches the surface, and what percent is direct sunlight versus what percent is the greenhouse effect. Do we have such a number, and have we tracked changes in it (and for how long?”

    Yes, NOAA tracks that, and reports on it every year in the Annual Greenhouse Gas Index, using 1990 as the baseline.

    NOAA’s May 2006 report, for 2005, found that the total “greenhouse effect” had increased by 21 percent since 1990.

    Comment by SecularAnimist — 2 Feb 2007 @ 6:17 PM

  63. In the SPM-0 table, in the 1993-2003 column, not only do the central values not add up, but the errors don’t compute either. If the Antarctic uncertainty was 0.35m/century, that would dominate the uncertainty in the sum which would therefore have to be much larger than 0.07m/century.

    Pretty surprising to see elementary errors like this in such a profoundly important document. Too many late nights? It’s still broken as of right now.

    [Response: It’s a simple unit conversion error, some values (including their error bars) are accidentally in mm/yr, not in m/century, hence they are a factor of 10 too large. -stefan]

    Comment by Stuart Staniford — 2 Feb 2007 @ 6:28 PM

  64. More evidence of global warming:

    PUNXSUTAWNEY, Pennsylvania (AP) — A new pair of hands pulled Punxsutawney Phil from his stump this year, so it was only fitting that the groundhog offered a new prediction.

    Phil did not see his shadow on Friday, which, according to German folklore, means folks can expect an early spring instead of six more weeks of winter.

    Comment by SecularAnimist — 2 Feb 2007 @ 6:30 PM

  65. #52: Walt: Figure SPM-2 in the new summary shows the (direct) anthropogenic contribution to the greenhouse effect of 1.6 W/m2 (0.6 to 2.4 W/m2 bounds). One presumes there would be a further indirect effect of increased water vapor forcing and albedo change from melting ice that aren’t quantified here (though they do quantify albedo change from black carbon in snow and land use).

    This compares to: average sunlight: about 240 W/m2 (that’s 1368 W/m2 divided by 4 for surface area of a sphere vs. a circle times 0.7 for earth’s albedo) (said insolation keeps us at 255 K), plus natural greenhouse of about 150 W/m2 (bringing us to 288 K). With about 0.1 W/m2 solar increase since 1750.

    They don’t report the increased forcing from the 6 SRES scenarios, but I would guess (looking at temperature changes) that the direct forcing increases range from 3.5 W/m2 to maybe 12 W/m2 above preindustrial.

    So perhaps 8 W/m2 direct anthropogenic forcing, with additional forcing from water vapor/cloud and ice albedo changes of perhaps 3 times the direct effect (a rough estimate based on a climate sensitivity of 3), means 32 W/m2 human caused forcing, which would be equal to an increase of 20% in natural forcing or a 13% increase in the Sun, or an 8% increase in all forcing. That’s pretty big (enough for 6 degrees C above preindustrial at equilibrium). Obviously, changes in climate sensitivity estimates or emissions forecast can increase or decrease that number by a lot.

    (RC moderators, please correct me if I’ve made any calculation errors)

    Comment by Marcus — 2 Feb 2007 @ 6:41 PM

  66. re:53. “How desperate will these political puppets get?”

    Money talks a lot for the likes of them.

    Comment by Dan — 2 Feb 2007 @ 6:41 PM

  67. Re 49 … a lot of extra precpitation looking for somewhere to go. Where will it all end up?

    A lot of the extra precipitation will end up falling as rain in the higher latitude regions.

    The increase in humidity will increase latent heat.

    The significance of latent heat for snowmelt has been described by Dunne and Leopold (1978):

    �If water from moist air condenses on a snowpack, 590 calories of heat are released by each gram of condensate. This is enough energy to melt approximately 7.5 gm of ice, which when added to the condensate yields a total of 8.5 gm of potential runoff�.

    Comment by Pat Neuman — 2 Feb 2007 @ 6:48 PM

  68. Re: 59 – Excellent URL with good, pragmatic information. IMHO I don’t think it is realistic to assume 60 to 80% alt energy is achievable without nuclear. While I can’t speak for the other sources, I know from work experience that solar has major challenges, and even the authors of the article don’t describe potential outcomes as “likely”. But any amount would be an excellent start.

    BTW, secularanimist, go lite on us conservatives(ala 34 and other comments on RC) that don’t always agree with you.

    Comment by SolarNTrains — 2 Feb 2007 @ 7:00 PM

  69. “The major natural greenhouse gases are water vapor, which causes about 36-70% of the greenhouse effect on Earth (not including clouds); carbon dioxide, which causes 9-26%; methane, which causes 4-9%, and ozone, which causes 3-7%. It is not possible to state that a certain gas causes a certain percentage of the greenhouse effect, because the influences of the various gases are not additive.” Greenhouse Gas via Wikipedia.

    Well what is it for CO2? 9% or 26%? That looks to me a pretty big margin of error. A multitude of 3 margin of error, ouch.


    99 ppm added CO2 from pre-industrial to 2007.

    So how much more thermal energy is added to earth per square kilometer, with 99 more ppm, and how much would that theoretically raise the temperature of the earth in total? Theoretically speaking. No need to adjust for clouds, water vapor, etc, just how much more thermal energy is added.

    [Response: Funny guy. You should probably investigate where that information came from – I’m sure it’s reputable and they’ll probably explain what the range means…. (hint) – gavin]

    Comment by RepublicanGuy — 2 Feb 2007 @ 7:34 PM

  70. RepublicanGuy: 9% to 26% is not _margin of error_ it is a fundamental difficulty in assigning a number. The number you get by taking a vacuum and adding 270 ppm of CO2 is a lot different than the number you get by taking the preindustrial atmosphere and subtracting 270 ppm CO2 (I would guess that 26% is the first approach and 9 % the second). This occurs because the various gases have overlapping spectra.

    The SPM states that the increase in CO2 leads to a 1.66 W/m2 increase in forcing. I know that doubled CO2 (4 W/m2) has about a 0.8 degree C direct contribution to temperature (along with .7 to 3.7 degrees feedback), so 1.66 W/2 would be about 0.3 degree C, with 0.3 to 1.4 degree additional feedback expected. We’ve seen 0.8 degrees of warming, and expect 0.6 degrees more, which falls within that range.

    Does that answer your question?

    Comment by Marcus — 2 Feb 2007 @ 7:49 PM

  71. The current scientific consensus is (found in comparing AR-4 to TAR) based on far greater certainty that global warming is due to human actions, that the sharp rise in heat trapping gases since the 1950s is not a natural cycle, and this condition will not soon go away. The evidence is clear that actions must be taken soon because the rates at which carbon dioxide, methane and nitric oxide are increasing are unprecedented. Present levels of carbon dioxide in the atmosphere have not been detected on earth for over 600,000 years.

    Because of these facts, ocean chemistry and temperature are undergoing an accelerating change. Levels of rainfall are increasing in the polar latitudes. Heavy precipitation events occur more frequently and rapid runoff of rainwater increases the rate of erosion. In the sub-tropics there is less rainfall predicted. Given such trends, our inability to manage water, protect low-lying coastal areas and reduce the loss of topsoil should promote widespread caution.

    These facts make it clear that actions needed to cap and then reduce the rate of heat trapping gas emissions will have greater impact if taken sooner, than if we stall in efforts to be more energy efficient. Because warmer oceans and land areas will persist for decades, if not centuries, institutional changes must be encouraged now to assist the most vulnerable and curb inherent inefficiencies in power consumption and transportation.

    As the U.K. government campaign is fond of saying tomorrow’s climate depends on today’s actions.

    Comment by Joseph Siry — 2 Feb 2007 @ 8:12 PM

  72. Does anyone have any insight as to how Richard Lindzen developed views that are so far out of the scientific mainstream? Is he just kissing the hand that feeds him or are his views of climate change part of a monetary (Grover Norquist-like) or religious (rapture – obsessed) conservative ideology?

    [Response: Somebody else can figure out the psychology of Lindzen’s denialism, but it’s not really important. What’s important is whether he has any arguments that bear scrutiny. The last actual argument he published was the IRIS cloud feedback mechanism, a good many years back, which did not stand up to scrutiny. All of his earlier arguments (cumulus drying, super-lapse-rate feedback) were demonstrably wrong. So far as I can tell he has stopped making scientific arguments. That’s what counts. He’s playing his MIT professorship for all that it’s worth, but that’s all he’s got going for him right now. –raypierre]

    Comment by Dave — 2 Feb 2007 @ 9:25 PM

  73. I think Lindzen’s always been a maverick and because of that has asked questions about what others just assumed to be true. This approach may be wrong 99% of the time, but it’s the 1% that wins scientific awards. Hopefully he’ll stop wallowing in the 99% soon and move on.

    Comment by Roger Smith — 2 Feb 2007 @ 9:52 PM

  74. I’ve got to ask — what is the deal? I posted (#8), and my colleague (#64, and others) posted on how the AR4 math is wrong, showing that global sea level rise is not well accounted for in the publicly released document.

    I am forced to ask — considering some “Freudian Slip” situation — how the release of this long-awaited 2007 document could both 1) do the math wrong and 2) discount current sea-level rise trends from the big ice sheets in Greenland and W. Antarctica.

    I eagerly await some reponse — or “rationalization” — as to how this can be explained.

    Comment by Dave Cohen — 2 Feb 2007 @ 9:59 PM

  75. #71 Sorry that you disliked my post sufficiently to zap it, Dan. I’m retired, but I was a successful and (I think) respected scientist for almost 40 years. I do know a little bit about what constitutes science. Computers have made our work immeasurably easier, but they haven’t yet replaced the ability of human beings to think logically and collect data objectively. Clever computer programming is a valuable skill, but it isn’t science.

    Comment by Lee Morrison — 2 Feb 2007 @ 10:15 PM

  76. #61. Thanks very much for the link to this report! It does indeed talk about renewables and energy efficiency, as carbon mitigation measures for the U.S. and proposes we can reduce carbon emissions by 60-80 percent this way. Unfortunately, the report is a theoretical treatise–its authors were asked what they thought could be potentially accomplished, given resource assessments and technological capabilities. No consideration is given to many real world aspects, such as the politics of land use and ownership, full costs of deployment and existing power plant replacement, grid adjustments, ecological problems (due to the very large land requirements for large scale solar and wind), and much much more. These sorts of pie in the sky studies have plagued renewables from the beginning and torture us with the prospect of revolutionary change, but they do a disservice to an industry that is now in the throws of real practical expansion, due to both high energy prices and climate change worries. But these forces have their limits, as do renewables themselves. As presently conceived, renewable sources will not run the world, or even a large portion of it. They are currently less than 1 percent of global energy use, and though very important for a range of countries, from Iceland to India, they are far from equal to the task of turning over the 12 trillion dollar fossil fuel system. The future lies with energy diversity, an expanding and increasingly flexible portfolio of sources. Technology won’t solve it all, by any means, but it will help enormously. For a good discussion of energy issues related to climate change, see John Holdrens article The Energy Innovation Imperative, at
    The future lies with a diversity of sources

    Comment by Scott L. Montgomery — 2 Feb 2007 @ 10:18 PM

  77. Doing some late night reading on this subject as a result of the vast media coverage of the IPCC report. I personally haven’t really had any doubts about the human impact on global warming, but I am merely a student of Computing and have no deep scientific understanding of the subject (one tries though).
    This is just a thank you to the authors for this blog.

    Comment by Robin Henkys — 2 Feb 2007 @ 10:38 PM

  78. To the editors:

    According to The Guardian, the AEI (American Enterprise Institute) thinktank is offering $10,000 to anyone who will cast doubt on the report, scientists and economists included.

    I suggest you get a copy of that letter and publish it here, together with who funds the AEI.

    Comment by Stormy — 2 Feb 2007 @ 10:41 PM

  79. #37 Pat, Rebound has been continuous process since the last ice age, quite severe in the Arctic, where you find very old Bow head whale skeletons, ancient half burried walruss skeletal heads 160 meters above sea level! Present rate around where I live is about 2 cm a year, where raised beach ridges are a common shoreline sight..
    What recent GW does to rebound is a very good question…

    Comment by wayne davidson — 2 Feb 2007 @ 10:44 PM

  80. I blogged on the new IPCC report and my take here. Take a look and let me know what you think.

    [Response: Hi, Andrew. I think this is a very nice summary of the highlights of the report. I’ll leave it to Mike Mann to comment on your take on whether the nuances of the NAS statement on climate of the past millennium is significantly different from what the SPM says. It all comes down to details of how one estimates the uncertainty in reconstructions of medieval warmth. Nobody can say that the Medieval was definitely warmer (hemispherically) than the present, but some might say that the error bars are large enough that one cannot rule out the possibility. In some sense you are right that there were no real scientific breakthroughs reported in this round. The improvements were incremental, and the big news was in how fast the Earth’s climate is changing. The SAR, in contrast, introduced a breakthrough in the aerosol connection to interrupted warming, whereas the TAR had some breakthroughs in coupled ocean-atmosphere modelling. The timing of AR4 just missed the next big breakthrough — which will be in improved and coupled modelling of glacier dynamics, including fracture mechanics, ice shelves and all that stuff. I think one mustn’t discount a breakthrough of a technological sort in AR4 though: The number of model runs exploring more of scenario and parameter space is vastly increased, and more importantly, it is available in a coherent archive to the full research community for the first time. The amount of good science that will be done with this archive in the next several years is likely to have a significant impact on our understanding of climate. –raypierre]

    [Response: One clarification on the point made by Ray P above. Actually, the IPCC statement is stronger than what Ray suggests. The careful choice of wording by the IPCC on this indicates that they did think we can rule out the possibility that Medieval large-scale warmth was comparable to the present at a moderately (likely=67%) high level of confidence, and that is of course taking into account the fact that there are uncertainties. –mike]

    [Response: As we note in the piece above, the NRC did endorse the key conclusions of IPCC (2001) with regard to millennial reconstructions, hence news reports in e.g. Nature such as “Academy Affirms Hockey-Stick Graph”. Nonetheless, the NRC report was a rush job, was forced to ignore key papers in the pipeline, and had limited representation of experts in paleoclimatology (perhaps seeking breadth but sacrificing depth in this key area in their selection of panel members). By contrast, the IPCC was a long, careful, deliberate process, based on several years of thorough assessment of the literature, the IPCC paleoclimate chapter was written by leading experts in the field of paleoclimatology, and input was solicited from essentially every leading expert in the field. It should be unsurprising that they came to a somewhat different (and in my view, more accurate) bottom line. I hope that answers the question for you Andrew? –mike]

    Comment by Andrew Dessler — 2 Feb 2007 @ 10:51 PM

  81. Neal Boortz is on the attack :
    25 Reasons to blah, blah, blah ……

    Comment by Colorado Bob — 2 Feb 2007 @ 11:22 PM

  82. What are your thoughts regarding Christopher Monckton’s analysis of the 4AR?

    Comment by Peter — 2 Feb 2007 @ 11:53 PM

  83. Bodman et al. Embrace IPCC Report Sort Of

    After the IPCC Committee delivered its report, officials from the U.S. government gave their take on it. Energy Secretary Sam Bodman, NOAA Administrator Conrad Lautenbacher and EPA Administrator Stephen Johnson each made remarks and answered questions. (shown on CSPAN2).

    They said that they and the Bush Administration embraced the IPCC report and that without the funding for scientific research sought for and received by the president starting in 2002, the IPCC would not have been able to deliver its final product. In other words, U.S. government funded research was responsible for much of the scientific content in the report.

    Bodman cited 7 DOE supercomputers funded by the Bush administration as key elements in generating this scientific work.

    All three repeatedly referred to the $29 billion spent by the Bush administration over the last 6 years on climate change research and greenhouse gas mitigation.

    So where did this figure of $29 billion originate? Only a few years ago the White House was claiming that it spent $2 billion a year on climate research and then $3 billion and now the $29 billion figure so frequently quoted by administration spokesmen today.

    That would work out to about $5 billion per year and indeed seems be consistent with the numbers in a WH press release from last year. See below.

    From 2001 To The End Of 2006, The Federal Government Will Have Devoted Over $29 Billion To Climate Programs, More Than Any Other Nation. The President�s 2007 Budget proposes $6.5 billion for climate change activities.

    However, others, including the National Environmental Trust, the GAO and AAAS haven’t had much success in verifying these numbers.

    Some people, like James Hansen, for example, have openly complained about budget cuts in monitoring programs. What then is the true story of the $29 billion? The link below to the USAID provides a breakdown by agency and area.

    The money spent in 2006 was about as follows:

    Climate Science $1.9 billion of which $1.3 was from NASA.

    Climate Change Technology Program $2.8 billion of which $2.5 was from DOE

    Tax Credits $1 billion

    The proposed increase in 2007 is mostly due to a big increase in the tax credits, while the science funding drops off.

    EPA and NOAA’s funding are less than $200 million each, although Lautenbacher and Johnson did not seem concerned about this.

    Of the DOE’s budget, around $1.2 billion is in the category Energy Efficiency and Renewable Energy. Somewhere between $500 million and $1 billion is associated with carbon capture and sequestration.

    The biggest complaint about these numbers is that the Bush administration has continually broadened the definition of what constitutes climate change research and mitigation, thus making it appear that the funding for this area is skyrocketing when in fact it is actually going down in some categories.

    Bodman also said that the U.S. would not adopt a GHG cap unilaterally, out of concern this would drive jobs overseas to countries with no caps and lax air pollution standards, thereby making the overall problem worse.

    A reporter then pointed out that Germany has had caps in place for several years and has experienced job growth. Bodman said he was sure someone would perform an economic analysis that would clarify this.

    Another reporter asked that since California now has its own version of a GHG cap in place, wouldn’t it be expected to lose jobs? Bodman said he thought this would be the outcome.

    One hopeful note. Bodman said that U.S. scientists would be made available to talk to the media about the IPCC report. Of course, he didn’t say which scientists and under what circumstances. After all, buried somewhere in the $29 billion is a line item titled Salaries.

    Comment by Alvia Gaskill — 3 Feb 2007 @ 12:16 AM

  84. (Re: 2

    Could tectonic rebound from ice loss on Greenland and Antarctic result in additional significant increases in sea level? )

    However there are not the observed temperature changes in the Antartic, so isn’t that
    putting the cart before the horse? ….

    “Climate Change 2007: The Physical Science Basis Summary for Policymakers
    Working Group I”
    IPCC WGI Fourth Assessment Report, (Feb 2007) report

    …..”Some aspects of climate have not been observed to change. {3.2, 3.8, 4.4, 5.3}

    “â?¢ Antarctic sea ice extent continues to show inter-annual variability and localized changes but no statistically
    significant average trends, consistent with the lack of warming reflected in atmospheric temperatures
    averaged across the region. {3.2, 4.4} “….

    …”It is likely that there has been significant anthropogenic warming over the past 50 years averaged over each continent except Antarctica (see Figure SPM-4).”….

    …”â?¢ Global average sea level in the last interglacial period (about 125,000 years ago) was likely 4 to 6 m higher than during the 20th century, mainly due to the retreat of polar ice. Ice core data indicate that average polar temperatures at that time were 3 to 5°C higher than present, because of differences in the Earthâ??s orbit. The Greenland ice sheet and other Arctic ice fields likely contributed no more than 4 m of the observed sea level
    rise. There may also have been a contribution from Antarctica. {6.4}”…

    …”Current global model studies project that the Antarctic ice sheet will remain too cold for widespread surface melting and is expected to gain in mass due to increased snowfall. However, net loss of ice mass could occur if dynamical ice discharge dominates the ice sheet mass balance. {10.7}”…

    and one could refer to any of the following as well for other science on the matter

    ECORD: IODP Expedition 310-Tahiti Sea Level

    “So far, the only sea-level record that encompasses the whole deglaciation is based on offshore drilling of Barbados coral reefs which overlie an active subduction zone and was located close to the former ice sheets during the Last Deglaciation. Vertical tectonic movements in such areas may be large and are often discontinuous, implying that apparent sea level records may be biased by variations in the rates of uplift. Hence, there is a clear need to study sea level changes in tectonically stable regions or in areas where vertical movements are slow and/or regular. Furthermore, the eustatic function is best estimated from sea level data collected far from the former ice margins where the the influence of glacio-isostatic rebound is minimized”…

    Volcanic and tectonic processes coinciding with glaciation and crustal rebound: an early Holocene rhyolitic eruption in the Dyngjufjöll volcanic centre and the formation of the Askja caldera, north Iceland
    Bulletin of Volcanology 64 (3-4), 192 (2002)

    “A pronounced volcanic production maximum on the rift zones through Iceland coincided with rapid crustal rebound during and after glacier melting at the Pleistocene/Holocene boundary. At peak glaciation, ice thickness over central Iceland may have reached 1,500-2,000 m, causing 400-500-m depression of the crust. Rapid climatic improvement caused glacier melting and removal of the ice load within about 1,000 years. Low mantle viscosity resulted in rapid crustal rebound which was completed in about 1,000 years, with an average rate of uplift on the order of nearly half a metre per year over central Iceland.”..”A model is proposed involving uplift of tectonically well-defined crustal blocks to the north and west of the Askja caldera, combined with downsagging caused by voluminous outpouring of basaltic lava. The southern and eastern borders of the caldera are remnants of a subsidence following the 10-ka Plinian eruption, partly reactivated by the 1875 A.D. Plinian eruption. The model provides a satisfactory explanation for the enigmatic Ã?skjuop pass, and it is in agreement with a gravity survey of the Dyngjufjöll centre. The uplift coincided with rapid crustal rebound which was amplified by crustal deformation (doming) of the volcanic centre caused by high magmatic pressure in the plumbing system of the volcano. This is supported by emission of very large lava flows produced in the first millennia of the Holocene. ”

    Decontaminating tide gauge records for the influence of glacial isostatic adjustment: The potential impact of 3-D Earth structure
    Geophysical Research Letters 33 (24), 24318 (30 Dec 2006)

    Observation of glacial isostatic adjustment in â??stableâ?? North America with GPS
    G F Sella et al.
    Geophys. Res. Lett 34 (L02306), (26 Jan 2007)

    RE: (51. …”Yet the report forecasts droughts and reductions in rainfall most places.”)

    “Climate Change 2007: The Physical Science Basis Summary for Policymakers
    Working Group I”
    IPCC WGI Fourth Assessment Report, (Feb 2007)

    ..”â?¢ The frequency of heavy precipitation events has increased over most land areas, consistent with warming
    and observed increases of atmospheric water vapour. {3.8, 3.9}”…

    RE: (46. Where is the discussion of natural variability in all this?”)

    “Climate Change 2007: The Physical Science Basis Summary for Policymakers
    Working Group I”
    IPCC WGI Fourth Assessment Report, (Feb 2007)

    ….”â?¢ Difficulties remain in reliably simulating and attributing observed temperature changes at smaller scales.
    On these scales, natural climate variability is relatively larger making it harder to distinguish changes
    expected due to external forcings. Uncertainties in local forcings and feedbacks also make it difficult to
    estimate the contribution of greenhouse gas increases to observed small-scale temperature changes. {8.3,

    and the footnote

    “1 Climate change in IPCC usage refers to any change in climate over time, whether due to natural variability or as a result of human activity. This usage differs
    from that in the Framework Convention on Climate Change, where climate change refers to a change of climate that is attributed directly or indirectly to human
    activity that alters the composition of the global atmosphere and that is in addition to natural climate variability observed over comparable time periods.”

    Comment by BarbieDoll Moment — 3 Feb 2007 @ 12:54 AM

  85. why to the IPCC use the “Virtually certain”, “Extremely likely”, “Very likely”, “Likely”, “More likely than not”, “Unlikely”, “Very unlikely” and “Extremely unlikely” qualifiers? it makes it difficult to read. it would make much more sense to just use a range of likelyhoods – “it is 90-99% likely that x will happen.” much easier to read, and also less restrictive, as figures such as 85-95% could be used, or specific figures with uncertainties: 90% ±4%. this would make the entire report that little bit more accurate, and MUCH, MUCH easier to read.

    the same could go for the “High Confidence” etc.

    #26: absolutely classic. I haven’t heard a comment so backwards for years! I’m gonna have fun with comments like these in the next few weeks.

    Comment by naught101 — 3 Feb 2007 @ 12:55 AM

  86. A quick question for the RC crew or any other scientist re Polar cap changes. ‘Are there any studies about the possibility of a orbital shift for the planet with the change in mass from ice to water?”. I note a recent private published book by Prof Lance Endersby who suggests that such orbital shifts may have been induced by glacial change in the past. A suddent orbital shift would be more than catastrophic it would suggest a major extinction event. Any responses would be appreciated

    Comment by Mike Hart — 3 Feb 2007 @ 2:44 AM

  87. I gather that this prelim policy laymen’s type of summary report is not the actual technical bling-bling we should expect of the IPCC AR4 coupled climate models, because according to LLNL, such will be released in chapter 8?

    As far as a sense of homogeneity across the models, what actual number of modeling input factors (ex: Co2, solar, clouds) would encompass the said physical sciences of “atmosphere, land surface, ocean and sea ice” that were submitted specifically to the IPCC AR4 for consideration? Ten ? More, less?

    Additionally, will the release of chapter eight further quantify the uncertainties, bias, differences and so forth in relation to the various model versions simulations, within their range and scope, in consideration to their ability to reproduce, replicate, and or be in some form of a consensus data output agreement?

    Or will we have diverging model outputs that persist in diverging projected climatic opinions or lack of certaintities? Excusing of course the nonlinearity factors of the natural climate systems which will always, I assume, interject its whims; especially at the shorter intervals versus longer climate patterns; further compounding the matter for modelers.

    About IPCC Model Output
    …”the PCMDI is archiving coupled ocean-atmosphere general circulation model output to support the Working Group 1 component of the IPCC’s 4th Assessment Report. The data archived by the PCMDI from each participating coupled ocean-atmosphere model is a subset of that model’s output. Working Group 1 of the IPCC focuses on the physical climate system — atmosphere, land surface, ocean and sea ice — “…

    Important Information for Analysts and Authors
    ..” The overall purpose of Chapter 8 of the AR4 is to assess the ability of the global climate models to make projections of future climate change.”…

    IPCC Climate Model Documentation, References, and Links

    Comment by BarbieDoll Moment — 3 Feb 2007 @ 2:45 AM

  88. (RE:2 ..”Greenland glaciers finally melt (either slowly or in a big whoosh) tectonic rebound will probably increase the frequency and magnitude of earthquakes around the world.”…)

    If the thought intrigues you, there are research papers out there
    discussing the topic and or similar trains of thoughts.


    “In a new study, NASA and United States Geological Survey
    (USGS) scientists found that retreating glaciers in southern
    Alaska may be opening the way for future earthquakes.”…”Even though shrinking glaciers make it easier for earthquakes
    to occur, the forcing together of tectonic plates is the main
    reason behind major earthquakes.”…

    “Earthquakes in Greenland: Are They Related to Postglacial Rebound?”
    Chung, W. AGU 2000 Spring Meeting“S32A”

    “An intriguing observation in Greenland is a clear spatial correlation between seismicity and deglaciated areas along passive continental margins, a piece of evidence of earthquake triggering due to postglacial rebound. Another piece of evidence of induced seismicity due to deglaciation is from earthquake source mechanisms.”…”These and two prior events support the theory that the shallow part of the lithosphere beneath the deglaciated margins is under horizontal extension. The observed stress field can be explained as flexural stresses due to removal of ice loads and surface loads by glacial erosion. These local extensional stresses are further enhanced by the spreading stress of continental crust and reactivate preexisting faults. Earthquake characteristics observed from Greenland may be typical of those along the deglaciated passive margins elsewhere. ”

    Lateral viscosity variations beneath Antarctica and their implications on regional rebound motions and seismotectonics
    Wu, P. P.; Kaufmann, G.; Ivins, E. R. American Geophysical Union, Spring Meeting 2004, abstract #G33A-13 (05/2004)

    …”Fault stability is predicted over much of Antarctica today, indicating that the seismically quite state is probably due to the presence of the thick ice. At the site of the 1998 Balleny Island Earthquake (Mw=8.1), the induced fracture stresses are relatively small by comparison, and interestingly become more prone to stress failure when a three-dimensional earth model is assumed.”

    Glacial isostatic stress shadowing by the Antarctic ice sheet
    Ivins, Erik R.; James, Thomas S.; Klemann, Volker Journal of Geophysical Research, Volume 108, Issue B12, pp. ETG 4-1, CiteID 2560, DOI 10.1029/2002JB002182 (12/2003)

    “Numerous examples of fault slip that offset late Quaternary glacial deposits and bedrock polish support the idea that the glacial loading cycle causes earthquakes in the upper crust. A semianalytical scheme is presented for quantifying glacial and postglacial lithospheric fault reactivation using contemporary rock fracture prediction methods”…”A thick lithosphere, of the order of 150-240 km, augments stress shadowing by a late melting (middle-late Holocene) coastal East Antarctic ice complex and could cause present-day earthquakes many hundreds of kilometers seaward of the former Last Glacial Maximum grounding line.”

    Comment by BarbieDoll Moment — 3 Feb 2007 @ 3:48 AM

  89. Re #74: Dave, obviously the arithmetic error in the table is a bit embarrassing, but it’s really just another sign that the just-released document was itself still somewhat a draft. The point is that the substance of the document isn’t affected. I’m sure they’ll fix the problem pronto.

    Regarding your specific concern, I think the SPM made it clear that all that can be done now is to allow for sea level rise from 1) thermal expansion, 2) melt in place and 3) a more or less linear extrapolation of the small amount of dynamical melting that has been observed so far. While it is the expert judgement of many glaciologists that dynamical melting will accelerate very rapidly, there aren’t the needed models or terrain surveys in place as yet to be able to do more than make educated guesses. As a result, all that could really go into the AR4 was the vague statement to the effect that dynamical melting could make things much worse. Really I’m just re-stating what was said toward the end of the post, but hopefully I’ve made things a bit more clear.

    Comment by Steve Bloom — 3 Feb 2007 @ 4:23 AM

  90. One other small point, we do not have anywhere near enough fossil fuels reserves to achieve the higher and hence more alarmist scenarios unless we invoke large scale positive feedback loops for large releases of CO2 from natural sources such as the siberian permafrost, or rain forests etc and as RC are always telling us the Science does not tell us that until temps reach 3 C above now. By 2030 Oil and Gas would have peaked and coal cannot scale to take there place so the REALITY of the climate situation is that we are going to get around 1 to a 2 C rise in temps as a maximum.

    So lets not get too alarmist about the doomed world.

    [Response: Would that this were true. There is more than enough coal to go to at least 4xCO2, depending somewhat on how fast you burn it, and if they figure out how to tap into seafloor methane clathrates, it could go even higher. What’s the support for your statement that “coal cannot scale to get there”? –raypierre]

    Comment by pete best — 3 Feb 2007 @ 6:17 AM

  91. Excerpt from interview transcript posted at Climate Science Watch website regarding sea level issue, BBC World News, February 2, 2007.

    … Interview with Sharon Hays, Associate Director/Deputy Director for Science [OSTP] at the White House Office of Science and Technology Policy, leading the United States delegation, and Rick Piltz, Director, Climate Science Watch.

    BBC interviewer in Paris: �[Sharon Hays] told me what she learned:

    BBC: And the sea level rise is one of the issues that is most contentious through the week. Many people have said, many people are saying that, what you�ve agreed is effectively too conservative, it�s too low, that sea level is rising quicker than what is reflected in this report.

    Hays: Right. What happened with this report is that the model projections we know don�t fully take into account the melting of the ice that we are seeing. And I think that the report dealt with this issue in a very a satisfactory way in that it reported the projections that the models have put out�and I should note that those models now have less certainty than they did in the previous report�but it deals with the fact that this ice is melting at a faster rate than we expected and is not accounted for in the models, by simply stating that. And it states it in the report very clearly and makes it clear that the projections are a baseline, so to speak, that we expect the melting to be greater.

    Comment by Pat Neuman — 3 Feb 2007 @ 6:23 AM

  92. pete best (now #57) said:

    Currently annual emissions increases are 2 ppmv but recent years have seen 2.6 and 2.5 ppmv increases, if that accelerates to 3 ppmv somehow then we could be out of time as 100 ppmv increase to 480 ppmv which would take 50 years at 2 ppmv will only take 33 years at 3ppmv.

    Last 10 years annual mean CO2 rise (ppmv), from NOAA’s ERSL, global monitoring division :

    1997 1.96
    1998 2.90
    1999 1.38
    2000 1.24
    2001 1.84
    2002 2.36
    2003 2.23
    2004 1.65
    2005 2.41
    2006 2.25

    Note the Mauna Loa results at the top of the same page have slightly higher numbers for some years:

    1997 1.98
    1998 2.95
    1999 0.91
    2000 1.75
    2001 1.61
    2002 2.55
    2003 2.31
    2004 1.54
    2005 2.54
    2006 2.34

    But for this purpose, point samples should not be used alone when global averages are available.
    This is not to say that 3 ppmv global annual increases are not possible, but there has not been anything above 2.5 since 1998.

    Comment by llewelly — 3 Feb 2007 @ 7:23 AM

  93. What is the potential albedo effect relating to increased desertification, has anyone researched the potential of desert albedo to offset global warming, and due to the higher angle of incidence would this have more or less effectthan the melting of the artic per unit area(assuming the desert is near the equator)? Do you think I could convince Lindzen that this is his next big idea?

    Comment by matt — 3 Feb 2007 @ 7:39 AM

  94. It seems that CO2 cycle feedback are, in AR4, included.
    It’s said in this report that this feedback explains till +1°C for the high value of the range(for A1F1).
    Were this effect also included in TAR?

    Comment by Pascal — 3 Feb 2007 @ 8:05 AM

  95. It is interesting to me that so-called skeptics have chosen to attack the climate change issue based on the science, when in reality the source of their opposition is clearly the economic consequences that may result from combatting climate change. My experience is that they often understand economics much better than they understand climate science. I think there is a constructive role in the debate for conservative economic opinion. We certainly will not be able to address climate change if our economy is weakened. Continuing to attack the science at this point is merely a recipe for moving yourself to the margins of the debate.

    Comment by Ray Ladbury — 3 Feb 2007 @ 8:50 AM

  96. Could someone elucidate the section on page 10 under the “projections of future climate changes” heading? I’m looking at the part about “even if all concentrations of ghgs and aerosols had been kept constant at year 2000 levels, a further warming of about 0.1 c per decade would be expected.” Am I right in reading that to mean that if, for example, we’d gone to work hard in 1988 and done everything we needed to do to stop emissions growth by 2000 we’d now be seeing increases in temperature at about half the current rate? I think it’s interesting if that’s the correct reading, because it should give us some sense of the scale of change that real efforts could produce. But I’m not sure I’m reading it correctly (and I have to say that this SPM is not as well-written as the TAR)

    [Response: Thanks for stopping by Bill, its an honor. Your read on this is correct, its the so-called ‘commitment to warming’ rearing its head once again. The mid and deep ocean continue to warm for decades in response to any given perturbation in greenhouse gas concentrations. This makes stabilizing global mean surface temperature a bit like steering a supertanker. This is why many, such as Jim Hansen, have indicated we don’t have much time to act (a decade perhaps) if we are to avoid crossing thresholds that may represent ‘dangerous anthropogenic interference with the climate’. –mike]

    Comment by bill — 3 Feb 2007 @ 8:52 AM

  97. Re: We should also be aware of less absorption of atmospheric CO2 by oceans as the waters keep warming and out-gassing of CO2 from some shallower and warmer sea regions.

    Comment by Pat Neuman — 3 Feb 2007 @ 8:58 AM

  98. are so upset at what they see as political interference in the IPCC scientists’ report that they have leaked the full drafts of the fourth assessment:

    Comment by Phil — 3 Feb 2007 @ 9:10 AM

  99. RE #45 & natural climate variability. I see it like this, the ocean has waves, up & down, and ebb & flood tides. But then something outside this system happens, an ocean earthquake, and we get a tsunami.

    We all felt very bad re the tsunami victims, that they didn’t even know what was coming though the signs (to the knowledgeable) were there. Let’s become wise, listen to the knowledgeable & act now to avoid disaster.

    As Sen. McCain recently said, the debate is over; it’s time to act. Something I was saying 17 years ago, before science reached scientific certainty on this. Would a person take poison because it was only 94% likely to kill, and not 95% certain? Would a doctor tell a patient they won’t remove the lump because it’s only 94% certain to be cancerous, so come back in a year & see if it reaches 95% certainty?

    Comment by Lynn Vincentnathan — 3 Feb 2007 @ 9:50 AM

  100. Re: #95

    I think there is a constructive role in the debate for conservative economic opinion.

    I agree. But I don’t think the attacks on the science are coming from those who are truly economic conservatives.

    There’s a vast difference between economic conservatives and robber-barons. The present U.S. administration serves the latter, while paying lip service to the former. What kind of true economic conservative gives us the biggest federal budget deficits in the history of the world — isn’t paying your bills fundamental to sound economic conservatism? It’s high time we (the voting public) stopped accepting plain old greed as “economic conservatism.”

    Perhaps the best analysis of global warming from an economic standpoint is the Stern report. And the so-called conseratives (actual robber-barons) are about as angry about that, as they are about the IPCC report.

    Comment by tamino — 3 Feb 2007 @ 9:51 AM

  101. I was wondering, by what will be the global temperature be increased, if all known oil & gass resources are turned into CO2 ? Is that mentioned somewhere?

    Comment by alex — 3 Feb 2007 @ 9:56 AM

  102. Re #71: in order to claim that CO2 is the highest in 600,000 years you have to show that physically a blip like the current one cannot occur naturally (a difficult thing to prove). The ice cores don’t have the sample length resolution to do that since centuries of CO2 levels get averaged into a single reading. Juxtaposing recent ice cores or other actual measurements doesn’t change that fact.

    Comment by Eric (skeptic) — 3 Feb 2007 @ 11:00 AM

  103. RE #11, #41, #43 (Sea Level data) – I do get 0.11 for 1961-2003 by changing decimal places for both Greenland and Antarctic as follows:

    0.042 (Thermal) + 0.050 (Glaciers) + 0.005 (Greenland) + 0.014 (Antarctic)

    That value for Greenland seems pretty low, but I suppose that one could check this against the estimates in the TAR?

    Comment by Don Thieme — 3 Feb 2007 @ 11:01 AM

  104. Don’t think anyone has mentioned it, so here is my favourite take on the IPCC, courtest of The Independent (UK). Absolutely hilarious:

    +6.4°: Most of life is exterminated

    Warming seas lead to the possible release of methane hydrates trapped in sub-oceanic sediments: methane fireballs tear across the sky, causing further warming. The oceans lose their oxygen and turn stagnant, releasing poisonous hydrogen sulphide gas and destroying the ozone layer. Deserts extend almost to the Arctic. “Hypercanes” (hurricanes of unimaginable ferocity) circumnavigate the globe, causing flash floods which strip the land of soil. Humanity reduced to a few survivors eking out a living in polar refuges. Most of life on Earth has been snuffed out, as temperatures rise higher than for hundreds of millions of years.

    Comment by SteveF — 3 Feb 2007 @ 11:12 AM

  105. RE: 96 It is probably even worse than that. I haven’t read the summary yet, but at least before yesterday it was accepted that sulfate aerosols in the troposphere from fossil fuel combustion provided a negative forcing of around 1.5 W/m2. As the aerosol precursor source is gradually removed during the next 50 years due to reductions of sulfur in petroleum and the control of SO2 emissions from power plants, the offsetting effect of these aerosols will be greatly diminished.

    Thus, not only will we have to deal with the new positive forcing from future emissions of CO2 and other GHGs, and the latent warming from old emissions, we also will have to deal with a more full realization of the forcing from GHGs without the benefit of the obscuring veil of air pollution that everyone agrees should be removed for health and other environmental reasons. The earlier posting that listed the CO2 increases year over year failed to take into account these “hidden charges” that like rising interest on a loan or a balloon payment can not only ruin your day but your species.

    Comment by Alvia Gaskill — 3 Feb 2007 @ 11:15 AM

  106. #92, what worries me more than these recent CO2 increases (and I believe an acceleration over several decades?), is whether these are caused by human emissions, or whether a growing part of the increase is due to nature responding to the warming & sending its own emissions, or nature’s inability to absorb CO2 as in the past, due to saturation or heat stress and other GW-related conditions. We may reach a point at which, even if human emissions drop to well below the point at which nature previously could reaborb the emissions in a cooler climate, nature takes over and reduces absorption and/or starts emitting net its own GHGs, which causes further warming (also enhanced by reduced albedo), which causes further emissions from nature, which causes further warming, and so on. I call this “runaway warming,” though the scientists here would like to reserve that term for permanent runaway warming, as on Venus. Someone here offered me another term, “hysteresis,” which I think is used for similar mass extinction due to warming events in the past (55 mya & 251 mya).

    As our moms used to tell us, we shouldn’t play with matches.

    Comment by Lynn Vincentnathan — 3 Feb 2007 @ 11:20 AM

  107. Solar irradience is not the only issue with respect to the sun, and to dismiss the sun in two lines (p3)is disturbing. And on p9,what anthropogenic activities contributed to early 20th century warming–it wasn’t CO2.Fig SPM-4 shows a temperature trend for N.America that does not correspond to the USHCN data.Table SPM-0 shows a projected sea level rise from melting Antarctica as .14+/-.41 m/century. That error limit (1 sigma?)tells me we have no idea what will happen.
    Finally, the U.S. DoE (AIE)projects < 5% contribution to kWh consumption in the 2030 from sun, wind, biomass etc.Looks like coal will still be king, or with draconian legislation, the U.S. will be a third world country, along with everyone but China.

    Comment by John Stubbles — 3 Feb 2007 @ 11:28 AM

  108. Re 32
    Chip, if you really want to correct global temperature data for short time (annual to multiannual) effects, you should not just account for volcanoes, but also other important effects, mainly El Nino and eventually natural variability on the multiannual to decadal timescale (related to solar cycle or internal).

    I don’t know which data you used, but for CRU data I get a linear trend of 0.23K per decade for 1990-2006 in the raw data. If you compensate for the El Nino and volcano signal I get a trend of 0.21K per decade for 1990-2006 ( I did not exclude 1992/1993 but interpolate between 1991 and 1994 which might be as appropriate as skipping).

    In addition you find a roughly 10year oscillation in the “compensated” data set for the last 50 years and also farther back in the instrumental data set. (I doubt if it is of solar origin because it is sometimes in parallel and sometimes opposite to the solar cycle). And this cycle is on its top around 1990 and on its bottom around 2006 (as is the solar cycle). So accounting for natural variability on a timescale relevant for a 15 year trend would result in a higher trend (e.g. starting also at the bottom in 1994 gives 0.25K per decade).
    Of course, if you calculate the trend farther back to the 60ies and 70ies it will be less because warming has accelerated since then.
    I have not calculated for GISS and NOAA data, but I think they have even higher trends.

    Re 45
    Concerning cooling since 1998. Apart from the nonsense to calculate trends over a few years, as has been explained many times before:

    If you account for the effect of El Nino on global temperature, 2001 and 2002 are the warmest years on record, and 2006 is the third warmest (only a tiny 0.005K below).
    And multiannual variability is at the bottom now (see above)…
    Just besides: the cycles 1925 to 1947 to 1976 to 1998 are related to some teleconnetcion indices (mainly representing circulation and pressure patterns in the Pacific region, including El Nino, Pacific Decadal Oscillation, etc). But they have no evident signal in global temperature.

    Comment by Urs Neu — 3 Feb 2007 @ 11:34 AM

  109. This mornings NYTimes has a pretty good frontpage overview of the SPM. The Times was very strategic in this, letting all the momentary journalistic fray occur and the dust settle a bit before delivering its own more fulsome summary of the summary. It has a spread showing several of the graphs, a discussion of the crucial numbers, some decent quotes from scientific personnel, and euphemized humiliations for some of the usual suspects, such as James Inhofe and also our beloved Energy Secretary Sam Bodman, who has been rather busy before the cameras helping the Bush administration take credit for the advances of climate science during the past 5 years. Politics doesn’t just make for strange bedfellows, but also for mutant offspring… We do know how deeply this administration has gestated and nurtured unfettered scientific work, not to say its uncensored distribution.

    Several things about the Times article are striking. First, it does not drum up controversy, but instead emphasizes the consensus aspects of the report. Indeed, it even gives perspective to the sea level debate that it’s article yesterday so hyped, offering perhaps a kind of corrective here. Second, it mostly, though not entirely, avoids the blanket terms “scientist” and “researcher” and instead notes the specific field of each interviewee. This may seem trivial, but it reflects a more sophisticated awareness of how journalism can too often represent science as a vast intellectual black box. Third, it includes a quote from Susan Soloman in which she plainly rejects the invitation to expound upon how society (meaning, of course, the U.S., not the developing world) should act. Her words are powerful:

    I honestly believe that it would be a much better service for me to keep my personal opinions separate from what I can actually offer the world as a scientist.

    This is significant, because, as experts, climate researchers are always being urged by others, the media above all, to be founts of knowledge in general and to comment on areas that are well beyond their area of knowledge. When this happens, the results are often embarrassing and, still worse, able to cast suspicion back upon the person, his or her credentials, and even the ultimate value of their scientific work. As an employee of NOAA, Soloman may well be playing it safe here, politically speaking. But the fact is that she’s right. Her real service to society in this matter is her power to create and distribute the knowledge in her domain. She is showing a style of discipline that might be followed elsewhere, difficult as it may be.

    [Response: Nice remark. (But “fulsome” might not be the best choice of word here, because of possible ambiguity between the 19th century meaning and the more recently revived medieval meaning. See ). I admire Susan Solomon’s stance; I understand Suki Manabe generally feels the same way. I wouldn’t presume to say all scientists should take this route though. While to advocate specific actions risks compromising a scientist’s role as a font of objective information, there have been many cases in which a scientist felt ethically compelled to take action based on what he or she had learned from scientific investigations. That is a valid imperative as well. In the end, it takes both types to get the work of the world done. –raypierre]

    Comment by Scott L. Montgomery — 3 Feb 2007 @ 11:49 AM

  110. I was wondering, by what will be the global temperature be increased, if all known oil & gas resources are turned into CO2 ? Is that mentioned somewhere?

    IANACC: Unfortunately the IPCC couldn’t even try to put forward projections of such scenarios since the science of Peak Oil is still new and the available data on recoverable resources and possible extraction rates are corrupted by the human element.

    Many of these climate scenarios ironically might turn out to be incorrect, not because of bad science, but simply because instead of cutting emissions voluntarily, we’ll be struck by an economic recession when demand of these resources finally exceeds the rate of supply we are able to produce.

    No one knows for sure for example how badly the world’s largest oil fields have been geologically damaged by over-production. In fact keeping up with many of the projected CO2 emissions curves by the IPCC scenarios seem unrealistic with the current under-investment in oil and gas industry. The worst outcomes might actually be curbed by the greed and short-term vision of the very industry that is the contributing to the problem.

    Yes, I’m a bit of a pessimist. But as long as humanity is run by politicians and business people instead of scientists I don’t see much reason for hope…

    Comment by Ransu — 3 Feb 2007 @ 11:52 AM

  111. RE #63: Since we moved the decimal place on the individual rate numbers, it would make sense to do the same for the error. So that makes:

    Greenland ice sheets: 0.005 ± 0.0012 (1961�2003), 0.021 ± 0.007(1993-2003).
    Antarctic ice sheets: 0.014 ± 0.0041 (1961-2003), 0.021 ± 0.0035 (1993-2003).

    Not sure how this propagates to the error of the sums, but it should make them a lot smaller than what you found.

    Comment by Don Thieme — 3 Feb 2007 @ 11:58 AM

  112. Yesterday I had a post which didn’t seem to make it past moderation.
    All I asked was where will all the rain go? In a warmer world there wil be more evaporation in the oceans, and a warmer atmoshere will hold more moisture. Also the tropical rain belt should expand. Yet in the report most of the world seems to be getting dryer. Can somebody explain this?

    [Response: Not sure what happened to your last post, but anyway your question is perfectly reasonable. One thing to keep in mind is that only a very small proportionof total precipitation falls over land. Most falls over ocean, so any constraints on total global precipitation tell us essentially nothing about what must happen over land. Secondly, warming does not necessarily mean more total evaporation, since the hydrological cycle (rate of flux of water through the system) can go down. As it turns out, this effect makes the rise in global precipitation weaker than what you’d expect from the rise in moisture-holding capacity of the atmosphere. This was discussed in our post on the Vecchi et al paper. The precipitation rate in the most extreme land events can indeed go up as fast as the moisture holding capacity (Clausius Clapeyron) or even faster, since again they do not dominate the total; something like this seems to be happening in many places, and the trend is projected to continue. Finally, “drying out” is not just a matter of precipitation, it’s precip minus evap. Precip can go up, but evap can go up faster, leading (over land) to loss of soil moisture with all the usual consequences. –raypierre]

    Comment by David Price — 3 Feb 2007 @ 12:11 PM

  113. Eric, to appear credulous belies a claim to be skeptical — to be a skeptic, check your beliefs and what people tell you against real science. I put words from your statement of belief into Google here, as a quick first check. You can look this stuff up and sort out sense from nonsense. Read a few dozen articles by scientists rather than just believing what the PR sites try to fool you with. Try it:

    Comment by Hank Roberts — 3 Feb 2007 @ 12:20 PM

  114. My apple trees are blooming two weeks early. Seasonal relationships between agriculturally important plants, animals, bugs and birds rare changing. Anyone that does not accept the fact of climate change should go talk to the nearest farmer. Anyone that still does not believe should go talk to the nearest apple tree. As my Mother says,â?? You can not argue with an apple tree.â?? You want proof of global warming? Look at your motherâ??s and grandmotherâ??s diary on when the apple trees bloomed.

    Comment by Aaron Lewis — 3 Feb 2007 @ 1:12 PM

  115. Re #90 – There is not known current or intended projects for Methane Clathrates to be used for energy production as far as I understand it at the present time and I will give Humanity some credit for not using it without coming up with a means of sequestering the methane first of all as it would be climate suicide to even consider it otherwise, surely?

    In this graph ( James Hansen has Oil and Gas not peaking until around 2030 but that is the best case scenario and 2010 to 2015 is more likely and hence to a degree Climate Scientists and the IPCC are making up extreme case scenarios in order to show us that 550 ppmv is likely with a BAU scenario when it is extremely unlikely that it will ever happen because I doubt that coal can scale to replace Oil and Gas when they both Peak because of what Oil is used for (mainly transport, coal cannot scale to replace that) and having to replace central heating units for electricity in some way (Gas) is not possible.

    Who is going to replace millions of Gas Central heating systems around the western world and a lot of people use Oil to. Sure Coal and replace Gas for electricty generation to some extent but that is going to be solars, PV, Wind, and Wave/tidal and geothermals job is it not. To start building a lot more coal fired power stations without sequestration will be politically impossible, well unless we are freezing to death that it.

    Comment by pete best — 3 Feb 2007 @ 1:37 PM

  116. Re 106, there is not evidence for this scenario and hence it may be a warry but a distant one. The obcious issue is the breakdown of natural systems ability to absorb CO2 such as the forests and the oceans etc but scenarios that take this into account see it as a gradual (linear) decline and not a sudden (non linear) one.

    Comment by pete best — 3 Feb 2007 @ 1:40 PM

  117. From the SPM: “The carbon dioxide radiative forcing increased by 20% from 1995 to 2005, the largest change for any decade in at least the last 200 years. {2.3, 6.4}”

    Does anyone know how that is possible if CO2 concentration only increased about 5%?

    Comment by Steve Reynolds — 3 Feb 2007 @ 1:59 PM

  118. The SPM states that the increase in CO2 leads to a 1.66 W/m2 increase in forcing. I know that doubled CO2 (4 W/m2) has about a 0.8 degree C direct contribution to temperature (along with .7 to 3.7 degrees feedback), so 1.66 W/2 would be about 0.3 degree C, with 0.3 to 1.4 degree additional feedback expected. We’ve seen 0.8 degrees of warming, and expect 0.6 degrees more, which falls within that range.

    Does that answer your question?


    *laughs* Are you telling me that the earth adds to the 0.3 C in some sort of a positive “Feedback” process, to bring it up to your pre-determined number of 0.8 C? God forgive my cursing. Increased heat (wattage per square meter) evaporates more water, which creates more clouds, which increases albedo, if there is a feedback it is a NEGATIVE feedback, not a POSITIVE feedback! Good Lord.

    [Response: Water vapor is unquestionably a positive feedback. It is possible for low clouds to dissipate on warming, owing to changes in the boundary layer — you can mix in more dry air from aloft. In cases where this happens, low clouds provide a positive feedback. High clouds can be either a positive or a negative feedback, depending on the balance between cloud albedo effect and cloud greenhouse effect, –raypierre]

    Comment by RepublicanGuy — 3 Feb 2007 @ 2:26 PM

  119. Pete, look a little harder: there are clathrate projects being designed now. Look up “pingo” and “Svalbard” for examples. While the geology journals are still debating whether pingos are caused by freezing water or by methane hydrates, the energy journals have funded work to determine that the gas bubbling out is indeed methane.

    This is like the early oil days, when they had gushers — self-pumping oil, the cheapest possible way to get the fossil fuel: (1) poke a hole in the deposit, (2) fuel rushes out, (3) Profit!!

    And if it doesn’t come out on its own, inject steam:

    “… this paper proposes combining the process of steam reforming, which is commercialized worldwide, with use of untouched natural gas hydrate (NGH) resources. Gas hydrate deposits, which are distributed worldwide, hold great amounts of methane gas and have hardly been touched. This paper presents the economic parameters of NGH development and discusses the concept …”

    Comment by Hank Roberts — 3 Feb 2007 @ 2:27 PM

  120. Many thanks for the help on #96, and for today’s renewed demonstration of just what a valuable resource this place is.

    At the risk of being dense, let me rephrase my question to make sure that, in essence, this answer about commitment works both ways Would it be accurate to write: “If world leaders had heeded the early warnings and by 2000 done the work to keep ghg emissions from growing any higher, we would now be expecting decadal increases of ,1 Celsius instead of ,2”

    I’ve never seen the #s arranged in quite this way before, which is why it’s intriguing me


    [Response: Thanks again for the comment Bill. The issue can (and indeed has) been framed in this way. This graphic from IPCC (1996), admittedly a bit out of date, shows the equilibrium temperature changes resulting from various CO2 stabilization scenarios. If we had been able to initialize those scenarios, say, 20 years earlier, then the “branch” point where the various curves spread out, would have been moved to the left 20 years, and thus down to a concentration of about 335 ppm. This would have made it much easier to follow a scenario that e.g. achieves stabilization at, say, below 450 ppm, thus avoiding breaching the 2C warming (relative to pre-industrial) threshold. That is now quite tough. And every 10 years we wait, it gets that much tougher. -mike]

    [Response: As Steve Pacala says, this is a problem with a very high procrastination penalty. We’ve already incurred a lot of the penalty, and every additional day delayed adds to the debt. Steve illustrates this to his Princeton students by adding one page to the term paper requirement for every beyond the due date it is turned in. –raypierre]

    Comment by bill — 3 Feb 2007 @ 2:57 PM

  121. > the breakdown of natural systems ability to absorb CO2 such as the forests and the oceans etc
    > but scenarios that take this into account see it as a gradual (linear) decline and not a
    > sudden (non linear) one.

    averaged worldwide, maybe, but I’d like to see your source for that.

    Things like spruce budworm aren’t gradual, and nature works rather suddenly on a species basis sometimes. Losing much of the Northern forests due to warming-insect-fire can happen very quickly.

    The more ‘work’ the forest has already done exporting wood to market and topsoil to the ocean, the quicker those events happen the next time.

    So it probably depends on what’s in your own back yard or watershed, whether you see this kind of thing as sudden.
    Sometimes the perspective from the top of Mauna Loa (“well mixed” average) is too reassuring, I suspect.

    Comment by Hank Roberts — 3 Feb 2007 @ 3:07 PM

  122. It is interesting that we still seem to have “skeptics” grasping at straws–questioning ice-core resolution, looking for the tiniest inconsistencies. They seem to have no understanding of the science and the overwhelming evidence for anthropogenic causation–thinking that if they find any tiny issue, the whole problem will go away.
    The real argument now is over what to do, and the scientific community has been remiss in providing credible guidance here. The science shows Kyoto will barely slow climate change, even if fully implemented. Indeed, if the so-called skeptics truly wanted to argue for doing nothing, they could mount a credible argument that we can’t stop using the IPCC’s own reports.
    I believe this is the next battle front–which strategy has the greater benefit: do nothing and react to changes as they occur or try to slow warming–and risk slowing the economy–so we have more time to adapt to the inevitable warming that will occur.
    Anyone still attacking the science is a straggler left behind on the last battlefield.

    Comment by Ray Ladbury — 3 Feb 2007 @ 3:10 PM

  123. Re no.115.
    There is in existance a technology which may be able to relace gas (and other fossil fuels) for central heating. The device is called a heat pump. This acts like a refrigerator in reverse and draws heat from the ground and boosts it. It uses electricity to drive it, but requires no fuel itself. In Sweeden most new buildings have them.

    Comment by David Price — 3 Feb 2007 @ 3:21 PM

  124. re 79.

    Wayne, could you make a questimate of the amount of area and volume associated with the chunk of land that’s now about 160 meters above sea level?

    Comment by Pat Neuman — 3 Feb 2007 @ 3:26 PM

  125. Pat, its differing from Arctic region to region, 1 or 2 cm a year should be good for the entire North American High Arctic, don’t know about Siberia or European Arctic, suspect it may be less.. But the larger question is what does AGW do to rebound? Given that Glaciers are melting everywhere, and that the sea and ground is slowly warming up… I don’t know, suspect that rebound rate may be very slightly stronger, U. of Washington may have some answers.

    Comment by wayne davidson — 3 Feb 2007 @ 3:45 PM

  126. One conlcusion in the SPM that intrigued me was the projection that major storm tracks would migrate polweward during the 21st century. I have not seen many papers that have addressed this issue and I was surprised that it rose to the level of inclusion in the SPM. Could comment on how robust you think this particular projection is, particularly as it might apply to the mid-Atlantic and northeastern US? And, how widely held do you think this view is in the field of storm tracking?

    [Response: I’m glad you brought this up. When I said a few comments back that there were no major overall breakthroughs in AR4, I did not mean to imply that there hadn’t been places where there had been substantial and profound advances in individual bits of the science. The growing understanding of storm track shifts is one of these areas. The storm track shift is a very robust feature, going from cold ice-age climates through to warm Cretaceous climates. Some aspects can be reproduced in simplified theories though most of that isn’t in press yet. The AR4 full report will no doubt provide a full literature summary on the subject, but meanwhile you can take a look at the paper by Fu et al for an observational perspective (see Enhanced Mid-Latitude Tropospheric Warming in Satellite Measurements Qiang Fu, Celeste M. Johanson, John M. Wallace, and Thomas Reichler Science 26 May 2006 312: 1179 [DOI: 10.1126/science.1125566]) What they directly observe are temperature gradients, but those are closely connected to both jet streams and storm tracks. I’ll eventually be doing a post on this issue. One of the many on the back burner…. –raypierre]

    Comment by Tom Huntington — 3 Feb 2007 @ 4:04 PM

  127. I am surprised that in the SPM none of the historical sea-level rise is attributed to the net transfer of groundwater to the oceans due to overdrafting. I think that there are credible estimates on the order of 200 cubic kilometers per year of cumulative net groundwater depletion in recent decades. The problem with these estimates has been in the lack of good quality long-term data. I would imagine the estimates of net glacier and ice sheet mass losses have their own uncertainties, but they don’t seem to have faced quite the level of skepticism that groundwater depletion has. I don’t think that water storage in impoundments on the other side of the ledger can offset this large transfer (I believe the TAR made this argument).

    Comment by Tom Huntington — 3 Feb 2007 @ 4:18 PM

  128. It may depend on whether the storm tracks are over water? One of a few articles I found:

    “We explore this issue by systematically studying the response of atmospheric heat transpor in a GCM to a very broad range of global mean temperatures and meridional gradients. We find that heat transport increases with global mean temperature when the latter is less than about 15C; above this value, heat transport saturates, becoming insensitive to surface temperature. … as temperature increases the storm-tracks as a whole migrate poleward over cooler waters, and thus do not experience the full global-mean surface temperature increase. …”

    Comment by Hank Roberts — 3 Feb 2007 @ 4:37 PM

  129. #126 Papers are helpful , but recent reality , much better. A North Atlantic Cyclone brought a thunderstorm with Rain showers in the Arctic, last year in February, with huge temperature differences from the norm from the surface and within the Upper Air. Thundershowers in February over South Central Baffin Island above the Arctic circle (approx. 65 degrees North) , totally unheard of, from a system very much Polewards. At the time I congratulated the GCM model guys who wrote a paper on this before it happened, models sometimes are amazing.

    Comment by wayne davidson — 3 Feb 2007 @ 4:56 PM

  130. Thanks Hank (113) and re: 122. It’s not the question that matters, but the answers. The answer to my question is to show how natural processes cannot produce a spike like the one we are currently seeing. It’s a hard point to prove since there are many possibilities: geological and ocean being the biggest. Looking again my links and Hanks (e.g. I see 40,000 years per cm at 144,000 years. Considering that slice thickness is portions of a mm, it’s a huge span of time for each measurement. So stating that CO2 is the highest in 650,000 years based on ice cores is not realistic, there has to be other analysis included because a hundred or couple hundred year blip would be invisible.

    [Response: You also need to bring in what’s known about the lifetime of CO2 in the atmosphere, which imposes a kind of time scale on the problem. Given that it takes about 1000 years for the first 80% of the carbon dioxide to disappear into the ocean, and 10,000 to 100,000 years for the rest to go away, it would be hard to make a century-scale rise like we are making without it being reflected in the record. Anyway, I’m not entirely sure what point you’re trying to make. One doesn’t need the ice core record to prove that the current CO2 rise is anthropogenic. There are more direct ways of doing that and nobody (not even most of the skeptics) disputes the attribution of recent CO2 increase. Our current CO2 rise will elevate the CO2 for centuries, so even if there were some way of making a very short transient spike in the earlier Pleistocene that didn’t show up in the records, the point would remain that we haven’t seen a sustained period of elevated CO2 of the sort we are now making –raypierre]

    Comment by Eric (skeptic) — 3 Feb 2007 @ 5:10 PM

  131. I have a couple of questions if someone would be so kind
    1. What is the Special Report on Emission Scenarios and where can I find the examples?
    2. What is the significance of this line?
    “The SRES scenarios do not include additional climate initiatives, which means that no scenarios are included that
    explicitly assume implementation of the United Nations Framework Convention on Climate Change or the emissions
    targets of the Kyoto Protocol.”

    3.”Anthropogenic contributions to aerosols (primarily sulphate, organic carbon, black carbon, nitrate and dust)
    together produce a cooling effect, with a total direct radiative forcing of -0.5 [-0.9 to -0.1] W m-2 and an
    indirect cloud albedo forcing of -0.7 [-1.8 to -0.3] W m-2. These forcings are now better understood than at
    the time of the TAR due to improved in situ, satellite and ground-based measurements and more
    comprehensive modelling, but remain the dominant uncertainty in radiative forcing. Aerosols also influence
    cloud lifetime and precipitation. {2.4, 2.9, 7.5″

    Does this have consequences for clean air initiatives?

    Comment by doug newton — 3 Feb 2007 @ 5:41 PM

  132. Re #52, #54, et al, on suiting the science to the policy summary: My guess is that you’ve never been involved in putting together a very, very large report before that’s being written by many different people (credited and uncredited) and read by people with wildly different backgrounds. I’m currently working as co-author on a report on the oil industry for the AGs of five northeastern states. Our process involves research, drafting, and comments from our consulting firm, academics, and staff in the AG’s office. We’ve spent months researching, writing, re-writing, correcting, etc., the body of the report, which will be a few hundred pages. We know that for whoever reads any of this report, the vast majority will only read the executive summary. So now that we are in the final stages, we’ve had extensive discussions about the exec. summary, to make sure we got the language describing our conclusions exactly right. Having done that, we are now going back through the body of the report and correcting the text to match the summary.

    Your mistake is in thinking that because we are changing the body of the report, we are altering the research to suit the summary for policy makers, or some other non-scientific purpose. The summary is the extension of the report. It’s when everyone sits down and thinks very carefully about what the report does and does not say. It is wholly based on the research in the body of the report. When we’ve finally fixed (as in “set in stone”, not “corrected”) the language in the summary, then we change the body of the text–not because the research in the body was wrong, but because the body (due to sheer size) was not vetted as carefully as the summary. The language that gets changed in the body is not changing the science; it’s changing the descriptions of the science in a draft that has been edited, re-edited, re-edited, and re-edited to make sure the conclusions in the text are every bit as precise as the carefully considered summary.

    Comment by mlmitton — 3 Feb 2007 @ 5:53 PM

  133. Re. #83: I really wish the Dept. of Energy hadn’t published that $29B figure, when so much of it seems to consist of tax credits and re-labeled energy technology investments. Since the 1990’s NASA spending on Earth Science research and technology, including satellite construction and operations, has declined by about 25% when adjusted for inflation. (See the pre-publication draft of the latest Decadal Survey from the National Academy of Sciences,

    Disclaimers: I do have a vested interest in this, in the sense that NASA budgets affect whether projects I think are important can go forward. That said, even with the declining budgets I still have plenty of interesting work to do and have little personal financial interest in which projects get selected or dropped. Opinions/comments here are my own and in no way represent official NASA policy, etc.

    Back to science and the 4th assessment: I was struck by some references to carbon cycle feedbacks.
    P. 10 “The new assessment of the likely ranges now relies on a larger number of climate models of increasing complexity and realism, as well as new information regarding the nature of feedbacks from the carbon cycle and constraints on climate response from observations.”
    P. 11 “Warming tends to reduce land and ocean uptake of atmospheric carbon dioxide, increasing the fraction of anthropogenic emissions that remains in the atmosphere. For the A2 scenario, for example, the climate carbon cycle feedback increases the corresponding global average warming at 2100 by more than 1°C.”
    BUT (same page) “The sea level projections do not include uncertainties in carbon-cycle feedbacks, because a basis in published literature is lacking.” and “Models used to date do not include uncertainties in climate-carbon cycle feedback nor do they include the full effects of changes in ice sheet flow, because a basis in published literature is lacking.”
    Then on page 12: “Climate-carbon cycle coupling is expected to add carbon dioxide to the atmosphere as the climate system warms, but the magnitude of this feedback is uncertain. This increases the uncertainty in the trajectory of carbon dioxide emissions required . . .”

    Problems like terrestrial carbon-cycle feedbacks are very hard. In ecosystems, genetic information helps sustain far-from-equilibrium thermodynamics and thus ecosystems respond in rather non-physical ways. The information content changes over time and moves around in space. Think of species ranges expanding or contracting and human-assisted biological invasions. (Of course, ecosystem responses are consistent with the laws of physics and chemistry, it’s just the resulting dynamics may not look like those embedded in most physical models.) Yet to represent these responses in coupled ecosystem-atmosphere models we have to come up with simple quasi-physical approximations. That when there’s still a lack of consensus on seemingly basic issues such as the causes of variation in biological diversity. (See Science, 1 July 2005.)

    Different subfields of ecology have different definitions of “plant functional type” emphasizing different features of morphology, life history, competitive ability for different resources, and so on. No wonder the leading ecological models that could simulate multi-annual to multi-decadal feedbacks use different numbers and lists of plant functional types and parameterize their responses differently. Plus that humans tend to have this fondness for promoting some functional types, such as large-seeded palatable grasses and flowering shrubs, and removing others, such as large slow-growing trees with strong wood.

    I wonder about the assessment’s conclusion that precipitation decreases are likely in subtropical regions (p. 12). That seems more like a statement informed by opinion, perhaps implicit in the models, about which feedbacks and scales will dominate (synoptic circulation changes, mesoscale precipitation feedbacks, changes in leaf-level water use efficiency, plant population dynamics, changes in human land-use patterns, ???). There’s a lot of work to do here on understanding which of various measured or experimentally demonstrated effects are most likely to be important at the relevant time scales, especially when changing information content gets factored in. Funds to do that work are becoming more scarce.

    Also we badly need global observations of on-going changes in ecosystem composition. To be (un)fair with respect to satellite observations of ecosystems, there have been a lot of smart people trying to teach pigs to sing. The existing global data sets barely go beyond saying: green/not green. For example, for woodlands with average tree covers estimated at 40 to 60% a state-of-the-art “global continuous fields” estimate of tree cover has an uncertainty almost as large as the estimated values. While algorithms using satellite data have advanced, the information content of satellite images made with a few broad spectral bands is no greater than when those few bands were selected 2 decades ago. That’s where we’ll be until some government collects or buys much more information-rich satellite data, globally, and makes those data widely available.

    Comment by Bob — 3 Feb 2007 @ 6:05 PM

  134. Is this true?

    1. All previous natural (non-manmade) warmings or coolings took place veeeeeeeeeeryyyyy slowly, over thousands or millions of years not within a couple decades like this.

    2. That the ice cores show that it is 650,000 years since Co2 has been this high.

    3. That there are also natural causes to raise Co2, and they caused warming too, but because it was over thousands of years, it caused only gradual extinctions. And they could cause non manmade warming also in the future, over thousands of years, with gradual extinctions resulting.

    But the speed of the current manmade Co2 rise is unprecedented.

    The fact that there have been gradual warmings/coolings natually in prehistory is not an argument for allowing a rapid Co2 rise now.

    4. That IPPC scientists wanted it to say 99% as all agree AGW is happening, and that it was their government minders in the US that wanted it pulled back to 90%. A battle between scientists and governments.

    5. Bring up the Waxman hearing in this context: the Bush administration censoring of government scientists to downplay global warming.

    This is my Laymans guide to the IPPC Report!
    Feel free to correct me, scientists…

    Comment by Susan — 3 Feb 2007 @ 6:11 PM

  135. Considering the general acceptance of the urgency of dealing with man made global warming, will the next IPCC reports then be prepared more frequently ?

    Five years is a long time, when we are talking about a point of no return within possibly 10 years time !

    Comment by gorm larsen — 3 Feb 2007 @ 6:53 PM

  136. To Scott:
    Are these guys like Bodman political appointees?

    If we science-sympathetic laymen in the evidence-based community can get a science sympathetic president elected, can we get rid of all the deadwood preventing action? Or do bureaucrats remain festering long after the administration that selected them is gone?

    re yr ….our beloved Energy Secretary Sam Bodman, who has been rather busy before the cameras helping the Bush administration take credit for the advances of climate science during the past 5 years….

    I diary at dailykos on global warming from an activist- laymans POV: how to elect AGW problem-solvers,and remove the obstacles.
    I worry about our chances of reversing action without a clean sweep.

    Comment by Susan — 3 Feb 2007 @ 6:57 PM

  137. Re #92: Llewelly, I think those 2006 CO2 numbers aren’t complete. See this article.

    Comment by Steve Bloom — 3 Feb 2007 @ 7:00 PM

  138. Is lifetime of CO2 the same as or related to residence time? According to this: the residence time is about 3 years. Maybe a better way to look at it is the impulse response function, a simple one is here: The chart shows the carbon dropping to about 1/3 within 100 years. A naturally occuring impulse might be impossible, but would not show up in the ice core samples.

    Comment by Eric (skeptic) — 3 Feb 2007 @ 7:06 PM

  139. Re 132:
    >…mistake is in thinking that because we are changing the body of the report, we are altering the research to suit the summary for policy makers…

    You may be right that it is easier to write a large report the way you say, but if the objective is to get skeptics to believe it, being transparent about how the summary is supported by the science is essential.

    Comment by Steve Reynolds — 3 Feb 2007 @ 7:15 PM

  140. Re. 134

    Susan, before saying what I think of your Report, I’d like to tell you that I have a science background in hydrologic modeling. Many scientists have background in meteorology or atmospheric science but little or no background in hydrology. Climate is more than atmosphere and weather of course. Hydrology of snow and ice is a big part of what climate science should be.

    My specific background (30 years) was in hydrologic modeling and flood prediction with NOAA’s National Weather Service. I focused on snowmelt and ice hydrology. My background included observations of hydrologic climate change in the Upper Midwest, western Great Lakes and northern Great Plains. My study and research on climate change and hydrologic change was done mainly on my personal time. I was not allowed to talk about climate and hydrologic climate change while at work for NWS North Central River Forecast Center in Chanhassen, MN.

    I agree with all but one of your points. The one I disagree with pertains to extinctions. Based on what I’ve studied, there were two extinctions involving or caused by global warming which were probably not gradual. The extinctions at around the end of the Permian (about 240 or 250 million years ago) and the marine extinctions which occurred at the Paleocene Eocene boundary (55 million years ago). I could give you references on those if needed.

    Comment by Pat Neuman — 3 Feb 2007 @ 7:17 PM

  141. [[Do we have some sort of numerical representation for the greenhouse effect? In other words, a measurement of total solar energy which reaches the surface, and what percent is direct sunlight versus what percent is the greenhouse effect. Do we have such a number, and have we tracked changes in it (and for how long?]]

    Yes. A good summary can be found here:

    Comment by Barton Paul Levenson — 3 Feb 2007 @ 7:31 PM

  142. [[IMHO I don’t think it is realistic to assume 60 to 80% alt energy is achievable without nuclear.]]

    Sure it is. It won’t happen today, but it will happen soon if we make a concerted national effort.

    Comment by Barton Paul Levenson — 3 Feb 2007 @ 7:35 PM

  143. [[A quick question for the RC crew or any other scientist re Polar cap changes. ‘Are there any studies about the possibility of a orbital shift for the planet with the change in mass from ice to water?”. I note a recent private published book by Prof Lance Endersby who suggests that such orbital shifts may have been induced by glacial change in the past. A suddent orbital shift would be more than catastrophic it would suggest a major extinction event. Any responses would be appreciated ]]

    Compare the mass of the cryosphere to the mass of the Earth. Then compare the mass of the Earth to the mass of the Sun. Do the math. If you want the equations, post here again and let me know. The answer is: not very likely.

    Comment by Barton Paul Levenson — 3 Feb 2007 @ 7:43 PM

  144. [[Re #71: in order to claim that CO2 is the highest in 600,000 years you have to show that physically a blip like the current one cannot occur naturally (a difficult thing to prove). The ice cores don’t have the sample length resolution to do that since centuries of CO2 levels get averaged into a single reading. Juxtaposing recent ice cores or other actual measurements doesn’t change that fact. ]]

    The burden of proof is on the affirmative. Show us evidence that such an event happened, and we’ll take it into consideration. In the meantime, saying “we don’t have the evidence, therefore it could be there” reminds me of UFO fans.

    Comment by Barton Paul Levenson — 3 Feb 2007 @ 7:50 PM

  145. Pat Neumann. If you agree that the warming occurred extremely slowly, how is that consistent with the rapid extinctions. I am not saying it is not consistent, I just want to understand how these two phenomena jive.

    Susan. Assuming your summary was essentially correct, thank you. Ultimately, the audience that really matters is the layman public and the politicians.

    Unfortunately, I am not sure most people really care about extinctions and assume they can handle a change in temperature of several degrees. Just turn up the air conditioning. In fact, a few years ago, that was one of Bush’s responses to global warming. Just get more air conditioning.

    So far, the impact of this new report on the Bush administration is approximately zero. Obviously, all this warming is not considered a big deal when potential job losses are considered more important. This is kind of the reverse precautionary principle. If there is the slightest chance that any policy will impact jobs and GDP, then we must err on the side of destroying most of the planet.

    First, I can envision dozens of investments that will support jobs and improve the economic well being of those making the investments. When we have exhausted all those investments which have lowered our costs to heat and electrify our homes and run our automobiles and run our industries and companies, then we can talk about tradeoffs between lower energy use and GDP.

    Comment by tom street — 3 Feb 2007 @ 7:51 PM

  146. Re 144, with all due respect, lack of evidence does not prove lack of existence! I don’t think it’s simple to show with any degree of certainty a physical proof in either direction. I was objecting to using the ice cores as proof as the report seems to imply.

    Comment by Eric (skeptic) — 3 Feb 2007 @ 8:12 PM

  147. Re: #86

    there any studies about the possibility of a orbital shift for the planet with the change in mass from ice to water?

    The effect of the re-distribution of earth’s mass on its orbital changes, is exceedingly tiny. But it’s not zero. Since earth is not a perfect sphere, its gravitational field is not perfectly “spherically symmetrical.” The accumulation/wasting of ice sheets alters the mass distribution, and therefore alters the “dynamical form factor” which describes the 1st-order deviation from perfect spherical symmetry.

    The effect appears to be important when computing earth’s orbit on timescales of 40 million years or so. In fact, it’s one of the sources of uncertainty in computing orbital parameters in the very-long-distant past (which is important for relating past climate to earth’s orbital variations), but it is taken into account in the most precise, and longest timescale, calculations.

    Comment by tamino — 3 Feb 2007 @ 8:15 PM

  148. I am confused by some terminology in the SPM which is “non-standard” as far as statistics goes. The SPM uses the terminology “high confidence” to mean “an 8 out of 10 chance of being correct” whereas statistics (as a field of study) uses the phrase “highly significant” for a 99% confidence level.

    The SPM uses the term “very high confidence” to refer to a 9 in 10 chance of being correct whereas statistics uses the phrase “very highly significant” to refer to the 99.9% confidence level.

    Other figures are given using a “likely” or “very likely” valuation to mean 66% and 90% probability respectively but there is a footnote indicating some of these figures are based on “expert judgement”. What does that mean and how do we interpret a probability and a confidence interval based on “expert judgement” rather than statistical calculation?

    Perhaps this will be clarified in 3 months in the first of the actual science report?

    Comment by Ed — 3 Feb 2007 @ 8:15 PM

  149. Is it fair to say that all of the fossil fuel reserves will be burnt eventually, and that it’s merely a question of how slowly or quickly we burn them? Seems to me this is a fairly important factor, especially from the point of view of adaptation strategies.

    Also, there doesn’t seem to be much account taken of the benefits of emitting activities. Hundreds of millions of people have been dragged out of poverty in India and China in the last 30 years, largely thanks to activities that generate major emissions. What is the economic cost-benefit equation for climate change? I would like to see an attempt at estimating the net cost or net benefit of the expolitation of the remainder of fossil fuel reserves at various rates. Where there is a net cost, this would give us an idea of how much we should efficiently spend on emission reduction etc.

    Put another way, it would tell us the economically most efficient rate at which to burn the remaining fuel. If the cost of exploiting fossil fuel reserves more slowly is lower than the climate change adaptation costs that are avoided by doing so (among other things), then it’s rational to slow down fossil fuel consumption.

    Furthermore, I imagine once all the fuel is burnt we will be faced with an emerging global cooling scenario?

    [I am obviously not a climate scientist.]

    Comment by Asa — 3 Feb 2007 @ 8:23 PM

  150. re: 145.

    Tom, my view is that thousands (but not millions) of years is not veeeeeery slow thus I ignored question 1 in #134 in my previous reply. In ignoring question 1, I was thinking of the reference below:

    … ‘when global temperatures shot up by 5 degrees Celsius (9 degrees Fahrenheit) at the PETM,’
    ‘an abrupt shift in the Earth’s climate took place as the result of a massive release of carbon into the atmosphere in the form of two greenhouse gases: methane and carbon dioxide.’

    Comment by Pat Neuman — 3 Feb 2007 @ 9:08 PM

  151. For some reason, my comment #107 was truncated.I wanted to say that according to the DoE-EIA 2006 Annual Report, even by 2030, the collective contribution of wind, solar, geothermal and biomass to U.S. kWh will be less than 5% (250 billion vs >5000 billion kWh annually).Coal will still be king unless we have draconian legislation to curb CO2 and destroy our economy. Of course,curtailed oil imports would be an even bigger problem, since we really don’t have a substitute for oil. In 1900, they must have been worried about the supply of horses. Where will we be in a hundred years?

    Comment by John Stubbles — 3 Feb 2007 @ 9:33 PM

  152. The ref in my newsvine link also includes this statement:

    “The emissions that caused this past episode of global warming probably lasted 10,000 years. By burning fossil fuels, we are likely to emit the same amount over the next three centuries,”.

    Thus, thousands of years, or 10,000 years, is viewed by Prof. James Zachos as an abrupt shift in Earth’s climate…

    fast enough to result in widespread marine species extinctions.

    Related articles can be found at my Newsvine site:


    My agreement with 2 in # 134 was based on the text below:

    “Careful measurements have confirmed that CO2 is increasing in the atmosphere and that human activities are the primary cause. CO2 measurements have been taken directly from the atmosphere over the past few decades. CO2 trends for earlier times have been derived from measurements of CO2 trapped in air bubbles in glacial or polar ice. The 36% increase (in 2006) in atmospheric CO2 observed since pre-industrial times cannot be explained by natural causes. CO2 concentrations have varied naturally throughout Earth’s history. However, CO2 concentrations are now higher than any seen in at least the past 650,000 years”.

    Comment by Pat Neuman — 3 Feb 2007 @ 9:39 PM

  153. Re: 131: SRES refers to the IPCC’s Special Report on Emissions Scenarios. It can be found with the other IPCC publications on In the most basic terms, one of the largest uncertainties associated with climate model projections is the role of human activities. The future concentration of atmospheric greenhouse gases will depend on numerous socio-economic factors. Each of the SRES scenarios assume different global characteristics with respect to population, economies, etc and hence represent different pathways for the time series of atmospheric greenhouse gas concentrations. I hope this also answers your second question – none of the SRES scenarios consider decreases in greenhouse gas emissions consistent with Kyoto or other agreements that would otherwise limit emissions.

    Comment by Justin Schoof — 3 Feb 2007 @ 9:58 PM

  154. To Susan, #134. Yes, Bodman and staff are very definitely political appointees, like much of the executive branch as a whole. A cleanly swept White House and cabinet wouldn�t be enough, however, as there are the legislative and judicial branches of the great democratic tree to prune or tune also. The reality is that the executive is largely inactive, in narcotic denial.

    Things, however, are happening in the other two branches. Recall that there are now four very different bills before Congress on various schemes to limit greenhouse gases, plus the current case before the Supreme Court, Commonwealth of Massachusetts vs. EPA, regarding the possible designation of carbon dioxide as a gas that should fall under regulatory statutes associated with the Clean Air Act. I am certainly wondering if the SPM will have any effect on the latter, as the case won�t be finally decided most likely for a few months.

    The bills before Congress right now have a great deal to do with personalities and related politics, not just the issue alone. There are stormy times in progress on the House floor, as the women from California, meaning Pelosi, Feinstein, and Boxer, make their presences forceful. Pelosi has convened a special committee on the climate change issue and therefore grabbed turf away from Dingell�s Energy and Commerce Committee. Dingell is a very powerful, smart, savvy career democrat from Michigan, the auto state, and has acted partly as a roadblock to major, effective climate change legislation.

    In any case, the four bills can be briefly described as follows:

    Jeff Bingaman: cap and trade, economy wide, but upstream only, requiring a whopping 7% reduction from current levels by 2050, i.e. a Bud Lite carbon bill.

    Diane Feinstein: cap and trade for electric utilities, requiring a 45 percent reduction in ghg emissions from current levels by 2050, i.e. a compromise bill with molars but no incisors, so to speak

    Bernie Sanders and Barbara Boxer: range of measures aimed at increased energy efficiency, low carbon trading program, and market based programs, calling for an 85 percent reduction in ghg emissions by 2050. Represents the other end of the spectrum from Bingaman. A full set of teeth in this one.

    McCain and Lieberman: the yet again bill, calling for 70% reduction by 2050 through a combination of cap and trade and regulation of power plants, refineries, and other major energy users. This bill has been proposed before, of course, mainly as a gesture of good faith and intentions, since its chances of passage in a Republican controlled Congress were essentially nil.

    Most observers feel certain that something will be done this year, that one of these bills will get passed, in modified form, and probably not Bingaman�s, as that would simply be a euphemism for inaction and would bring down no small calumny on our beloved representatives.

    But you see that a cap and trade system is by far the most likely mitigation action that�s going to be taken. Obviously, I can�t guarantee this, but it seems extremely likely now that Congress has been retaken by the dems.

    Comment by Scott L. Montgomery — 3 Feb 2007 @ 10:21 PM

  155. Timing is all, Asa.
    “So theyâ��re gone, so what?
    “As a foundation of the food chain, a loss of pteropods will affect all other life. …The attached picture tells the story: Where it is blue, there is not enough aragonite for the small animals, the pteropods, to live and grow shells. They will vanish. This picture is the middle, or median, estimate of ten models that were calculated. These ten models ranged from minimum additional levels of industrial carbon dioxide into the ocean; based on the most minor of climate change, to the highest climate change estimates.

    “… These chemical effects are well known and measurable and it is basic science. …

    “Researchers have run experiments where they have watched pteropod shells dissolve when the seawater becomes acidic at the levels of carbon dioxide that will be reached in fifty years. The problem with global warming is that itâ��s a growth game. The earlier we make cuts to greenhouse gases the less reduction we have to make.”

    Comment by Hank Roberts — 3 Feb 2007 @ 10:24 PM

  156. Wrote this earlier but it seems to have been lost: Re #117 (and another lost post)

    I believe that what they’re saying (look at footnote 2) is that the 280 ppm CO2 that was there in pre-industrial times doesn’t count as a “forcing”. If you go from 360 to 379 ppm, the anthropogenic part has gone from 80 to 99, which is somewhat more than 20%.

    I’m not sure that the radiative forcing is proportional to the CO2 density, but that’s how I read it.

    Comment by Mitch Golden — 4 Feb 2007 @ 11:52 PM

  157. RE#149, Asa here’s a quote from the 2007 IPCC report:
    “Annual fossil carbon dioxide emissions increased from an average of 6.4 [6.0 to 6.8] 5 GtC per year in the 1990s, to 7.2 [6.9 to 7.5] per year in 2000-2005” (1 GtC = one billion tons of carbon atoms)

    Now, the estimated total fossil fuel resources left to burn (as of 2000) from
    Conventional oil – 263 (GtC)
    Shale oil, etc. – 525
    Natural gas – 422
    Coal bed gas, etc – 450
    Coal – 3370

    The atmospheric carbon dioxide content (as carbon) was 580 GtC (280 ppm) in 2000 was 750 GtC (380ppm)

    How many gigatonnes of carbon per year stay in the atmosphere? Around half, so if current total CO2 emissions (as carbon) are at 7.2 GtC (only looking at fossil fuels), then around 3.6 Gt of carbon stay in the atmosphere each year – and it’s worth wondering what processes account for the uptake of the other half. See the Woods Hole discussion of the missing carbon sink. What you don’t know can hurt you… meaning that it’s possible that more CO2 could start lingering.

    If we burn all the fossil fuel, that means adding 5000 GtC to the atmosphere, (if half stays up, that’s 2500 Gt) and warmer oceans and stressed forests will probably absorb less CO2, resulting in a minimum CO2 content of around 1500 ppm (and probably quite a bit higher, due to sink limitations.. and the oceans may degas methane and CO2 if they warm up a lot … odd that no mention of ocean / permafrost methane & carbon stores is made, other then that the permafrost is thawing…). There’s also no reason to assume that all that CO2 wouldn’t stay in the atmosphere for millennia, either – meaning no ‘global cooling effect’ after the fuel is gone. This is a bit beyond the worst-case scenario in the IPCC report.

    Fossil fuel industry spokespeople will tell you that people absolutely need oil, and we’ll just keep burning it till it’s all gone – but the fact is that recent economics indicate that renewables become economically preferable as oil approaches $100 a barrel, and another fact is that you can replace all fossil fuel demand with a mixture of renewables (solar, wind and biofuels), temporary nuclear and tight energy conservation – but only if we figure out how to stop the endless growth of energy demand in the US, China, India, and the rest of the world. It turns out that the only barriers to a global renewable energy economy lie in an entrenched growth-driven economic and political system that is very resistant to drastic and disruptive changes – which are coming anyway, due to global warming. Thus, the task is daunting but not hopeless – but a large fraction of global fossil fuels must remain in the ground, unburnt.

    Comment by Ike Solem — 5 Feb 2007 @ 12:39 AM

  158. #130 (Raypierre comment)

    “Given that it takes about 1000 years for the first 80% of the carbon dioxide to disappear into the ocean, and 10,000 to 100,000 years for the rest to go away”

    I’m amazed by these orders of magnitude. Half-life of a CO2 is often estimated at 100-150 yrs in textbooks, and I don’t know how we presently calculate the long-term rate of capture by the different sinks (in the particular case of a rapid growth like modern process, ie out of a natural equilibrium of emission/sequestration).

    Do you have some references from recent carbon cycle models on that point? Thanks.

    Comment by Charles Muller — 5 Feb 2007 @ 1:05 AM

  159. RE 146, if I understand you right you are saying that it might be possible there there were some periods where CO2 naturally rose to levels similar today and then fell back again without leaving a record in the ice cores.
    That sounds to me like “the truth is out there.” I think the IPCC report can be stated to be based on the evidence we have today, not based on what could be true but where we have no evidence. Feel free to try to disprove it by drilling ice cores.
    Of course, either way we know that recent CO2 levels are from human activity and not some unknown process that spikes CO2, so it seems largely irrelevant.

    Comment by Roger Smith — 5 Feb 2007 @ 1:40 AM

  160. Ike Solem (#157) thanks for the great answer. Very interesting info.

    I guess I would like to see an economic model of what would happen with no emissions measures, ie. measuring the costs and benefits of fossil fuels continuing to burn until there are none left or they become uneconomical, like in your US$100 a barrel scenario.

    I would then like to see a model of the economically most efficient scenario. The difference between the two would give us — in economics terms at least — a policy guidance.

    I think once fossil fuels become spent or uneconomical you will see a very swift transition. Completely retooling global infrastructure may seem expensive and daunting now, but when the economics come into line I think it will happen very rapidly and cheaply. Vast global infrastructures can spring up and/or disappear within a decade or two (eg. the Internet).

    Comment by Asa — 5 Feb 2007 @ 3:13 AM

  161. Re 158: My original comment was concerning the CO2 measurements in the atmosphere. My second link in #138 shows the impulse response of the CO2 in the atmosphere calculated from the flows between the reservoirs in the diagram (well agreed-upon). That worked out to about 33% left in the atmosphere after a century. The disintegration of CO2 into other carbon forms (i.e. more permanent storage) was was Raypierre was referring to (the Archer paper). That time is about an order of magnitude longer (i.e. 17-33% left after 1000 years).

    Comment by Eric (skeptic) — 5 Feb 2007 @ 4:29 AM

  162. Re 159: Roger, I do not dispute the evidence we have today, I just pointed out that it is not proof that spikes did not exist since it has poor resolution (centuries at best at the time scales mentioned (650,000 years). My ice cores unfortunately would not be any better. But I am very hopeful that fossilized proxies will be discovered with annual resolution (and I believe they are). As is the nature of proxies they will show a lot more measurement variation and it will a difficult and perhaps controversial problem to map their readings to CO2 measurements.

    Comment by Eric (skeptic) — 5 Feb 2007 @ 4:35 AM

  163. Who are you and what makes you qualified to be so certain?

    First, I want to express my overwhelming appreciation for this forum because it is environment that fosters the embracement of complexity, whereas the vast majority of recent IPCC coverage, on both sides of the debate, demonstrates a paucity of scientific detail. What I find most heartening is that most contributors who support the conclusions of the report, rarely resorts to ad hominem level rebuttal, but rather back their claims with thoughtful prose.

    Nevertheless, from this layman’s point of view, the deep sense of conviction intoned by the prose of those who are inclined to affirm the IPCC conclusions and are vastly more educated and experienced in the field than myself does not justify the supercedure of the instinct of many to seek a greater truth to the causation of the current global warming trend. If the mission of RC is to elucidate the public on the true nature of climate issues facing this planet, its efficiency would be greatly enhanced by the posters providing a brief CV or making it a separate field in posting process; to be published directly below the name and timestamp. Some may respond to this by recommending I follow the hyperlink of each individual poster, but before you do, remember the simple goal is efficiency.

    [Response: Click on the ‘people’ button above (or here)]

    In reality, my greater goal is context. Although I earlier applauded the thoughtfulness of most contributors as they key accolade for the quality content purveyed by the form, there are further efforts made to add context to close the credibility gap for us irksome fence-sitters on the matter. The answer, albeit in my lesser mind, is metadata. Publish the metadata of the individuals along with the content, specifically the scientific background. Without it, those skeptical inquirers among us are left to assume that most contributors are climate scientists preaching to the choir; which leads to the deepest part of my agenda.

    Fully opening the kimono of my inquest, I mostly eager to understand the true makeup of the superlative consensus of ‘scientists’ affirming anthropologic global warming touted by most mainstream media outlets. Such a generalization of the vaunted title may serve to mollify the mass’ appetite for oversimplification, however any true scientist, I postulate, would never eschew far greater distinctions. The intellectual barrier I would need to overcome in order to accept the IPCC affirmations is derived from this simple logic:

    The sun is approximately 333,000 times the mass of Planet Earth.

    The sun is the major factor in the daily 25 F degrees or so temperature fluctuation in my region (Albuquerque, New Mexico to be exact).

    The sun is an entity in flux, never in a constant state.

    How is it that on the scope and scale of factors that the sun, an entity in flux, presents to our planet on a cyclical basis, not a major consideration in this discussion?

    The only answer I can assume is that most of the world’s physicists are not participating in the aforementioned consensus. Forgive my glibness, but I am in close proximity to some of the greatest minds in the physical sciences, where this world there are physicists and the rest are mere mortals. My suspicion about the lack of their participation is not relegated to the lack of consideration of solar effects on global warming, but extends to the even deeper realms of quantum mechanics. Would Albert Einstein support the recent conclusions of the IPCC?

    My intent is not ridicule the validity of scientific achievements of those who dedicated their lives to environmental science by appealing to perceived higher authority, but to ensure scientists of ALL backgrounds have seat at the table of those arbitrating the conclusions. That is not clear, and perhaps someone will be kind enough to point out a URL with a concise list of SPM contributors and their scientific background. I’d love to eat crow about all this and settle the issue in my mind quickly, but as I previously mentioned I am an irksome fence-sitter.

    Some of you may be inclined to dismiss my writings as the rantings of an uneducated rube, for, in the interest of full disclosure; I am only salesman by trade. Nevertheless, I have natural knack for the soft science of psychology having convinced some of the smartest to spend millions to affect billions; and if you believe that no human emotion entered into the most recent IPCC conclusions, thus an artifact of pure science…I have a bridge to sell you.

    So tell me, who are you and what makes you qualified to be so certain?

    Marty Chavez – Albuquerque, NM – Business Development Professional – BS in Health Sciences

    Comment by Martin Chavez — 5 Feb 2007 @ 6:15 AM

  164. Martin, do you pose the same questions to your primary care physician when the diagnosis is not to your liking? If you are like most of us, you get a second, maybe a third opinion. You try to get a consensus to satisfy your concern or fear that your doctor was correct.

    That is basically how the IPCC began and now operates. Lots of opinions from people who do the researach, gather the data, synthesize what they observed/learned and throw it out to the world community of scientists to accept or reject.

    Does that begin to answer your questions?

    Comment by John L. McCormick — 5 Feb 2007 @ 9:16 AM

  165. My understanding that the IPCC predicts that Indonesia will lose 2,000 islands by 2030. Is this true? If so, what are the factors this prediction based on? Surely sea level rise alone cannot account for that!

    Comment by Ben Hocking — 5 Feb 2007 @ 9:26 AM

  166. What’s the source of your understanding, Ben?

    I’ve seen it, but never seen it attributed to any IPCC source. Do you have a source?
    I found it here, for example, a second or third hand story:

    Comment by Hank Roberts — 5 Feb 2007 @ 10:32 AM

  167. Someone here presciently observed that you don’t need the water to rise so much the city’s inundated — all you need is the water high enough that the sewers don’t drain downhill.
    Even heavy rain on overlogged Indonesia, with cities on low lying land, accomplished that:

    340,000 Flee Deadly Floods In Indonesian Capital Jakarta 5 Feb 2007 05:31 GMT
    … 340,000 Flee Deadly Floods In Indonesian Capital Jakarta Water bursts from the banks … “and the toilets cannot flush,” Brahmanta said. Environment Minister Rachmat Witoelar has blamed the floods … had not paid enough attention to the ecological impact of their construction projects.

    Comment by Hank Roberts — 5 Feb 2007 @ 10:46 AM

  168. Re #138, Eric
    I am not a climate scientist, but I looked at the equation in your 2nd link, and one of the time constants used (the “tau’s”) for about a 31.6% fraction of the CO2 pulse is only 2.57 years, so that fraction of the CO2 is gone in about half a decade.
    My guess is that this time constant can be understood to refer to processes that are already assumed to be at equilibrium in the longer term models. Whan I see numbers presented for CO2 emissions, humans are actually emitting about 6-7 GtC/yr, but the net increase in the atmosphere is only about half that amount due to CO2 fluxes from the atmosphere to the oceans and land. (See, for example, the Technical Summary of the IPCC 2001 Working Group I report.) Measurements of CO2 increase in the atmosphere are different than a CO2 pulse because effects with short term time constants are already in approximate equilibrium.

    Comment by Ed G. — 5 Feb 2007 @ 11:58 AM

  169. I am waiting with bated breath for the description of what’s really new. By that I mean, not reasonings about interpretation but rather, what facts are now in hand that were not available for use in the third assessment of 2001.

    All of the news has been about what seems to be a “willing oneself up” by scientists and policy-wonks to a greater estimate of the probability of human activity being most responsible for the warming trend. Arctic ice loss seems to be the one item that is new, and actually little has happened there since 2001.

    We still do not have evidence that the earth’s mean temperature is higher than it was in CE 900; only that the rise in that temperature in the last 50 years is without precedent.

    Comment by Peter Namtvedt — 5 Feb 2007 @ 12:06 PM

  170. [[We still do not have evidence that the earth’s mean temperature is higher than it was in CE 900]]

    I believe some recent historical reconstructions have pushed back past 1000 years to 1300 years. Gavin, Ray? Does anybody have a cite?

    Comment by Barton Paul Levenson — 5 Feb 2007 @ 12:19 PM

  171. Hank, I probably just conflated it in my head because the news came out at about the same time as the AR4.

    Comment by Ben Hocking — 5 Feb 2007 @ 12:47 PM

  172. Re Eric 162

    Let me see if I understand your logic. You make an assertion with no evidence that it is true. Then you state that since it cannot be proved to be false, we must assume that it may be true. Hmmm… Have I got that right?

    Comment by Ron Taylor — 5 Feb 2007 @ 12:51 PM

  173. Barton Paul Levenson said:

    [[We still do not have evidence that the earth’s mean temperature is higher than it was in CE 900]]
    I believe some recent historical reconstructions have pushed back past 1000 years to 1300 years. Gavin, Ray? Does anybody have a cite?

    From the AR4 SPM:

    Paleoclimate information supports the interpretation that the warmth of the last half century is
    unusual in at least the previous 1300 years. The last time the polar regions were significantly warmer
    than present for an extended period (about 125,000 years ago), reductions in polar ice volume led to
    4 to 6 metres of sea level rise. {6.4, 6.6}


    Average Northern Hemisphere temperatures during the second half of the 20th century were very likely
    higher than during any other 50-year period in the last 500 years and likely the highest in at least the past
    1300 years. Some recent studies indicate greater variability in Northern Hemisphere temperatures than
    suggested in the TAR, particularly finding that cooler periods existed in the 12 to 14th, 17th, and 19th
    centuries. Warmer periods prior to the 20th century are within the uncertainty range given in the TAR. {6.6}

    Both from page 8 .

    Unfortunately thaat’s just a summary. Beyond that I only know of RC’s many articles on the hockey stick and related papers.

    Comment by llewelly — 5 Feb 2007 @ 1:18 PM

  174. I tried to post this last night, but it disappeared.
    Ben Hocking said:

    However, as I understand it (I have not read any of the AR4 myself), the IPCC itself is saying that Indonesia should expect to lose 2,000 islands.

    I would like to know where you read that, Ben. The AR4 SPM says nothing specific about island loss (beyond what is implied by 18cm – 59cm + ice flow SLR), and the rest of the AR4 isn’t due out for a couple of months. Some TAR statements about islands can be found here and here . I cannot find in the TAR a specific number of islands expected to be lost.

    Since few if any places have 0 elevation change, I can’t understand how any individual island loss can be solely or discretely attributed to global warming (similar to how no individual hurricane or tornado can be attributed solely or discretely to global warming) . What is needed is not the ability to blame global warming (beyond recognizing the role of AGW-induced sea level rise), but the ability to make a projection of each island’s habitability for a given scenario of future emissions, erosion control, land reclamation, etc.

    Comment by llewelly — 5 Feb 2007 @ 1:22 PM

  175. Re 156:

    >Re #117 (and another lost post)[tamino]
    >I believe that what they’re saying (look at footnote 2) is that the 280 ppm CO2 that was there in pre-industrial times doesn’t count as a “forcing”.

    You are right; I should have looked at the footnote.

    But now that calls into question the rest of the SPM statement:
    “The carbon dioxide radiative forcing increased by 20% from 1995 to 2005, the largest change for any decade in at least the last 200 years. {2.3, 6.4}”

    I calculate (roughly, based on figure 2.4 of the draft IPCC WG1 Fourth Assessment Report) that the increase in radiative forcing from 1970 to 1980 was from 0.84 to 1.06 W/m^2, which is 26%. So the SPM statement appears to be incorrect that the largest % change was 1995 to 2005. Any comment from RC staff?

    Of course this is due to % change in forcing from 1750 being a likely poor way of characterization. 1865 to 1875 appears to show a 34% change using this method!

    Comment by Steve Reynolds — 5 Feb 2007 @ 1:27 PM

  176. Land typically becomes uninhabitable long before sea level rise inundates it. All it takes is a significant rise in occasional flooding due to storm surges or destruction of fresh water sources due to salt water leakage. Lots of areas have a significant percentage of the inhabitable area only a meter or two above the highest high tides (especially islands). If storms are also tending to get stronger the situation only gets worse.

    Comment by Ed G. — 5 Feb 2007 @ 1:31 PM

  177. Re: #164

    Mr. McCormick,

    I thank you for your prompt response and effort to begin to explain the IPCC mechanism. In my profession, there is a cliche about high level executives, that basically serves as an equalizer, it goes something like “he puts his pants one leg at time, just like any other man” (apologies for this male centric metaphor). I approach any Medical Doctor, Nuclear Physicist, or Politician the same way – there is no self-respect in sycophantism. Nonetheless, the direct answer to your question is that I would only obtain a second, third, etc.. opinion based upon graveness of the diagnosis.

    Which segues nicely with my main point, and one, with all due respect, you neglected to even begin directly answering. If I had liver cancer, I would not only consult an oncologist but also an endocrinologist, an interest, and cancer victims as well; plus many many more sources. And you can very well be assured that I would be fully aware of credentials and full experience of each; which is all I am asking here.

    The grave diagnosis for Planet forwarded by the IPCC, deserves the full attention of the greatest minds of all scientific backgrounds. I am indeed confident that the “scientists” (The ” ” are emphasizing the generality of the term and NOT any kind of derision) that affirm the claims are well qualified to do so, and have done so with conscientious diligence. I would further assert that their credentials are well documented. However, they do not seem to be well aggregated enough to promote efficient scrutiny; which I am heretofore unaware of such a source.

    I currently maintain that the superlative “consensus” promoted by media, non-scientist activists and politicians, is nothing more than extreme rhetorical hyperbole, meant as a well-intentioned (hopefully not a path to Hades) call to action to the at large public. Again that is summed up by the simple sun logic presented in my previous post (#163) and the basic question where are the physicists? I don’t think I am going to get the answer from Charlie Gibson anytime soon.

    Furthermore, if the vast majority of contributors are climate scientists, and little input comes from outside that community, I am gravely concerned about the bias that kind consensus breeds. I want to be clear, I believe the planet is warming and alternatives to hydrocarbon based energy sources should be pursued with extreme vigor, mostly for political and economic stability reasons, and definitely for sheer integrity. My goal is to understand the perspective of individuals that make of the body the consensus on AGW. If it is indeed lacking for prominent physicists, statisticians, economists, et. al. outside the discipline of environmental sciences, then the conclusions, I submit, are far from closed to debate.

    To me it is a fools errand to assume all of the causation for any GW forcing is solely on a global scale with out considering those perpetrated by factors on a solar, galactic, universal or even sub-atomic scale. My overall request is that everyone layout relevant their biases with there content, it what Teddy Roosevelt called the arena of ideas, and furthermore the AGW debate must not be closed before credible evidence from outside CS community is submitted for consideration.

    I’ll leave you with on inescapable fact, not only does every man put his pants on one leg at a time, he also has possesses an emotional ego that leaves a fingerprint on everything he does. That doesn’t mean he is wrong to do so, but admitting it only enhances his credibility.

    Marty Chavez – Albuquerque, NM – Business Development Professional – BS in Health Sciences

    Comment by Martin Chavez — 5 Feb 2007 @ 1:38 PM

  178. Re #163: You say “The sun is the major factor in the daily 25 F degrees or so temperature fluctuation in my region”, but a little thought should show you that that’s not in fact the case.

    Your problem here is one of perspective: Do you remember an old song (maybe ’70s?) about how a “fool on a hill sees the sun going down, and the eyes in his head see the world spinning ’round”? It’s not any change in the sun that causes your temperature fluctuations, it’s the turning of the world that makes day & night, just as its axial tilt makes the seasons and other orbital variations the ice ages – and all this would still be happening if the sun were absolutely constant & invarying.

    There’s a simple answer to the question of why solar variations aren’t included in climate models (though in fact they may be in some): there have been satellites in orbit for the last 40 years or more, making careful measurements of the sun’s output. From those we know to a fraction of a watt per square meter (IIRC) just how big the variation is, and it’s not anywhere near large enough to cause significant temperature changes. There are several articles on the subject here, if you want details.

    (As to your question about my scientific qualifications: I started with a degree in math & physics, but have mostly (barring occasional forays into commercial software) worked in computer modeling, in fields ranging from electric power systems to weather & mesoscale climate to my current interest in neurobiology.)

    Comment by James — 5 Feb 2007 @ 1:51 PM

  179. > causation for any GW forcing is solely on a global scale with
    > out considering those perpetrated by factors on a solar, galactic,
    > universal or even sub-atomic scale.

    You’re wrong about that. This has been considered, because we can observe several other planets — which ought to reflect any solar, galactic, or universal forcings. Start here:

    Comment by Hank Roberts — 5 Feb 2007 @ 2:07 PM

  180. Mitch (#156), thanks, that explains it for me!
    Now one remaining question (hope I didn’t miss another footnote) regarding expected warming by 2030 (2nd bullet on page 10 of 21):

    “Warming by 2030 is very likely to be at least twice as large as the corresponding model-estimated natural variability during the 20th century .”

    Can somebody explain me what a warming of twice a variability means?

    Thanks in advance!

    Comment by Ark — 5 Feb 2007 @ 2:10 PM

  181. In the popular press, there have been a number of apocalyptic descriptions of what is implied by various temperature rises. These may or may not be accurate predictions.
    What I have not seen is any sober predictions and analysis of what variability we can expect, and what implication this has for agriculture. If there is anything that is worse for agriculture than change, it is more weather.

    Comment by Peter — 5 Feb 2007 @ 2:15 PM

  182. Re: #163, #177, #178

    Regarding physicists: it is patently false to claim that “the physicists” have been left out of the scientific research on climate. Climate scientists are physicists — the ones who specialize in earth’s climate. Including particle physicists or cosmologists or those from a host of other subdisciplines, who generally have little expertise in the details of earth’s systems, would be of little help. Those who wish to learn the ins and outs of climate science, and contribute to research, are not in any way excluded.

    Regarding the sun: its variations are indeed far too small to account for the temperature increase in the modern global warming era. But they are not negligible, and are included in all realistic climate models. Without accounting for solar variations, the models fail to match the early-20th-century warming very well; with them, the models match the entire 20th century with stunning accuracy.

    Regarding credentials: those of the moderators are trivially easy to discover, and you’ll find they are among the world’s leaders on the subject of climate science. Most comments come from non-scientists, but there are a fair number of working scientists (myself included) who comment here regularly. I have a fairly long list of publications in peer-reviewed scientific journals — but not in climate science, so parading my credentials would be of little use. And before I venture to add to the scientific research on climate, I’d be sure to learn all I could from actual climate scientists who have, for the most part, devoted entire lifetimes to its study.

    Comment by tamino — 5 Feb 2007 @ 2:19 PM

  183. Re: #178


    Thank you for the thoughtful and engaging response. Your Fab Four metaphor is duly appreciated. While my perspective may not fit the more accepted explanation, I remain confident we agree on the fact that it is solar irradiance that is mostly responsible for the energy that warms the ambient temperature throughout the day and its absence is the culprit for the majority of cooling at night. To me that seems empirically evident in the variations between temperatures in the shade and direct sunlight and the major reason that significant remnants of December snow, despite above freezing daylight temperatures, that persist in my north facing driveway while those of my neighbors across the street are bone dry vs. radial momentum of the Earths orbit being the prime energy source for such phenomena.

    Regardless, your main point is that solar energy fluctuations are not significant enough to be considered in most climate models. I will read up on it as you suggest, however I hope that those assertions are made by those most qualified to make them. That is not to say, the valid perspectives of others outside of solar scientists should not be considered, by all means they should. I am sure you see my point.

    Now its time to shut up and read. By the way, very cool of you to provide your background.

    Marty Chavez – Albuquerque, NM – Business Development Professional – BS in Health Sciences

    Comment by Martin Chavez — 5 Feb 2007 @ 2:47 PM

  184. But now that calls into question the rest of the SPM statement:
    “The carbon dioxide radiative forcing increased by 20% from 1995 to 2005, the largest change for any decade in at least the last 200 years. {2.3, 6.4}”
    I calculate (roughly, based on figure 2.4 of the draft IPCC WG1 Fourth Assessment Report) that the increase in radiative forcing from 1970 to 1980 was from 0.84 to 1.06 W/m^2, which is 26%. So the SPM statement appears to be incorrect that the largest % change was 1995 to 2005.

    Percent of what?
    Let’s try the AR4 SPM statement again, with a bit of editing to show what the ‘20%’ figure is a percent of:

    The combined radiative forcing due to increases in carbon dioxide, methane, and nitrous oxide is +2.30
    [+2.07 to +2.53] W m-2, and its rate of increase during the industrial era is very likely to have been
    unprecedented in more than 10,000 years (see Figures SPM-1 and SPM-2). The carbon dioxide radiative
    forcing increased by 20% [of the 1750 to 2005 change in radiative forcing] from 1995 to 2005, the largest change for any decade in at least the last 200
    years. {2.3, 6.4}

    Bold text is my inference from context.
    Now let’s try your statement again, with a bit of editing to show what your ‘26%’ figure is a percent of:

    I calculate (roughly, based on figure 2.4 of the draft IPCC WG1 Fourth Assessment Report) that the increase in radiative forcing from 1970 to 1980 was from 0.84 to 1.06 W/m^2, which is 26% [of the 1750 to 1980 change].

    Bold text is my inference from context.

    If my inferences are correct, you are comparing apples to pears.
    This is a general problem with percent – one must always read carefully to determine ‘percent of what‘ .

    Comment by llewelly — 5 Feb 2007 @ 3:23 PM

  185. llewelly: It appears that I’ve managed to conflate the prediction that Indonesia will lose 2,000 islands with the IPCC. I suspect that the source where I originally got that information might have been partly responsible for that, but perhaps I did it all on my own. Again, thanks on your link last night (which appears to have been lost to the database gods), which did manage to answer many of my questions.

    Comment by Ben Hocking — 5 Feb 2007 @ 3:28 PM

  186. RE: #130 – Please describe the experimental procedure(s) used to characterize the rate of oceanic CO2 fixing.

    Comment by Steve Sadlov — 5 Feb 2007 @ 3:44 PM

  187. Re 184:
    >The carbon dioxide radiative forcing increased by 20% [of the 1750 to 2005 change in radiative forcing] from 1995 to 2005…

    llewelly, I think that you are calculating the same way Lord Monckton did to get 17% rather than 20%. I believe they are using: % of the 1750 to 1995 change in radiative forcing from 1995 to 2005.

    Comment by Steve Reynolds — 5 Feb 2007 @ 4:02 PM

  188. >rate of oceanic CO2 fixing

    Here ya go, Steve, these abstracts will get you started on the methods:

    Comment by Hank Roberts — 5 Feb 2007 @ 4:09 PM

  189. [[There’s a simple answer to the question of why solar variations aren’t included in climate models (though in fact they may be in some): there have been satellites in orbit for the last 40 years or more, making careful measurements of the sun’s output. From those we know to a fraction of a watt per square meter (IIRC) just how big the variation is, and it’s not anywhere near large enough to cause significant temperature changes. ]]

    While I agree with the thrust of your comments, I want to point out that most climate models do take Solar variation into consideration, especially if they’re doing multi-year simulations. The Solar intensity variation over the 11-year cycle isn’t huge, but it’s big enough to be noticeable.

    Comment by Barton Paul Levenson — 5 Feb 2007 @ 4:25 PM

  190. [[Warming by 2030 is very likely to be at least twice as large as the corresponding model-estimated natural variability during the 20th century .”

    Can somebody explain me what a warming of twice a variability means?]]

    What they’re saying is that the warming will be large enough that we can rule out natural variability as the cause. In fact, I think that’s already happened.

    Comment by Barton Paul Levenson — 5 Feb 2007 @ 4:26 PM

  191. re #189
    don’t forget the 100,000 years cycle……..

    “*Sun’s fickle heart may leave us cold”
    There’s a dimmer switch inside the sun that causes its brightness to rise and fall on timescales of around 100,000 years – exactly the same period as between ice ages on Earth. So says a physicist who has created a computer model of our star’s core.

    [Response:“utterly implausible” (last paragraph). – gavin]

    Comment by lars — 5 Feb 2007 @ 4:44 PM

  192. 90.) “One other small point, we do not have anywhere near enough fossil fuels reserves to achieve the higher and hence more alarmist scenarios unless we invoke large scale positive feedback loops for large releases of CO2 from natural sources such as the siberian permafrost, or rain forests etc “…

    149) “Is it fair to say that all of the fossil fuel reserves will be burnt eventually, and that it’s merely a question of how slowly or quickly we burn them?”…

    Perhaps conventional is the keyword here. Additionally, fossil fuel emissions are not the only source of greenhouse gas emissions that we have to contend with;
    albeit one can find ambigious or diverging viewpoints on what could or could not be the outcomes (positive versus negative) in relation to emission sources.

    {As I posted this on the 3rd, I’ll assume that mine was one of the “lost” postings.}

    “Peak Oil, Exxon Mobil” Money Week (9-28-06)

    …”In later comments, Mr. Nolan explained the Exxon â??viewâ?? that â??the world has abundant energy resources.â?? He stated, â??According to the U.S. Geological Survey (USGS), the Earth currently has more than 3 trillion barrels of conventional recoverable resources and so far weâ??ve produced 1 trillion of that. Conservative estimates of heavy oil and shale oil push the total recoverable resource to over 4 trillion barrels.â??”…

    Energy Information Administration / International Energy Outlook 2006
    Chapter 3 World Oil Markets


    International Petroleum (Oil) Reserves and Resources

    World Proved Reserves of Oil and Natural Gas, Most Recent Estimates
    Table Posted: January 9, 2007

    Under footnote 2)
    …”BP notes that “the figure for Canadian oil reserves includes an official estimate of Canadian oil sands ‘under active development’.”…

    footnote 3)
    …”Oil & Gas Journal’s oil reserve estimate for Canada includes
    5.2 billion barrels of conventional crude oil and condensate reserves and 174.0 billion barrels of oil sands reserves.”…

    footnote 4)
    …”World Oil states that its
    Canadian oil reserves estimate “Includes reserves that are recoverable with current technology and under present economic conditions. Includes
    7.58 billion bbl [barrels] of oil sands and bitumen.” “…

    “About Oil Shale”
    United States Department of the Interior, Bureau of Land Management (BLM)/Argonne Labs
    ..”Present U.S. demand for petroleum products is about 20 million barrels per day. If oil shale could be used to meet a quarter of that demand, the estimated 800 billion barrels of recoverable oil from the Green River Formation would last for more than 400 years1.”…..


    Expedition to the Deep Slope
    NOAA Ocean Explorer, (Jun 2006)
    “The â??Expedition to the Deep Slopeâ?? expedition is the first systematic exploration of hydrocarbon seep communities deeper than 1000m in the Gulf of Mexico.”…

    Stable carbon isotope records of carbonates tracing fossil seep activity off Indonesia
    Geochemistry Geophysics Geosystems 7 (11), 11009 (2006)
    “”Stable isotope records of carbonates from up to 20 m long sediment cores from the forearc basin of the Sunda arc display significant 13C depletion, deviating from expected normal marine levels by 5 to 40â?° (Peedee belemnite (PDB)). This depletion is interpreted to be caused by methane seepage and associated authigenic carbonate precipitation in sediments near the seafloor. “…

    Contribution of anthropogenic and natural sources to atmospheric methane variability.
    P Bousquet et al. Nature. 443 (7110), 439-43 (28 Sep 2006)
    …”Since 1999, however, they indicate that anthropogenic emissions of methane have risen again. The effect of this increase on the growth rate of atmospheric methane has been masked by a coincident decrease in wetland emissions, but atmospheric methane levels may increase in the near future if wetland emissions return to their mean 1990s levels.”


    [edited — sorry, we can’t allow excessively long posts, otherwise everyone else’s comments get lost. please feel free to link to some site elsewhere where you can provide more extensive information]

    Comment by BarbieDoll Moment — 5 Feb 2007 @ 4:44 PM

  193. RE: #188 – Close but no cigar.

    Comment by Steve Sadlov — 5 Feb 2007 @ 4:54 PM

  194. Re #163, #183, etc. Other physicists keep climate physics from straying too far:

    There is also a reason involving sociology of science. Among the most important regular scientific meetings for Climate Science is the Fall meeting of the American Geophysical Union. The society includes sections focused on Space Physics and Planetary Sciences. The December 2006 meeting had 32 sessions organized around Solar and Heliospheric Physics ( Given how mind-numbing it can be to listen carefully to several days of rapid-fire presentations in your own subdiscipline, taking in a few interesting talks in another field is one way to clear your head. (That’s at least in my experience.) If climate modeling methods required overly dubious assumptions about solar variability and behavior, at least once a year leading experts in heliophysics need only walk to another room down the hall to start to set things straight–the “embarrassing question from the back of the hall” being a common way to begin such a corrective process. [tongue partly in cheek] In addition, there are places where Cosmologists regularly attend invited scientific lectures by Climate Scientists, and vice versa. (The Goddard Space Flight Center being one of those places.)

    So even if the IPCC does omit recruiting experts working on the unification of General Relativity and Quantum Mechanics, the approaches used in Climate Science do have to stand up to some level of scrutiny across disciplines.

    [Response: Well – maybe my previous (brief) life working on General Relativity is of some use after all? -stefan]

    Comment by Bob — 5 Feb 2007 @ 5:02 PM

  195. llewelly, I think that you are calculating the same way Lord Monckton did to get 17% rather than 20%. I believe they are using: % of the 1750 to 1995 change in radiative forcing from 1995 to 2005.

    If so I apologize. Unfortunately there is no way I can be sure – the AR4 SPM does not say what the change in forcing from 1750 to 1995 was, and my interpretation of their 20% figure was only an inference – the AR4 does not specifically say what the 20% is of.

    Comment by llewelly — 5 Feb 2007 @ 5:09 PM

  196. Re 194:
    >Unfortunately there is no way I can be sure – the AR4 SPM does not say what the change in forcing from 1750 to 1995 was…

    Please see figure 2.4 in IPCC Working Group I Contribution to the Fourth Assessment Report of the IPCC
    Second-Order Draft:

    Comment by Steve Reynolds — 5 Feb 2007 @ 5:30 PM

  197. REPOST DUE TO DATABASE CORRUPTION: I am definitely surprised that AR4 has come to a stronger conclusion than the TAR. Yes, there has been much work since the TAR and the models are much better, but that is the problem. We also now know much more about how flawed the models are. AR4 has ignored the draft reviewers and their own diagnostic subprojects, such as Roesch that showed ALL of the models had positive surface albedo biases (against solar) that are much larger than the global energy imbalance thought to contribute to the warming. They should have no confidence in model projections and climate sensitivity after that.

    There are no model independent assessments of climate sensitivity that have the same coupling to the climate as the well mixed GHGs. The inability to explain 20th century warming without the GHGs should come as no surprise when the models are throwing away 2.7 to 3.8 W/m^2 of solar forcing, when the annual imbalance is only 0.5 to 0.8 W/m^2 of warming, both figures globally and annually averaged.

    The anti-solar bias figures are obtained by applying the net solar flux from

    of 198 W/m^2, to the globally and annually averaged positive surface albedo biases found reported by Roesch.

    So much for “peer review”. It appears that AR4 came to their conclusions before they started, and were unwilling to rebuke the overly “confident” TAR.

    Roesch A. (2006), Evaluation of surface albedo and snow cover in AR4 coupled climate models, J. Geophys. Res., 111,D15111, doi:10.1029/2005JD006473.

    Comment by Martin Lewitt — 5 Feb 2007 @ 5:36 PM

  198. Re: #163, 164, 178, 182, 183 & 189

    Another skeptic bites the dust…

    To all who took the time and requisite patience to open my eyes to a new understanding of AGW, I thank you. Here’s a few boilerplate reference URL’s for the next spade of lay entrants in to your realm that present the what about solar energy variation? question:

    …and there are the physicists, where they were the whole time. I especially appreciated the writings of Spencer Weart, who took a historical approach to the science. It goes to show you that is about how you tell the story to some people.

    So the consensus is justified, and there is a huge challenge ahead. As a businessman, I know that the greater the challenge, the greater the opportunity, which markets truly respond best to overtime, much more than the short term effects of fear. The point is that if AGW is truly the next disruptive change for humanity, then those who develop the commercial solution will be the economic winners. It is not hard to imagine the great fundamental shift in wealth a fossil fuel alternatives become the dominant global energy source. Don’t count out the Oil giants as partners in this future. There ifrastructure goes way beyond fossil fuel exploration & petrochemical processing…think distributin and marketing. Although it was inevitable that politics was the natural vehicle to bring the issue to prominence, I would not place much faith in its remedies to such a complex issue, otherwise we would have conquered disease, famine, and have sustained world peace long ago.

    Nevertheless, I wish the skeptics well, and my hope is that they will not be crucified by the mob. I urge you to allow them into arena of ideas for perpetuity. They will only sharpen your skills to forge better arguments and perhaps we’ll all breath a sigh of relief if they turn out to be right. Furthermore, insisting on holding the monopoly on the orthodoxy has its own set of nasty consequences.

    Lastly, I want to apologize to anyone offended about my assertion around physicists holding special place in the pantheon of science, and implying that climate scientist’s credibility may be less significant. It’s ironic that I got what I wanted through a little agitation through oversimplification, when I claim to eschew such tactics. If its any consolation, I am most embarrassed about this last point.

    Thanks again for sending me on my way, better educated and more humble. I look forward to the innovation that will meet this most grave challenge.

    All the best!

    Marty Chavez – Albuquerque, NM – Business Development Professional – BS in Health Sciences

    Comment by Martin Chavez — 5 Feb 2007 @ 6:09 PM

  199. > It is not hard to imagine the great fundamental shift in wealth
    > as fossil fuel alternatives become the dominant global energy source.

    Practically and parochially speaking, it’s the only way the United States can hope to redeem the debt now held by the Chinese government. If we can create the tools to make it through the next century, they’ll want to buy them.

    And they have all those US Treasury Bonds, so we know they can pay, if we can create the technology faster than they can.

    See today’s Wall Street Journal, for a discussion of how the “Chinese plus US” economy can be considered as one large economy, Eastern and Western branches but with most of the “ChiMerican” trade internal to that set.

    “Out of great need comes great ingenuity.” I forget who said that.

    Comment by Hank Roberts — 5 Feb 2007 @ 6:24 PM

  200. Re #89

    While it is the expert judgement of many glaciologists that dynamical melting will accelerate very rapidly, there aren’t the needed models or terrain surveys in place as yet to be able to do more than make educated guesses.

    Sorry, Steve but this does miss my point. As far as I can see, data for flows from the ice sheets are not considered after 2003. Sometimes the best data you have is what you are looking at right now. I acknowledge that the trend is short, but why wasn’t the “expert judgement” of the people who know what they are talking about included in the summary?

    Perhaps it really doesn’t matter. The world will add a cost to carbon emissions or not, right? The sea level problem is major, in my view — “downplayed” in the report — but perhaps that won’t matter, it will be overwhelmed by every other unfortunate consequence. Still, if you wait six years for a “definitive” statement, and then parts of it suck, disappointment follows.

    Comment by Dave Cohen — 5 Feb 2007 @ 7:43 PM

  201. Re #197: Martin, you keep overstating the significance of the Roesch results. Can you quote something from the paper that backs up your POV? The abstract sure doesn’t seem to:

    “Surface albedo (ALB), snow cover fraction (SCF) and snow water equivalent (SWE) of state-of-the-art coupled climate models are compared and validated against ground-based and remote-sensed climatologies. Most IPCC AR4 climate models predict excessive snow mass in spring and suffer from a delayed spring snow melt while the onset of the snow accumulation is generally well captured. This positive SWE bias is mainly caused by too heavy snowfall during the winter and spring season. Seasonal cycles of snow cover area (SCA) at continental scales are captured reasonably well by most participating models. Two models clearly overestimate SCA over both Eurasia and North America. Year-to-year variations are reasonably well captured over both Eurasia and North America in winter and spring. The most pronounced underestimation in the interannual SCA variability is generally simulated during snow melt. The pronounced negative SCA trend that has been observed from 1979 to 2000 is only partly reproduced in the AR4 model simulations. Furthermore, the computed trends show a large spread among the models. Results from time slice simulations with the ECHAM5 climate model suggest that accurate sea surface temperatures are vital for correctly predicting SCA trends. Simulated global mean annual surface albedos are slightly above the remote-sensed surface albedo estimates. The participating AR4 models generally reproduce the seasonal cycle of the surface albedo with sufficient accuracy while systematic albedo biases are predicted over both snow-free and snow-covered areas, with the latter being distinctly more pronounced. The study shows that the surface albedo over snow-covered forests is probably too high in various state-of-the-art global climate models. The analysis demonstrates that positive biases in SCA are not necessarily related to positive albedo biases. Furthermore, an overestimation of area-averaged SWEs is not necessarily related to positive SCA anomalies since the relationship between SWE and SCF is highly nonlinear.”

    Also, to say that the WG1 SPM “ignored the draft reviewers” on this point is a rather strong statement. Evidence for that?

    Comment by Steve Bloom — 5 Feb 2007 @ 8:03 PM

  202. Re #200: Dave, the AR process is designed to be conservative, and this is a good example of why. New research that only has one or two years of data behind it (as is the case with the dynamical melting) and appears in the last year before publication isn’t going to be reflected very well, and the problem is compounded by the long lag between ARs. OTOH I think the climate science community recognizes the importance of this research, and as we saw with the well-timed Science article (that got picked up in much of the coverage) can be relied upon to give it appropriate emphasis. That emphasis will increase greatly if the next year or two of data bear out the apparent trend, and at that point I don’t think it will be a problem that the AR4 didn’t say much about it.

    Comment by Steve Bloom — 5 Feb 2007 @ 8:23 PM

  203. Re 186, 188: Steve, not sure. But my 2nd link in #138 is obviously inadequate since atmospheric CO2 can’t go to zero over time without fixation. I thought I was only considering diffusion and transfer in the impulse response. Hank, thanks for the link, that will get me started.

    Comment by Eric (skeptic) — 5 Feb 2007 @ 9:50 PM

  204. The Report says that “very likely” means more than 90%. But what does 90% mean, in a scientific sense? How was it calculated? I know they don’t mean that 9 out of 10 worlds would have a certain level of warming. I also don’t think it means that 9 out of 10 people on the panel believe something, or that 9 out of 10 computer models find something. So I am puzzled. How did they derive this 90% number?

    Comment by SteveB — 5 Feb 2007 @ 9:54 PM

  205. RE: “rate of oceanic CO2 fixing”

    Have a try at these.

    DOE (1994) Handbook of methods for the analysis of the various parameters of the carbon dioxide system in sea water.Version 2, A. G. Dickson & C. Goyet, eds. ORNL/CDIAC-74

    “Program Developed for CO2 System Calculations (Ernie Lewis and Doug Wallace of Brookhaven National Laboratory. ORNL/CDIAC-105)”

    And you could also refer to

    GLobal Ocean Data Analysis Project

    Oceanographic Numeric Data Packages

    Comment by BarbieDoll Moment — 5 Feb 2007 @ 10:22 PM

  206. Steve Reynolds, you link to the draft. It is not the final document; it cannot resolve this confusion.

    Comment by llewelly — 5 Feb 2007 @ 10:23 PM

  207. re the speculation that rising sea levels from GW will innudate 2000 Indonesian islands: Doesn’t the sea level around Indonesia already vary by 1/2 to 1 meter just from the El Nino oscillations?

    Comment by Rod B. — 5 Feb 2007 @ 11:12 PM

  208. ‘There is so much ice here that if it all melted, sea levels globally would rise hugely – perhaps as much as 80m. Say goodbye to London, New York, Sydney, Bangkok, Rio… in fact, the majority of the world’s major cities.
    But will it happen?’

    – My answer is yes. I don’t know the specific timing of the jumps to higher levels but I’m confident that the governments should begin major action to get ready for them. – comment on Newsvine at:

    Comment by Pat Neuman — 5 Feb 2007 @ 11:39 PM

  209. Just to clarify re #s 95, 100, et al, which is kind of a side issue but I think important to these discussions. The basis of the debate from many/most skeptics is, of course, economic. Despite the often poo-pooing by many AGW proponents of the economic consequences (some it seems even delight in it), those consequences are in fact tremendous. (Most of) us skeptics naturally and properly think this should not be accepted because of the warnings from a few (O.K. a lot) scientists without extreme scrutiny, even if they prove correct. I see nothing perverse or pernicious about that. I see it as responsible.

    As an aside, (most of) us skeptics prefer not to “attack” the science/scientists. Scrutiny and attack are not the same thing. Though I admit the process, unfortunately, seems to be progressing to attack – re-attack – attack back, and is leaving scientific discourse, heated as it might be, in the dust.

    Comment by Rod B. — 5 Feb 2007 @ 11:42 PM

  210. llewelly> Steve Reynolds, you link to the draft. It is not the final document; it cannot resolve this confusion.

    OK, but it appears to me that either the SPM is wrong or the draft figure 2.4 is wrong on the issue of radiative forcing % change. I guess we will find out in May how IPCC handles it.

    Is RC staff who have seen a more recent draft allowed to comment on this?

    Comment by Steve Reynolds — 5 Feb 2007 @ 11:54 PM

  211. Re: # 34

    ” Would the moderators consider deleting the ignorant, sneering, hostile, insulting, content-free and completely worthless remarks from the flame troll identifying himself as “juandos”? Such drivel belongs on Free Republic or some other right-wing hangout, not here. ”

    I don’t agree at all, since I found the response to juandos’ insinuation most valuable. Now, if people accuse IPCC scientists of screwing the world for money I have some information to use.

    Comment by Pavel Chichikov — 5 Feb 2007 @ 11:57 PM

  212. I’d like to use this thread to make a small complaint about the IPCC website and the confusion I think they’ve sown about what was released last Friday.

    The graphic at the top of that page says “The first volume will be released” and above that is “Paris, 2 February 07”. This makes one think its WG1 that will be released. But we know it’s just the SPM of AR4’s WG1 report.

    And its needlessly difficult to find out when the actual WG1 report will be released. You first have to click on “About IPCC” and then “Working Group I” which takes you to this page where you finally find that the report will be on the web in May and in book form in late June.

    A final annoyance (and I hope embarrassment for the IPCC webmasters), if you click on “Calendar of Events” on the main IPCC website you go to a calendar of meetings…for 2006.

    Great job on the publicity leading up to the SPM, turning off the lights on the Eiffel Tower and all that. And this was just the SPM. What will they do for the real WG1 report?

    Comment by Rob Jacob — 6 Feb 2007 @ 12:00 AM

  213. RE#183 and the role of physics in climate,
    It’s true that climate involves a lot of physics, but it also involves a lot of biology – so climate science falls into the ‘interdisciplinary category’. One of the most interesting and noteworthy pieces of work on this is the recent report, which describes the use of the tropospheric emission spectrometer to get a unique picture of water vapor and ozone distributions.

    The abstract on their research is at Nature, Feb 1 2007, “Importance of rain evaporation and continental convection in the tropical water cycle”, John Worden, David Noone and Kevin Bowman and The Tropospheric Emission Spectrometer science team and data contributors.

    To quote from the ScienceDaily report, “The team also found evidence that water transported upwards by thunderstorm activity over land originates from both plant “exhalation” in large forests and evaporation over nearby oceans. The balance between these two different sources tells us how vegetation interacts with climate and helps maintain regional rainfall levels.

    “This link between vegetation, hydrology and climate has implications for how societies choose to manage their ecological resources,” said Noone. “Our measurements provide a baseline against which future changes in vegetation-climate interactions can be measured.”

    The link between the biosphere and the physical climate system has always been a matter of contention, but here we see how the different traditional branches of science all cooperate in the study of this system, from engineering to physics to biology and chemistry. This also demonstrates the threat of deforestation on a global basis to the climate system, i.e. less net uptake of CO2 as well as regional drying and drought.

    It also demonstrates the importance of continuing to monitor the Earth from space – and since one of the main uncertainties in the IPCC report was the meridional overturning circulation changes, a network of ocean sensors is also needed. However, funding is lacking and many satellites need to be replaced, according to the National Academy of Sciences:
    Aging weather satellite fleet at risk: According to a new study, crucial weather and environmental satellites soon will fail, and their replacements are insufficient and behind schedule.

    This is an unbelievable state of affairs. Is it gross incompetence, or a deliberate effort to prevent data from being collected?

    Comment by Ike Solem — 6 Feb 2007 @ 2:26 AM

  214. As a former, now retired researcher I follow with great respect the highly professional and fast advancing work on a scientific understanding of the climate. I feel a responsibility to help communicating the results to the broader public. A completely out-of-perspective emphasis is put by many skeptics on the IPCC 90 % statement of human influence. Behind the unspecified 10% a lot of people try to hide. I think that examples of scenarios in this 10% space and the underlying unrealistic combinations of parameters would be helpful. Is this possible? I would be glad, if someone from the research community could comment on this?

    Comment by Klaus Ragaller — 6 Feb 2007 @ 3:19 AM

  215. Re: Steve Bloom #201,

    To quote from the Roesch full text:

    “The mean annual surface albedo of the 15 AR4 models amounts to 0.140 with a standard deviation of 0.013. All AR4 models are slightly above the mean of PINKER (0.124) and ISCCP-FD (0.121). However, on a global scale, differences among the models, as well as the biases between the models and the remote-sensed climatologies, are small. Three (MRI-CGCM2.3.2, INM-CM3.0, and CSIRO-Mk3.0) out of the 15 AR4 models are more than 1 standard deviation above the all-model mean; two models (GISS-EH and PCM)are more than 1 standard deviation below the all-model average.”

    Notice, that ALL of the models are above are above the surface albedo data, even those that are more than one standard deviation below the all model mean. I don’t know what lead Roesch to characterize the model errors as “small”. Perhaps if he had characterized them as large, or as several times the net annual global energy imbalances, he would have had a harder time getting published. The positive surface albedo biases of the models are 0.140 minus 0.124 and 0.140 minus 0.121 against the two data sets respectively. Apply these globally/annually averaged surface albedo biases to the corresponding solar surface flux of 198W/m^2 and you get the correlated model biases of 2.8 to 3.8 W/m^2.

    As to my “ignored the draft reviewers” claim. I am one of the draft reviewers, and pointed out that this correlated bias was several times the energy imbalances we are trying attribute and project. I pointed out that not only was the paper relevant to Chapter 9, for which it had been submited but also for Chapter 10 on global projections. My calculations on the time were based on TOA fluxes, but in a follow up letter I translated that to the surface fluxes, and suggested that if they couldn’t bring themselves to drop Chapter 10 since the models had been invalidated, that they at least delay AR4 until the models could be corrected and the scenerios rerun.

    The solar surface flux is from:

    Comment by Martin Lewitt — 6 Feb 2007 @ 4:08 AM

  216. #204 Steve, you should read the Guidance Notes for AR4 lead authors therafter. Likelihood (point 14) express either a quantitative analysis, or elicitation of expert views. The second kind of likelihood is of course more subjective.

    Comment by Charles Muller — 6 Feb 2007 @ 5:02 AM

  217. #183
    Tamino : “Regarding the sun: its variations are indeed far too small to account for the temperature increase in the modern global warming era. But they are not negligible, and are included in all realistic climate models. Without accounting for solar variations, the models fail to match the early-20th-century warming very well; with them, the models match the entire 20th century with stunning accuracy.”

    Yes, but have a look at Table 10.2.1 in Second Draft. It summaries the radiative forcing agents models take account of, for the 20th simulation and 21st projection. If I correctly understand, solar forcing is omitted or put as constant in the great majority of models. So, how do you expect these models are correct, notably for 1915-45 warming?

    Comment by Charles Muller — 6 Feb 2007 @ 5:14 AM

  218. #90 and #157, I wish to add another viewpoint to the usability of coal. Our current infrastructure prefers oil and gas, but much of the growth in China is based directly on coal. Coal can be turned into oil and gas – the overhead cost per barrel is about 15 dollars and investment requirement is about 50 thousand dollars per one barrel/day calculated from the latest plant being built in China. The total investment cost to double todays natural oil production by using coal would be only a few trillion dollars. There are already several large plants being built for this purpose in China. These investments are generally considered profitable when price of crude oil is constantly higher than 60-70 dollars per barrel. The higher the price, the faster the return of investment. When crude oil is over 90 dollars, this industry has so high profitability / return on investment that there is scarcely money left for any other investments even though they also would be profitable. So the scenario that alternatives to fossile fuels would become economically attractive when oil gets scarce is not clear. And if you ask where all these trillions come from – it is easy. Oil producers get several trillion each year. There is money, it is sucked away from every other profitable investment scenario.

    This is not a good omen for voluntary controls. If I look at the different scenarios from the viewpoint of a general futurist, it seems that the A1FI is most likely based on existing trends and facts. All lower scenarios include wishful thinking that we could get our act together and get strong enough mandatory global controls. This is naturally my wish also but from the times of TAR, according to Shell Global Scenarios to 2025, the energy efficiency of the world has decreased and I claim we have followed A1FI and still are. And converting coal to oil will only make things worse from the efficiency perspective. I understand that this is a discussion for climate issues but as the different scenarios in the IPCC reports are so crucially different it might be a good idea to start one discussion on the different scenarios and assumptions behind them – and perhaps analyse which scenario we have followed from the time these scenarios were first introduced in IPCC reports.

    Comment by Risto Linturi — 6 Feb 2007 @ 6:49 AM

  219. Re 95 and 120, not only does the problem of climate change have a high procrastination penalty, in the context of US politics it has immediate political penalties. The US lost its chance to actually do something at low economic cost, not in this administration, but in the 1990s. The Republican Congress bears much of the blame, but the decision of the Clinton/Gore administration to push the science while spending no political capital on actually doing anything was a disaster whose fruits we reap today.

    Comment by Eli Rabett — 6 Feb 2007 @ 8:46 AM

  220. RE #218

    Risto, you provide a stark view of the post-oil world feeding greater demand as living standards improve in two of the most populated nations. I strongly agree with your comment. Coal to liquids and gas are here and now.

    RC threads are challenged when contributors try to launch comprehensive discussions on oil-gas-coal-nuclear options because they attract the simple solution advocates of energy efficiency and renewables. Regrettably those approaches are not sufficient to meet the AGW future and increasing demands of an expanding global population. And, yes, they help and will more so when a carbon tax is finally implemented.

    The dedicated sponsors of this web page (contributing their valuable time) are not strong on energy policy but, in the modeling work, they rely upon projections borne out of scenarios. I do not have much faith in the IPCC scenarios because IMO they do not give enough focus to coal as the alternative to oil and gas. It is inevitable because the nearly 500 million car global fleet will not run on wind and solar (OK, a few will).

    If you are making a motion to the RC managers, I second it and urge them to invite contributors such as Jae Edmonds to lead the discussion.

    Comment by John L. McCormick — 6 Feb 2007 @ 9:10 AM

  221. Just noting that solar variability is vastly understated.

    Just look at this chart. The 11-year cycle varies by about 1 W/m2 over the cycle (averaged) but the daily/annual irradiance varies by as much as 4 W/m2.

    If you look at solar irradiance proxies over time, the average varies by as much as 4 W/m2. Converting this variance into percentage terms (0.1 per cent which is actually 1-4 W/m2), just masks the total energy variation which is more than CO2 currently.

    [Response: Wrong. You are (again) confusing TSI variation with the radiative forcing which is smaller by a factor of 0.7/4 = 0.175 (due to albedo and geometric effects). -gavin]

    Comment by Jeff Weffer — 6 Feb 2007 @ 9:30 AM

  222. Re: #217

    When you say “Table 10.2.1 in Second Draft” what exactly are you referring to?

    If you go to this page, and scroll down to the third graph (actually part “a” of the 2nd figure), you’ll see that the time series of effective forcing due to solar irradiance not only shows a secular increase in the early 20th century, it also shows a cyclic variation (due to the solar cycle). You can even get the numeric data here.

    Comment by tamino — 6 Feb 2007 @ 9:43 AM

  223. Re #95 “I think there is a constructive role in the debate for conservative economic opinion. We certainly will not be able to address climate change if our economy is weakened.”
    I’m very dubious about the first sentence here, although I suppose it could depend what kind of conservative economic opinion you mean: serious measures against climate change are going to require at the very least controls on the operation of “free markets” of a scale and depth unprecedented in capitalist economies. This is why the right-wing thinktanks are full of denialists: anthropogenic climate change shows up their economic nostrums (if everyone follows their own selfish interests, and governments stop interfering, the magic of the market will make us all rich and happy) for the nonsense they are. The second sentence is also doubtful: it is the strongest economies that are contributing most to the problem. Suppose some new disease were to wipe out humanity next week, removing the economy entirely: result, so far as I can see, a fall in GHG emissions faster than anyone has proposed trying to achieve. On a smaller scale, a 1929-style crash and subsequent slump would at least temporarily reduce emissions. There are plenty of good reasons not to want this to happen, but it would give us a few more years to bring emissions under control. Of course one can argue that a slowdown would reduce investment in new technologies, but until we can be confident such investment will reduce rather than increase emissions, I think the truth is more or less the opposite of what you claim: the stronger the economy, the faster the problem will get harder to solve. The basic problems are not technological, but political: unless and until both governments and publics of the major emitters are ready for serious action, emissions will go on climbing unless there is a slump; once they are, the technical problems are surmountable.

    Comment by Nick Gotts — 6 Feb 2007 @ 11:21 AM

  224. How about using a 15 mile long nanoshooter orbiting the earth that collects CO2 and methane and sends it escape velocity to mars? This would help Mars’ atmosphere and rid ours of that pesky stuff that is heating us up. It would give many scientists research jobs and could be funded by the upcoming carbon tax imposed on large users.

    Comment by Paul M — 6 Feb 2007 @ 11:54 AM

  225. [[ It is inevitable because the nearly 500 million car global fleet will not run on wind and solar ]]

    Unless the wind and solar are used to generate hydrogen, or plug-in electric cars come into widespread use.

    Comment by Barton Paul Levenson — 6 Feb 2007 @ 12:11 PM

  226. [[How about using a 15 mile long nanoshooter orbiting the earth that collects CO2 and methane and sends it escape velocity to mars? This would help Mars’ atmosphere and rid ours of that pesky stuff that is heating us up. It would give many scientists research jobs and could be funded by the upcoming carbon tax imposed on large users. ]]

    Huh? What? Come again?

    Comment by Barton Paul Levenson — 6 Feb 2007 @ 12:14 PM

  227. The reader discussion on the New Tork Times (free registration required, I believe) is very revealing about the public reaction to the SPM and anthropogenic climate change issues.

    It seems to present a broad sample of opinion, perhaps rather broader than we see on focused sites like this one. There is quite a range of understanding, as might be expected, though the “truth must be somewhere in between these two extremes” camp is perhaps underrepresented. People repeating even the most baseless fabrications of the naysayers present an interesting if discouraging sample. For example, the NYT discussion seems to have reached a vague consensus that glaciers are growing worldwide. Those who are familiar with climate science and unfamiliar with climate politics would do well to grit their teeth and plow through the discussion to really understand what we are up against.

    I think that climate change is in itself very important, of course, but I also think the way that the debate has proceeded is itself a matter of great concern.

    Even if we manage to muddle through the greenhouse problem, the ways in which organized promulgation of misinformation can so effectively damage public discourse will continue to limit the capacity of democratic process to cope with the increasing complexity we face. Humanity has become the dominant force in an increasingly artificial environment. Willy-nilly, we have replaced nature. It’s hard to understand how we can do a decent job of it if the forces of confusion and doubt can be so much more effectively funded and armed in the public debate than the forces of reason and evidence.

    For me it comes down to this. If private interests are encouraged to devote as much PR effort as may be profitable to promulgate their self-interest, while public agencies are effectively enjoined from making comparable efforts to elucidate and promote the public interest on the grounds that it might intersect with their self-interest, how is the public interest to be effectively weighed in the public conversation?

    Comment by Michael Tobis — 6 Feb 2007 @ 12:23 PM

  228. re: 224. Why does a version of Marvin the Martian’s “Illudium Q-36 Explosive Space Modulator” come to mind when reading that? ;-)

    Comment by Dan — 6 Feb 2007 @ 12:39 PM

  229. Re: My own post #215,

    Upon rereading Roesch (again), I find his characterization of the globally and annually averaged albedo bias as “small”, to probably be “small” relative to the much larger local albedo errors he documented in the Snow Cover Area, and other data. The globally averaged albedo biases of 0.016 and 0.019 are “small” compared to the local albedo changes when going from a Snow Cover Area to one that isn’t, as high as 0.7 or 0.8. Roesch found that even within Snow Cover Areas, the model albedos were also significantly higher when those areas were forested.

    Although Roesch discussed how these discrepencies might be diagnostic of the problems the AR4 models have especially at northern latitudes, he did not appear to notice the significance of the impact on their global attribution and projection. He also found positive surface albedo biases in the tropical deserts, but did not discuss the impact of these at all, probably because he is somewhat of a snow specialist. I am curious about what it is that is confounding the modelers there.

    Comment by Martin Lewitt — 6 Feb 2007 @ 12:49 PM

  230. Move over, Wally! Former skeptic (and NHC head) Hugh Willoughby has come up with the new best AGW metaphor:

    “Hugh Willoughby, senior scientist at the International Hurricane Research Center at Florida International University, a one-time global warming skeptic himself (15 years ago, before the data became overwhelming), said Monday that what worries him, more than the known problems cited by the panel, are what he calls ‘the unknown unknowns,’ the unanticipated climate changes.

    “Weather patterns and ocean currents, the product of ‘unevenly heated rotating fluids,’ are already difficult enough to predict. ‘It’s like being at a bank when a crack addict robs it. You don’t want to get the crack addict excited.‘”

    Comment by Steve Bloom — 6 Feb 2007 @ 1:51 PM

  231. RE#218 and #220,
    The issue of coal-to-liquid and ‘clean coal’ also illustrates some of the problems at preeminent US universities. Take (as the outstanding example) Stanford Universities Global Climate and Energy Project (GCEP) which looks pretty good at first glance – a program designed to lower greenhouse gas emissions.

    However, the details are disturbing. The lead sponsor for the program is Exxon Mobile, and not only do they (along with GE and Schlumberger oil services, and Toyota) control decisions on which projects are to be funded, they also control all patents created through the research:
    From the agreement:

    6.05 Subject to paragraphs 6.07 and 8.04, the University and each Sponsor will have, without restriction and in its sole discretion and without conferring with or accounting to anyone, a perpetual, nonexclusive, worldwide, irrevocable, royalty-free right and license to use, disclose, publish, republish, distribute, copy, prepare derivative works, sell, or otherwise transfer without limitation to any third party, whether affiliated or not, all or any part of the Project Technology, with or without extending to that third party the right to sublicense, sell, or otherwise transfer the Project Technology to other third parties.

    It’s hard to find exactly how they distribute funds, but their support for Advanced Coal certainly does not seem to fit their stated goal of ‘reducing greenhouse emissions’.

    In any case, universities engaged in renewable energy research using any public funds should be required to make any patents produced through such research available to all interested parties using non-exclusive licensing of university-owned intellectual property – in other words, everyone gets to use the knowledge produced.

    Comment by Ike Solem — 6 Feb 2007 @ 2:41 PM

  232. Re: 230

    For clarification, Hugh Willoughby was never head of the National Hurricane Center. He was head of the Hurricane Research Division of the Atlantic Oceanographic and Meteorological Laboratory before going to Florida International University.

    Comment by Harold Brooks — 6 Feb 2007 @ 2:42 PM

  233. This is why the world is going to fry like an ant under a dirty seven yr olds magnifying glass. 15 yrs ago, Hugh Willoughby, whatever he was, head of hurricane research or hurricane center, or a hooters hurricane drink mixer, was ostensibly a global warming skeptic himself. Now he is an advocate for change. that may make a good made for TV movie and even his anecdodal analogies to a bank robber are cute, it does absolutely nothing for remedying the global crisis we have. So get a chuckle out of Hugh’s cute remark, but remember Rome isn’t burning, the planet is burning. A twenty yr old student today can realize the earth’s climate is changing, but fifteen yrs ago might have had a different opinion while he or she was peeing on their kindergarten teachers floor. Just like they may have been playing policeman or fireman fifteen yrs ago, Hugh was playing climatologist, and he got it wrong. Again, call a novelist, it is quite human, but it does nothing for change. Stop the mental masturbation with the coal, oil co2, answers, that is not even close to the answer. We need a new paradigm and we need it fast. Unfortunately I don’t think humans, or at least anyone over the age of 16 is going to do it. So someone better start thinking outside of the outside of the box, or be prepared to take a dirt nap with an electric blanket like feel.

    Comment by Paul M — 6 Feb 2007 @ 3:08 PM

  234. Re #208(?): Pat Neuman — Thanks for the link to the BBC article. The number given there for the melting of the West Antarctic ice sheet, 5 m, is seriously smaller than the estimates in the Wikipedia article.

    As an amateur, I’ll opine that the East Antarctic ice sheet is not going to melt, even under ‘business-as-usual’ scenarios. So supposing that just the West Antarctic ice sheet and the Greenland ice sheet melt, both totally, that gives a sea stand rise of 12 meters.

    That will be bad enough…

    Comment by David B. Benson — 6 Feb 2007 @ 3:33 PM

  235. The sea level change issue does indeed seem to be understated – from the IPCC summary paleoclimate section, we learn that global sea levels in the last interglacial were very likely about 4-6 m higher then they are today mainly due to retreat of polar ice; polar temperatures were 3°-5°C higher then they are today.

    So, the question then is will it really take 1000 years for the Greenland and West Antarctice Ice Sheets to respond to the higher temperatures? Temperature anomalies relative to the 1961-1990 baseline period in the Arctic are already at 4C in the summertime:

    There is no evidence that this trend is going to return to lower values; warming equatorial waters continue to export heat to polar regions, and more water vapor in the atmosphere means an increase in latent heat transport.

    So, what is the response time of the Greenland Ice Sheet under these conditions? When does the buffering capacity of the Antarctic Ice Sheet on southern polar temperatures get overridden? Antarctic sea ice extent is probably a good indicator of this, but detailed knowledge of temperature changes in the Southern Circumpolar current would also be good to have.

    It’s worth going back and looking at the 3rd IPCC 2001: “Results from ice sheet models for the last 500 years indicate an ongoing adjustment to the glacial-interglacial transition of Greenland and Antarctica together of 0.0 to 0.5 mm/yr. These ranges are consistent. We therefore take the ongoing contribution of the ice sheets to sea level rise in the 20th and 21st centuries in response to earlier climate change as 0.0 to 0.5 mm/yr. This is additional to the effect of 20th century and future climate change.”

    While this current version is the summary, and not the detailed report, they probably should have included a statement on the failure of ice models to predict the dynamic behavior of the ice sheets. Is it possible that the response time is closer to 100 years then to 1000 years?

    Comment by Ike Solem — 6 Feb 2007 @ 4:13 PM

  236. Question about Table SPM-1: The column labeled “Likelihood of human contribution” rates all the phenomena as “Likely” or “More likely than not”. While on page 8, under “Understanding and Attributing Climate Change” it says that “most of the observed increase in globally averaged temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations.” Then it refers back to SPM-1. Can someone explain the discrepancy? How is “human contribution” different from “anthropogenic gases” and how are we supposed to use SPM-1 as a supporting table to this paragraph?

    And by the way, thanks for this posting. It’s great to have a place to post questions to better understand the document. And many thanks to any of you who’ve been involved in IPCC. This is very important work and it’s heartening to see so many come together like this and work to get real information out so we can actually hope to address the problems.

    Comment by Julia R — 6 Feb 2007 @ 4:27 PM

  237. Apparantly 70 countries across the globe have large coal reserves compared to 60 % of Oil and Gas reserves being found in the middle east that amounts to around 155 years worth at present usage levels. As demand for energy surges in the coming years and as Oil and Gas peak Coal will be asked to fill the energy gap maybe but as James Hansesn states that without clean coal technology using coal would be madness and only server to burn available stocks faster. Coal could well run out by 2100 if usage levels for whatever rason increase significantly as they surely will unless viable alternatives are found. So do we embrace climate change and hope that the use of all fossi fuels end up producing viable alterntives or do we go for efficiency gains of which there are many to prolong the life of fossi fuels, bring online current alternatives to offset increased demand in the coming years and hope and pray that ethenol and hydrogen can save the day before 2150 – 2200 and we run out of fossil fuels anyway.

    I opt for the latter, energy efficiency gains coupled with all viable alternatives and then R&D into creating the real energy future (if it exists) and also hope for fusion to work at some point before either it all becomes to expensive and politics take over or we get the energy breakthroughs we require ?

    Comment by pete best — 6 Feb 2007 @ 4:46 PM

  238. Global Warming is not due to human contribution of Carbon Dioxide

    Global Warming: The Cold, Hard Facts?
    Dr. Tim Ball, Chairman of the Natural Resources Stewardship Project (, is a Victoria-based environmental consultant and former climatology professor at the University of Winnipeg. He can be reached at

    Global Warming, as we think we know it, doesn’t exist. And I am not the only one trying to make people open up their eyes and see the truth. But few listen, despite the fact that I was the first Canadian Ph.D. in Climatology and I have an extensive background in climatology, especially the reconstruction of past climates and the impact of climate change on human history and the human condition.â??Few listen, even though I have a Ph.D, (Doctor of Science) from the University of London, England and was a climatology professor at the University of Winnipeg.â?? . For some reason (actually for many), the World is not listening. Here is why.
    No sensible person seeks conflict, especially with governments, but if we don’t pursue the truth, we are lost as individuals and as a society. That is why I insist on saying that there is no evidence that we are, or could ever cause global climate change. And, recently, Yuri A. Izrael, Vice President of the United Nations sponsored Intergovernmental Panel on Climate Change (IPCC) confirmed this statement. So how has the world come to believe that something is wrong?

    Comment by lars — 6 Feb 2007 @ 5:31 PM

  239. # tamino 222
    > When you say “Table 10.2.1 in Second Draft” what exactly are you referring to?

    Table in the Second Draft of AR4 (released in April 2006), chapter 10, pg 10. title : “Radiative forcing agents in the multi-model global climate projections”. This table offers a complete list of the factors included by models for “the simulations of the 20th century and of the future”

    If you check the column “Solar”, you observe that GISS-ER and GISS-EH do include a “time-varying forcing”, but all others are “constant” or “omitted”. As you explained, I use to read in attribution-detection papers that 1900-1950 warming cannot be simulated by anthropic factors alone (but eventually by natural factors alone, according to Min and Hense 2006 thereafter). So my question is: how a majority of AR4 models correctly simulates XXth century trends with a contant or omitted solar forcing? Maybe this table is confusing (no solar factor is logic for projection, because we cannot anticipate sun’s behavior; but quite strange for simuations 1900-2000)

    Min, S.-K., A. Hense (2006), A Bayesian assessment of climate change using multi-model ensembles. Part I: Global mean surface temperature, J. Climate, 19, 3237-3256

    Comment by Charles Muller — 6 Feb 2007 @ 5:33 PM

  240. Some questions. I often read from RC the “no trend in past 50 yrs of solar activity” argument. I remember here a Rasmus article on that point, and also a guess text by Muscheler. But should we consider this argument as a “likely”, “very likely”, “more likely than not”… assertion? More broadly, a “consensus position” (in spite of Solanki, Usoskin, Krivova, Scafetta & West, etc.)? And, on a more theoretical point of view, what is more important for a comprehensive view of climate response: trends between each cycle (19/20, 20/21, 22/23, etc.), or multidecadal comparisons (19-22 compared to 15-18 for example)?

    In fact, the AR4 SPM has aggravated my lack of understanding about solar factor. Model intercomparisons usually conclude that we need natural forcings in order to simulate 1900-50 (and eventualy a minor part of 1950-2000). But if Maunder/Modern difference is 0,2-0,4 K TOA (and 1750-2000 0,1 K TOA), I guess 1900-50 solar forcing is totally negligible. So, what are the “natural forcings” necessary to simulate 1900-50 (0,41 K warming between 1916 and 1945 according to Nasa Gistemp, not so far from 0,49 K on the same base for 1977-2006)?

    Comment by Charles Muller — 6 Feb 2007 @ 6:00 PM

  241. Re #232: Thanks for the correction, Harold. I’ve confused them before, but hopefully now I’ll remember.

    Comment by Steve Bloom — 6 Feb 2007 @ 6:32 PM

  242. RE#240,
    You say, “Model intercomparisons usually conclude that we need natural forcings in order to simulate 1900-50 (and eventually a minor part of 1950-2000). You seem to be implying that solar forcing is needed to explain the record, which simply isn’t the case.

    The issue relates to the following statement within the IPCC 2007 summary report: (pg 9)

    It is very unlikely that climate changes of at least the seven centuries prior to 1950 were due to variability generated within the climate system alone. A significant fraction of the reconstructed Northern Hemisphere interdecadal temperature variability over those centuries is very likely attributable to volcanic eruptions and changes in solar irradiance, and it is likely that anthropogenic forcing contributed to the early 20th century warming evident in these records.

    If we compare this to the paleoclimate summary on pg 8:

    Average Northern Hemisphere temperatures during the second half of the 20th century were very likely higher than during any other 50-year period in the last 500 years and likely the highest in at least the past 1300 years. Some recent studies indicate greater variability in Northern Hemisphere temperatures than suggested in the TAR, particularly finding that cooler periods existed in the 12 to 14th, 17th, and 19th centuries. Warmer periods prior to the 20th century are within the uncertainty range given in the TAR

    First of all, this means that internal climate variability doesn’t explain the current warming trend, and secondly, that on a historical basis changes in solar irradiance wouldn’t be expected to explain the current warming trend either.

    There was a previous post on this issue at RC: Did the Sun hit record highs over the last few decades? Guest commentary by Raimund Muscheler
    “The 14C tree ring records indicate that today’s solar activity is high but not exceptional during the last 1000 years.”
    and also:
    “Regardless of any discussion about solar irradiance in past centuries, the sunspot record and neutron monitor data (which can be compared with radionuclide records) show that solar activity has not increased since the 1950s and is therefore unlikely to be able to explain the recent warming.”

    In addition, wouldn’t solar forcing be expected to warm the stratosphere, which is actually cooling?

    Comment by Ike Solem — 6 Feb 2007 @ 7:47 PM

  243. #242 Ike

    – I agree with your quote of SPM AR4 : “significant fraction of the reconstructed Northern Hemisphere interdecadal temperature variability over those centuries is very likely attributable to volcanic eruptions and changes in solar irradiance”. So we’re OK, there is a significant contribution of solar forcing to climate during the past 7 centuries (I don’t speak of internal or intrinsic or chaotic climate variability, but of a radiative forcing from natural or anthropic factor, in a classical IPCC style, natural being either volcanic or solar).

    – Stratosphere cooling…
    > …is recently measured (1978-present),
    > …may be associated to ozone depletion (remember, the great concern of 80s and 90s, and still recent breakthrough in records: the less ozone, the less UV reaction, the less strato. warming I guess, and there is not much cooling in the UAH past 10 yrs),
    > …eventually inform us of 21-to-23 solar cycles trends (no problem, it’s weak if any), not of 19-23 cycles compared to priors (no reason to expect a linear and direct response of surface temperature, if not we should observe a semi-11 yr response at each cycle, and we don’t observe it, at least for global surface T).

    – If solar irradiance change 1750-2000 implies a 0,1 W/m2 TOA forcing (AR4 new estimate), it’s negligible (inferior to the difference between a minimum and a maximum of Schwabe cycle, 1 W/m2 TSI > 0,18 W/m2 TOA). So, why should I expect any solar influence on climate, after all? The “significant” contribution of solar forcing is therefore a problem.

    – R. Muscheler says one thing, Solanki or Usoskin other things. As a layman, how can I favour one and dismiss other ? Solanki leads the MP Institute for solar studies, I suppose we should take care of his conclusion, don’t you?

    Comment by Charles Muller — 6 Feb 2007 @ 9:04 PM

  244. RE#243
    Yes, but temperature variability over that period is significantly less, with dips into cooler periods – unless you have problems with the paleoclimatology-based temperature reconstruction?

    The issue is not “Solanki vs. Muscheler” but rather what the data & analysis shows – it’s not a question of competing expert opinions – especially on this particular site, we should be able to work through the various arguments.

    See Climate: The Vanishing Solar Factor, by Dan Whipple Boulder CO (UPI) Jul 26, 2004.

    What did Solanki & Usokin actually do? They analyzed the concentration of Beryllium-10, (an isotope of Be produced by cosmic ray radiation in the atmosphere) in ice cores. However they only analyzed two cores, one from Greenland and one from Antarctica, and only used the last 100 years from Greenland, not from Antarctica.

    We can also take Solanki’s own comments on this issue:
    In the 2002 Harold Jeffreys Lecture to the Royal Astronomical Society in London, Solanki said: After 1980, however, the Earth’s temperature exhibits a remarkably steep rise, while the sun’s irradiance displays at the most a weak secular trend. Hence the sun cannot be the dominant source of this latest temperature increase, with man-made greenhouse gases being the likely dominant alternative.

    As well as those of Raimund Muscheler and Caspar Ammann:
    My conclusion about past solar activity based on radionucleide records would be the following: Solar activity was relatively high during the last 50 years, but there were similar periods during the last 1,000 years, Muscheler said.

    Ammann added: If you would take averages of all the ice cores, you would not get this increase in (solar activity) in the last 50 years, but it would stay relatively flat. It is only one core that shows the rise. This is not the common feature of all of them.

    There are multiple other lines of evidence that the solar forcing factor is actually overestimated in climate models; I suggest reading the above article, and reconsidering your position on this issue.

    Comment by Ike Solem — 7 Feb 2007 @ 12:06 AM

  245. After reading over the IPCC Fourth Assessment SPM, I have to say there is something I find disturbing, to say the least – and if someone could explain it to me, please do.

    Why are they using the time period 1980-1999 as the baseline for their “temperature change predictions”?

    Table SPM-2
    Figure SPM-5
    Figure SPM-6

    I’ve been wondering why NOAA switched their baseline from the widely accepted 1961-1990 baseline period to the 1971-2000 baseline, and now the IPCC has switched their baseline up to the 1980-1999 period – an even bigger distortion? I still haven’t gotten an answer from NOAA as to who made this change or what their rationale was, and there is no stated rationale for this change in the IPCC either???

    I mean, let’s go back to the 2001 IPCC report and look at their discussion of appropriate baselines:
    Climate Change 2001, Working Group I: The Scientific Basis – Section 13.3: Defining the Baseline

    13.3.1 The Choice of Baseline Period

    The choice of baseline period has often been governed by availability of the required climate data. Examples of adopted baseline periods include 1931 to 1960 (Leemans and Solomon, 1993), 1951 to 1980 (Smith and Pitts, 1997), or 1961 to 1990 (Kittel et al., 1995; Hulme et al., 1999b).

    There may be climatological reasons to favour earlier baseline periods over later ones (IPCC, 1994). For example, later periods such as 1961 to 1990 are likely to have larger anthropogenic trends embedded in the climate data, especially the effects of sulphate aerosols over regions such as Europe and eastern USA (Karl et al., 1996). In this regard, the ‘ideal’ baseline period would be in the 19th century when anthropogenic effects on global climate were negligible. Most impact assessments, however, seek to determine the effect of climate change with respect to ‘the present’, and therefore recent baseline periods such as 1961 to 1990 are usually favoured. A further attraction of using 1961 to 1990 is that observational climate data coverage and availability are generally better for this period compared to earlier ones.

    Whatever baseline period is adopted, it is important to acknowledge that there are differences between climatological averages based on century-long data (e.g., Legates and Wilmott, 1990) and those based on sub-periods. Moreover, different 30-year periods have been shown to exhibit differences in regional annual mean baseline temperature and precipitation of up to ±0.5ºC and ±15% respectively (Hulme and New, 1997; Visser et al., 2000; see also Chapter 2).

    How can you compare the 2001 report to the 2007 report if you change the baseline?

    I’m honestly flabbergasted – if someone, anyone could explain or justify this, I’d love to hear about it.

    Comment by Ike Solem — 7 Feb 2007 @ 12:19 AM

  246. 6.05 Subject to paragraphs 6.07 and 8.04, the University and each Sponsor will have, without restriction and in its sole discretion and without conferring with or accounting to anyone, a perpetual, nonexclusive, worldwide, irrevocable, royalty-free right and license to use, disclose, publish, republish, distribute, copy, prepare derivative works, sell, or otherwise transfer without limitation to any third party, whether affiliated or not, all or any part of the Project Technology, with or without extending to that third party the right to sublicense, sell, or otherwise transfer the Project Technology to other third parties.

    This is the sort of Langauge that is the reason for the current state of the planet in my humble opinion. It does nothing for the layman. It is the layman that ultimately makes the decisions that will shape our future. The everyman will vote in the next election wherever on the planet.And the everyman has tremendous power, not because they are strong or powerfull or influential, but because they are numerous. You folk who are at the helm of science need to give the everyman something that they really can understand. The present situation of the climate is one that most of us can observe in our own backyards.

    One does not need to be a rocket scientist to see this. In the last 20 years I have seen with my own eyes the melting back of glaciers in the Canadian Rocky Mountains that I was taught would take hundreds of years. I am reminded of the Launching of the Titanic “she is Unsinkable” to paraphrase the thinking at the time. Well we all know what happened to the Titanic!

    The policies of the next governments of the global community need to hear in a loud voice what we the everyman need to tell them. we need the information about the science in clear understandable language that will help us make the right decisions. regarding our future.

    regards Michael

    Comment by Michael Mott — 7 Feb 2007 @ 12:54 AM

  247. Re 236
    Very likely is mentioned in relation to the human impact on global mean temperature. Table SPM-1, however, is about extreme events. The mentioning of Table SPM-1 on page 8 only refers to the last sentence: Discernible human influences now extend to other aspects of climate (than global mean temperature), including … (some of the following phenomena are listed in table SPM-1). While the attribution of global mean temperature is very likely, the attribution of most of the extremes is not more than likely (until now).

    Re 245
    Ike, you are confusing two different things. The 1961-1990 baseline period is for records of climate anomalies. That means you compare measurements to a reference period to calculate anomalies.
    The 1980-1999 baseline period, however, refers to the starting point of model projections, which is 1990, and also has been in the TAR. Model results for a certain year (1990, 2030, 2100, etc.) always represent the mean over 10-30 years around this year to account for interannual variations, which are of course also present in the models. In the TAR, projections of temperature increase were allways given with respect to 1990 (which in fact was the 1980-1999 mean). In AR4 they have not changed the baseline, but only reveal what they in fact calculate. Thus warming 1990 to 2100 in the TAR is the same as 1980-1999 to 2090-2099 in AR4.
    1990 is the latest starting point representing today’s state, if you have to calculate a mean around that year, or at least was in 1995 and 2001. But for reasons of comparision, this starting point has not been changed.

    Comment by Urs Neu — 7 Feb 2007 @ 3:39 AM

  248. Re #238, So Lars what is it due to then or is there no warming at all and all of the instruments are somehow calibrated incorrectly?

    Whay would 000’s of climate scientists be wrong and you right if what I always ask and why does RC and others manage to always successfully defend their position against the skeptics?

    Comment by pete best — 7 Feb 2007 @ 5:00 AM

  249. Re 245: NOAA probably switched to the 1971-2000 baseline because (IIRC) that’s WMO policy. Thirty year baselines are used in Meteorology, and every ten years or so, the baseline is moved on by ten years. This is because most of the time, the met organisation wants to indicate anomalies to the population based on what is relevant. As twenty or thirty year old baselines become beyond the recollection of those for whom you’re forecasting or reporting, there is little point in using them. This is especially true in a changing climate.

    If you are doing long-term comparisons, then it is useful to stick with a standard baseline, but that becomes climatology rather than the grey area where meteorology & climatology mix. Besides it shouldn’t change the graph much, but shift it on the y-axis (earlier anomalies will tend to be more negative, and more recent ones less positive).

    Comment by Adam — 7 Feb 2007 @ 6:03 AM

  250. #244, Ike

    I think you rather than me should reconsider more closely the case and be more cautious before drawing definitive conclusion. After all, IPCC SPM istelf acknowledges a low level of undestanding of solar forcing. Any reason to think our real level is medium or high ?

    Muscheler and Solanki “dispute” (Nature, 2005) shows that they differ in the statistical analysis of the trends / correlation (neutron monitors, Cheltenham chamber, C14, Be10, Ti44, etc.) of Q and phi. If you precisely know which interpretation is closest to reality, chapeau! Thereafter, pdf of the debate.

    Unusual activity of the Sun during recent decades compared to the
    previous 11,000 years S. K. Solanki, I. G. Usoskin, et al. Nature 431,

    Muscheler responds: R. Muscheler et al. Nature 436, 28/7/05.

    Solanki et al. reply. Reply to: R. Muscheler et al. Nature 436, 28/7/05.

    Same remarks for the “overestimation” of solar forcing. See comments #217 and #239 on how the GCMs currently take account of it (if my interpretation of Table 10.2.1 Second Draft is OK). And some model intercomparisons (e.g. Stott 2003) observed, to the contrary, an underestimation of solar factor.

    My point is not solely the precise detection-attribution of 1950-2005 warming but, more broadly, the compatibility between a very weak solar forcing 1750-2000 (0,1W/m2, comparable to minimum-maximum intracycle difference) and a significant influence on surface temperature trends during the past 250 yrs (#240, 243). You do not precisely answer to these questions. If your own hypothesis is no influence at all (or nearly), that’s coherent.

    Comment by Charles Muller — 7 Feb 2007 @ 7:05 AM

  251. [[Global Warming, as we think we know it, doesn’t exist. ]]

    I agree. And the stars are painted on the sky.

    Comment by Barton Paul Levenson — 7 Feb 2007 @ 8:11 AM

  252. There is a lot of attention being paid to the climate contribution from burning oil by flying, driving etc, but oil is limited. Coal may be a more serious problem.

    IPCC seem to accept CERA figures for future oil production, while these are regarded as nonsense in the Peak Oil community.

    The IPCC claim in their â��Summary of Policy Makersâ�� it will take another 490 [375 to 600] Gt of carbon emissions to give us +2C and 450ppmv yet, according to the latest ASPO newsletter, there is only 162 Gt of carbon remaining in all the available liquids fossil fuels over the coming century. The media seem to have oil in their sights as climate change public enemy number one when that just isn’t the case.

    I’m not saying we don’t face climate disaster – just that oil isn’t half as responsible as people make out.

    Comment by biffvernon — 7 Feb 2007 @ 8:23 AM

  253. RE # 242

    Ike, you said

    [In addition, wouldn’t solar forcing be expected to warm the stratosphere, which is actually cooling? ]

    You might look into the very low Antarctic ozone concentrations measured in 2006 and recently. Low concentrations of ozone in the stratosphere would enhance cooling I believe.

    In a later post, I will link several reports on extremely low Antarctic ozone DU readings.

    Comment by John L. McCormick — 7 Feb 2007 @ 8:36 AM

  254. #242 and #243. If you look at the measurements and attribution of cooling in the stratosphere, you see that relatively little of it is due to ozone depletion overall. As a matter of fact if you follow the links to the Stratospheric Ozone Textbook, you will see that there is essentially NO depletion in the tropics (slight exaggeration for point to be made). Therefore, if the entire process is solar driven you would see higher temperatures there, if nowhere else.

    Further, the ozone argument breaks down in the mesosphere and ionosphere. In particular, it would be indicative of solar/cosmic ray influences to know if O2 populations have decreased above the stratosphere due to photolysis, electron/ion chemistry(above~100 km most of the oxygen is found as O atoms).

    Comment by Eli Rabett — 7 Feb 2007 @ 9:23 AM

  255. RE #106 & 116, I didn’t think there was any evidence we had passed the point of no return….just suggesting that GW-induced mass extinctions had happened in the past (55 mya & 251 mya) & could happen now (esp since our AGW is so much more rapid). If & when there is evidence of this hysteresis upon us, it would be way too late to turn back (I figure scientific certainty about it will be reached AFTER the fact). So, it’s just fine there’s no current evidence. We really don’t want evidence on this, so we need to stop the experiment now.

    RE #163 & 177, the people who post the main articles here are top climate scientists, who publish in peer-reviewed science journals and are employed by top universities and gov research institutes, like NASA. The rest of us are a mixed batch. I’m an anthropologist and criminologist. Perhaps you should know this blog’s purpose is for scientists to explain climate science to laypersons in simple and understandable language. I’ve learn a lot, and I share what I’ve learned with my students, academic community, church, and others. So it is climate science for Mr/Ms Everyperson.

    My main contribution, since I did my thesis on environmental victimology, is to keep pointing out that science is very cautious in its claims, requiring high standards that something is happening before making claims, while (you’d think)policy-makers, victims, environmentalists, moral persons, people living in the world would be more interested in avoiding “false negatives,” avoiding doing nothing to solve a problem when it is actually happening. They’d like high probability a problem is NOT happening, before ceasing to be concerned about it. (Sorry to the regulars here that I sound like a broken record on this.) And I sometimes bring up the human dimension of climate change (as my education is in the human sciences), since humans are causing this and will be affected by it. However, we only know that psychological (cognitive/emotional), social (politics/economics/kinship and so on — the “other people” and social relations factor), and cultural (beliefs, values, ideology, technology) factors play into climate change in various ways, but the human sciences are not that great in predicting as the physical sciences are, hence the wide range of human emission scenarios in the IPCC reports — from “if people are really good and smart” up to “if people are really bad and stupid.”

    But you can take climate science & global warming or leave it if you wish — that’s what I tell my students when I teach evolution, they don’t have to believe it, they only have to learn it to pass the test. So, if you take a course in climate science, I’d suggest learning it for the test, even if your religious or political beliefs disallow you believing in it.

    Comment by Lynn Vincentnathan — 7 Feb 2007 @ 9:50 AM

  256. RE#249,
    Adam, Switching the baseline does matter when you are trying to make a determination of how climate changes relative to a given historical average, as well as when you are comparing th output of a 2001 climate change report and a 2007 climate change report.

    Clearly, using a higher baseline lowers the temperature anomalies, and since anomalies are often discussed as data in place of temperature records, it realy amounts to fudging data to make the observed temperature changes look lower then they actually are relative to the 20th century average.

    If you wanted to look at the variability index, what you’d want to do is compare temperature spikes to the five-year running average.

    For example, look at

    This shows the anomaly record relative to the 1950-1980 period, when global warming had not become evident (although the atmospheric CO2 content was increasing)

    If the IPCC report claims that sea levels were 4-6 m higher in the last interglacial 125,000 years ago, when temperatures were 3-5C higher then they are today, what ‘today’ are they talking about? The ‘today’ they reference in the 2001 report (the 1961-1990 period) or the ‘today’ in the 2007 report, the 1980-1999 period.

    Note that the IPCC report states explicity that 11 of the 12 warmest years on record were in the past 12 years, and that means that they are including the warming trend in their baseline – so what do you think they mean when they say “today”?

    The same argument applies to NOAA, who in their 2005 “State of the Arctic” report discuss ‘warm and cool anomalies’ even though they don’t discuss the fact that they raised the baseline from 1961-1990 to 1971-2000.

    Comment by Ike Solem — 7 Feb 2007 @ 10:28 AM

  257. re #248 and @251
    I guess you did not notice it was not me saying it, it was:

    Dr. Tim Ball, Chairman of the Natural Resources Stewardship Project (, is a Victoria-based environmental consultant and former climatology professor at the University of Winnipeg. He can be reached at

    As for so called scientific consensus, there have been many and completely wrong, remember the flat earth people, remember the earth as the center of the universe, etc etc etc….

    Comment by lars — 7 Feb 2007 @ 11:02 AM

  258. RE#255,
    Lynne, you say – “But you can take climate science & global warming or leave it if you wish — that’s what I tell my students when I teach evolution, they don’t have to believe it, they only have to learn it to pass the test”

    Ouch! I winced when I read that – pardon me, but that is the worst approach to teaching science that exists – rote memorization and regurgitation. Science is based fundamentally on reliable and exchangeable information – Richard Feynman, a great scientist and a great teacher (a truly rare combination) explained science as something you explain to someone else on the other side of the world through a telephone – i.e. if you set up the experiment I describe, then you should get this result; pass a light beam through a glass prism, you should see a rainbow of colors – it’s all about independent verification, not about rote memorization of some text.

    Really, there is no worse way of teaching science then the method you just described!

    Comment by Ike Solem — 7 Feb 2007 @ 11:37 AM

  259. rE: 257. Oh please. There was never a scientific consensus about the earth being flat (I believe this has been discussed at length here at RC). That is a tired, very old red herring that is constantly repeated with no evidence to support it. Simply repeating what someone may have told you is not a fact and spreading disinformation. For example, Columbus did not sail off from Spain thinking he would fall off the face of the earth. Maps of the earth showing it was round existed.

    Please learn about the meaning of scientific consensus, specifically how a consensus is attained and the methods that are followed. To make any assumptions without a fundamental understanding of what is involved is disingenuous. And to disavow literally thousands of scientists compared to a personal belief that does not stand up to scientific, peer review is simply wrong.

    Comment by Dan — 7 Feb 2007 @ 12:36 PM

  260. RE#250,
    Charles, first if we look at the IPCC report (which is clearly consevative in terms of the science), the solar and volcanic forcings are indeed included. Look at figure SPM-4, where the blue band represents the 5-95% confidence interval for runs of 19 models using only solar and volcanic forcings – your question seems to be, what accounts for the pre-WWII excursion of the actual temperatures above the ‘natural forcings’ – well, people were buring a lot of fossil fuels in those days as well – there’s no need to call on an additional ‘natural forcing’ – humans are ‘natural’, aren’t we?

    So, why does Solanki’s reconstruction, based on a single Greenland ice core, find such a widespread acceptance among contrarians? They say that the ‘period of high solar activity in the last 60 years is unique during the past 1,150 years. However, the solar maximum peaked back in 2001 – see NASA scientists who monitor the Sun say that our star’s awesome magnetic field is flipping – a sure sign that solar maximum is here. Feb 2001

    So, what effect does this have on climate? The notion that cosmic ray fluxes causes changes in cloudiness thereby controlling climate has been disposed of. So, what is the variation in solar irradiance? There is only 25 years or so of satellite data on this issue, meaning that there is plenty of wiggle room for those who wish to blame global warming on something other than human use of fossil fuels. One must rely on the paleoclimate record.

    There are two approaches: 14C in tree rings, and 10Be in ice cores, both of which are produced by cosmic rays striking the top of the atmosphere. The 14C tree ring record has also allowed researchers to show that the accumulation of carbon dioxide in the atmosphere is due to burning of fossil fuels (since million-year old fossil fuels are lacking in 14C). The 14C record does not agree with the single ice core record that Solanki and the contrarians rely on for their claims of a dominant solar influence on climate, and neither do other 10Be records.

    Thus, if the 14C and 10Be records all agreed with one another, and with the neutron data, then they might have an argument – but they don’t. In addition, since we are now approaching a minimum of the 11-year sunspot cycle, the climate should be cooling if global warming was due to solar forcing (see above link) – but instead we see a continued warming trend with new record temps being set every year.

    However, the public relations departments have picked up on this argument, and are widely promoting it; see for example:Talking Point#40: Sun is Real Culprit in Global Warming, 1998 According to that, we’re supposed to be entering a period of ‘global cooling’…

    Comment by Ike Solem — 7 Feb 2007 @ 12:42 PM

  261. #254 Eli

    Thanks for the link and the textbook. I don’t understand where the first graphic come from. In fact, there is some ozone depletion in low-latitudes and mid-latitudes, less pronounced than over South Pole, not located at the same geopential for the maximal amplitude (see a recent assessment from Brunner et al. 2006 thereafter).

    Atmos. Chem. Phys., 6, 4985-5008, 2006
    Variability and trends in total and vertically resolved stratospheric ozone based on the CATO ozone data set
    D. Brunner1,*, J. Staehelin1, J. A. Maeder1, I. Wohltmann2, and G. E. Bodeker3
    PDF available at

    Have a look at channel TLS (1979 – 2006) on RSS (maps thereafter) : there’s a quite heterogene distribution of cooling and warming zones for lower stratosphere, but mid- and high- latitudes southward have clearly the max. cooling.
    On the same page, the graph under the TLS map : no clear trend between 1995 and 2006, cooling was much more pronounced between 1980 and 1995 (before Montreal protocole first effects, maybe, but just an hypothesis).

    I’m still skeptic about GHGs as a main driver of cooling stratosphere. Anyway, as I explained, these recent trends (past 20 yrs) are not really interesting, so far everybody agree there is few if any solar trends between cycle 21 and 23. I question if yes or no 19-22 cycles (approx.1950-90) are the most active of the past 150 years, if solar signal may be delayed by oceanic thermal inertia (so far solar warms the first 100 meters of oceans, 70% of globe surface), if our current undestanding (low) of solar variability and solar-climate connexion are sufficient for any “very likely” conclusion, etc.

    Comment by Charles Muller — 7 Feb 2007 @ 12:42 PM

  262. #258, very much agreed, Ike. I do that just to avoid endless, disruptive debate in class, since I’m here in the Bible belt & evolution is a dirty word (like communism). I just had a class last week in which I told them I was a religious person who believed in evolution, that the 2 are not incompatible, that in fact evolution and science in general even strengthen my religious beliefs. And that led to an endless debate, wasting half a class period. I have to think about the other students, who want to learn.

    Same with climate change contrarians, some are so set in their disbelief, that at some point it becomes a waste of time trying to convince them (in fact, that may be one of their ploys — getting people to waste their time, so as not to do anything about GW).

    RE #198, Martin, I posted my #255 comment before reading your #198 comment (I wrote it yesterday, then posted today). Yes, a shift to a society reducing its GHGs will open up a lot of business opportunities, and if you read NATURAL CAPITALISM, you will get a sense of how the economy can even improve in doing so (see: ). As for a social science scenario, I look forward to a “revitalization (or social) movement” in which people try to construct a more satifying culture and society. These happen rather quickly (like an ice sheet breaking off), not like cultural evolution. So we could wake up any day now, and nearly everyone will be tauting solutions to GW. For now it’s “in my dreams!”

    Comment by Lynn Vincentnathan — 7 Feb 2007 @ 12:43 PM

  263. Re #259

    Ok Einstien…. are you a big bang universe or steady state universe?

    are you a Closed universe, Open universe or Flat universe?

    a theory is only a theory, until it can be proved…..

    BTW Einstien was a steady state universe guy….. does that make him stupid?

    Comment by lars — 7 Feb 2007 @ 1:06 PM

  264. [[As for so called scientific consensus, there have been many and completely wrong, remember the flat earth people, remember the earth as the center of the universe, etc etc etc…. ]]

    Who were “the flat earth people,” exactly? Aside from Cosmas Indicopleustes, that is.

    Comment by Barton Paul Levenson — 7 Feb 2007 @ 1:19 PM

  265. [[Lynne, you say – “But you can take climate science & global warming or leave it if you wish — that’s what I tell my students when I teach evolution, they don’t have to believe it, they only have to learn it to pass the test”

    Ouch! I winced when I read that – pardon me, but that is the worst approach to teaching science that exists – rote memorization and regurgitation. Science is based fundamentally on reliable and exchangeable information – Richard Feynman, a great scientist and a great teacher (a truly rare combination) explained science as something you explain to someone else on the other side of the world through a telephone – i.e. if you set up the experiment I describe, then you should get this result; pass a light beam through a glass prism, you should see a rainbow of colors – it’s all about independent verification, not about rote memorization of some text.

    Really, there is no worse way of teaching science then the method you just described! ]]

    I don’t think she was talking about rote memorization, or not only that. Nothing she said ruled out helping students to understand the concepts involved.

    Comment by Barton Paul Levenson — 7 Feb 2007 @ 1:21 PM

  266. [[Ok Einstien…. are you a big bang universe or steady state universe?
    are you a Closed universe, Open universe or Flat universe?
    a theory is only a theory, until it can be proved…..
    BTW Einstien was a steady state universe guy….. does that make him stupid? ]]

    No. Einstein died in 1956. Although there was already some evidence by then that the ratios of Seyfert and N-galaxies fell off with distance, which shouldn’t happen according to Steady-State, it would be nine years before Penzias and Wilson discovered the cosmic microwave background, thus moving the Big Bang into consensus and pretty much killing Steady-State.

    Comment by Barton Paul Levenson — 7 Feb 2007 @ 1:26 PM

  267. re: 263. “a theory is only a theory, until it can be proved…..” Ah yes, the tired and very dated attack on the scientific method now (we do live in the 21st century now, not the Middle Ages). Look, “proof” is a mathematical property. Until you learn that fundamental concept and how the scientific method works (it was used to develop the basics for computers such as the one you are typing on), your conversation is dead. See

    Einstein is the perfect example of someone who followed the scientific method. He had a hypothesis, he gathered data, conducted experiments, published them for peer-review, and made new hypotheses based on the information he and others found for further research. If you are going to reference someone, be sure he supports your point.

    Comment by Dan — 7 Feb 2007 @ 1:35 PM

  268. 21st Century Science, Medieval Hot Air
    It’s a puzzle which to choose, isn’t it?

    Comment by Hank Roberts — 7 Feb 2007 @ 1:42 PM

  269. Re #257: “As for so called scientific consensus…remember the earth as the center of the universe…”

    In fact, though, there was never a _scientific_ consensus on geocentrism. There was a cultural and religious one, within which early protoscientists were constrained to work. As soon as scientists like Copernicus started actually looking at the data, that consensus fell apart.

    Comment by James — 7 Feb 2007 @ 1:56 PM

  270. Re 266

    The idea of a static universe is one which demands that space is not expanding nor contracting but rather is dynamically stable. Albert Einstein proposed such a model as his preferred cosmology by adding a cosmological constant to his equations of general relativity to counteract the dynamical effects of gravity which in a universe of matter would cause the universe to collapse. After the discovery by Edwin Hubble that there was a relationship between redshift and distance, Einstein declared this formulation to be his “biggest blunder”.

    Hubble’s law is the statement in physical cosmology that the redshift in light coming from distant galaxies is proportional to their distance. The law was first formulated by Edwin Hubble and Milton Humason in 1929[1] after nearly a decade of observations. It is considered the first observational basis for the expanding space paradigm and today serves as one of the most often cited pieces of evidence in support of the Big Bang.

    Re #367

    your link goes to Page Not Found….. good one……..

    Comment by lars — 7 Feb 2007 @ 1:59 PM

  271. Re: #269

    As far as my knowledge of the history of science goes, there was indeed a truly scientific concensus on geocentricism, stretching from the days of ancient Greek science until its overthrow by Copernicus, Galileo, Kepler, and eventually Newton.

    Very few would dispute the point, that consensus is not proof. But it is the best we’ve got. The stronger the consensus, the more likely it is to be correct, and the concensus on global warming is as strong as you’ll find. Furthermore, the consensus on global warming is not an old, tired consensus being attacked by new theory. It is itself the “new kid on the block” that has overthrown the old, tired, and mistaken consensus that the human race is too puny to cause global climate change.

    Comment by tamino — 7 Feb 2007 @ 2:52 PM

  272. Clarification please:

    You write “Note that some media have been comparing apples with pears here: they claimed IPCC has reduced its upper sea level limit from 88 to 59 cm, but the former number from the TAR did include this ice dynamics uncertainty, while the latter from the AR4 does not”

    I look at the TAR and see this explanation:

    “The region in light shading shows the range of all AOGCMs for all 35 scenarios. The region delimited by the outermost lines shows the range of all AOGCMs and scenarios including uncertainty in land-ice changes, permafrost changes and sediment deposition. Note that this range does not allow for uncertainty relating to ice-dynamical changes in the West Antarctic ice sheet.”

    It read as it the TAR also did not consider ice dynamics uncertainty. Can you clarify this please?


    [Response: The TAR range included mass-balance estimates for the Greenland and Antarctic ice sheets (though did not include dynamical changes – i.e. changes due to changes in ice streams, calving, grounding line movement, etc which were then thought to be small). Recent observations point to the vital importance of such terms in assessing the net mass balance, thus since they are highly uncertain, it was thought more prudent to not include the mass-balance terms this time around. Our statement above should probably state that “the former number from the TAR did include some ice-sheet mass balance uncertainty, while the latter from the AR4 does not”. -gavin]

    Comment by Roger Pielke, Jr. — 7 Feb 2007 @ 3:57 PM

  273. Has anyone else noticed that the SPM available at the link provided has gone from 21 pages down to 18? I haven’t sorted out what exactly is missing, but the scenario descriptions are now on the last page, and they used to be back on page 14. Has there been a revision? Shouldn’t that be mentioned somewhere?

    Comment by Lance Armstrong — 7 Feb 2007 @ 4:44 PM

  274. re: 270 “your link goes to Page Not Found….. good one……..”

    Gee, a very simple inspection of the URL address would tell you to leave off the period at the end, sport. As in
    It is not rocket science to figure that one out.

    And please do not forget to read up on the meaning of the “scientific method” and what the concept of “proof” is all about.

    Comment by Dan — 7 Feb 2007 @ 4:56 PM

  275. Re:#149 and 160.

    Asa, if you’re after an economic interpretation of the costs of climate change, see Sir Nicholas Stern’s review on it, published in the UK last year. It is an excellent report, broken into chapters on things like mitigation, adaptation, modelling etc. Whilst I’m not sure if it covers fossil fuels directly, it is implied, and well worth a look.

    The one drawback is that as it was published in 2006, it draws projections from the Third Assessment, but you, as an economic-based person, could look at the difference in projections from the AR4 and roughly tell which direction the costs go.

    Hope that helps.

    Comment by Vicky — 7 Feb 2007 @ 5:29 PM

  276. [edit]

    Among other facets shared by the various fields of inquiry is the conviction that the process must be objective so that the scientist does not bias the interpretation of the results or change the results outright. Another basic expectation is that of making complete documentation of data and methodology available for careful scrutiny by other scientists and researchers, thereby allowing other researchers the opportunity to verify results by attempted reproduction of them. This also allows statistical measures of the reliability of the results to be established. The scientific method also may involve attempts, if possible and appropriate, to achieve control over the factors involved in the area of inquiry, which may in turn be manipulated to test new hypotheses in order to gain further knowledge.

    Comment by lars — 7 Feb 2007 @ 6:01 PM

  277. re: 276. That last sentence is not an acccurate description of the scientific method whatsoever. Especially the crock about “achieving control over the factors”…”which may in turn be manipulated…” Sorry, that is simply not the way it is done. New hypotheses are tested but it is not due to “manipulation” over the factors involved. Manipulation removes objectivity and does not jive with the method.

    Comment by Dan — 7 Feb 2007 @ 6:22 PM

  278. re: 277. I neglected to add that yes, I know that came from Wikipedia’s supposed definition of the scientific method. Such as it is.

    Comment by Dan — 7 Feb 2007 @ 6:30 PM

  279. Re 272: Roger, I see you have an article on this subject on your blog:

    I’m not sure that you’ve grasped the distinction between mass balance uncertainties and ice-sheet dynamics uncertainties, but, hey, what do I know?

    Perhaps Gavin or Stefan could comment.

    Comment by Mark Hadfield — 7 Feb 2007 @ 6:37 PM

  280. Doesn’t an increase in atmospheric, anthropogenic CO2 mean a decrease in atmospheric O2, and a decrease in atmospheric volume(before considering expansion due to warming)?

    I recall the classroom experiment that demonstrates the air volume reduction commensurate with the burning of carbon (a candle) in a closed system (bell jar inverted in water). While consuming oxygen and releasing CO2 and H20, the floating candle rose up in the jar some 20% (by memory) before extinguishing, even with the system temperature having risen (unmeasured, but likely several degrees C) .

    Assuming botanical sequestration (and photosynthetic O2) deals with a quarter of our global 9Bn T output of CO2, that still leaves the other three-quarters of the volume reduction effect. With the Earth’s photosynthetic capacity diminished(rainforest destruction, desertification, forest fires), shouldn’t we be talking about O2 levels and atmospheric volume (and including them in our climate models)?

    [Response: Try the math yourself. Take a million molecules of air. How many molecules of O2 do you have? Now how many of those do you need to use to double CO2 (i.e. add about 280 molecules of CO2)? So how much does that change the fraction of O2 in the air? It’s small, but as a diagnostic of fossil fuel burning it’s interesting. However, we’re not going to run out of air to breath and the associated surface pressure changes (extra credit: does surface pressure go up or down in this process?) are not going to change the circulation to any significant degree. In fact, the main influence of global warming on surface pressure comes from the additional water vapor in the atmosphere. Still a small effect, but bigger than the CO2 effect. –raypierre]

    Comment by Aaron Custance BSc (UK) — 7 Feb 2007 @ 6:44 PM

  281. What? Scientists don’t (shouldn’t) manipulate controlling factors to test hypotheses? Damn, so that’s what I’ve been doing wrong!

    Comment by Mark Hadfield — 7 Feb 2007 @ 6:54 PM

  282. Re 280: the bell jar experiment has always puzzled me. I mean, assuming the fuel is a solid hydrocarbon, CnH2n+2 or similar, C + O2 -> CO2 gives no reduction in gas volume and 4H + O2 -> 2H20 gives an increase. Does the reduction occur when the H20 condenses and/or the CO2 dissolves?

    Comment by Mark Hadfield — 7 Feb 2007 @ 7:21 PM

  283. Re 272 and 279: I am growing more confused on this issue. My assumption from reading the SPM was that the only thing left out was a possible change in ice dynamics. If I read Gavin correctly, he’s telling me that they also left out non-dynamic ice mass balance uncertainties, but I don’t know quite how to interpret that. The ice dynamics are explicitly assumed to exhibit a constant flow rate based on observations from the recent past, but what about melting? Same as before? Increasing linearly with temperature? And what about snowfall in the interior? I don’t know if I’m just being muddleheaded or if there’s a technical use of some terminology that I’m missing, but a more complete explanation for dummies would be much appreciated.

    Comment by S. Molnar — 7 Feb 2007 @ 7:45 PM

  284. Hiya all,

    I think the FAR has had quite alot of success, judging by the traffic RC is getting.

    Talk about rattling the contrarian/confusniks cage. Good grief! :-)


    Comment by mark s — 7 Feb 2007 @ 7:55 PM

  285. RE#262, 265
    Lynn & Barton: Well, I suppose I meant that saying “you don’t have to believe it, you just have to learn it in order to pass the test” gives students a poor idea of what science is about – if you don’t believe it, you should ask questions about it. I imagine there are very few people who actually think that a divine being placed fossils in the ground to test the faith of the true believers, after all.

    For example, take this baseline issue. If your students asked, “what do they mean by the temperature is increasing? Increasing from what? It’s warm in the summer, and cold in the winter – what do they mean when they say it is going to get ~3C warmer as the CO2 level doubles from it pre-industrial level? That’s not very much!”, how would you respond? (That seems like a reasonable question for a student to ask.)

    Well, you’d first have to explain what was meant by the ‘normal climate’ – and you could explain that scientists picked a certain time period as a baseline to compare changes to, and that they all use the same baseline so that they can compare their results to one another. You could also explain that the 3C is a global average, and and that the poles will get much warmer than their baseline temp (10C?), and the equator would not warm as much.

    You could also discuss how temperature and heat relate to one another, and show them that it is a truly massive amount of heat (a good example would be in terms of say, 1 megaton nuclear weapons – how many 1 megaton nukes would you have to set off in the atmosphere to raise the average temperature of the planet by 2 degrees C – anyone want to take a stab at that?)

    Then your students ask you, “well, all these reports use different baselines! 1950-1980, 1961-1990, 1971-2000, 1980-1999 – if they say the ‘equilibrium climate sensitivity’ is 3C, that’s compared to what?” How do you respond to that?

    Comment by Ike Solem — 7 Feb 2007 @ 7:58 PM

  286. > increase in CO2 …. decrease in O2?

    This is a misunderstanding that I think goes in skeptical circles back to a misapprehension by an economist(?) named Curtin, which started with his asking

    “… what happened to the 100 ppm of the atmosphere displaced by CO2 since 1750?” by: Tim Curtin | June 19, 2006 08:37 AM ”

    The issue was rather well thrashed out. It’s a rowdier forum than this one. Basic confusion was that measurement in ‘parts per million’ does not mean the total number of molecules has to be exactly one million. it’s not a zero sum game because photosynthesis is so good at adding oxygen from water so the level of oxygen in the air overall doesn’t go down as carbon is burned.

    Comment by Hank Roberts — 7 Feb 2007 @ 8:06 PM

  287. RE 283: I thought the SPM *was* a summary for dummies … oops, policymakers.

    Seriously, if you’re a policymaker who is not hung up on the question of whether AR4 differs from TAR (and why would you be?) the AR4 message is not all that confusing: there’s some stuff we think we understand and here are the results and there’s some other complicated stuff that we’re not at all sure about and we’ll get back to you later on that. Simple!

    Oh, you want to *understand*? Ah, well that’s a bit harder…

    Comment by Mark Hadfield — 7 Feb 2007 @ 8:18 PM

  288. #280 Ralph Keeling has done some beautiful work on O/N changes in the atmosphere and O isotope ratios. The effect of combustion is observable.

    Comment by Eli Rabett — 7 Feb 2007 @ 9:17 PM

  289. Re: #280, #282

    There’s an excellent paper on the bell-jar experiment in the journal of chemical education here. Fascinating reading.

    BTW Raypierre, my guess is that the surface air pressure goes up, because replacing a single O2 with a single CO2 doesn’t change the number of gas molecules, but does make the atmosphere heavier. Atmospheric pressure is, after all, the weight of all that air over our heads. Do I get the extra credit?

    [Response: Right, you got it. It’s the hydrostatic law in action. You’re just moving carbon from formerly buried fossil fuels into the air. –raypierre]

    Comment by tamino — 7 Feb 2007 @ 11:02 PM

  290. Along these lines (#289), I have a question that is perhaps naive: As the sky falls (a previous post on RC) does the amount of the Sun’s radiation that is refracted (or whatever) in the atmosphere toward the Earth’s surface change?

    Comment by Steve Latham — 8 Feb 2007 @ 2:33 AM

  291. Re 256,285
    Ike, maybe you missed my comment to the baseline problem in 247.

    Comment by Urs Neu — 8 Feb 2007 @ 3:17 AM

  292. [[You could also discuss how temperature and heat relate to one another, and show them that it is a truly massive amount of heat (a good example would be in terms of say, 1 megaton nuclear weapons – how many 1 megaton nukes would you have to set off in the atmosphere to raise the average temperature of the planet by 2 degrees C – anyone want to take a stab at that?)

    Then your students ask you, “well, all these reports use different baselines! 1950-1980, 1961-1990, 1971-2000, 1980-1999 – if they say the ‘equilibrium climate sensitivity’ is 3C, that’s compared to what?” How do you respond to that? ]]

    1. To raise the temperature of the atmosphere 3 K, I calculate as follows. The mass of the atmosphere is about 5.136 x 10^18 kilograms. The specific heat of average wet air is about 1,010 Joules per Kelvin per kilogram. So you need 1.556 x 10^22 Joules.

    A kilogram of TNT releases about 4.18 million Joules when detonated. A ton is 4.18 billion, a megaton is
    4.18 x 10^15 J. Therefore, you would need to detonate 3.72 million 1-MT bombs to heat the atmosphere that much. (Actually, some of the energy goes into blast, large-scale air motions, and not directly to temperature — so you’d need even more.)

    2. The equilibrium climate sensitivity being 3 K means, if you double the amount of carbon dioxide in the air, then, taking into account all the known climate feedbacks, the surface temperature of the Earth would rise by about 3 K.

    Comment by Barton Paul Levenson — 8 Feb 2007 @ 7:57 AM

  293. Re 256:

    There may or may not be some in NOAA (or above) who are quite happy for confusion to set in, but NOAA is not alone in this sort of thing. See the MetO & NOAA websites:

    You’re right that NOAA’s a bit ahead of the game, as the WMO still uses 61-90 (I was wrong earlier), and there is no mandate to update to a newer one until 2021 (I think). However some countries are already seeing the 61-90 baseline as a bit meaningless.

    The IPCC needs to be clear what baselines it’s using, and so does any other use of anomalies. See post 247 for more.

    If you use the 61-90 baseline then you will have less -ve anomalies and more +ve and if you use the 71-00 baseline you’ll have more -ve and less +ve. “Now” will always mean the latest baseline (as it should – in twenty years time why should “Now” refer to the 1960s?).

    This can make +ve anomalies to pre-AGW pattern emergence look smaller to the casual viewer, which is (possibly) why the GISS (and I guess the CRU) keep their baseline constant. If however you’re giving a forecast or a meteorological summary, you would say that “above average” is above what the population see as currently average.

    The “State of the Arctic” report may well have needed to make a bigger point of the new baseline, but if it means that a year in the ’60s was average is now below average, it would still show past years to have more -ve anomalies than before. I don’t know though, as I’ve not read it.

    Re 285

    “Then your students ask you, “well, all these reports use different baselines! 1950-1980, 1961-1990, 1971-2000, 1980-1999 – if they say the ‘equilibrium climate sensitivity’ is 3C, that’s compared to what?” How do you respond to that?”

    Compared to the average temperature at the previous equilibrium (before you started adding CO2). In this case, pre-industrial times. The value will be the same, but the anomaly will change (eg “from 1 less than now to another 2 on from now” or “from 0.5 less than the 1960s to another 2.5 on from the 1960s” – I’ve made the figures up BTW).

    Comment by Adam — 8 Feb 2007 @ 9:51 AM

  294. RE #284, well, actually, Ike, while I allow students to stick with their religious beliefs re evolution (which some feel is an extreme threat to all they hold dear in life), I do not allow anyone their own beliefs re AGW. I don’t really teach this topic (and I barely touch on evolution, since I’m a cultural, not physical, anthropologist), but I do occasionally mention AGW, and make it clear the science is in on it.

    For the most part students don’t have the foggiest of what I’m talking about, so it’s all new to them. However, I did get 2 grad students last semester who debated me bitterly, stating that AGW was not supported by science. One even said her father was an eminant greenhouse gas scientist in ?Utah?, who totally disclaimed AGW. But I held to my guns and said they were wrong, and suggested they read science journal articles on it. To which the other one said she gets Science delivered to her home, and their articles disprove GW. I only have time to read an abstract now and then, so based on that I again said she’s wrong. To avoid wasting more time I had to change the subject back to the day’s topic.

    I don’t have the background or ability to argue about GW much scientifically, except the basics. Thank goodness for this site. I just refer people to it, especially if the argument goes over my head.

    Comment by Lynn Vincentnathan — 8 Feb 2007 @ 2:06 PM

  295. And, of course, I refer them to the IPCC, which I’ve been doing for years, even before RC.

    Comment by Lynn Vincentnathan — 8 Feb 2007 @ 2:10 PM

  296. [[One even said her father was an eminant greenhouse gas scientist in ?Utah?, who totally disclaimed AGW.]]

    It sounds like she was snowing you. What the heck is a “greenhouse gas scientist?” A chemist? If so, that hardly qualifies him on climatology. A physicist specializing in radiative transfer? Then he ought to know better.

    I have the strong suspicion her father is some kind of engineer, and she thinks he’s a scientist.

    Comment by Barton Paul Levenson — 8 Feb 2007 @ 2:51 PM

  297. If compliance targets for anthropomorphic CO2 emissions still call for CO2 emmissions at or near current levels. Even with cut backs in the developed world, How are we going to even have a chance of impacting on CO2 levels while at the same time have developing economies in Asia, Latin America & Africa increasing their carbopn footprints without strageties that sequester massive amounts of Carbon. Has additional research has been done with Iron-Catalyzed Plankton Restoration? What I have seen so far looks promising.

    Comment by A. ROSARIO — 9 Feb 2007 @ 11:36 AM

  298. So much excellent work is being done by so many people around the world, but it seems to me that communicating the results to policy makers and the public is a dismal failure, leaving it to the press, TV and film makers to do their best to interpret things.

    The SPM is a Summary for Policymakers. I would hazard a guess that less than 1 in 100 policymakers will understand it, so they will all have it interpreted by their own scientists, thus introducing a totally unnecessary layer of confusion. It is not at all surprising that people pick up on the 88cm dropping to 59cm – its tough reading to do more than glance at a few tables and pick the highlight.

    In business, a report is targeted at its audience – SPM seems to be more of a summary for climate scientists of yesterdays news (given that it misses out the recent developments, and gives an artificially good picture).

    It also refers to 6 scenarios, which I know are well understood by climate scientists, but policy makers don’t have that background, and even if they did, a Summary should describe them in a clear fashion – eg reduce emissions to 1990 levels by 2020 and population stays under x and air travel doesn’t proliferate etc. The table stuck at the end of the SPM is just not going to make sense to our politicians – it needs to be stated near the start of the report, in terms PMs will understand.

    The whole point of the work being done around the world is to help policy makers make the right choices. The SPM should clearly show a range of scenarios, and what is the likely outcome from each one, albeit with caveats.

    The summary might be better presented as a small introduction, then a section on each scenario, with its resulting CO2, temperature and sea-level outcome. Then, because there is too much slack between CO2 and temperature/sea-level estimates, just describe the resulting situations for a set of temperature/sea-level combinations, noting which scenarios are likely to result in that situation. That would also help deal with the contrarians who say that it is not CO2 or not human changes, but that it is natural. The consequences are there no matter what the cause.

    The SPM fails to mention just about any real world consequences of the various scenarios. A good report should include examples that will be understood by the target audience. Rather than only say vague things like “Increased incidence of extreme high sea level”, give examples for each scenario, such as Thames Barrier needing renewing by x date, Bangladesh population needing relocating by y or whatever it is.

    The report needs to push back a lot of the superfluous details and actually tell policy makers about the consequences of the detailed report, in understandable terms, for each of the scenarios. So far, it is programs such as the David Attenborough ones and Al Gore’s movie that have best explained it in ways policy makers will understand, but they are interpretations only, and both are short on what the background scenario was. I won’t knock either, but I think the IPCC should be setting the background for those sorts of things, rather than them being left to the tv and film makers and their scientific advisers.

    Table SPM2 is typical of the meaningless data in the SPM – it doesn’t even say which scenario it refers to – as if all the scenarios are equivalent – the whole point of having multiple scenarios is to show how the choices we make will affect the outcome.

    Also, while I do care about things like Polar Bears starving and know that things such as the arctic getting warmer has huge knock-on effects for us, I am not sure that it carries much weight with policy makers. They care about how they are going to feed their populations, whether they are going to have to spend trillions on sea defences and relocating people, whether thousands of people are going to die every summer in heat waves. The SPM should have less comment about obscure happenings far away from anyone, and more about the consequences of those happenings on human populations around the world.

    Also, we should stop assuming that all badness happens at 2100 and then stops getting worse – it doesn’t, but there are very few indications of that in the SPM. There is talk of huge inertia in the system, but the real world explanation for scenario A1F1 should say that sea levels will rise by up to 59cm by 2100, causing x, y and z, followed by another xxcm rise by 2200, causing p, q and r. Similarly for other consequences such as ocean acidification and drought.

    Unless the IPCC report writers want the same set of folks (journalists and government scientific advisers) to re-interpret the report for policy makers, the SPM needs renaming to SCS (Summary for Climate Scientists) and a real SPM writing that clearly shows how the choices we make about emissions reductions will affect the outcome in 50, 100 and 200 years.

    Comment by Jeremy Kenyon — 9 Feb 2007 @ 12:29 PM

  299. It seems to me that much of the discussion following the release of the Fourth Assessment SPM has been about the prospects for sea level rise. However, as far as I know, even in the worst-case scenarios sea level rise would be expected to take many decades at least. Clearly that is a huge challenge given the major cities all over the world that would be affected, but sea level rise is not something that is going to be a sudden catastrophe, as in the global warming fantasy movie The Day After Tomorrow.

    However, there is something that it seems to me could be a major sudden catastrophe: drought. Drought is the sort of “extreme weather event” that global warming might be expected to lead to, and unlike sea level rise, it could occur suddenly and without any advance warning.

    Consider the drought that is currently affecting Australia. Now, imagine that a similarly intense, extreme, and prolonged (i.e. multi-year) drought hits the North American grain producing regions, and that perhaps simultaneously, other major grain producing regions of the world are also afflicted by drought. This could lead to mass starvation — the deaths of tens or hundreds of millions of people from starvation — within only a few years.

    What does the science have to say about the possibility of such an event?

    Comment by SecularAnimist — 9 Feb 2007 @ 1:24 PM

  300. Lynn Vincentnathan wrote: “… I allow students to stick with their religious beliefs re evolution (which some feel is an extreme threat to all they hold dear in life) …”

    Even more than that, for many people whose religious beliefs deny evolution, evolution is an extreme threat to their hopes of an afterlife. Thus evolution denies their hopes for immortality, and forces them to confront their own impermanence.

    Comment by SecularAnimist — 9 Feb 2007 @ 1:29 PM

  301. Re #298 & #299: Jeremy Kenyon & SecularAnimist — As an amateur, I opine that the sea stand will rise about 15 meters. But I have no idea how long this will take. Nonetheless, long range planning suggests stringent controls on development at lower elevations.

    Regarding drought, Hadley Centre offered some predictions regarding various regions. I believe the report stated that indeed the American Midwest will become dryer. Also of concern is the monsoon in South Asia, falling too soon back into the ocean instead of on the land.

    Comment by David B. Benson — 9 Feb 2007 @ 2:14 PM

  302. [[Even more than that, for many people whose religious beliefs deny evolution, evolution is an extreme threat to their hopes of an afterlife. Thus evolution denies their hopes for immortality, and forces them to confront their own impermanence. ]]

    In what way does accepting evolution prevent belief in an afterlife? It seems like a non sequitur to me. All I can say is that I believe in both.

    [Response: This is actually the telling point. Refusal to accept scientific results (whether evolution or climate change) rests upon perceived connections to values that are much more intrinsic than science. The key to avoiding such a response is not to insist on the science, but address the perceptions. i.e. demonstrate that evolution doesn’t have any implication for the after life (ask the Pope for instance), and that climate change doesn’t mean that everyone has to go back to living in caves. – gavin]

    Comment by Barton Paul Levenson — 9 Feb 2007 @ 3:17 PM

  303. Barton Paul Levenson: “In what way does accepting evolution prevent belief in an afterlife?”

    Wow, this is surely getting way off-topic not only for this thread but for this site — I know, I started it.

    What I had in mind was people who have specific beliefs about an afterlife for their “eternal soul” that are part of a religious belief system that also includes beliefs such as the Biblical creation story (the Earth is 6000 years old or whatever). To the extent that evolution challenges their beliefs about the origin of life and of human beings, it may challenge the entire structure of their religious belief system, and thus not only their sense of their place in the world as a “special creation” of God, but their specific beliefs about “eternal life” after death.

    Of course it is entirely possible to have naturalistic beliefs about some sort of continuation of what we think of as consciousness, or of elements of the human personality, beyond death; and this is a subject that is and ought to be within the bounds of scientific consideration and examination. The work of researchers such as Ian Stevenson into “cases of the reincarnation type” — i.e. young children who spontaneously talk about what they experience as “memories” of a “previous life”, which are found through investigation to correspond to the actual experiences of an actual deceased person that the child could not know about through conventional means — would be a good example of this.

    Comment by SecularAnimist — 9 Feb 2007 @ 3:36 PM

  304. It was already pointed out in this thread but not continued that the raised CO2-level causes health problems. I just read a research report (in Finnish -sorry) showing that 800ppm is the threshold. When office rooms get over 800 ppm, people have quickly increasing number of symptoms and health problems. Today this is mainly problematic in cold climate as you have to insulate buildings well and through ventilation you loose energy. But quite soon it will be difficult to maintain indoor CO2-levels below 800ppm. My empty conference room downstairs has moderate ventilation running all the time and 500ppm according to my Vaisala CO2-sensor. When it is occupied with fifteen people and the ventilation is running on maximum, it is difficult to keep below 800ppm. How much more difficult this will become when we get to outdoor 600ppm. Will we all get a permanent headache even when outdoors if we reach 800ppm. How do we fare in 1250ppm as that also is inside the possible IPCC scenarios. Perhaps this is not climate science, but us futurists are generalists and this certainly is closer to the topic of this thread than religious wonderings why chimpanzees and bonobos are not part of the genus Homo as they should be if the naming rules of evolutionary science were obeyed even in the field of biology itself instead of religious dogma – or the afterlife that actually was discussed.

    Comment by Risto Linturi — 9 Feb 2007 @ 4:49 PM

  305. Nowhere does Global Warming address if the frequency of Volcanic eruptions has decreased in the last 200 years. I do feel we must take care of our home (earth) but is the earth’s core heating up from other sources as well?

    Comment by Marguerite Rathbone — 9 Feb 2007 @ 5:58 PM

  306. Re #304: Any information I could find on carbon dioxide health effect says they start at 1% (10,000 ppm). For example, this source states: “The Occupational Safety and Health Administration (OSHA) and the American Conference of Governmental Industrial Hygienists (ACGIH) have set workplace safety standards of 5,000 ppm as an 8-hour time weighted average (TLV-TWA) exposure, and 30,000 ppm as the short term exposure level (STEL).”

    This is a long way from 800 ppm. Perhaps other pollutants are associated with high carbon dioxide levels in office buildings.

    Comment by Blair Dowden — 9 Feb 2007 @ 9:57 PM

  307. Yeah, they’d let you run a skip loader, but would they let you drive a car? run a corporation?

    Workplace safety rules aren’t meant to be levels not to exceed but okay to almost reach; they’re meant to warn of conditions where people are likely to be hurt.

    They’re not saying those levels define a level the workplace can all but attain regularly.

    And remember too, workplace exposure hour totals are reached around one workday, then interrupted by many more hours of non-workplace exposure.

    A lower residential exposure for more hours may be worse, answering that takes work — good work that’s statistics. Like understanding second hand smoke, eh?

    It’s interesting to me to look back a bit at the history of earlier products that had consequences the market didn’t foresee, wilfuly blind often enough. Lead in gas, lead pipe, lead in paint, mercury, vinyl carbonyl, chlorofluorocarbons, coal, formaldehyde, trans fats.

    I felt like I got an education and a half watching the public showboating around climate change, while being tempted ever cynically as to what seemed to be going on in politics with reasons never clear, or added at the last minute, before a bill was signed.

    I wonder if in retrospect the other big battles over materials in the marketplace in the past also show the fine hand of the professional opinion-maker. It’s certainly not novel now, but media spinning must have been a bit heavyhanded in the past, in retrospect, and might be interesting to dig into. Certainly tobacco’s been good at it for decades and still is.

    Comment by Hank Roberts — 9 Feb 2007 @ 11:04 PM

  308. Re #304, thank you. The other pollutants can well explain the results of the study. The study mainly concentrated on the required ventilation level and they measured also levels of small particles etc. and found a good correlation with the level of CO2 of 800ppm but they did not measure CO2 levels independently or rule out the other pollutants as it was not their research aim. Sorry I was too hasty and made a wrong conclusion.

    Comment by Risto Linturi — 10 Feb 2007 @ 2:31 AM

  309. The SPM says there is no significant anthropogenic warming at Antarctica. Yet it also says that “New data since the TAR now show that losses from the ice sheets of Greenland and Antarctica have very likely contibuted to sea level rise over 1993 to 2003.” Can someone at RC please explain why there is no significant warming in Antarctica and if this is true how the Antarcitic could have contributed to sea level rising?

    Comment by Tavita — 10 Feb 2007 @ 6:42 AM

  310. Re #307: I was hoping for some facts, ie. what studies have actually been done on carbon dioxide exposure at low (by industrial standards) exposures. For example, what testing was done to set the OSHA 5,000 ppm standard? How valid is the Finnish study mentioned in #304? I am suspicious of single studies that come up with results greatly different from the scientific consensus.

    And by the way, there have been flawed studies exaggerating the effects of chemicals or second hand smoke, as well as bogus “science” trying to cover up the problem.

    Just give me the facts, preferably in peer reviewed papers.

    Comment by Blair Dowden — 10 Feb 2007 @ 8:50 AM

  311. Sure, Tavita. The ocean’s warmer. The ice around the edges, where the glaciers run down to the sea then push out from there to become floating sheets of ice, has melted from underneath and cracked (flexing as tides and waves move the floating part at the edge of the ‘grounded’ ice). During the warmest periods, meltwater on the top in the summer can run down through the cracks. Meanwhile, back at the middle of the continent, the two mile thick ice cap still is quite cold all the time, so snow continues to fall and accumulate there. So far, anyhow.

    There has been a whole lot of science done on these issues.

    This reply from me, an amateur reader here like yourself. An expert will be along to correct and improve my answer soon, I trust. Look for responses from the people named in the sidebar under “Contributors” for real scientists’ answers here.

    Comment by Hank Roberts — 10 Feb 2007 @ 9:08 AM

  312. Re: #308

    Sorry I was too hasty and made a wrong conclusion.

    Risto, a willingness to admit a mistake, and a preference for the truth over being “right” all the time, are hallmarks of enlightenment. They’re also exceedingly rare, especially on the internet. You just moved up a dozen or so notches on my credibility scale.

    Comment by tamino — 10 Feb 2007 @ 9:27 AM

  313. >306
    see also:
    “ASHRAE standards allow for up to 700ppm CO2 above background in office buildings …”

    There are no standards for private residences I can find, but the ASHRAE level is far below the lowest one Pete found for industrial jobsites.

    Comment by Hank Roberts — 10 Feb 2007 @ 9:54 AM

  314. [[Nowhere does Global Warming address if the frequency of Volcanic eruptions has decreased in the last 200 years. I do feel we must take care of our home (earth) but is the earth’s core heating up from other sources as well? ]]

    I can’t see how it could. The radioactive elements in it have been decaying for 4+ billion years (which is one reason the interior of the Earth is as hot as it is); tidal friction from the Sun and Moon can’t really affect the heat of the interior on a large enough scale, and in any case, they’re not changing on a human time scale. I’m not saying you’re wrong, but as far as I can tell there’s no known mechanism to heat up the core any more than it already has been.

    Comment by Barton Paul Levenson — 10 Feb 2007 @ 11:04 AM

  315. Re #313: Carbon dioxide is being used as a proxy for general air quality, because it is easy to measure. The ASHRAE Journal states: “The ASHRAE guideline value is based on the association of elevated carbon dioxide concentrations with unacceptable levels of body odor, and not on any health or comfort impacts of carbon dioxide itself.”

    The only valid way to study this question would be to add pure carbon dioxide into a variety of existing working environments and see at what threshold there are measurable effects. Of course, the participants must not know this is happening as that would bias the results. I don’t know if such studies have been done. There may be ethical questions about gassing people without their consent.

    Comment by Blair Dowden — 10 Feb 2007 @ 12:29 PM

  316. Hank, thanks for answering my question concerning sea leve rise at Antarctica. I should have looked harder before bothering the thread. I ran across this link that answers the other part of my question concerning lack of warming at Antarctica.

    Comment by Tavita — 10 Feb 2007 @ 4:21 PM

  317. From the WMO, Dec 11, 2006 – “A consensus of 125 of the worldâ��s leading tropical cyclone researchers and forecasters says that no firm link can yet be drawn between human-induced climate change and variations in the intensity and frequency of tropical cyclones.”

    From the IPCC 4AR SPM, page 16 – “Based on a range of models, it is likely that future tropical cyclones (typhoons and hurricanes) will become more intense, with larger peak wind speeds and more heavy precipitation associated with ongoing increases of tropical SSTs. There is less confidence in projections of a global decrease in numbers of tropical cyclones. The apparent increase in the proportion of very intense storms since 1970 in some regions is much larger than simulated by current models for that period. {9.5, 10.3, 3.8}”

    “After some prolonged deliberation, I have decided to withdraw from participating in the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC). I am withdrawing because I have come to view the part of the IPCC to which my expertise is relevant as having become politicized. In addition, when I have raised my concerns to the IPCC leadership, their response was simply to dismiss my concerns.”

    [no “yelling” please. Bold font should not be used in extended blocks. Next time post will be deleted]

    Comment by MrGreen — 11 Feb 2007 @ 8:01 AM

  318. >add pure carbon dioxide
    I dunno, did you read that PDF cite? They took two university buildings and ran their HVAC systems differently, so one accumulated higher CO2 levels, as you suggest. Agreed, they didn’t add pure CO2, but that never happens in real life either. It’s not clear from your quote whether people actually produce more body odor with enhanced CO2 or just smell each other because of poor ventilation. Point being if the background level doubles, ventilation isn’t going to take indoor environments below it, regardless.

    Don’t commercial greenhouses boost CO2? As I’m sure some university experiments have done. Again I don’t know if anyone actually adds the pure gas.

    What became of the Biosphere II record data, anyone have access to it? They filled the dome in a hurry at the end of the setup, and loaded it with pure topsoil instead of layering rock and mineral soil under a layer of thin topsoil, duff and leaf litter, which doomed their experiment before they even closed the seals — buried too deep, topsoil dies, it’s mostly living organisms after all. But it probably did produce a relatively pure boost in CO2 in that situation, and they didn’t have a big crowd of people in a small room as with the other studies.

    Comment by Hank Roberts — 11 Feb 2007 @ 1:16 PM

  319. Re #310, #318

    I found other studies that also referreed to special circumstances in specific factories, submarines etc. The research I refer now was used to decide the allowed CO2 level, suggested was 5.000ppm. 8.000ppm has been shown to cause problems as a long time level and 5.000ppm in some animal tests. The topic has been under quime much study in Finland and my sources are in Finnish. But I quote the references of the last paper I checked. The health effects that correlated with the 800ppm must have been caused by other issues and CO2 was only a good proxy for the general office air quality. The study itself was of good quality by the state research centre and did not make the claim that I mistakenly did.

    Borum, VF, Schaefer, KE ja Hastings, BJ (1954): The Effecto of Exposure to Elevated Carbon Dioxide Tension over a Prolonged Period on Basal Physiological Functions and Cardiovascular Capacity, US Navy Med Res Lab Rept 241, 1-19.

    Ebersole, JH (1960): The New Dimensions of Submarine Medicine, N Engl J Med 262, 599-610.

    Echt, A, Burroughs, GE, Rubman, MH, ja muut (1998): Carbon Dioxide Exposures to Medical Personnel as a Result of Wearing Surgical Isolation Suits, Appl Occup Environ Hyg 13, 87-90.

    Edge, CA (1987): Indoor Air Quality Lessons from Submarine Environmental Systems, Proceedings of the ASHRAE Conference IAQ 87, May 18-20, Arlington, Va, 255-260.

    Gray, SP (1950): Pulmonary Ventilation and Its Physiologic Regulation, Chas. Thomas Pub., Springfield, IL.

    Gros, P, de Madre, J ja Dobel, M (1987): Fatal Accident in a Computer Science Centre: Prevention of Roisks Caused by Accidental Discharge of Gaseous Extinguishing Agents, Securite Med Travail 76, 40-42.

    Guillemin, MP ja Horisberger, B (1994): Fatal Intoxication due to an Unexpected Presence of Carbon Dioxide, Ann Occup Hyg 38, 951-957.

    James, JT ja Gardner, DE (1996): Exposure Limits for Airborne Contaminants in Spacecraft Atmospheres, Appl Occup Environ Hyg 11, 1424-1432.

    Louis, F, Guez, M, Le Bacle, C (1999): Intoxication par Inhalation de Dioxyde de Carbone, DMT- Documents Med Travail 79, 179-194.

    Messier, AA, Heyer, E, Braithwaite, WR, ja muut (1983): Undersea Med; viittaus MAK-Werte, Kohlendioxid, 4.7.1983.

    Nutall, JB (1958): Hazards of Carbon Dioxide, JAMA 168, 1962.

    OVA (1994): Hiilidioksidi. Onnettomuuden vaaraa aiheuttavat aineet. Turvallisuusohje, Chemas Oy, Helsinki, 8 s.

    Riley, RL, Bromberger-Barnea, B (1976): Monitoring Exposure of Brewery Workers to CO2: A Study of Cellar Workers and Controls, Arch Environ Health, 92.

    Schulte, JH (1964): Sealed Environments in Relation to Health and Disease, AMA Arch Environ Health 8, 438-451.

    Seter, AJ (1994): Allowable Exposure Limits for Carbon Dioxide during Extravehicular Activity, Govt Reports Announcements & Index (GRA&I), No. 1, 1994, 42 s.

    Zugibe, FT, Costello, JT, Breithaupt, MK, ja muut (1987): The Confined Space-Hypoxia Syndrome, J Forensic Sci 32, 554-560.

    Comment by Risto Linturi — 11 Feb 2007 @ 2:09 PM

  320. Re #319: Thank you, Risto. I think it is pretty clear that carbon dioxide has no direct health effect (on people, at least) until it reaches a few thousand parts per million. This should not be surprising, because complex life evolved under CO2 levels higher than 1000 ppm, and that has been the normal state except for a few ice age periods, such as now. So while there are many reasons it is not a good idea for the Earth’s atmosphere to reach 800 ppm, direct health effects of carbon dioxide is not one of them.

    Comment by Blair Dowden — 11 Feb 2007 @ 5:41 PM

  321. I haven’t yet had time to read all the comments, so please forgive me if this is already covered, but:

    Are there any maps (surface or other) on easily accessed sites showing not just (seasonal and annually averaged) projected temperature and precipitation, but pressure, winds and currents, humidity and cloud cover (of various types), etc. In particular with the cloud cover, this may make it easier to understand how cloud cover feedback would work and what the uncertainty in this feedback would mean – and what is the magnitude of that uncertainty anyway?

    One thing I would like to find is a quick (if that’s at all possible) summary of how the components of the climate-weather system might change – does the Hadley cell speed up, and how would that affect momentum transport? Would the Hadley cell expand (I’ve gotten the impression that’s a yes)? If greater energy release in tropical cyclones were not realized, would the heat instead be released in disorganized activity or be transported poleward into midlatitude weather? Would midlatitude storm systems move more slowly (longer rainy/cloudy periods with longer sunny/dry periods in between, perhaps) or have shorter or faster lifecycles? If the diurnal temperature range decreases, would that cause the mixed boundary layer – to the extent that it is convectively mixed as opposed to wind-mixed – not get as deep during the day but persist longer into the night (which would suggest to me, given same surface relative humidity, that daytime low-level cloud cover would be reduced where it is part of the boundary layer)? I’ve heard that the boundary layer might actually do the opposite – get deeper – which could then increase low level cloud cover, where it is near the threshold for doing so.

    It would be interesting to break it down – for example, with cloud feedback – frontal and extratropical cyclone clouds, mesoscale convective system clouds, tropical cyclone clouds, other deep cumulus clouds, low clouds over mid-high latitude oceans, low clouds over cold currents in subtropical oceans, etc…

    Is there a way to estimate minimum and maximum conceivable cloud feedbacks – ie if all the parameterizations go one way vs another?

    Comment by Pat — 11 Feb 2007 @ 9:43 PM

  322. [[Are there any maps (surface or other) on easily accessed sites showing not just (seasonal and annually averaged) projected temperature and precipitation, but pressure, winds and currents, humidity and cloud cover (of various types), etc. In particular with the cloud cover, this may make it easier to understand how cloud cover feedback would work and what the uncertainty in this feedback would mean – and what is the magnitude of that uncertainty anyway?]]

    There’s a project called ISCCP (International Satellite Cloud Climatology Project) which is attempting to quantify and map cloud occurrence. You can find a lot about it on the web; here’s one link:

    That being said, at least some of what’s being published on the web in ISCCP’s name seems amateurish. For instance, I saw one page where the cloud fraction at each level was simply added to provide a figure for mean world cloud cover of 76.8%. The correct procedure is to assume random overlap (see, e.g., Kiehl and Trenberth 1997 — Bull. Amer. Meteor. Soc., 78, 197-208), and applying that to the data given comes up with 56%, which is much more in line with other published estimates.

    [Response: Actually it’s a correct procedure, but it’s a function of how ISCCP sees clouds – i.e. since the satellites look down they does not see clouds that are hidden from above. The ISCCP total is more like 63% though (maybe you were thinking of the HIRS analysis?). A bigger issue is whether ISCCP can detect the very thin cirrus clouds that are very optically thin (which is most of the uncertainty). – gavin]

    Comment by Barton Paul Levenson — 12 Feb 2007 @ 9:17 AM

  323. The Telegraph are claiming “Cosmic rays blamed for global warming”. Do they have a point or is it their usual Monckton-type stuff?

    Keep up the good work


    Comment by Mike — 12 Feb 2007 @ 12:42 PM

  324. RE the science v. religion thread (#300, 302), I think this is important for the topic of the IPCC report.

    First, as a professor who teaches on religion (& its differences from/similarities to other belief systems, such as common sense, magic, science), we need to clarify these differences/similarities. Religion is both a belief & value system; while science is only a belief system (with values kept at bay or shelved, if you will). In this regard, religious values, such as “thou shalt not kill” are pertinent and linked to the IPCC report, since it does imply that we are or will be killing people through the various effects of AGW; religions and humanistic value systems that hold this value would also need to include as killing, the farmers who commit suicide due to GW-enhanced severe drought conditions. We’re not talking about establishing guilt in a court of law, but in a court of morality.

    Religion deals with both the “seen & unseen” (the material/empircal world and the spiritual world); while science is limited to the material/empirical world (and that is one of its strengths). So anything science has to tell us must be taken seriously by religion, even if it goes against the earlier prescientific dictums in the holy books (in the past there was no separate field of science; there was only religion/science/philosophy/ethics/history as one endeavor). If the belief is that, say, God created the material/empirical world, and also made humans intelligent, then a religious person cannot deny anything science reveals, or they would be denoucing the Creator. Therefore truly religious people MUST accept the IPCC report (with all its caveats, of course), but the moral aspect of religion, requires religious persons to focus on the high end, and to the extent that they think the science might be wrong, then wrong in underestimating the problem. Also there is even a higher end danger, since religion also deals with the unseen, and that is the person’s soul could end up in a place even hotter than a globally warmed world, if they persist in failing to mitigate AGW (there is absolutely no way science can disprove a spiritual afterlife, since the spiritual realm is not in its purview, and is a matter of faith-belief, not empirical-science belief).

    Hence there is nothing in the IPCC to dissuade a religious person from accepting and responding positively to it; in fact such a person must accept it, if they really believe God created the world (which science has revealed was done through the awesome and intricate and astounding process of evolution & not with a presto-chango magic wand).

    However, alas, we are not only religous or cultural (belief/value) beings, but also psychological and social beings, so it is uncomfortable & inconvenient to accept one’s guilt in AGW, or that one might be more closely related to apes than one would like to be, the cockaroach too (though from a purely religious view, there is nothing ugly about being more closely related to any of God’s wonderful creation).

    Anyway, what Gavin pointed out (#302), about AGW being (falsely) linked to having to retreat to the cave, is pertenant here, and those who are not religious enough to trust in God’s providence, and thus may be stymied or angered with this fear, should be advised that it is a false fear & there is much evidence to the contrary, that reducing GHGs can make us better off economically, while increased GW will surely harm us economically.

    Would that America truly be a religious nation; then we would see ready acceptance of the IPCC report and enthusiatic and vigorous action to mitigate GW.

    Comment by Lynn Vincentnathan — 12 Feb 2007 @ 1:51 PM

  325. Lynn, I think you’re taking a battering ram and rushing through an open door. I don’t think “religion” has had much influence on the AGW debate at all. It’s right-wing politics and big corporate money that are behind AGW denial, not “religion.”

    Comment by Barton Paul Levenson — 12 Feb 2007 @ 1:58 PM

  326. Looking at this from the business layman’s (non-scientific) perspective. Why can’t science develop a process (similar to photosynthesis is my non-scientific guess) that extracts CO2 from the aptmosphere thus lowering the levels of CO2 causing greenhouse gas? We can desalinate water, convert oil to any number of products and reverse any number of other processes why not this one? Is it that complex, impossible?

    One other note part of the problem particularly in the US, IMHO, is the method and message that for the past two decades that has been utilized to warn about global warming. The message has been one of dire consequences in the year 2100 and sacrafices in emissions that need to happen now. Americans are so short sighted that all they see/hear are the sacrafices they will need to make now with no payback in their lifetime. Heck they can’t agree on how to fix social security and medicare which are going to be technically bankrupt in 30 years or so how do you expect them to care about the temperature in the year 2100 which is 93 years away?

    Comment by H. M. Ward — 12 Feb 2007 @ 2:47 PM

  327. Re #326: Such processes exist: the reasons they’re not likely to prove practical all come down to cost. It takes energy to extract CO2 from air, still more energy to store it as gas, while to convert it back to carbon takes more energy than you got by burning the fossil fuels to begin with.

    As for your second point, I still can’t manage to see where the sacrifices are going to come in. For instance, I’ve made a bunch of energy-saving improvements to my house, and as a result my power & heating bills are probably less than half what my neighbors pay. If that’s a sacrifce, I say lead me to more of them!

    Comment by James — 12 Feb 2007 @ 3:37 PM

  328. To change the subject a bit, I am a climate change policy advisor in one of the provinces in Canada and am having a lot of trouble explaining the IPCC projected temperature rise “best estimate” and “likley ranges” in terms that senior executives and elected Ministers can follow. I know that the best estimate and “likely range” are relative to a 1980-1999 baseline, but this doesn’t help much when explaining it to a lay person. Further, to the average person, a warming of a few degrees doesn’t sound bad – especially in Canada in February (currently -19C)! We were thinking of comparing these projected rises to the global average pre-industrial revolution temperature (around 13 C I think?) – would this be a fair comparision? Is this the right number? Does anyone have a more layman’s description, or story, of what these projected temperature rises could mean, even if it isn’t from IPCC approved text? I promise not to quote anyone!

    Thanks………..Don Mac

    Comment by Don Macdonald — 12 Feb 2007 @ 4:37 PM

  329. Re #328: Don Macdonald — I encourage you to find the Hadley Centre report which describes projected changes on a regional basis. In general terms, the changes will be not good to bad for farmers and foresters. Look at what a few warm winters have done to the forests of eastern British Columbia.

    Locally, the expectation is for wetter winters and longer, dryer summers. The agricultural scientists are already working on new cultivars for the projected conditions in this region. I suspect the Canadian prairie provinces will respond similarly.

    Stressing the biological changes should find receptive ears. We all have to eat…

    Comment by David B. Benson — 12 Feb 2007 @ 5:06 PM

  330. Hi there,

    I’ve just been reading New Scientist (Feb 10), and it makes reference to the suggestion of some scientists, that the greenland ice sheet will physically collapse long before it melts!

    I’ve had a poke about and found some interesting stuff, like that Greenland is probly three islands, with 2 horizontal ‘superfjords’ in it! Also, because of the thickness of the ice sheet, most of greenland is well below sea level (up to 500m alledgedly), which reminds me of Pat Neuman’s questions, about isostatic rebound.

    Anyone got any idea what the ‘superfjords’, and the land level means, for the physical collapse, which would come long before melting?

    Does anyone have any more on this? because I havent read this suggestion before… Maybe the KGB have been meddlin :-)

    By the way, i thought the scientists were ultra-conservative on AR4, i would have liked to see them hockey-stick there neck out a bit more, really!

    I’m not really very nationalistic, but who thought it was a good idea to hand the leadership on AR4 to the NOAA. Is there something i should know about the Met Office (who led on the first 3 reports)? subliminal leftist messages in our UK weather forcasts? We should be told. :-)

    Never mind though, folks, its only the planet we are gamblin with. ha ha(not!).

    I’m off to go an listen carefully, to a weather forecast!


    Comment by mark s — 12 Feb 2007 @ 5:34 PM

  331. Just adding to the concern of Global Warming,I may only be 11 years old but I know alot about the enviroment and whats happening to it,I also have an extreme love and passion for wildlife,but enough about me, another reason Global Warming might be happening could be the exause from our cars and trucks ( trucks in perticular).

    Ever drive down the the street and see this monster truck then look up and see this little pipe at the top bellow out black smoke,and see the smoke just disappear?

    Have you ever wondered where that black smock goes,(well I dont have the exact answer), but it goes into the enviroment, I know that much.And at that perticular moment, I get real fired up about how were going to kill our selves by eather drowning our selves or just having so much natural disasters that we ripe the Earth apart.I mean it’s rediculose how much black,discusting smoke goes into the air every day,(again, I dont have the exact answer, but I know it’s alot)

    All we need to do( and I really mean “need”)is to eliminate all those big,bulky discusting trucks and that alone will make a huge difference, and to have a bonus, people could actully start using those battery opperated cars, I mean there cute! And you’ll save loads of money on gas.

    This will help animals in the arctic like polar bears, pengiuns, and seals have a better life and us too!

    love Ella

    Comment by Ella — 12 Feb 2007 @ 9:04 PM

  332. Re #273, I’ve printed out the two versions of the SPM and compared them. As far as I can see, no text has been left out in the more recent 18 page document compared with the earlier 21 page version (still available at the BBC site.) The main differences are as follows.

    The figures and tables have been incorporated into the text, and the SRES box moved to the end.

    The margins are narrower, hence more type on the page.

    The footnotes are in larger typeface.

    Some bits have been cleaned up, eg Figure SPM-5 and the error identified earlier.

    There still seems to be a problem at the top of page 3. The increase of carbon dioxide emissions between the 1990s and 2000-2005 is given, but when it comes to land-use only the 1990s is identified. So the more recent value and the comparison are lost.

    By the way it is small comfort to know that our persistent droughts in Australia are only more likely than not linked to human contribution.

    Comment by Brian Bahnisch — 13 Feb 2007 @ 3:08 AM

  333. re 331
    Ella the black smoke is soot, not CO2, and there are good filters that can take that out. Some scientists think it’s the soot that causes the glaciers to vanish.

    Comment by Hans Erren — 13 Feb 2007 @ 5:43 AM

  334. Re: #331

    Ella, to understand the workings of something as complex as global climate takes a lot of knowledge; this can be learned in school. To put that knowledge to good use takes the will to do so; this can’t be learned. But it seems to me that you’ve got it already.

    I apologize for all the hardship my generation is dumping on your generation; you deserve better. Many of us are trying to make a difference, so you’ll have a better world to grow up in. If you learn about earth and the environment, and hold on to your will to do something about it, you can make a much bigger difference. Keep hope alive. Good luck.

    Comment by tamino — 13 Feb 2007 @ 8:47 AM

  335. RE # 331

    Ella, it is good to see another young person drop in on RealClimate.

    While much of what is said on these pages might be a tad above your learning curve, I urge you to begin reading and asking your parents, teachers and librarians for answers and book titles.

    There is so much to learn about our home -planet- and it is truly a fascinating and complex system of ocean, air, ice,land and vegetation interacting and making life possible for 6.5 billion of us and the countless hundreds of billions of critters large and small.

    Global warming is the consequence of what our and past generations have caused and it will take the caring and wisdom of many future generations to protect our planet.

    Please start today to educate yourself about the basics of the changing global atmosphere and how it is interacting with the entire planet. You will find a fascinating and rewarding life of science ahead. I promise you.

    Comment by John L. McCormick — 13 Feb 2007 @ 9:03 AM

  336. James,

    the sacrifices are people will not be able to drive their big SUV’s live in their big McMansions etc. [edit] Furthermore industry will be required to cap their emissions, that involves additional costs which then requires that shareholders sacrifice profits. Most shareholders of corporations are large institutions (mutual/hedge funds) that are rated/graded/paid on performance. If the current return on shares is diminished by additional costs related to reducing emissions that will not have any benefit for 100yrs guess what the shareholders are going to think of these new costs.

    As for the processes involved couldn’t we use Hydrogen Fuel cells to eliminate the CO2 from the atmosphere? I have to believe the technology is there or available that will make this a viable process and then separating the C and the O into their separate parts and storing the C somewhere. I readily admit I am no scientist and there are far smarter people right on this site that could probably develop this process. Bottomline if this issue is setting us up for such dire consequences in the future why isn’t someone working on something like a process like this instead of just consistently bombarding us with “the sky is falling, the sky is falling” reports and instead focus on finding a solution that is something other than “you need to stop doing what you are doing”. Yes conservation is part of the solution but it can’t be the only solution yet it appears to this lay person the only one scientists are offering.

    One other point that I take personal issue with is the whole idea/link that I read so often in the media claiming that Global Warming is coming from humans “polluting” the air. Last time I checked CO2 is the most abundant green house gas that is causing global warming (please correct me if I’m wrong) and the last time I checked CO2 is not a pollutant unless of course you consider everytime a living thing exhales polluting the air.

    Comment by H. M. Ward — 13 Feb 2007 @ 11:15 AM

  337. #333, Hans brings up an important point. Our actions that produce GHGs, such as driving gas-guzzlers, also cause many other harms. We really do need a holistic picture of all this. Global warming in conjunction with all the concomitant environmental harms from our wasteful & thoughtless actions will be much much worse than global warming alone. It’s probably even a multiplier effect of harm, rather than an additive effect.

    So it extremely behooves us to reduce our GHGs, & along with that the same corrective measures will also reduce our other harms.

    By using a low-flow showerhead, you not only reduce the energy to pump & heat the water (and the GHGs and other pollutants & harms involved in mining, shipping, and burning those fossil fuels), but you also save water & slow the quick retreat of our water tables. Future generations will also need water, especially on those hot globally warmed days that are already in the pipeline. And we reduced our shower consumption by 1/2 (we actually tested it with a bucket and a timer) without feeling any difference from the wasteful showerhead. And finally we figure the savings in water bills and water-heating costs at about $100 a year, or $2,000 over the 20 year lifetime of that $6 showerhead (with off/on soap-up switch). And reducing shower time by 30 seconds or a minute saves even more!

    So, Ella (#331) & all who have eyes to read, there is something you can do (if your house doesn’t already have them)–install low-flow showerhead–and get your friends to do so. That would be a great start & the money you save can be used for compact fluorescent bulbs and other measures. Then all the savings from all those measure, plow it into something like the extra cost for wind-power (we have to pay about $5 to $10 more each month for 100% wind power from GreenMountain).

    Some say reducing GHGs is too expensive, but if they can only raise that initial $6 (which I remember B.E.C. (before environemtnal correctness) as being very hard to raise, but where there’s a will, there’s a way), the rest is easy.

    Comment by Lynn Vincentnathan — 13 Feb 2007 @ 12:14 PM

  338. Re #331

    I can’t help but admire (and be inspired by), that post. Thanks Ella.

    Comment by mark s — 13 Feb 2007 @ 12:19 PM

  339. Professor Timothy Ball says “The other thing that you are seeing going on is that they have switched from talking about global warming to talking about climate change. The reason for that is since 1998 the global temperature has gone down — only marginally, but it has gone down. In the meantime, of course, CO2 has increased in the atmosphere and human production has increased. So you’ve got what Huxley called the great bane of science — “a lovely hypothesis destroyed by an ugly fact.” So by switching to climate change, it allows them to point at any weather event — whether it’s warming, cooling, hotter, dryer, wetter, windier, whatever — and say it is due to humans. Of course, it’s absolutely rubbish.”

    Does he have a factual basis for this global cooling? If so, can you tell me where to find it?

    [Response: No. To find out what’s going on (and it’s still globally warming) look directly at the temperature records (e.g. GISTEMP) – there are ups and downs because of the ‘weather’ noise, but there is a sustained and obvious long term trend. And it’s the trend that we are talking about -not the wiggles. -gavin]

    Comment by Ian Perrin — 14 Feb 2007 @ 6:47 AM

  340. I really dont know much about these climate changes & Global warming, but i do hav lots of doubts regarding these. Will global warming lead to extreme hot of cold places & extreme cold of hot places? Some of the Scientists say that the symptoms of global warming has already started & the climate is going unpredictable & they hav no idea about what will be the real cause behind this…
    Moreover there has been many Natural Disasters in several places that has never experienced before in these many years. Does these Natural Disasters hav anything to do with the Magnetic Field Changes of the Earth…? i mean i’ve read somewhere that the magnetic field is changing from the direction of North to South to the direction of south to north which has been discovered through the study of Rocks found on the Ocean floor & measurements of the magnetic field polarity in ancient volcanic lava flows. And this seems to be a routine with a time gap of some thousand years. Will this be one of the reasons for Earth Changes?
    Will you please tell me the right answers to my doubts & questions? And above all can u tell me whats going on around here?

    Comment by Priya — 14 Feb 2007 @ 9:58 AM

  341. Priya — don’t fear “Earth Changes” too much. Natural disasters occur at about the same rate they always did, with the exception of storms becoming more powerful due to global warming. The Earth’s magnetic field really doesn’t have much influence on the climate. It’s an extremely weak field, for one thing — about 0.5 Tesla, as I remember. Cosmic rays do get through the atmosphere better when the magnetic field is low, and there’s some thought that that might affect cloud formation, but no clear evidence as of yet.

    The Earth will survive global warming and magnetic field reversals; it has in the past. Global warming will hurt mankind economically for a while, but civilization will still survive.

    Comment by Barton Paul Levenson — 14 Feb 2007 @ 12:25 PM

  342. I have mostly managed to disprove “confusnic” claims against AR4, presented in a local Finnish blog run by the largest newspaper. I have hoped professionals would enter the discussion to help but the Finnish professionals mainly enter the discussion only through traditional media. I have found good answers here to many questions and have learned quite much while searching and reading through the older threads also. But now I have a question that I cannot answer even though I know that the burden of proof should fall onto the other side. I am not even sure that I understand the question as I have difficulty to understand where the excess energy goes.

    Does Lindzen claim that according to the calculated effects of the greenhouse gases the earth should be 75C but as it is only 15C, the dynamic effects of the earth somehow loose the excess. And thus if the direct effect of CO2 is from 0.5C to max 1.2C this should also be reduced by the same multiplier and the real effect is 0.1C to 0.3C.

    I have answered as I believe myself that the climate models are themselves theories of the major effects and the causal effects that they include and if they fit to the measudred data and known physical laws, then the burden of proof is elsewhere. However I would appreciate some more advanced student to teach me or point me to a source where I can study this so that I could answer the question better.

    [Response: Sorry, I have no clue as to the source of the claim that the planet should be 75deg C without greenhouse gases. The standard calculation for a planet with the same albedo but no atmosphere gives -18 deg C. The climate sensitivity is around 3 deg C for a doubling of CO2 (see our older posts for why). -gavin]

    Comment by Risto Linturi — 14 Feb 2007 @ 12:31 PM

  343. Re 339,
    How long has the IPCC been called that? Was it called IPGW prior to 1998? No, this is just Tim Ball (someone with little credibility) diminishing his credibility further. Being Canadian, has some good stuff on him including the impending failure of a lawsuit in which he tries to clear his good, er, tries to get legal backing for his overstatements regarding his credentials.

    Comment by Steve Latham — 14 Feb 2007 @ 12:52 PM

  344. Gavin, I am familiar with the climate sensitivity, but the rumor level claim put to Lindzens mouth did not refer to the planet without greenhouse gases but actually claimed that the calculated temperature of earth _with_ the greenhouse gases (I guess starting from the base level you refer and adding the calculated effects of all the greenhouse gases) should be +75 deg C, and as it in practice is less, then there “must be” dynamic effects that get rid of heat and so the calculated direct effect without multipliers “must also be” reduced by the same proportion – (I guess by multipliers what was meant was that increasing CO2 increases temperature and that increases humidity and that again increases temperature and this is how you get the 3 deg C). I am sorry this is murky as I am only guessing what the person intends to claim and he only refers to Lindzen but does not give me any reference to peer review -level papers. Basic intent of the person was to deny the practical effect of CO2 or minimize it down to 0.1 to 0.3 deg C. I understand that the models give 3 deg C and they fit with data but I still have difficulty disproving the claim in any intelligent way as he has read many of the denial papers and very often refers to Lindzens models.

    I do really appreciate your patience with us laypeople. We do learn (slowly and some parts).

    [Response: Thanks for the clarification, however, I’m still none the wiser. There is no calculation I am aware of that indicates that temperatures should be as high as 75 deg C – unless you can get a reference, you are fully entitled to ask your correspondent to ‘put up or shut up’. With respect to climate sensitivity, this does NOT come from the models – it comes from the observations (as outlined in the post I linked). That the models give roughly the same thing is a validation of the models, not a proof. -gavin]

    Comment by Risto Linturi — 14 Feb 2007 @ 1:05 PM

  345. Thank you Gavin. I did browse the posts you pointed to me, I do appreciate that there is a huge amount of measurement behind the current climate sensitivity and I did learn that the instead of multiplier I should have used feedback. English is my second language and climatology perhaps the tenth. I did find one older paper by Lindzen which I read without any possibility to fully understand it, but it did resemble the claim that my correspondet gave me. Page 351 he talks about 350K without convection Рunder the topic climate dynamics referring to M̦ller&Manabe 1961. (annual Reviews in Fluid Mech. 1994. 26 353-78)
    My correspondent did acknowledge my claim that Nasa has tested and disproved Lindzens claims with measurements but claimed that Lindzen has since then explained what went wrong. These explanations have not I assume been published in scientific journals. I already told him that it is up to him to prove that IPCC is wrong and not me as a layperson to disprove things that he cannot show support for other than with causal claims. I guess I will stick with that. And it may well be that Lindzens theories are too tough for a layperson to disprove with any causal logic anyway and I guess prediction and consequent measurements are always the final proof anyway to the scientists. Not the rhetoric. But sadly rhethoric does work with opinion building amongst the laypeople. My current rhetoric in this case is that Lindzen is the only scientist making this claim and all the others believe that he is wrong and have evidence for it that we as laypersons are unable to read or understand properly without excessive studying and not always even then can people give up the dead ends as I would believe Lindzens case seems to show.

    Comment by Risto Linturi — 14 Feb 2007 @ 2:26 PM

  346. I estimate that the result of AR4 that the temperature of the earth will rise to 300C.

    Comment by chen — 14 Feb 2007 @ 9:18 PM

  347. Re 322: Thanks

    Re 345: Yes, that seems familiar – the argument being that without convection, radiative equilibrium produces a much higher lapse rate (rate of temperature decrease with height) in the troposphere – this part is true. The ability of warm air to rise/ cool air to sink sets a maximum allowable lapse rate in the atmosphere, the dry adiabatic lapse rate. Moist convection tends to reduce the lapse rate even further.

    It is silly to argue that this implies the warming should be reduced from a change in CO2 relative to that given by the IPCC, because even a simple 1-dimensional (ie a single column of atmosphere representative of a global average) model will take into account convection. (Of course, uncertainties in changes in convection will lead to uncertainties in feedback, but in principle it is accounted for)

    Comment by Pat — 14 Feb 2007 @ 11:28 PM

  348. [[[Response: Sorry, I have no clue as to the source of the claim that the planet should be 75deg C without greenhouse gases. The standard calculation for a planet with the same albedo but no atmosphere gives -18 deg C. The climate sensitivity is around 3 deg C for a doubling of CO2 (see our older posts for why). -gavin]]]

    I think he meant 0.75 C, which is what Lindzen did try to identify as the climate sensitivity in one of his papers — can’t find the cite offhand, but I remember the paper. It was ripped to shreds by several papers written in response shortly thereafter.

    Comment by Barton Paul Levenson — 15 Feb 2007 @ 8:10 AM

  349. #347 Thanks Pat, I guess this was what I was searching for, but clearly I need to learn to formulate my questions better. I will try to find a source to explain the structure of the models that I could use as a source to show that convection has already been included (I have basic modelling experience on some other scientific fields but naturally that does not help much with climate models). The thread where I have been arguing against the denialists with two other amateurs is maintained by the largest and most influential Finnish newspaper and is probably read by some of the reporters and editors. Over 300 posts now and mostly I think I have coped well with the help of IPCC AR4 and this site and the links I have found here but this was too tough to solve in a short time.

    Generally the discussion in Finland is going towards consensus of the threat. Opinions differ what actions should be taken and a new atomic power plant is on the agenda for many. Acceptance levels of the general population to regulative measures on cars and other issues are high enough to allow the politicians to make desicions but some industries are still very hesitant claiming that we need to get China committed and we need to take care of our competitiveness. Jorma Ollila, who is chairman of both Nokia and Shell, gave a very committed interview on the necessity that there has to be political action now and even if China would not immediately follow. Jorma Ollilas appearance before AR4 changed the atmosphere of the Finnish discussion as much as the IPCC report or maybe more as he has been very prominent in Finland being the man who was CEO of Nokia during the phenomenal rise of Nokia. Prominent industry leaders have quite an impact if they dare make their personal opinion clear.

    And Gavin, thanks – validate, not prove. This is not mathematics. Sloppy of me.

    Comment by Risto Linturi — 15 Feb 2007 @ 2:53 PM

  350. Hello Barton,
    Thank u very much for your kind response. But i just want to tell u that i’m not afraid of all these earth changes. i was just eager to know what’s going on… Moreover, my main hobby is collecting information about earth, beyond space, the unexplained phenomenon, black holes, Bermuda Triangle, underworld civilizations & several other spots that has wierd science & mysteries behind it. I hav been doing this for about 5yrs(since i was 14), but i have’nt got any clear evidences. I know i’m too small to learn about all these things. But i’m very much intrested in this. I admired to become a researcher or a scientist to learn about all these in detailed, but due to certain circumstances, i could’nt do so. Besides i always had a thought that several research centers & scientists hav found something about the wierd things happening around the world or is about to happen. But they kept it secret for some reason. Is it true…?. But my mum told, that sometimes certain unacceptable things cannot be revealed to the world, as people always need proof to prove it and there will be a lot of Oppositions. So better hide for good. I hope she’s right as these things really don’t hav any proofs isn’t it…?
    Well, likewise i had lots of questions in my mind, but i did’nt hav a chance to get it cleared as i could’t find a relevent person. U are the first one to give a good response to me. Thank u once again…

    Comment by Priya — 16 Feb 2007 @ 3:39 AM

  351. hi: did anyone here read the recent article (2/13) in the ny times by john tierney on the richard branson offer of 25 million to invent a carbon eating technology?

    in the course of that report, the author made assertions about the ipcc report–suggesting among other things that the issues around sea level rise are hyped and that we will see only slow changes, nothing rapid, no tipping points.

    I think that in his discussion of sea level rise he may have made the mistake referred to above–he asserts that predictions of sea level rise has gone down (instead of making the point above about apples and oranges comparison where one measurement leaves out dynamical effects)

    anyway, are there any serious criticisms the experts here would make of this article, either on grounds of interpreting the ipcc report or on plausibility of seeking out miracle (carbon eating nano) technologies to deal with global warming as a substitute for reducing ghgs?



    Comment by greg meyerson — 16 Feb 2007 @ 11:16 AM

  352. [[Thank u very much for your kind response. But i just want to tell u that i’m not afraid of all these earth changes. i was just eager to know what’s going on… Moreover, my main hobby is collecting information about earth, beyond space, the unexplained phenomenon, black holes, Bermuda Triangle, underworld civilizations & several other spots that has wierd science & mysteries behind it. I hav been doing this for about 5yrs(since i was 14), but i have’nt got any clear evidences.]]

    All interesting stuff, but not really relevant to this blog, which is mostly about global warming. If you want to e-mail me about any of this I’ll try and tell you what I know, which may not always be much. :)

    Comment by Barton Paul Levenson — 16 Feb 2007 @ 11:48 AM

  353. Yes, i know Barton. These are really not relevant to this blog. But i tried through email. It did’nt reach u…

    Comment by Priya — 16 Feb 2007 @ 1:52 PM

  354. [[Yes, i know Barton. These are really not relevant to this blog. But i tried through email. It did’nt reach u… ]]

    It reached me, I just didn’t have anything to say in response.

    Comment by Barton Paul Levenson — 16 Feb 2007 @ 3:27 PM

  355. Global Warming is bad! =]

    Comment by Danny — 20 Feb 2007 @ 9:16 AM

  356. i,m not a scientist and not really up on all the jargon that they use….after several years of listening to theorys about how the planet is being destroyed,my thoughts have dedused a theory of my own,one that i have not heard anyone comment on before,maybe i am not well read enough or it is something that may have been brushed under the to speak….not dismissing that polution and all the other things that have been commented on help,but to me it seems the rapidness over the last 30 years of global warming coencides with mans overwhelming desire to venture into space….now as i said,i am no scientist but,if you continually keep breaking through the atmosphere with rockets and satalites,not only are you burning all that fuel so close to the ozone layer….the thing they say which is causing the problem….maybe momentarily you are creating a hole,all those harmful radiations must be able to get through?how many and how many times have we done this?this has got to weaken our ozone layer surely?how many planes are flying in the skies now?burning all that fuel so close to the ozone,think we need to look higher to solve this problem we have…..dont you?

    Comment by mark — 27 Feb 2007 @ 2:26 PM

  357. [[if you continually keep breaking through the atmosphere with rockets and satalites,not only are you burning all that fuel so close to the ozone layer….the thing they say which is causing the problem….maybe momentarily you are creating a hole,all those harmful radiations must be able to get through?how many and how many times have we done this?this has got to weaken our ozone layer surely?how many planes are flying in the skies now?burning all that fuel so close to the ozone,think we need to look higher to solve this problem we have…..dont you? ]]

    It’s an interesting idea, but I don’t think the holes created by spacecraft last long enough to have an effect on the planet’s climate. That, and consider how physically small they are compared to the size of a planet. The biggest spacecraft out there in terms of width might be the US space shuttle, which is what, 50 meters across? Compare that to an Earth with an area of 510 trillion square meters. Similar comments for airplanes, I think, although of course there are a lot more of them.

    Comment by Barton Paul Levenson — 28 Feb 2007 @ 8:04 AM

  358. Re #356:

    At the present time, there aren’t enough spacecraft launched per year to have any major effect, but I do believe that airplanes have an effect on ozone levels via their stratospheric emissions.

    If space travel becomes much more frequent, perhaps because of space tourism, then it does have the potential to cause serious harm as it is orders of magnitude more harmful per passenger or per kg of payload than commercial aircraft flights.

    Comment by yartrebo — 28 Feb 2007 @ 9:54 AM

  359. I’m trying to read the SPM and got all the way to page 5 before getting stuck. Table SPM-0 is a list of sources of sea level rise (thermal expansion, glaciers and ice caps, Greenland, and Antartica, with numerical values for each). The next line is “sum of the individual climate contributions to sea level rise”. I was expecting that to be the “sum” of the four listed components, but it’s certainly not.

    I’m sure you have noticed and explained this already – please just point me to where..thanks

    Comment by rick hanheide — 28 Feb 2007 @ 7:37 PM

  360. Hmmm. Maybe no one is reading this topic anymore. I’ll try my question on a current discussion.

    Comment by rick hanheide — 1 Mar 2007 @ 1:46 PM

  361. What sort of people work for the IPCC? [edit]

    Page 5 of the summary, the first table, none of it makes any sense. First, its in meters, then they sum up the results in millimeters and exxagerate the numbers by a factor of 10. Then, the estimated contributions to sea level rise, simple do not add up. Just do the math.

    Are the authors and everyone, everyone that reviews the summary making up numbers, or are they unable to do simple math? In addition to models being completely wrong. Conversions do not make sense, addition is wrong, coupled with a wild model that is no where close to the observed rate.

    0.18 meters is 1.8 millimeters?

    0.16+.077+0.21+0.21 = 0.28?? (coincidenatlly close to the observed rate?)

    Comment by WJG — 5 Mar 2007 @ 6:11 PM

  362. my mistake – the authors made a table on a scale of 100 years, while discussing the result son a scale of one year.

    However, it still stands that the math does not add up.

    Do the reviewers own a calculators? As it stands – the summary for sea level can only be discarded because no one in the IPCC can do math.

    [Response: See comment #11. This typo is already fixed in the downloadable version. -gavin]

    Comment by WJG — 5 Mar 2007 @ 6:16 PM

  363. @Rick and WJG
    Please download a newer version. At first there was a mixture of units in the table, this is corrected now, all values in mm/yr: SPM2.

    Comment by Henk Lankamp — 5 Mar 2007 @ 6:35 PM

  364. re: 361 and 362.
    It is not all that difficult to do a quite simple search here at the top of the page and find the SPM reviewers are listed in post 48 at

    So you can now contact through Google Scholar each scientist listed and specifically ask them if they are “making up numbers” or “are (you) unable to do simple math?”.

    Comment by Dan — 5 Mar 2007 @ 6:43 PM

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