RSS feed for comments on this post.

  1. Thanks for clarifying this term Gavin. Your explanation covers usage of CO2-e for atmospheric concentrations, which is what Tim Flannery was talking about, but it would probably be useful to explain its usage for emissions as well.

    As I understand it, when referring to greenhouse gas emissions, “carbon dioxide equivalent” refers to the amount of carbon dioxide that would give the same warming effect as the effect of the greenhouse gas or greenhouse gases being emitted. It is normally used when attributing aggregate emissions from a particular source over a specified timeframe. It is used in this way at national and international levels to account for greenhouse emissions and reductions over time. Importantly, Article 3 of the Kyoto Protocol states targets for emissions reductions in terms of “aggregate anthropogenic carbon dioxide equivalent emissions of the greenhouse gases listed in Annex A.” [Annex A lists six gases: carbon dioxide (CO2); methane (CH4); nitrous oxide (N2O); hydrofluorocarbons (HFCs); perfluorocarbons (PFCs); and sulphur hexafluoride (SF6)].

    Using this approach, for example, Australia’s net greenhouse gas emissions across all sectors in 2004 totalled 564.7 million tonnes of carbon dioxide equivalent (see expected carbon dioxide equivalent emissions from burning different fuels can also be calculated using a standard methodology (see e.g.

    Also, it may be a useful point of clarification to note that some authors and inventories refer to “carbon equivalents” when discussing quantities or atmospheric concentrations of greenhouse gases. Figures for “carbon equivalents” can be converted to “carbon dioxide equivalents” by multiplying by 44/12 to take account of the different molecular weights. The IPCC guidelines use “carbon dioxide equivalents” for GHG but “carbon equivalents” is more meaningful than “carbon dioxide equivalents” when discussing the amount of carbon stored in fossil fuels and sinks such as the deep ocean where the carbon is not in gaseous form.

    I am not a climate scientist so could you please clarify whether my understanding is correct?

    [Response: Yes, that is correct. When used for future emissions over a specific timescale – usually a century, you take the actual emission and multiply it by the Global Warming Potential (GWP) for that gas and that time period. This is good for the well mixed GHGs (CH4, N2O, CFCs) but breaks down for the short-lived species (NOx, VOCs etc.) that are ozone precursors or for aerosols. – gavin]

    Comment by Chris McGrath — 11 Oct 2007 @ 6:05 PM

  2. I don’t yet comprehend how the ‘dangerous’ level can be set so high.

    My reasons are solely based on the Eemian intergalcial (Termination II), about 134 kya. At that time it seems that carbon dioxide in the atmosphere peaked at about 292 ppmv (Vostok Ice Core analysis only, average of the three studies on the NOAA Paleoclimatology site). During the Eemian the sea high stand was about 4 meters higher than today’s sea stand.

    I conclude that, roughly, any concentration greater than about 280 ppmv eventually leads to sea stand rise, hence we are currently in peril of eventually seeing quite a substantial sea stand rise. If so, that will be quite a calamity, even if it takes centuries to reach the highest stand.

    [Response: There were other differences during the Eemian – specifically orbital configuration changes that meant that NH summers (May-Sep) were much warmer than today. Even though global temperatures were only about 1 or 2 deg warmer than now, Greenland temperatures were more liek 3 to 5 deg C warmer. So if you are looking for predictions, look for cases where Greenland is likely to be that warm (most BAU scenarios by 2100 as it happens – see Overpeck et al, 2006 Science). -gavin]

    Comment by David B. Benson — 11 Oct 2007 @ 6:21 PM

  3. Gavin, for the total forcing how do they get the 5.35 number? I’ve seen various number up to 6.2 (ie or is it just observation?

    Not so sure we haven’t commited ourselves to 450 ppmv- anything lower seems entirely unreasonable from a common sense point on how things are moving along. Also would be hard to define “dangerous” levels- to some we already hit that point, but I think ~2 C warming is the beginning of where “alarming ” is. Of concern now seems to be how feedbacks will react and give us more CO2 or more warming- we’ve gotten more humid from the water vapor feedback from the latest Willett et al (Nature) paper, the decline of CO2 sinks (Le Quere et al 2007). Looks like aerosols will mitigate some warming, but I suspect that even those would decline as we get “cleaner” which ironically could give us more warming.

    [Response: “5.35” comes from a fit to line-by-line radiation model results for different CO2 concentrations (Myhre et al , 1998). – gavin]

    Comment by Chris — 11 Oct 2007 @ 7:28 PM

  4. Gavin,

    Thanks for covering this. I’ve seen the statement by Flannery used in several places so far.


    Comment by Chris Dudley — 11 Oct 2007 @ 7:58 PM

  5. Just to clarify – does mean that the ‘danger level’ is 455ppmv CO2_e (total) rather than 455ppmv CO2_e (Kyoto)?

    Comment by George Darroch — 11 Oct 2007 @ 8:02 PM

  6. Sorry, I can’t follow the technical explanation too well. Are you saying that Tim Flannery has made incorrect claims that we are ahead of the predicted schedule based on his misreading of the draft report, or are you saying that the media did not accurately report what Flannery meant to say?

    [Response: I think it’s clear that Flannery made incorrect statements. – gavin]

    Comment by Holly Stick — 11 Oct 2007 @ 8:15 PM

  7. Thanks for giving the background to the recent statements on CO2-eq concentration, this has been raising many questions.

    If I may add to your explanation though: The figure of 455 ppm CO2-eq comes from converting the value of 2.63 W/m^2 given in WG I Chapter 2, Table 2.12, for the total radiative forcing of “long lived greenhouse gases” to a CO2-eq concentration using the formula that you cite. In your calculation you added the indirect effects of CH4 on stratospheric water vapor but those were classed separately in the WG I report.

    What to include, and what not, is, as you have implied, somewhat subjective, but the fact that different radiative forcing agents have very different degrees of persistence into the future, and that the shortest lived components are negative (i.e. cause cooling) is very policy relevant. If all anthropogenic emissions stopped completely tomorrow, total radiative forcing (and warming) would increase – not decrease – due to the rapid removal of aerosols from the atmosphere and the disappearance of their cooling effect. This fact underlies the difficulty that those constructing mitigation scenarios for the 21st century have in coming up with plausible ways of avoiding a warming of 2C.

    Of course I agree fully with your final comments on those who leak material from draft IPCC reports. This is usually done inaccurately and out of context. In this case reference to the radiative forcing projections given in the Third Assessment Report shows that there is no basis for saying that long lived greenhouse gases are now 10 years ahead of the projections of a few years ago.

    Comment by Martin Manning — 11 Oct 2007 @ 8:25 PM

  8. I’m not sure we’re all referring to the same quantity.

    From the Stern Review summary:

    “The risks of the worst impacts of climate change can be substantially reduced if greenhouse gas levels in the atmosphere can be stabilised between 450 and 550ppm CO2 equivalent (CO2e). The current level is 430ppm CO2e today, and it is rising at more than 2ppm each year.”

    The same report shows a 50% chance of a 2 C increase if with a 450 ppm stabilization.

    If you’re referring to total forcings, then what is the 50% chance of a 2 C atmospheric level?

    [Response: Stern used CO2_e (Kyoto) for today’s level, but CO2_e (Total) when discussing stabilisation scenarios. They shouldn’t have been compared like that. Using a standard sensitivity, 450 ppm gives about 2 deg C – so if you think that we are as likely to be greater than that as less than that (reasonable guess), then 450 ppmv is indeed the level that gives us a 50% chance of avoiding > 2 deg C. – gavin]

    Comment by Karen Street — 11 Oct 2007 @ 8:38 PM

  9. Could you comment on how the lifetime of aerosols effects all this.

    In particular, as I understand it a reduction in fossil fuel use will lead to a reduction in emissions of aerosols (the majority of which have a cooling affect). Aren’t the atmospheric lifetimes of these aerosols far shorter than that of the warming gases. Won’t this result in a situation where as we reduce CO2 emissions, some of the current cooling effect will be reduced, while most of the current warming effect remains?

    Does your analysis above assume that the total cooling effects of aerosols do not decline?

    Also, thanks for all your great work.


    Comment by Michał Górnisiewicz — 11 Oct 2007 @ 8:54 PM

  10. The low value of CO2eTotal is less comforting if the negative forcings arise from the same activities as the positive forcings (e.g. dirty coal combustion). Then measures that reduce CO2 emissions or clean up local air pollution reduce the masking effects on a short time scale, while long-lived gases remain in the atmosphere, so that CO2e would rise rapidly. This effect would seem to make the headroom between 375 and 450 somewhat illusory.

    [Response: You are absolutely correct. I was just about to enter my own comment to this effect, but you have done it for me. David]

    Comment by Tom Fiddaman — 11 Oct 2007 @ 9:28 PM

  11. Data quality analysis as reported in IPCC WG1 Chapter 2 is not adequate for risk assement data used for decisions affecting large populations. In risk analysis, we are not talking about the fate of clouds, we are talking about the fate of people. We need data of known quality! Data with “wide error bars” does not qualify. At the very least, we need a numerical estimate of how wide those error bars are. That number is not in the text, I do not see a protocol for calculating such a number, or the raw data that could be used in such a calculation. I was on the ASTM Technical Committee for Data Quality for Human Health Risk Assessment. I know that numerical estimates of data quality are not easy. Worse, I know what a blow to the ego such an analysis can be, But, this site is not about “easy”. This site is about honest and correct.

    If we do not have good estimates of the error bars, then we need to apply safety factors; as we did when we started doing human health risk assessments of National Priority List hazardous waste sites. Put in a safety factor, and 375 might well become the new 450. Certainly, Gavin might not like that when it is first presented to him. But, if we are considering something that affects 6 billion people, then being only 99.9999% certain says that we do not care about an event that kills three times more people than 911. If we are only 99% certain then, we can expect 70,000,000 to die as a result of our ignorance. How many people’s lives are we willing to lose because we did not do our homework on data quality?

    I am not advocating zero risk. I am saying, “Let’s make decisions based on knowledge.”

    For background material see

    Comment by Aaron Lewis — 11 Oct 2007 @ 9:53 PM

  12. I guess this has to be clarified. Was Flannery talking about forcing or greenhouse gas concentration? I think it was the latter. If that’s the case, as people at the Hadley Center have shown, we are already at a concentration of over 450ppm of carbon dioxide equivalents, which is dangerous. Yes, you have aerosols and other factors, but we have no clue how much of a cooling effect they’re actually having. We also know that they will probably be gone in the next 10-20 years. After that happens, the full forcing of greenhouse gases currently in the atmosphere will show, pushing us beyond 2C. It’s also important to mention that we have a 50% chance of avoiding 2C if we keep concentrations (of greenhouse gases minus the cooling) at current levels. Because of keeping these things out of discussion, people are setting absolutely wrong targets (i.e. halving world emissions by 2050).

    Comment by Carlos Rymer — 11 Oct 2007 @ 10:13 PM

  13. Gold standard work as ever Gavin. I think the fact that this level is within reach is disturbing enough under any scenario, but the damage occurs when AGW realists like Flannery who is already pilloried by the usual suspects, reach too far beyond the data.

    I think the IPCC estimates are biased conservatively, as usually is the case in science, but journalistic hyperbole does the issue a great disservice and makes weakens the effort to turn this thing around. We don’t need that.

    Comment by Mark A. York — 11 Oct 2007 @ 10:20 PM

  14. Holly, I think the problem is the journalists have no one to verify any claims that their source is quoting from a discussion draft. The people who do know what’s in the drafts and comments have promised not to leak them.

    The last round there was a lot of stuff in the press that didn’t turn out to be right.

    Comment by Hank Roberts — 11 Oct 2007 @ 10:54 PM

  15. Gavin:
    Speaking of outliers.Pat Michaels complains today about peer review at RC in that learned journal ,The American Spectator-

    [Response: Michaels doesn’t bother to notice that RC actually doesn’t have anything to do with Hansen (whose personal thoughts on climate are available here). Hansen’s (and my) peer reviewed output is available at , and I don’t think that Jim is a slouch in that department. – gavin]

    Comment by Russell Seitz — 12 Oct 2007 @ 1:20 AM

  16. I’d really appreciate a comment of Gavin in the light of contributions #9, 10, 11 and 12. As Gavin himself stated in his response to contribution #1: GWP calculation for specific time horizonts is good for long lived GHGs but breaks down for short-lived species (e.g. aerosols).

    Comment by Helmut Wolf — 12 Oct 2007 @ 2:37 AM

  17. 1.) Thanks for this post, as it (once again) makes clear for those laymen like me,

    – how difficult it is to put emerging chunks of research information into its place even for scientists who are not immediately involved

    – how easily you can achieve a (not even intentional) distortion of research results into facts without proper context, with all the possibly disastrous impact on the broader public.

    2.) I’d really appreciate a similar assessment of ‘thawing permafrost’ or ‘melting’ in general.

    Several times I stumbled over the assertion, that there are no surprises to expect from thawing permafrost or, recently, accelerated melting in Greenland as well as in Antartica.

    At least, those Dansgaard-Oeschger events did happen. And the record minimum arctic sea ice this year definitely shows what is meant by ‘highly nonlinear behaviour’. So I am curious why permafrost thawing should not involve some nasty surprises.

    Comment by Dietmar Temme — 12 Oct 2007 @ 2:58 AM

  18. What is the forcing for C02 without any knock on effects such as increased water vapour?

    [Response: “Forcing” doesn’t include those feedbacks – they make a difference to the sensitivity, not the forcing. – gavin]

    Comment by Nick — 12 Oct 2007 @ 3:56 AM

  19. Good article, but one fact that I think is missing is the choice of time horizon for the Global Warming Potentials (GWP) and the consequences for the calculation of CO2 equivalent emissions.

    IPCC reporting obligations still require the use of the older IPCC Second Assessment Report (SAR) 100-year horizon GWP for national inventories, defining a quasi “standard” for comparable CO2 equivalent emissions / total greenhouse gas emissions.

    But IPCC papers such as WG1 Chapter 2 (link in the original article, table 2.14, page 212) give different GWP for 20, 100(!) and 500 year horizons alongside the 100 year SAR values, making it hard for laymen (and even experts, sometimes) to find out which GWP to use for calculations.

    Comment by Patrick G. — 12 Oct 2007 @ 4:18 AM

  20. Congrats Al Gore and IPCC!

    Comment by Pinko Punko — 12 Oct 2007 @ 4:23 AM

  21. Quick off-topic announcement…

    … another bloody yank is walking away with the Nobel Peace Prize.

    Comment by Timothy Chase — 12 Oct 2007 @ 4:23 AM

  22. Congratulations to the IPCC and to Al Gore!

    Comment by Arun — 12 Oct 2007 @ 4:26 AM


    The Norwegian Nobel Committee has decided that the Nobel Peace Prize for 2007 is to be shared, in two equal parts, between the Intergovernmental Panel on Climate Change (IPCC) and Albert Arnold (Al) Gore Jr. for their efforts to build up and disseminate greater knowledge about man-made climate change, and to lay the foundations for the measures that are needed to counteract such change.

    Comment by Arun — 12 Oct 2007 @ 4:27 AM

  24. But a lot of the “negative” radiative forcing components have atmospheric residence lifetimes of ~week, so are irrelevant to a discussion of CO2_e levels in terms of reaching a stabilisation target.

    Isn’t that obvious?

    [Response: No. The reason why is that even with that short residence time, continual emissions mean that atmospheric levels stay elevated – contributing to long term changes. It is true that efforts to reduce aerosols (including black carbon) have immediate effects as opposed to CO2 emission cuts which take a while to make a difference to concentrations. – gavin]

    Comment by Timothy — 12 Oct 2007 @ 5:15 AM

  25. Congrats on winning the Nobel peace prize to Al Gore, the IPCC, and all of you folks that have contributed towards the research and the reports. AGW-naysayers will sooner or later run out of their excuses.

    Comment by NL — 12 Oct 2007 @ 5:39 AM

  26. Mixing sulphates and CO2 in CO2_e(total)?

    Don’t they have vastly different time constants of how long they stay present in the atmosphere?

    I see problems here.

    Comment by Tom Adams — 12 Oct 2007 @ 7:25 AM

  27. Response to #24 – I accept that. On a narrow point of what the instantaneous forcing is equivalent to, then, yes, you obviously have to include the short-lived aerosols.

    However, if we ever get to a stable level of CO2, we won’t be emitting sulphate aerosols any longer, or burning vast areas of rainforest (emitting black carbon). In the context of how close we are to various stabilisation targets, then, I think it makes sense to discount short-lived agents whose release is associated with anthropogenic sources of GHGs.

    Of course, this also means that you can have an overshoot scenario. In CO2_e terms you could go over the stabilisation target, but move back down to it by reducing levels of the shorter-lived GHGs such as CH4 and NOx. In that sense the non-CO2/CFC part of the CO2_e is not committed to the same extent. (And the fact that CO2_e(Kyoto) ~455ppmv is not quite as alarming).

    If it helps, I’m thinking of a timescale for stabilising GHG levels by 2050.

    Comment by Timothy — 12 Oct 2007 @ 7:33 AM

  28. Please address these simple questions for me, as an intelligent layman concerned about the future of our planet and our children:

    1. Even the food we produce and eat is not carbon-neutral, considering the huge amounts of fossil fuel used for producing fertilizers,irrigation,transportation,refrigeration,cooking, etc that go into the food production-consumption chain.

    2. Where is the carbon sink that can absorb the CO2 of other man-made consumption processes like automobiles, electricity, aeroplanes,trains, airconditioning, heating,manufacturing, mining etc. which are colossal and their effects cumulative?

    3. It appears to me that we are doomed like the mythical ICARUS whose wax-fixed wings melted as he showed off his flying before the sun. In short, no amount of fossil-fuel burning – no matter how less – is ultimately sustainable from the point of view of preventing accumulation of CO2 and waste-heat in the environment, and an eventual over-heating and melt down of the planet.

    4. Possibly, human knowledge, wisdom, compassion etc. – and a big dose of humility – may show us the path for a sustainable future, based on essential human needs and not human greeds, as Gandhi pointed out long time ago. Has anyone modelled such a future for some 10 billion humans/animals living on this earth – the life-style they can live without destroying the planet ?

    I look forward to learning on the above issues.

    Comment by Vinod Gupta — 12 Oct 2007 @ 7:34 AM

  29. Fair is fair. Shouldn’t Al Gore send a thank you note to all the right-wing nutjobs who have abandoned the scientific high ground and left him standing there alone. I mean after all, without climate change (which to be fair, he was among the first to embrace), he would just be another washed up politician. Now he has an Academy Award, a Nobel Peace Prize and bookies have cut the odds on his becoming President from 10:1 to 8:1. He couldn’t have done it without the editorial board of the Wall Street Journal, Senator James Inhoff, Rush Limbaugh, The Cato Institute, Exx-Mob etc. Come on guys step up and take a bow!

    Comment by Ray Ladbury — 12 Oct 2007 @ 7:59 AM

  30. Re different time constants, I believe that is considered when calculating CO2_e.

    Thanks, Gavin, for this clarification — I hadn’t checked the numbers for the Stern Review to see if they were internally consistent. Much steeper reductions would be needed to stabilize at 450 ppm if we’re already at 430 ppm, except that we’re already at 460 ppm.

    You can see why some of us are confused.

    Comment by Karen Street — 12 Oct 2007 @ 8:06 AM

  31. RE: 12 Aerosols from combustion sources will probably not be reduced to climatologically insignificant levels before 2050. That said, any forecasts need to take into account that their influence will be reduced a few percent every year. Thus, we will get to the 450ppm threshold sooner (say 2030 and not 2050) rather than later as the well mixed GHGs continue to increase in concentration. Tropospheric ozone will also decrease, helping a little bit. Due to the long lead times in developing and installing new energy sources, it is doubtful in my mind that we still have time to avoid the 450ppm level. Taking that into consideration, a prediction today that we are committed to passing a dangerous threshhold is not unreasonable.

    Comment by Alvia Gaskill — 12 Oct 2007 @ 9:06 AM

  32. Re #15:

    I pointed out the error concerning RC in Pat Michaels’ American Spectator article to him and he told me that he contacted the Spectator about it to have it corrected. So, presumably (hopefully) that will happen.

    -Chip Knappenberger

    Comment by Chip Knappenberger — 12 Oct 2007 @ 9:25 AM

  33. How good are the negative and positive forcing predictions in the emission scenarios climate modelors use? Hansen’s paper on where we are is good, but how predictable is the future? Specifically, how good are predictions about the timing of the clean up and then phase out (or beginning of CO2 sequestration) of coal fired power plants? Do the scientists involved think they have a good handle on how this will play out or is it a huge source of unpredictability in terms of future temperatures? What if this story’s actions play out in China and Russia? Do these governments have a plan they haven’t shared? Do the industries that seem to run (at times) our governments have a plan they haven’t shared? Should climate modelers be pouring over the minutes of board meetings?
    810,000 tons of pollutant reductions, 79% reduction in sulfur emissions, 69% reduction in nitrous oxides. Two opposing forcings being reduced simultaneously. Sorry, shouldn’t have had that extra cup.

    Comment by Andrew Sipocz — 12 Oct 2007 @ 9:56 AM

  34. Now the mean radiative forcing since 1850 is 1.6W/m2.
    We can say that the correspondant temp increasing is 0.8°C.
    We can say also that there is some 0.4-05°C “in the pipe”.
    Thus about 1.25°C in some decades.
    The consecutive sensitivity is something as 0.78°C.m2/W.
    With this sensitivity, for 450 ppm of CO2, we get a temperature increase of 2.63W/m2 * 0.78°C.m2/W = 2.06°C.
    My problem is the “0.4-0.5°C in the pipe” which depends on oceanic thermal inertia.
    If this inertia becomes very very great, the ocean keeps the heat and the temperature increase no more.(at least as far as complete absorption of CO2)
    In this perspective what do you think about the SH ocean cooling since 2003?

    Comment by Pascal — 12 Oct 2007 @ 9:58 AM

  35. re 14

    “Holly, I think the problem is the journalists have no one to verify any claims that their source is quoting from a discussion draft.”

    IMHO, another ongoing problem with the media is the lack of verification due to budget cut-backs. No more double and triple checking. Worse, in a very competitive “what have you got now?” market designed around sound bites and 30-second info-clips, the need to be the first to run with a story is subsuming accuracy in favor of profit.

    This is one of the reasons the climate “skeptics” are able to keep their game running.

    Comment by J.S. McIntyre — 12 Oct 2007 @ 10:11 AM

  36. To complete #33

    The SH ocean cooling is showed on this graph with Hadley data:

    you can see the difference between NH land and SH ocean.

    In this context what do you think about this study of Russel and the influence of southern hemisphere westerly winds on the ocean mixing?

    SO, I don’t contest GHG effects, but if there is a greater oceans mixing the warming should be weaker.

    Comment by Pascal — 12 Oct 2007 @ 10:15 AM

  37. Ahhh, so what is being said here is that all things considered via +ve and -ve forcings currently add up to Co2_e of 375 ppmv of net forcing. Does this mean that we need to continue polluting to soem degree or does coal do both for us anyway regardless?

    Comment by Pete Best — 12 Oct 2007 @ 10:27 AM

  38. > SH ocean cooling

    “….the mechanism triggering cooling over the region north of the Ross Sea is changes in the ocean circulation over the subdued warming region. Because the cooling in a warming climate is highly localized, it is important to analyze the oceanic processes on regional scales. Here we examine oceanic changes, focusing on the regional processes underlying the regional coolings in response to increased atmospheric GHGs forcing in the CCSM3…. ”


    Comment by Hank Roberts — 12 Oct 2007 @ 10:43 AM

  39. Yeah, “just Hansen” is warning of sea level rise, if you ignore the other 46 co-authors from this paper:

    Comment by cce — 12 Oct 2007 @ 11:04 AM

  40. Congratulations to Al Gore and the IPCC. Well done!

    American right wing talk radio is spinning up the lies and usual misinformation about Global Warming and Climate Change. Neil Boortz carried on for an hour this morning about how it’s all a lie forged by the anti-Corporatists. Meanwhile, in North Georgia there only remains about 3 months of water in most of the reservoirs. These people can’t believe their own eyes, much less scientists.

    Comment by catman306 — 12 Oct 2007 @ 11:16 AM

  41. Question: I have heard skeptics make the claim that many models use a future co2 rise of 1% increase per year, which is higher than co2 is actually rising. I assume they are confusing co2 increase with co2_e increase when they make this claim (?)

    [Response: 1% CO2 growth is just a standardised scenario that modellers use so that everyone does the same run, like 2xCO2 – it’s not a prediction. There are lots of more ‘realisitic’ scenarios that are done that have growth rates closer to observed and include all the other factors (like methane, aerosols etc.). – gavin]

    Comment by bobn — 12 Oct 2007 @ 12:03 PM

  42. re 14
    “Holly, I think the problem is the journalists have no one to verify any claims that their source is quoting from a discussion draft.”
    re 35
    “IMHO, another ongoing problem with the media is the lack of verification due to budget cut-backs. No more double and triple checking. Worse, in a very competitive “what have you got now?” market designed around sound bites and 30-second info-clips, the need to be the first to run with a story is subsuming accuracy in favor of profit.”

    I doubt it is entirely that innocent. If you know any journalists at all, then you are fully aware that advocacy reporting is the purposeful objective of many.

    [Response: I know many journalists and that is as far from the truth as it is possible to be – especially when it comes to science issues. – gavin]

    Comment by Lee Menningen — 12 Oct 2007 @ 12:04 PM

  43. Very strange bedfellows. If Richard Lindzen, Pat Michaels and John Christy served on the IPCC at one time or another, then aren’t they also being recognized along with Al Gore?

    Comment by Alvia Gaskill — 12 Oct 2007 @ 12:20 PM

  44. Catman306,
    Capitalists tend to be rational creatures. They will continue to ignore reality as long as it is profitable. As long as those royalty checks from Exx-Mob. keep roling in, they can save up to buy the house on the hill and they don’t need to worry if the rest of the town floods. I think it is important for them to realize that they have handed a very powerful issue to their political enemies. It’s gotten their nemesis Al Gore an Oscar and now a Nobel Prize. Bookies have reduced his odds of becoming president from 10:1 to 8:1. The Truth is a powerful weapon even when it is inconvenient.

    Comment by Ray Ladbury — 12 Oct 2007 @ 12:34 PM

  45. Can someone read through this article regarding CO2 future emissions and what cuts are required to see if it is of merit.

    It seems to be contradicting what is being said here in terms of termperature rises by 2050 and what emissions cuts are needed. 90% minimum

    Comment by pete best — 12 Oct 2007 @ 12:34 PM

  46. re 29
    “…Shouldn’t Al Gore send a thank you note to all the right-wing nutjobs who have abandoned the scientific high ground…”
    re 40
    “…right wing talk radio is spinning up the lies…”

    I am not scientific and I am one of those you are trying to convince. But when you (and others) use language like that (or find it necessary to whitewash or deny tenure to disagreeing colleagues) I tend to wonder whether you fear your view is indefensible.

    The anti’s include reports from the many scientists, including from Canada and Europe, (your colleagues) that point out logical discrepancies that the “for’s” never seem to address other than by denigrating name calling. So who am I supposed to believe, the anti’s, or the name-callers?

    The “other” viewpoint should have equal prominence in the news, and I mean equal. But it doesn’t. That fact alone raises red flags.

    The “we must prevent the earth from warming” viewpoint predominates in the news, yet no one has ever explained to me why. I remember from elementary school how the earth once had no ice at the poles and the fossil record in northernmost land shows it was tropical, yet the earth wasn’t flooded. Why?

    No one has explained why the current warming trend isn’t just another harmless 200-yr cycle. Do we deny cyclical warming and cooling trends?

    No one has explained to me why the news a generation ago was constantly lamenting a cooling earth with the same fervency they now lament its warming. Were they wrong then and right now? Or wrong now and right then? Or neither?

    On the other hand, that some slight warming has been detected I can accept, but given that, why does it follow that “man” has to do something about it? Why can’t we just live with it?

    That is why the subject is debatable, it has nothing to do with “right-wing” which I thought was a political term (and I don’t like politics).

    [Response: None of your objections have any validity, I’m afraid – that’s why when they get brought up over and over again, even though they have been debunked dozens of time, people get frustrated. I suggest that you look each of these points up over at Coby Becks guide, or the New Scientist Climate Change Myths page (linked from the ‘Start Here’ page). If you still think these are truly debatable issues, come back and we can discuss. – gavin]

    Comment by Lee Menningen — 12 Oct 2007 @ 12:38 PM

  47. Gavin — Thank you for the response to my comment #2.

    Vinod Gupta (28) — These topics, while interesting, are rather off-topic for Real Climate. There are many alternative sites listed in the sidebar under the heading Other Opinions. Some of those may be of more assistance to you.

    But in addition, I encourage you to follow

    for new developments regarding bioenergy and the relationships to clean potable water, food and animal feeds.

    Comment by David B. Benson — 12 Oct 2007 @ 1:11 PM

  48. Speaking of Hansen, he’s been pilloried in certain quarters for over-predicting sea-level rise for this century. But see this article and this release regarding a new paper (not actually published yet AFAICT, but the GRL draft is available for those who have that subscription):

    “Greenland is melting at record speed

    “The inland ice on Greenland is vanishing much faster than scientists previously believed. This can be seen from new research results from the Danish National Space Center.

    “Each year, in the south eastern part of Greenland alone, the glaciers produce a mass of icebergs which is equivalent to a gigantic ice cube measuring 6-1/2 km on all sides. And the reduction of the inland ice is accelerating. At the moment, four times as much inland ice is disappearing compared to the beginning of the decade.

    “‘If this development continues, the melt water from the inland ice will make the world’s seas rise by more than 60 cm this century’, says senior researcher Abbas Khan of the Danish National Research Center, who was responsible for the research project. The results were obtained in co-operation with the University of Colorado and have just been published in the international research magazine Geophysical Research Letters.

    “The researchers have measured the rate of melting with special, highly sensitive GPS stations placed on the mountains along the inland ice. When a quantity of inland ice disappears, the pressure on the surrounding mountains eases and they therefore rise slightly. This can be measured by the GPS stations. The measurements show that the mountains along the fast glaciers in south east Greenland are rising by 4-5 cm a year. Meanwhile, the rim of this inland ice will be 100 m thinner a year.”

    Comment by Steve Bloom — 12 Oct 2007 @ 1:13 PM

  49. A question – Why do GWPs vary with the time scale used time constant used? Wouldn’t the radiative forcing of the molecule, multiplied by it’s average lifetime in the atmosphere, give a GWP that is independent of time (as long as the time scale is long enough)? Or is it that we’re only looking at a time frame that is much longer than average lifetime of the gases?

    Comment by Noam Ross — 12 Oct 2007 @ 1:23 PM

  50. Vinod Gupta: #28 There are answers. 1. We all eat vegan diets, with the plant foods grown organically. 2. We get all our power from solar, wind, geothermal, waves, etc. No fossil fuels at all. This can be done. All we need to do is do it.

    Comment by Jack Roesler — 12 Oct 2007 @ 2:06 PM

  51. Re 42; it may be six of one and half a dozen of the other. I’ve seen journalists make a mess of reporting on another complicated issue because they simply did not know much about the issue; and it would take time to develop an understanding of it. How would a journalist know whether Flannery is wrong or not, unless they’ve studied the specific science or can consult someone knowledgeable?

    But you also do get the newspapers like Canada’s National Post, which has an agenda of pushing denialism.

    Comment by Holly Stick — 12 Oct 2007 @ 2:35 PM

  52. Question: Is the fact that the melt of Arctic sea ice has progressed faster than IPPC projects meaningful?

    If so, are not the IPCC projects possibly behind the curve?

    Comment by Stormy — 12 Oct 2007 @ 4:11 PM

  53. Stormy (52) — Yes and in my humble opinion, yes to your second question…

    Comment by David B. Benson — 12 Oct 2007 @ 4:23 PM

  54. Let’s use Lou Dobbs’ recent comment. “Some argue the science around global warming is questionable.” And in one fell swoop denialists gain equal standing in big media.

    Comment by Mark A. York — 12 Oct 2007 @ 4:49 PM

  55. Has Tim Flannery clarified which CO2 equivalent he was quoting in the light of these criticisms?
    (BTW, I ‘converted’ a strong AGW sceptic to an AGW believer by buying him Flannery’s book)

    Comment by Bob Clipperton (UK) — 13 Oct 2007 @ 10:28 AM

  56. Steve, I read that AlterNet piece and emailed the link to the Contributors here asking if they can check it. AlterNet’s thread is full of garbage. But the article looks unedited (unpaired quote marks so the reader can’t tell what’s a real quote; “Artic” [sic].

    I really want to see something better than that to support that story’s claims.

    Moulins the size of Niagra Falls?

    and this chunk is not checked by anyone for facts or punctuation:

    [a melt water lake 500 metres deep causing the glacier “to float on land. “These melt water rivers are lubricating the glacier…]

    I’d guess that’s the thickness of ice over top of the meltwater that’s below the ice. Can’t be as stated.

    I suspect gross failure of fact checking at AlterNet.

    Comment by Hank Roberts — 13 Oct 2007 @ 11:17 AM


    Comment by Hank Roberts — 13 Oct 2007 @ 12:17 PM

  58. Re: Nobel Prize (OT)

    Since IPCC got the Nobel Prize, I guess that means that all scientists contributing to the IPCC’s work were honoured. And of course that includes the people at RC. So congratulations to you!

    Although the political situation with respect to AGW seems as dismal as ever, I think this calls for a little celebration.

    Comment by Dick Veldkamp — 13 Oct 2007 @ 12:36 PM

  59. I want to confirm my understanding.

    Calculations of atmospheric GHG levels include assumptions about the lifetime of various greenhouse gases in the atmosphere. This value is decreased by the negative GWP of aerosols, not including their lifetimes but rather the assumption that pollution levels will continue high. If fossil fuel emissions are cleaned up more or less rapidly than assumed, this will change assumptions about atmospheric GHG levels.

    Comment by Karen Street — 13 Oct 2007 @ 1:29 PM

  60. Karen, the estimated ‘lifetime’ of the GHG changes, see the link I posted a few responses earlier.

    But that’s not because of changes in aerosols. The aerosols (some of them) reduce warming by reflecting incoming sunshine, so they’re a “minus sign” versus the GHG “plus sign” contribution — sulfates from burning high-sulfur diesel and coal, for example.

    They wash out within a few years — they have a shorter lifetime.

    But lifetime of sulfates doesn’t subtract from lifetime of greenhouse gases. The _effect_ of sulfates subtracts from the effect of the other at any particular point in time, but their lifetimes differ.

    Comment by Hank Roberts — 13 Oct 2007 @ 3:30 PM

  61. #52-53, Arctic is key, yet very little attention is given to present dramatically underestimated Polar Amplification effects. Imagine this, a vast new body of open sea water, still open, never yet filmed or reported in person, no human contact makes it detached as if this melt happened on Europa. “Out of sight out of mind” is more important to change, than presenting clashing scientific personalities, irrelevant they are, given that we have failed to measure the magnitude of this warming.

    Comment by wayne davidson — 13 Oct 2007 @ 4:07 PM

  62. An interesting perspective from our neighbor Venus:

    It would make sense that an anharmonic molecule would have broader absorption lines.

    Comment by Ray Ladbury — 13 Oct 2007 @ 4:52 PM

  63. Re 46 Lee Menningen
    To assert that so called “logical discrepancies” raised by skeptics never seem to be addressed, that no one has ever explained to you why “we must prevent the earth from warming”, or why the current warming trend isn’t just another harmless 200-yr cycle, or why the news a generation ago was constantly lamenting a cooling earth, or why it follows that “man” has to do something about it indicates that you have not been very thorough in your own research and reading.
    Apparently you have some work to do. I recommend you start here:

    Comment by Jim Eager — 13 Oct 2007 @ 5:14 PM

  64. Dick Veldkamp (#58) wrote:

    Re: Nobel Prize (OT)

    Since IPCC got the Nobel Prize, I guess that means that all scientists contributing to the IPCC’s work were honoured. And of course that includes the people at RC. So congratulations to you!

    Although the political situation with respect to AGW seems as dismal as ever, I think this calls for a little celebration.

    From what I have been reading the political situtation regarding climate change has improved a great deal – just not in the United States and a few other select countries. Countinental Europe? It gets taken seriously. Asia, Africa? For the most part it gets taken a great deal more seriously. United States? Not so much.

    But that will undoubtedly change. After a while.

    Comment by Timothy Chase — 13 Oct 2007 @ 5:46 PM

  65. Lee Menningen, Re:46, It would appear that my point was lost on you. I will spell it out: By embracing antiscience, conservatives have given a formidable weapon to their opponents. Al Gore has wielded that weapon to his advantage. Now, as we start to talk about mitigations and solutions, many conservatives–the ones I call the nutjobs–are still arguing about whether warming is occurring. They have left empty the place at the table where they could present their ideas and solutions. It would appear that either you have not been paying attention or you have some poor sources of information. However, the question of whether we are causing warming is now beyond debate. The conversation has moved on to what we should do about it. I would recommend using the resources on this site to come up to speed so you can discuss the situation intelligently.

    Oh, and re 42–have you ever even known a journalist?

    Comment by Ray Ladbury — 13 Oct 2007 @ 7:13 PM

  66. Re. #52, see Realclimate’s article covering the IPCC AR4 WG1 Summary for Policy Makers, which states:

    “For sea level rise the unknown is how large an effect dynamic shifts in the ice sheets will be. These dynamic changes have already been observed, but are outside the range of what the ice sheet models can deal with (see this previous discussion). That means that their contribution to sea level rise is rather uncertain, but with the uncertainty all on the side of making things worse (see this recent paper for an assessment ((Rahmstorf, Science 2007))).

    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.”

    So one would expect the IPCC sea level rise projections to be “behind the curve”, as you put it – it would be odd if they were not.

    Comment by Dave Rado — 13 Oct 2007 @ 7:16 PM

  67. Of course, the atmosphere doesn’t care whether the GHGs are emitted by humans or by nature responding to the initial warming humans are causing. If it were just a matter of humans reducing their emissions, we’d probably be more sure about being able to avoid a “tipping point.”

    However, if nature’s emissions in response to the current warming (including warming that’s already in the pipeline) are themselves slated to increase in a spiralling fashion, causing more warming, which causes more of nature’s emissions, which causes more warming and so on, then who knows, we may have already passed the tipping point, since CO2_e (Total — both from human emissions and positive feedback from nature) of more than 450 may be a done deal (for some point in the future) no matter how much we reduce. And then there’s the reducing albedo/warming positive feedback loop.

    The longer we wait to reduce our GHG emissions, the more it’s becoming a Russian roulette game with our life-support systems.

    Comment by Lynn Vincentnathan — 13 Oct 2007 @ 9:00 PM

  68. I’ve been a fan of both RC since it startyed, and Tim Flannery for even longer. Here in Australia his name is as recognisable as Gore’s on the subject of climate change but he has been a much bigger political thorn to John Howard.

    I also like the fact that RC will disagree with it’s supporters when they think their supporters have screwed up a technical point. I don’t have the patience to follow the math and attempt to judge who is technically correct, from my point of view both RC & Tim are credible scientific sources so I will wait for the IPCC.

    Quoting from the “implications” above – “It is even more of a stretch to state that we have all of a sudden gone past the ‘dangerous’ level“. Here I have equated “dangerous” to “tipping point” and if we are going to be subjective I’m putting my money on Tim since even the rabid doomsday alarmists grossly underestimated the recent extent of ice loss in the Artic.

    Comment by Alan — 13 Oct 2007 @ 9:02 PM

  69. Re 64 (Dick V)
    When you consider that each year: 4m die of malnutrition, 3m of HIV/Aids, 2m from lack of clean drinking water, I think you will find that those not living in a comfortable Western society have more immediate concerns. This IS happening NOW – not something predicted by computer models. How is it that these are all problems we could do so much more to address, but instead the international focus is on the more glamorous and popular priorities of Al Gore?

    Comment by PHE — 14 Oct 2007 @ 4:32 AM

  70. PHE, Your concern for the poor is touching. What have you done about it?
    Do you think that the poor will fare well in a warming world? The only place where I can think of where they have an advantage is Rio de Janiero and Salvador, where the favelas are on hills, while the expensive real estate is along the beach. Moreover, the way to help the poor is to facilitate growth in developing nations and poor regions within so-called developed nations. This growth will be derailed by climate change–which by the way IS happening NOW.

    If you would like a suggested itinerary for viewing the plight of the world’s poor, I can suggest travel tips.

    Comment by Ray Ladbury — 14 Oct 2007 @ 5:10 AM

  71. Some practical consequences of CO2 equivalence.
    1) methane flaring – either seeping from coal mines or perhaps 80% of the gas at an oil wellhead. Some carbon abatement schemes reward this flaring (note moles CO2 = moles CH4) but I think no GHGs at all is even better ie reinject rather than flare.
    2) nitrous oxide from fertilizer – rather than tax the farmer on N20 emissions I think it should be included in an upstream carbon equivalent cap or tax payable by the fertilizer manufacturer. This worsens the existing food vs fuel trade-off but it’s consistent.

    Comment by Johnno — 14 Oct 2007 @ 6:13 AM

  72. Just returning to one of the points made in the original posting : Quote “the full definition of CO2-eq concentration is lower and therefore 450 ppm CO2-eq (total) is still within reach while 450 CO2-eq (Kyoto-gasses only) is not”.

    1. Somehow we did get into a mode of thinking of stabilisation (UNFCCC calls for stabilisation; most model runs stabilise GHG concentrations). There is, however, a very reasonable alternative, i.e. peaking profiles that first “overshoot” an certain target, but further reduce concentrations after the peak is reached. There are already several papers published of authors showing the benefits of such strategies. Allowing for such overshoot implies that 450 is within reach both definitions.

    2. Given the fact that S/aerosols emissions are likely to be reduced (see e.g. comment 10) either for health/air pollution reasons and as a “co-benefit” (;-)) of climate policy implies that the two definitions will slowly converge over time. The CO2-eq (Kyoto) has “accididently” already accounted for the negative feedback of reducing S/aerosol impact; the more correct CO2-eq (total) definition has not. Therefore, the error made by Stern (using CO2-eq Kyoto for now; and CO2-eq total in the future), for instance, is less bad as it looks like from current forcing levels. Finally, according to (nearly) all scenarios of emission modellers in both cases we need to allow for overshoot to be able to get to 450 ppm CO2-eq (total) in the end. The reason is the inertia in reducing emissions.

    3. There are several scenarios published in literature that account for this – showing that 450 ppm CO2-eq is in reach, even including the removal of S/aerosols forcing – including an article we have published ourselves in Climatic Change earlier this year.

    P.S. The clear description of the CO2-eq concentration concept at the beginning of this post is pretty helpful. There is quite a bit of confusion on the CO2-eq concentrations (Kyoto vs. total) but also on CO2-eq concentrations vs. CO2-eq emissions. In recent IPCC discussions we decided to use W/m2 for forcing instead of ppm CO2-eq in order to avoid people (mistakingly!!!) using the arguments against the use of GWPs in CO2-eq emissions against the proposed forcing levels. There was a very obvious downside to this, however, as the group of people that had already got to know the meaning of certain CO2-eq concentration numbers (450 ppm co2-eq for instance) found themselves now in doubt on the corresponding W/m2 numbers.

    Comment by Detlef van Vuuren — 14 Oct 2007 @ 6:55 AM

  73. Off topic request:

    Gore’s film has been criticised by a UK court (don’t know how many scientists were attending). Most of the criticism is aimed at the way the information is framed but there are some items that appear to be at odds with the post on RC about the science in the film being being quite accurate.

    While I’m aware that RC does not usually concern itself with the political side of the debate, might some of the fact-based findings of the court (which found the film was broadly accurate) be worth a post?

    [Response: You can expect to see something from us on this very soon. – mike]

    Comment by barry — 14 Oct 2007 @ 7:08 AM

  74. Re #64 More pressing problems than AGW?

    We have no disagreement here. I think we should also address malnutrition, tropical diseases, lack of drinking water etc. But AGW will most probably makes all the aforementioned problems much worse, so we should be concerned about AGW as well.

    I don’t buy the Lomborg dichotomy, that we should choose between either solving AGW or the other problems. By the way, Lomborg is now acknowledging that AGW exists! But it’s just not serious, really, probably even a good thing.

    Comment by Dick Veldkamp — 14 Oct 2007 @ 7:26 AM

  75. re: 61

    I believe you are right, and that ice free arctic water in the summer is closer than you think.

    Taking the look at Cryosphere today, the ice has yet to recover significantly, and we are now at 3 million sq. km. below the long term average (off the bottom of the chart).

    Scientists are now whispering in the hallway (but not to the media) that we could have an ice free arctic by 2013. This will result in greater release of green house gasses by the melting of the permafrost, not to mention the possible release of methane-hydrates if the arctic ocean as it gets warmer.

    The denialists will still say this is part of normal varibility, and they will probably still say it even when half of Florida is under water.

    Comment by concerned — 14 Oct 2007 @ 7:29 AM

  76. Re 65 PHE: “How is it that these are all problems we could do so much more to address, but instead the international focus is on the more glamorous and popular priorities of Al Gore?”

    Why is it that you and your ilk, sir, continually attempt to portray the argument as an either or situation? You also seem to expect the public to conveniently ignore the fact that those in government and industry who take the lead in obfuscation on climate change are hardly leading the charge to address HIV/AIDS, malnutrition and drinking water. Seems like a classic case of deliberate misdirection to me.

    Comment by Jim Eager — 14 Oct 2007 @ 9:12 AM

  77. Re: 65
    I find that pitting one issue against another in this style, most popularised by Bjorn Lomborg, quite depressing.

    The fact of the matter is that the proposed solutions to many of the world’s problems would act synergistically.

    Contraction and convergence of CO2 emmissions would necessarily result in a redistribution of wealth from rich to poor nations. Furthermore the coupling of this transfer with tools to accelerate sustainable development, i.e. universal primary education, but specifically targeted at girls, and free access to birth control would result in a reduction of sexually transmitted diseases and a reduced fertility rate.

    To set up these problems against one another is to miss the point. It does allow us to dither. It is also quite something to hear the rich west go on about it when going on about it is pretty much all we have been doing for the last 50 years or so.

    Comment by Jody Aberdein — 14 Oct 2007 @ 9:31 AM

  78. Lee Menningen wrote: The “other” viewpoint should have equal prominence in the news, and I mean equal.

    No, when the “other” viewpoint is demonstrably objectively wrong, it should not be given “equal prominence in the news”.

    This is the case with the “viewpoint” that global warming is not happening, or is not caused by human activities, or is unlikely to have any serious negative consequences — it’s a “viewpoint” that is simply wrong, untrue, and incorrect. It is a “viewpoint” that should not be given any prominence in the news, except perhaps to note in passing that there remains a tiny group of people (some of them being paid propagandists for the fossil fuel industry and its political allies) who insist on denying the reality of anthropogenic global warming in spite of the overwhelming and utterly conclusive scientific evidence of its reality and its dangers.

    And yet this objectively wrong “viewpoint” is, in fact, often given equal or greater prominence in the “news” with the actual reality that global warming is happening, is caused by human activities, and is likely to have very serious negative consequences not only for the entire human species but for life on Earth.

    So, you are doubly wrong: what you are asking for is wrong; and you are also wrong to complain that you are not getting what you are asking for, since the “news” already gives unwarranted “prominence” to the objectively wrong viewpoint that you refer to.

    Comment by SecularAnimist — 14 Oct 2007 @ 9:39 AM

  79. This may be a repeat as the fist attempt didn’t go.

    Re: 69

    I find the pitting of these issues against one another, most popularised by Bjorn Lomborg, a depressing spectacle.

    Let us leave aside for the moment the exemplary behaviour of the richer nations in fighting the problems of food and water scarcity and the HIV pandemic. No doubt had climate change not hijacked the minds of the benevolent classes these issues would by now be consigned to history.

    The fact of the matter is that the solutions would happen to be rather synergistic.

    Contraction and convergence would by necessity result in a massive transfer of wealth from rich to poor nations.

    The decarbonization of society will by necessity result in improved public health, as we eat better and do more physical work.

    The sustainable development of poorer nations, paid for by this mechanism, primarily starting with universal primary education especially for girls, and freely accessible family planning, would result in great health advances, a reduced fertility rate, reduced population and therefore resource demands.

    The fact that we have pretty much failed to address these issues at least on one continent should be worrying in the face of climate change, because after all the brunt of the effects on disease, food supply, water supply, and land supply will be felt not by the rich but the poor.

    Comment by Jody Aberdein — 14 Oct 2007 @ 9:44 AM

  80. Re 75 concerned: “This will result in greater release of green house gasses by the melting of the permafrost…”

    It’s already happening. The closing segment on yesterday’s CBC Radio Quirks and Quarks science program was on permafrost melting.
    [2007-10-13 podcast mp3 file available here: ]

    In the segment, When The Permafrost is No Longer Permanent, physical geographer Dr. Scott Lamoureux of Queens University reports that annual average depth of permafrost melt on Canada’s Melville Island in the high Arctic has increased from aprox. 50 cm to over 1 meter in depth, leading to sloughing of entire hillsides. Plant biologist Dr. Merrit Turetsky of Michigan State University reports Increases in CO2 and methane off gassing have also been observed, although it turns out much of the CO2 is then taken up by new plant growth at the tundra surface.

    Comment by Jim Eager — 14 Oct 2007 @ 10:44 AM

  81. Jim Eager> Why is it that you and your ilk, sir, continually attempt to portray the argument as an either or situation?

    Probably because in reality, it is mostly either-or. Doubling (or more) the cost of electricity to mitigate AGW may be bearable for you personally, but for many it means no electricity at all in their shortened lifetime.

    I can understand questioning whether this is correct, but why do you (and others here) so question the sincerity of those of us who believe this?

    Comment by Steve Reynolds — 14 Oct 2007 @ 10:56 AM

  82. Steve Reynolds asked: “I can understand questioning whether this is correct, but why do you (and others here) so question the sincerity of those of us who believe this?”

    Steve, if someone brings up a concern for the poor whenever the need to mitigate climate change is mentioned, is it not fair to ask what they are doing to improve the lot of the poor in the absence of such mitigation? As I see no bold proposals coming from those most vocal in their protests, is it not fair to question their sincerity?
    In any case, the “choice” between development and climate change mitigation is a false dichotomy. If we concentrate on the latter at the cost of the former, poor nations will continue to grow in population and burn dirty fuels, spoiling our efforts. If we concentrate on development while ignoring climate change, the effects of climate change will frustrate our efforts. These are two sides of the same coin.

    Comment by Ray Ladbury — 14 Oct 2007 @ 1:18 PM

  83. #75, 2013? It all depends on this years refreeze, as an example from time immemorial, pack ice offers a reprieve from winds, facilitating freezing of its interspersed open water. If there is a wide open body of water, this refreeze is more difficult. there are winds, currents, tides and huge waves to overcome before the surface freezes, but there is also sea surface temperatures and its temperature profile from the surface downwards. In a wind storm mixing of the underlying water occurs. If it is much warmer than the air above this impedes
    the freeze up even further. Finally there is the cloud seeding biology factor,
    usually from creatures living under the ice cover, no ice no seeding production.
    2013 may not be too far off. So far I’ve seen near by sea water in relatively calm winds survive open even when temperatures dipped to -13 C (location 74 43N 94 57W). Whatever mini pack ice patches there was, freezing occurred in between the old ice cakes.

    But the question of when it wil the Arctic Ocean be wide open is not as important as to why it melted so fast this year. I suggest hot anticyclones
    as one of the reasons, the evidence about that seems quite clear. The long standing ongoing yearly momentum in a downward melting trend seems unstoppable.

    Comment by wayne davidson — 14 Oct 2007 @ 3:02 PM

  84. In economics there is a continual churning of prices. In the not so distant past I can remember buying gasoline for a $1.10 a gallon. It has more than doubled. Other things are cheaper, which is why there has been far less inflation than the doubling of a pervasive commodity in the economy might suggest would happen. The fact that other things are cheaper is a big reason why higher gasoline prices have not resulted in lower demand for gasoline.

    So it is not necessarily true that a doubling of electricity cost to mitigate AGW will have a negative impact on the overall economy. Nothing happens in isolation. There are robust economic opportunities – unless one is dumber than the rock Larry Kudlow is dumber than – in mitigating global warming.

    Comment by J.C.H. — 14 Oct 2007 @ 3:04 PM

  85. Re #73 AIT judged by UK Court – useful links

    A summary of the verdict is:
    1. The main claims of AIT are undisputed and solidly backed by science (curiously, all newspapers forgot to to mention this part)
    2. There’s a couple of details which are a little outside the consencus view.

    The New Scientist looked at the ‘errors’ in AIT:

    And Tim Lambert already wrote a good piece about the issue. See here:

    Comment by Dick Veldkamp — 14 Oct 2007 @ 3:15 PM

  86. Re 82 (Ray L). Al Gore is the one making the strongest arguments and winning the acolades. How does he demonstrate his sincerity? Carbon offsetting does not count. I agree with AGW compaigner and journalist George Monbiot on this – that it is the equivalent of the medieval buying of indulgences. If Gore can resist flying to Oslo to receive his Nobel prize in person, I would have a bit more respect for him. If he genuninely believes the threats he is claiming, it would be a powerful symbol to receive it by video link. Let’s see.

    Of course, a lot is being done to deal with problems in the developing world. But it seems the international establishment (with Oscars, Nobel prize, etc) is putting more emphasis on what is PREDICTED to happen sometime in the future than disasters of today. However much you accept AGW is real and happening today, the idea that impacts will be greater than today’s tragedies or natural disasters (of any time) is little more than speculation.

    Comment by PHE — 14 Oct 2007 @ 3:28 PM

  87. I’m sitting here in Africa frizzling away in higher and higher temps each year.
    It is my opinion that the powers that be – governments, the UN, the super wealthy, the world’s movers and shakers – WANT global warming, and they want it quickly and they are promoting, encouraging and advancing it.
    Why? OIL of course. The melting of the polar regions – north and south will open up huge oil reserves for easy access. The Northwest passage linking Asia and Europe has melted and is open for shipping. Shipping of OIL from the melting Siberian tundra oilfields….
    Media coverage is a pretence. I am sick to death of the northern hemisphere nations thinking they own the world and can mess it up at will.
    Thousands of scientists can sit and ponder the problem for the past decades and the decades to come. “At least we tried…” is what the govts will proclaim. The solution is simple: International laws need to be passed that will prohibit the use of gas guzzling, huge emitting vehicles to be manufactured; industry emissions must be cut to minimal – there are laws governing every aspect of our daily life. Why not to save our planet? People must be told – if you do not stop flying you will not have an earth to live on in 10 years time. Not 100 years time – not 50 years time. 10 years time… And if you don’t stop consuming like gobbling monsters you will wipe your one and only home, the earth, off the face of the universe.
    But above all – it does not take a thousand scientists to work out the most simple of all. It does not take a genius to arrive at the most easy solution. FORESTS. I will say it again – FORESTS. 24% of the earth’s surface used to be covered by forest. Not just rainforest – but all forest – arboreal, equatorial, arctic, etc. All that is left after our plunder and consumption is 6%. I will say it again – 6%. A fourth-grader knows that trees suck up carbon. No trees + more carbon = disaster. So simple solution – INTERNATIONAL LAW – NO MORE FOREST DESTRUCTION – PLANT MORE TREES. Every person, even those living on a suburban plot in a city must plant trees. Factories and industries must plant trees. USE EARTHWORM COMPOST TO FERTILISE THESE TREES (and get rid of waste at the same time in an ecologically mindful way). SIMPLE..
    Oh, and refreeze the arctic with liquid nitrogen (could this be done?????) Money and economics should not be an issue. Money is a man-made phenomenon, as is economics – money and what the cost would be cannot be of the slightest concern in this most dire calamity facing us.
    So, this sounds like unscientific claptrap? Well, I’m from Africa – what do I know?

    Comment by podwalker — 14 Oct 2007 @ 3:33 PM

  88. re post 83:- I have seen somewhere that 2 anti-AGW ‘experts’ advising in this case were Bob carter & prof ? Philip? Stott (london). I am trying to find out who put pro-AGW arguments.

    And re my earlier posts, back on topic, has Tim Flannery clearly stated which CO2 equivalent he used ? & Why, or has he conceded that he was not 100% correct?
    I just want to know the truth – having great respect for him and the RC team.

    Comment by Bob Clipperton (UK) — 14 Oct 2007 @ 3:52 PM

  89. Tim Flannery’s statement and statements in a similar vein from Al Gore that we need to “save the future of this civilization” – a direct quote – seem likely to push climate science from “important research” to abetting “hysteria.” At what point will the credibility of good people be ruined beyond repair by all of this.

    Comment by petefontana — 14 Oct 2007 @ 5:12 PM

  90. Ray Ladbury> Steve, if someone brings up a concern for the poor whenever the need to mitigate climate change is mentioned, is it not fair to ask what they are doing to improve the lot of the poor in the absence of such mitigation?


    Ray> As I see no bold proposals coming from those most vocal in their protests, is it not fair to question their sincerity?

    No. That assumes that the best solution will come from ‘bold proposals’. I see the people of China and India making faster progress in improving their lot than just about any people at any time in the history of the world. I can and do help them by investing in their development and buying their products.

    My (not so) bold proposal for the people of less rapidly developing areas (including our commenter from Africa) is to emulate China and India. My opinion is that involves massive reductions in government corruption.

    Ray> If we concentrate on development while ignoring climate change, the effects of climate change will frustrate our efforts.

    Maybe it is because I do not see AGW being quite the immediate crisis that many here do, I think there is time for the rapidly developing peoples to become rich enough to solve their pollution problems (and becoming rich appears to automatically solve population problems).

    I expect there are benefits to helping to educate the people of slowly developing nations (education is something difficult for a government to steal, and it reduces population growth).

    Comment by Steve Reynolds — 14 Oct 2007 @ 5:46 PM

  91. Re. #76, Jim Eager:

    You also seem to expect the public to conveniently ignore the fact that those in government and industry who take the lead in obfuscation on climate change are hardly leading the charge to address HIV/AIDS, malnutrition and drinking water. Seems like a classic case of deliberate misdirection to me.

    It’s even more hypocritical than that implies: the primary reason the US Government gave for not ratifying the Kyoto Protocol was precisely the fact that the protocol contained no target for developing countries to reduce their emissions. In other words, unless the poorest nations had to pay part of the price of tackling the problem from the very start of the agreement, the US wasn’t willing to pay any of it.

    See for example, Wikipedia, which states:

    “On July 25, 1997, before the Kyoto Protocol was finalized … the U.S. Senate unanimously passed by a 95–0 vote the Byrd-Hagel Resolution, which stated the sense of the Senate was that the United States should not be a signatory to any protocol that did not include binding targets and timetables for developing as well as industrialized nations” [The full text of the Byrd-Hagel Resolution is here].

    “The current President, George W. Bush, has indicated that he does not intend to submit the treaty for ratification, not because he does not support the Kyoto principles, but because of the exemption granted to China … Furthermore, the U.S. is concerned with broader exemptions of the treaty. For example, the U.S. does not support the split between Annex I [i.e. developed countries] countries and others [i.e. developing countries].”

    Comment by Dave Rado — 14 Oct 2007 @ 6:19 PM

  92. Nice post, and it’s nice to see the IPCC being recognized for their work despite the constant attacks they get from all sides. Keep in mind that they take the most conservative viewpoint, scientifically speaking.

    Journals and editors are busy and understaffed, but instead of jumping on IPCC leaks, they might instead want to spend more time looking at the recent scientific literature – which does attempt to address the issue of carbon cycle feedbacks, which seems to be the underlying theme here.

    Regarding CO2 equivalents usage: (quote) “There are two main ways it is used. Firstly, it is often used to group together all the forcings from the Kyoto greenhouse gases (CO2, CH4, N2O and CFCs), and secondly to group together all forcings (including ozone, sulphate aerosols, black carbon etc.). The first is simply a convenience, but the second is what matters to the planet. Many stabilisation scenarios, such as are being discussed in UNFCCC negotiations are based on stabilising total CO2_e at 450, 550 or 750 ppmv.”

    One point: due to the windows in the CO2 IR spectrum, can’t reducing the levels of some of the ‘window-filling’ gases have an effect that lies outside the “CO2 equivalents” notion? Thus, by reducing methane and nitrous oxide and CFC’s, we keep the CO2 windows open – an effect which is underestimated by the ‘CO2 equivalents’ measure?

    So, as I understand it the most recent IPCC report didn’t consider two issues due their uncertain nature: carbon-cycle feedbacks in a warming world, and ice-sheet dynamics. Hopefully they’ll attempt to address this in their new report. That might be something worth reporting on.

    Considering that in the past, CO2 and methane emissions have been triggered as a secondary effect of a warming planet, to what extent are we risking this under the above-mentioned stabilization scenarios? Do we really know at all? Considering the amount of carbon stored in permafrost and shallow sea sediments, and also considering the accelerating warming in the Arctic, and the potential for similar effects in the Antarctic, can we be sure these ‘stabilization scenarios’ would really be stable?

    Here are some news reports on papers addressing the carbon-cycle feedback effect:
    Melting Russian Permafrost Could Accelerate Global Warming, ENS 2006

    Polar ocean is sucking up less carbon dioxide, Nature News 2007

    This seems pretty important. Imagine if a 50% reduction in fossil fuel CO2 emissions had no effect on the rate of CO2 accumulation in the atmosphere due to a combination of ‘natural’ CO2 release and weakened CO2 sinks – that’s worrisome.

    Comment by Ike Solem — 14 Oct 2007 @ 6:29 PM

  93. OK, I see the need for a “CO2 equivalent”, but is CO2 itself all that simple to measure and simply report? It seems easy to just measure CO2 content at various places, but the concentration varies from place to place, with altitude and season, etc – Could someone give a primer on that, and also rebutt criticism from skeptics about a major CO2 monitoring station being near a Hawaiian volcano which often belches CO2, etc? Thanks.

    Comment by Neil Bates — 14 Oct 2007 @ 7:01 PM

  94. Re. #87, Bob Clipperton, the pro-AGW arguments were put by Peter Stott.

    Comment by Dave Rado — 14 Oct 2007 @ 8:03 PM

  95. I would like to offer congratulations to Tim Flannery for drawing attention to the importance of the contribution of fluorocarbons to rising global warming emissions. I eagerly await the Synthesis eport figures, but this really should come as no surprise as the IPCC established that halocarbons have been a very significant and rapidly growing slice of the emissions in 2005 – 13% relative to pre-industrial levels of greenhouse gases and 23% relative to 1970 levels – see below.

    Accumulation in the atmosphere of all refrigerants apart from CFCs are growing at alarming rates (see ), yet these very powerful greenhouse gases are much neglected in discussions of the causes and solutions of global warming.

    If the 20 year GWP timeframe for these gases were used (which is much more closely related to the atmospheric lifetimes of HCFC-22 and HFC-134a) the CO2-e values would be dramatically higher than currently accepted, and I would welcome some further comment from real climate on this issue.

    Huge opportunities exist to control the use and emissions of these dangerous gases by introducing an appropriate mix of polices to provide incentives for the development and uptake of technologies, and an effective carbon-equivalent price signal to create incentives to invest in low-GHG refrigeration and air conditioning products, technologies and processes, as recommended by the IPCC. Ammonia, carbon dioxide and hydrocarbons offer a wide range of solutions to reduce HCFC and HFC emissions, and there need to be much great efforts taken worldwide to reclaim the existing refrigerant bank.

    Much greater attention to these issues is urgently required from all stakeholders in the climate change debate.

    Brent Hoare

    [from p.25 of the Technical Summary of the IPCC Special Report on Safeguarding the Ozone Layer and the Global Climate System Issues related to Hydrofluorocarbons and Perfluorocarbons, 2005]

    2.4 How much do the halocarbon gases and their replacements contribute to positive radiative forcing of the climate system relative to 1970?

    The direct radiative forcing due to increases in halocarbons from 1970 to 2000 was 0.27 0.03 W m2, which represents about 23% of that due to increases in all of the well-mixed GHGs. The contribution to direct radiative forcing due to HCFCs is presently dominated by HCFC-22, while that due to HFCs is dominated by HFC-134a and HFC-23, with the latter being emitted mainly as a byproduct of manufacture of HCFC-22. [1.1, 1.5] 10

    Comment by Brent Hoare — 14 Oct 2007 @ 8:07 PM

  96. petefontana, re 88. What do you suppose will happen in a world with 11 billion people if we lose the ability to grow wheat? Potatos? What if precipitation becomes unpredictable and falls predominantly in destructive, impulsive events? What if it does not fall at all for years in many places? Ask Australian farmers about their futures.
    All of human civilization has evolved during the past 10000 years–a time of exceptional climatic stability. Remove that stability, and do you think that will be a boon to that civilization. There is an old saying: If you can keep you head when all around you are afraid, you probably don’t understand the situation.

    Comment by Ray Ladbury — 14 Oct 2007 @ 8:13 PM

  97. Tim Flannery’s statement and statements in a similar vein from Al Gore that we need to “save the future of this civilization” – a direct quote – seem likely to push climate science from “important research” to abetting “hysteria.” At what point will the credibility of good people be ruined beyond repair by all of this.

    petefontana, I realize this is off topic, and I understand if this post doesn’t make it to the board. I’ve been lurking here on and off for a while and over at other blogs so I can get a handle on the history and basis of this whole debate that should be past debate. I can understand the frustration people here feel with the politicization of the science. Politicization of an issue so fraught with economic interests and implications is inevitable and unavoidable. It’s the reality we face.

    Policy analysis is my profession and I can tell you that developing policy is maddeningly complicated and hair-pullingly frustrating. I compile (I don’t do it) the research; I have a sense of what should be done based on the research, but then the politics, resources, competing interests, etc., come into play and affect the policy process. Ultimately, if it isn’t in “the plan”, if it isn’t part of “the vision” – of the party in power or the administration – and no matter how convinced the analysts might be based on the science, it doesn’t matter what the science says. The politicians have the final say in what gets written.

    Conversely, if it is in the vision, it’s possible to twist the research to say what you want it to say or support whatever policy you want to put forward. Argh! I’ve seen both happen in my time.

    Part of me doesn’t like to see scientsts become politically active because then they lose a certain aura of objectivity and that adds an additional layer of complexity to the whole process. It’s also painful to see scientists used as pawns in a game they might not completely comprehend. That said, I can appreciate that scientists are citizens and have concerns based on the research they are conducting. I also don’t like to see laypeople get the science wrong and overstate case, for that also affects the policy process and political will and just adds to the aura of uncertainty. Earnest laypeople with an incomplete understanding of the science can throw a spanner in the works, so to speak.

    Policy makers need the very best unbiased science at hand in order to take us from the science to the best most effective policies and legislation and then on to the implementation and enforcement.

    Ultimately, if there is no political will, all the best most objective science will go nowhere. That’s what some are working to accomplish. Kill the political will that might exist already and/or prevent it from materializing.

    Comment by Surly — 14 Oct 2007 @ 8:32 PM

  98. Re. #91, Neil Bates.

    The Hawaiian volcano is covered on Gristmill.

    I’m not sure how the global mean concentration is calculated though.

    Comment by Dave Rado — 14 Oct 2007 @ 8:41 PM

  99. Man, is it going to get hot in the next 200 years. Once those landmasses start heating up, combined with the sea level rise and co2 levels that will keep those feverish temps in place, e don’t stand much of a chance. I personally believe both the ocean currents will stop and the ice shelf will fall into the ocean, you people are way too optimistic. The globe is warming, and we are in big, big trouble.

    Comment by PaulM — 14 Oct 2007 @ 9:25 PM

  100. A major point which appears not much commented on is most of the GHG equivalent consists of gases with relatively short atmospheric lifetimes. Thus their effect diminishes with time. This is caught in GHG potential over specific time periods, which captures both the IR activity of a gas and its atmospheric lifetime. For example, quoting from the Wikipedia on greenhouse gases:

    “Methane has an atmospheric lifetime of 12 ± 3 years and a GWP of 62 over 20 years, 23 over 100 years and 7 over 500 years. The decrease in GWP associated with longer times is associated with the fact that the methane is degraded to water and CO2 by chemical reactions in the atmosphere.”

    Comment by Eli Rabett — 14 Oct 2007 @ 9:51 PM

  101. There is a very long and important monograph which describes how volcanic and other effects were dealt with (and shown to be minimal in any case) and Mauna Loa. Unfortunately this has disappeared from the net when it was published (I think in the Journal of Climate), but an image is available via the wayback machine. You can find a description of the publications here

    Comment by Eli Rabett — 14 Oct 2007 @ 10:04 PM

  102. Sorry, the link to the wayback machine image here

    Comment by Eli Rabett — 14 Oct 2007 @ 10:07 PM

  103. Congrats to the IPCC contributors here on the Nobel — I wanted to say this earlier but the site was unreachable for a while, which I hope means a lot of people were trying to get there.

    Predictably, in Australia, we are already seeing letters in the press saying the Nobel was not deserved. HOWEVER: The Australian’s letters page in the same edition includes not one bit two corrections of a letter claiming that the recent adjustment of long-term US temperature data showed global warming wasn’t happening. This is a new one: The Australian is usually happy to let factual errors favouring the denial cause stand:

    Anyone up for nominating the denial crowd for an Ig Nobel ?

    Comment by Philip Machanick — 14 Oct 2007 @ 10:23 PM

  104. Re. #91, Neil Bates and the excellent responses by Dave Rado and Eli Rabett.

    A week and a half ago I was on the summit of Mauna Kea looking across to Mauna Loa and the location of the Mauna Loa Observatory. I, too, was wondering about the impact of eruptions on their measurements. But the observatory is at elevation of 3400 meters on the northern flank of Mauna Loa ( 4169 meters), and the eruptions of the past few decades have been on the south side of Mauna Loa and below 1000 meters. And the trade winds normally blow strongly from west to east, so the vast majority of emissions from the eruptions do not reach the observatory.

    Yes, there are some CO2 emissions from the summit caldera of Mauna Loa, but as seen from the articles referenced by Dave Rado and Eli Rabett, the observatory is well aware of them and have taken that into consideration in their measurements. Of course, when Mauna Loa erupts again from its summit, all bets are off.

    Comment by Jim Eaton — 15 Oct 2007 @ 12:41 AM

  105. Surly and Ray Ladbury, thanks. In my not so spectacular doctoral studies, I took away one thing of value. – It was this, science is special. The practice of it is wonderful and almost noble. I would rather die honest, than live crooked.

    Comment by petefontana — 15 Oct 2007 @ 12:51 AM

  106. Re:- #87 & #92
    I deliberately put question marks before ‘Stott’ because I know there are several scientists in the UK of that name*. Unfortunately, I can’t recall where I saw that a Stott was advising on the anti-AGW case so I assumed it was Phillip Stott –

    If this was the case, it must have been confusing for the judge – a case of Stott vs Stott.

    * I think there is another scientist ‘Stott’ in Reading University besides the 2 mentioned here.

    Comment by Bob Clipperton (UK) — 15 Oct 2007 @ 3:58 AM

  107. An outcry from Africa (#86) and nobody responds. Are we able to listen to others and response to their suggestions? What about the discrepancy between the view of podwalker (#86) and the alleged helpful growth proposal of Ray Ladbury (#70)? Will growth really cure the problems? (See for instance AR4 WG3 Chap. 1 Fig. 5 and the paper by Raupach et al. PNAS 104, 10288-10293 2007 who equate CO2 emissions growth to GDP and population growth and showed that true decabonization of growing economies still lack to be demonstrated.) And what if those who we are pretending to help with our cure oppose it? Wouldn’t it be better to ask them first?
    I think all of the propositions of podwalker are worth to be considered (with the exception of the liquid nitrogen freezing the polar Arctic Ocean).

    Comment by Helmut Wolf — 15 Oct 2007 @ 5:06 AM

  108. Bob Clipperton
    It’s even more confusing than this! P Stott and P Stott are on opposite sides of the debate. The only way to tell them apart is to realize that Peter Stott is a climatologist and knows what he is talking about, and Phillip Stott doesn’t.

    Comment by san quintin — 15 Oct 2007 @ 5:54 AM

  109. #104 Bob Clipperton,

    I think the Stott at Reading University may be the same Stott as at the Hadley Centre. Reading has a large meteorology & climate section, and has close ties with the Met Office (and thus the Hadley Centre). This was especially true when the two were just down the road from each other. However I apologise to both if I’m wrong.

    Comment by Adam — 15 Oct 2007 @ 6:32 AM

  110. [[Doubling (or more) the cost of electricity to mitigate AGW may be bearable for you personally, but for many it means no electricity at all in their shortened lifetime.]]

    Who in the world is proposing doubling the cost of electricity? Where did you get that idea?

    Comment by Barton Paul Levenson — 15 Oct 2007 @ 6:37 AM

  111. What is the net forcing in MJ integrated across the planet and over 100 years of 1000kg CO2 emitted today.

    Comment by John Carter — 15 Oct 2007 @ 7:03 AM

  112. Group, the Hansen et al paper referred to in post 39 above I have now read, thanks to the poster. For a non-expert like me it is difficult keeping up to date but I try, and reading RC every week helps me do that. Thanks to the Group and all (yes, all) posters.

    The paper was up dated in march 2007 : have there been any further developments since that date which are likely to significantly impact on the comments in section 6 or elsewhere in that paper, please? If you dont feel able to respond could you point me in the right direction please.

    Comment by Eachran — 15 Oct 2007 @ 8:47 AM

  113. Surly and Ray Ladbury, thanks. In my not so spectacular doctoral studies, I took away one thing of value. – It was this, science is special. The practice of it is wonderful and almost noble. I would rather die honest, than live crooked.

    Pete Fontana, in my similarly non-spectacular doctoral studies, I came to realize that there are a few honest politicians and a few dishonest scientists. The former make me feel my job is worth doing while the latter make us all knock our heads against walls.

    Comment by Surly — 15 Oct 2007 @ 9:00 AM

  114. RE # 69 & “When you consider that each year: 4m die of malnutrition…”

    Aside from the point some of that malnutrition is from lower crop yield due to global warming even now….

    The bigger point for me at least is that through GW we are NOW killing people now and well into the future. Some of our today’s emissions may last in the atmosphere up to 100,000 years in the future.

    When people die from natural causes, naturally occuring droughts & storms & disease vectors, and from their unwise behavior that’s only a sin of omission on our part (IF we could have prevented that). But anthropogenic global warming is fully a sin of commission.

    And victims of harms feel much more indignation if the harm has been caused by people rather than nature – even when the harm is at the same level.

    What we need is a victim-oriented (& you’d think policy-maker) approach (of avoiding harms from global warming) to balance out the scientific approach (of avoiding false claims about global warming happening & causing harms).

    Comment by Lynn Vincentnathan — 15 Oct 2007 @ 9:22 AM

  115. Just for my own enlighenment. the formula for CO2-e as given above as
    Total Forcing = 5.35 log(CO2_e/CO2_orig)
    where CO2_orig is the 1750 concentration (278 ppmv).

    This is equal to F= 5.35(lnCO2-e lnCO2-orig)

    In other words we’re subtracting the amount of CO2 in the atmosphere at the start of the industrial era,(278ppm)from the present, which is taken at the zero point as far as forcing is concerned. So what we are computing is the radiative forcing since the preindusrial period.
    I suppose this is done because the systems( carbon exchange between ocean and atmosphere et al) were pretty much in balance until this time.

    Comment by Lawrence Brown — 15 Oct 2007 @ 9:23 AM

  116. Lawrence Brown, Don’t forget the logarithms–they’re important. The subtraction of the logarithm just means we are interested in the incremental heating, which is what WE have contributed.

    Comment by Ray Ladbury — 15 Oct 2007 @ 9:46 AM

  117. Surly and petefontana, Since we all share the distinction of undistinguished doctoral studies, I thought I’d share, too. My wife worked for a while for a certain agency that is concerned with environmental quality. One day her boss was in despair over the fact that the 800 page report he was compiling would just be ignored by the political hacks making policy. My wife, ever the practical type, said, “It’s not our job to tell the politicians what to do. It’s our job to do the science so that when the politicians fail to do what’s right, the government gets sued and the proper policies get put in place.”
    It is extremely unfortunate that people continue to think that they can spin physical reality to their liking. What is even more unfortunate is that where risk is concerned, an unknown risk is of at least as much concern as a high risk. Risk management and science often have opposite tendencies. Science tends to state its conclusions conservatively. However, uncertainty with regard to the effects of climate change is not our friend here. Until we can reduce the uncertainty, it is prudent to assume that the worst case CAN occur.

    Comment by Ray Ladbury — 15 Oct 2007 @ 10:01 AM

  118. Re 81 Steve Reynolds: “I can understand questioning whether this is correct, but why do you (and others here) so question the sincerity of those of us who believe this?”

    Because I have seen this disingenuous, false dichotomy tactic used over and over in any number of public policy debates, almost always by those with an agenda that has nothing what ever to do with the alternatives put forth. Because, as Ray wrote, global climate change is happening NOW, and because it can only exacerbate the disruption, misery and death caused by HIV/AIDS, malnutrition and lack of potable water.

    Comment by Jim Eager — 15 Oct 2007 @ 10:53 AM

  119. I’d like to see another “total” — some total that would take into account the forcings over the entire life-time of my various GHG emissions (which would take into account the lifetimes of the different GHGs, including their breakdown molecules — since I understand methane breaks down into CO2 + other things). Of course, the negative forcings (& their lifetimes) should be included.

    So, for instance, using coal-based electricity or driving a petroleum ICE car, all the emissions entailed in, say using a KWH of electricity or burning a gallon of gasoline,and those leading to various positive (& negative) forcings on into the future up to their lifetimes in the atmosphere.

    Comment by Lynn Vincentnathan — 15 Oct 2007 @ 11:09 AM

  120. Steve Reynolds wrote: “Doubling (or more) the cost of electricity to mitigate AGW may be bearable for you personally, but for many it means no electricity at all in their shortened lifetime.”

    What in the world are you talking about? I buy 100 percent wind-generated electricity through my local utility company (PEPCO) in Maryland — not “wind credits” or “offsets” but actual wind-generated electricity supplied to PEPCO through the regional grid, by wind-turbine facilities in the mid-Atlantic region. And the price is nowhere near “double” the price of PEPCO’s “standard” mix which is about 80 percent coal-generated. The price of GHG-free wind-generated electricity is at most about 5 or 10 percent more than the predominantly fossil-fuel based electricity.

    And in the developing world which you claim to be so concerned about, many people in rural areas have no chance at all of ever getting electricity from large, centralized coal or nuclear powered generators, precisely because the cost of building a distribution grid to deliver the electricity is prohibitive. Instead, many of them are turning to small-scale (household or village scale) electricity generation with photovoltaics and wind. That’s why these technologies are growing worldwide at double-digit rates every year — there is a huge and hungry market for them in the developing world. They are the great hope for rural electrification in the developing word — a need that large-scale fossil fuel and nuclear electricity generation cannot meet.

    I submit that tossing about phrases like “double the cost of electricity” is exactly the sort of baseless scare-mongering that global warming deniers so often accuse global warming mitigation activists of engaging in.

    Comment by SecularAnimist — 15 Oct 2007 @ 12:35 PM

  121. Gavin,

    Have you seen this WSJ article on so-called albedo enhancment? I wonder what fashionable blog they’re referring to?

    What is to be blamed for global warming?
    Since the 1980s, man-made emissions of greenhouse gases have been designated as the principal culprit, especially CO2 emitted by the burning of coal and petroleum products.

    Numerous measures have been proposed to reduce these emissions. And since climate change does not stop at national borders, European governments, the United Nations and more recently the United States have tried to establish world-wide emission goals by organizing a cavalcade of international conferences — from the 1997 Kyoto conference to an upcoming convention in Bali.

    Yet no binding agreement has been reached on reducing global CO2 levels, let alone on the means to assure compliance. Decades into this debate, we have neither widely agreed-upon limits on future greenhouse gas emissions nor the administrative capabilities to implement such limits. Moreover, climate scientists warn that emission controls alone may not stabilize the climate.

    Is there anything that can be done?

    Actually, there is. One approach rarely discussed at global warming conferences is to develop capabilities for increasing the fraction of sunlight that is reflected outward by the upper atmosphere back into space. This approach is called “climate geo-engineering.” Expressed in terms of the metaphor of the “greenhouse effect,” it would work like this: Geo-engineering would put a “parasol” over the greenhouse to deflect 1% or 2% of the sunlight that now affects the Earth. Scattering this small fraction into space would reduce global warming. In the language of climate science, we would increase by a few percent the Earth’s “albedo” — the ratio of incoming sunlight reflected back into space relative to the total inbound from the sun.

    We know it would work because it happens naturally all the time. Clouds routinely deflect sunlight and thereby cool the Earth. Volcanoes — when they erupt and inject millions of tons of fine particulate material into the stratosphere (mostly sulfate aerosols) — have also cooled large regions of the globe. Mount Pinatubo in the Philippines erupted in 1991 and cooled most of the Earth for a few years, erasing for a short time roughly half of the global warming that took place during the entire 20th century.

    The idea of artificially increasing the Earth’s albedo is not new. In 1992, a report by the National Academy of Sciences found the prospect of stratospheric albedo enhancement “feasible, economical, and capable.” And there are a great many geo-engineering options apart from adding sulfate aerosols into the stratosphere.

    But beware. Do not try to sell climate geo-engineering to committed enemies of fossil fuels. Although several geo-engineering options appear to be highly cost-effective, ideological opposition to them is often fierce. Fashionable blogs are replete with conspiracy theories and misinformed attacks. Because of this intimidating opposition, no serious geo-engineering research programs have been started. And without some small-scale tests, not enough data will be available to assess the benefits, cost and possible harmful side effects of such approaches.

    Much could be learned about this other half of the global warming picture with a tiny fraction of the funds that have been allocated to climate-change studies focused on greenhouse gas emissions. Those who now oppose climate geo-engineering should understand that none of the suggested options is meant to be a free-standing, long-term solution to global warming. If the greenhouse effect continued to increase, the geo-engineering measures would not only have to be maintained indefinitely but also be gradually augmented to keep pace. Moreover, accumulating CO2 in the atmosphere would make the oceans harmfully acidic over the next few centuries.

    Clearly, we need both: adequately explored geo-engineering options for contingent climate stabilization, and truly effective, practical measures to reduce emissions of greenhouse gases.

    Mankind’s current energy system evolved during the 20th century as an offspring of the Industrial Revolution. It may take almost as long to replace this system with the novel energy sources and distribution networks that future generations will need. This huge transition would be greatly facilitated if geo-engineering options are developed and tested to provide a safe breathing space without a massive global-warming crisis.

    Mr. Iklé, an undersecretary of defense policy for President Ronald Reagan, is with the Center for Strategic & International Studies. Mr. Wood, a research fellow at the Hoover Institution, is affiliated with the Lawrence Livermore National Laboratory and Intellectual Ventures LLC. A version of this article will be published in the January issue of The National Interest.

    Comment by Mark A. York — 15 Oct 2007 @ 1:15 PM

  122. Re #120: [And in the developing world which you claim to be so concerned about, many people in rural areas have no chance at all of ever getting electricity from large, centralized coal or nuclear powered generators…]

    In regards to this, see this neat invention, the wind belt:

    Comment by James — 15 Oct 2007 @ 1:21 PM

  123. SecularAnimist> The price of GHG-free wind-generated electricity is at most about 5 or 10 percent more than the predominantly fossil-fuel based electricity.

    I’m interested in understanding your calculation. Can you provide more details (like the actual price you pay, are subsidies being paid, tax breaks included…).

    Also, are you really buying 100% wind generated electricity? Do they turn off your power when the wind stops?

    I’m all in favor of using wind energy, but I suspect that using it for more than a small percentage of the total load is not practical without very expensive energy storage.
    Good sites also seem to be in short supply.

    Comment by Steve Reynolds — 15 Oct 2007 @ 1:22 PM

  124. Re #99, no we are not as yet in big big trouble. If we at a forcing of 375 ppmv overall then that gives us some time to avert the dreaded 2 C threshold into long term positive climate feedbacks that could destabalise earths systems enough to cause humankind some serious issues.

    I doubt we are going to die out through climate change. I believe that 400 ppmv gives us a range of possibilities of upto 2C as a maximum. A more likle rise though is around 1 C for 400 ppmv which is probably 10 years away. 450 ppmv gives a range of 1.4 to 3 degrees with 2C being quite likely but this is a further 25 years away and hence we still have time to make the necessary changes.

    I personally am troubles by these time frames and I doubt that we ca avoid 2C to be fair but we do have the time to do it.

    Comment by pete best — 15 Oct 2007 @ 1:29 PM

  125. Maybe slightly off topic, but just a quick point regarding comments about the possibility of an ‘ice-free’ Arctic in the near future. (I’m assuming that we mean ice-free in the summer, by the way, at least to start with) There’s a fair bit of submarine ice offshore and by the coast of Canada and Alaska, and I presume likewise off the coast of Russia/on the other side of the ocean. I’m not sure what data there are on how deeply buried under sediment it is, but recalling a lecture some years back the ice itself is many metres thick, and there’s lots of it. Does anyone have info./modelling on how this ice is going to react or behave as the Arctic Ocean starts to absorb more heat, following melting of the surface ice?

    Comment by Nick O. — 15 Oct 2007 @ 1:32 PM

  126. Secular Animist,
    The developing world doesn’t need the same infrastructure as we’ve grown up with: no wired networks for phone and electric, no gas piping network. It’s the future there because it’s cheap and reliable. Maybe someday it will be our future here.
    How much energy could America save by turning off parking lot lighting and signage in strip malls when the businesses are closed? Motion detectors could turn on the lights when prowlers arrive. Police will quickly see where their presence is required. Good security and saving energy at the same time.
    OT warning
    60 Minutes had a segment about the incredible construction boom in Dubai. It’s all at sea level. I guess they don’t believe in Climate Change or the possibility of rapid sea level rise. I hope they are right.

    Comment by catman306 — 15 Oct 2007 @ 1:37 PM

  127. What about the trillions of watts of pure excess heat that mankind creates?

    I figure that even if all power generation is converted to nuclear or some other ‘clean’ form, we still would increase heat energy output. I know it’s less than energy received from the sun, but GW is all about margins, no?

    Comment by Markus — 15 Oct 2007 @ 2:20 PM

  128. Thank you Mr Helmut Wolf (107) for acknowledging my existence, (and giving credence to my views), whilst the rest of the posts pretended I wasn’t here…. This enforces my points entirely!!

    Comment by podwalker — 15 Oct 2007 @ 2:31 PM

  129. Re 123 Steve Reynolds: “I’m interested in understanding your calculation. Can you provide more details (like the actual price you pay, are subsidies being paid, tax breaks included…”

    You mean like the subsidies, tax breaks and limits on liability available to the coal, oil and nuclear industries?

    Comment by Jim Eager — 15 Oct 2007 @ 3:20 PM

  130. Re: 116 Ray says,”The subtraction of the logarithm just means we are interested in the incremental heating, which is what WE have contributed.”

    This is my point. I suppose this is splitting hairs, but this is a Delta F(incremental since the beginning of the industrial era) and not a total F.
    BTW I left out the minus sign in the equation F=5.35(lnCO2-e-lnCO2-orig).

    Comment by Lawrence Brown — 15 Oct 2007 @ 3:35 PM

  131. podwalker >…whilst the rest of the posts pretended I wasn’t here….

    My post #90 did acknowledge you in passing, but since it was ‘held for moderation’ for most of a day, you probably missed it.

    Also, from a previous post of mine:
    Interesting African take on mitigation vs. adaptation:

    Comment by Steve Reynolds — 15 Oct 2007 @ 4:27 PM

  132. Re 127 Markus

    All humans added together are a 200-400 GW heat source, and considering that we have reduced the biomass of other heat producing animals, the net effect is negligible. Nevertheless, some fancy highly insulated buildings can be heated purely by the people living in them.

    Comment by Carl — 15 Oct 2007 @ 5:08 PM

  133. RE: 121 I agree with most of what Lowell Wood said. However, I don’t think that blogs, including realclimate have had anything to do with the lack of funding of geoengineering projects.

    In this country, at least, nothing significant will happen on funding of geoengineering and GHG reduction strategies until the next administration unless congress decides to do something on its own.

    I will say that I have been unhappy with the way in which knowlegeable scientists seem eager and willing to be quoted about the the hazards of stratospheric aerosol enhancement to the extent that they exaggerate the potential problems. Since they know better, this has to be assumed to be deliberate.

    Examples: telling ABC News that use of the aerosol strategy would be like Mt. Tambora’s eruption. Tambora was at least 10X greater than Pinatubo, the model being considered for a man-made program. Telling reporters that the ozone layer would be destroyed and everyone would die. Or saying the sky would turn grey and we would all suffer depression. And never failing to bring up acid rain when they know it really isn’t a problem.

    There are issues to be addressed with regard to effects on the hydrological cycle, unilateral action, program continuity and the general concern that geo is a distraction. I discussed some of these issues in a response at John Tierney’s NY Times blog recently in comments 127 and 136 there:

    I don’t think realclimate is guilty of this kind of distorted reporting, mainly because it is a blog and the comments allow for a wide variety of views to be expressed. But this blog gets about 3000 visits a day and the news articles get a lot more. So what I would ask of the science media is that when you offer up a quote like the ones noted previously, ask yourself, is this really true? Just how realistic is this? Otherwise, people might get the idea you guys ARE biased against geoengineering.

    Comment by Alvia Gaskill — 15 Oct 2007 @ 5:43 PM

  134. This may be a little off topic however I feel it warrants some comment from someone with credibility. It is regarding Dr William Gray’s response to Al Gore’s Nobel peace prize.

    The following artical is one of the most viewed:

    With stories like this circulating, sadly, I cannot see any hope of a groundswell of public opinion occuring (which is required to effectively deal with this problem)

    Comment by Lawrence McLean — 15 Oct 2007 @ 7:07 PM

  135. First, an interesting comment by Paul Krugman on Al Gore’s Nobel Prize, and the lack of recognition of this achievement by the worst of your press, and the hatred of Gore by those on the right of the political spectrum. See “The Gore Derangement Syndrome”

    Secondly, I despair when it is proposed that part of the supposed solution to global warming could be geoengineering. There is only one sane solution to global warming, an immediate and substantial cut in global warming emissions until they are quickly brought down to about 10% of what emit now. The reason that this is the only sane solution is that, as these pages demonstrate, our knowledge of our planet, its climate and its atmosphere, its energy balance, is pathetically inadequate – we surmise a lot, but we truly know almost nothing. If humanity can’t get its act together to deal with the relatively simple matter of reducing CO2 emissions, then how on earth is it conceivable that humanity is wise and clever enough to interfere further with the natural function of our planet, the only one we have, without doing even more damage? And once we have started, how are we going to stop?

    How stupid can humanity be? We know that over many millions of years that the Earth will, if left to its own devices, control its own biosphere so as to be receptive to life. Lovelock’s Gaia theory tells us this. Why would humanity suppose that we could do any better? It’s literally crazy, to take on responsibility for the continued health of our planet, for ever, for a monstrous cost, when, if we leave the Earth to its own devices, it will do an infinitely better job, and for free.

    Comment by John Monro — 15 Oct 2007 @ 7:59 PM

  136. It is extremely unfortunate that people continue to think that they can spin physical reality to their liking. What is even more unfortunate is that where risk is concerned, an unknown risk is of at least as much concern as a high risk. Risk management and science often have opposite tendencies. Science tends to state its conclusions conservatively. However, uncertainty with regard to the effects of climate change is not our friend here. Until we can reduce the uncertainty, it is prudent to assume that the worst case CAN occur.

    Ray Ladbury, I concur. I apologize for posting political comments, but nothing infuriates me more than political spin especially about such far reaching issues as global warming. I mean, I don’t mind if politicians spin their last trip to the Bahamas, although it disgusts me, but spinning global warming?

    Where I live, the economy is currently booming due to fossil fuel development. There are policy people who know what’s what but it’s hard for politicians to resist raking in the petro dollars and encouraging greater development. It adds to the coffers, allows them to pay down debt, increase spending, give tax cuts, and that always looks good to the voters. We also live in a very energy dependent area of the country due to the weather and with all that fossil fuel available, governments have been slow to develop alternatives or consider ways of reducing GHG emissions. I don’t see much of anything happening to really address global warming or reduce GHG production.

    Policy hacks — believe me, most of us got into it with rose-coloured glasses, thinking we would be part of making the world better, using our education in order to develop and implement public policy. Afer a few years, that myth is whittled away as the political bottom line (getting re-elected) trumps research. I guess thats why I’m so surly.

    Political will — that’s the key. Only when politicans feel that they will be kicked out unless they act effectively, will the political will materialize. Hopefully at that point, the policy wonks will have the best research and evidence at hand so they can develop effective policy and programs.

    Comment by Surly — 15 Oct 2007 @ 8:07 PM

  137. For the last two years I have been trying to get one of the talk show “global warming naysayers” to agree to have an expert on their show to “debate” the global warming issue. John Zigler, the radio talk show host claims: “I fear nothing. There are no experts on your side that will come on. Like GOre, they are all cowards”. I am trying to get in touch with someone on this website who is willing to on with John Zigler see

    I would say he has a sizable audience. I found his arguments to be rather lame but he believes he knows the subject. (we have had perhaps 20 communications) He has had many naysayers on his show in the past including a few month’s ago Senator Inhofe.

    If there is someone with good credentials (and a thick skin) who wishes to go on his show please contact me. You would have an opportunity to speak to a very large audience and perhaps change a few minds.

    Waqidi Falicoff

    Comment by Waqidi Falicoff — 15 Oct 2007 @ 8:52 PM

  138. Lawrence McLean, thanks for the link. The problem is twofold – first with Gray’s statement:
    “[He] said a natural cycle of ocean water temperatures – related to the amount of salt in ocean water – was responsible for the global warming that he acknowledges has taken place.”

    It’s hard to tell what Gray was trying to say, or whether the reporter garbled the statement. Was Gray claiming that there was an increased northward flow of warm water from the tropics towards the poles? Actual current measurements indicate that such transport (in the Atlantic) has slowed somewhat.

    As has been said many times, there is natural internal variability in ocean heat content and other climate variables – but that variability is superimposed on a steady warming trend. The “AMO (atlantic mutidecadal oscillation)” explanation for increased sea surface temperatures as the cause of more hurricane activity hasn’t held up too well.

    The second problem was with the news reporter who filed the story, Steve Lytte. Even if this reporter didn’t know much about the topic (in which case he really shouldn’t be reporting on the topic), there are many many prominent climate scientists that he could have contacted for a rebuttal to that statement – yet he didn’t.

    In fact, what kind of a ‘reporter’ is Steve Lytte? Try a google search for his name – the only thing that comes up is that one story! (which was reposted to about a hundred different websites). How does a one-time reporter with no previous background manage to get into the pages of the Sydney Morning Herald? Apparently this is the first story that Mr Lytte has ever written! That’s very odd indeed.

    Comment by Ike Solem — 15 Oct 2007 @ 9:06 PM

  139. Well Alvia Gaskill perhaps if the authors didn’t phrase their thesis in the form of the usual ad hominem one could take them more seriously? Beware of anyone offering pie-in-the-sky star wars style solutions to ground level problems. Especially from a Star Wars proponent! It reminds me of many of my carpentry problems. If only I had a skyhook. Tierney isn’t exactly known for his great understanding of science either. He’s a political opinion writer with no discernable appeal to authority of any kind.

    Comment by Mark A. York — 15 Oct 2007 @ 10:07 PM

  140. just a correction to the name of the talk show host challenging me to come up with a global warming expert to debate him on his show: It should be spelled John Ziegler.

    Comment by Waqidi Falicoff — 15 Oct 2007 @ 10:29 PM

  141. All trees aren’t created equal — at least not in their effect on global warming. Almost any other ground cover reflects more than do trees, and of course, anything that obstructs snow cover will actually contribute to global warming. Only in the tropics do trees grow fast enough and sequester enough carbon to offset their effective decrease in albedo.

    With careful choices, the boundaries can probably be shifted a little, but hardly materially.

    Comment by Dan G — 15 Oct 2007 @ 10:38 PM

  142. RE: 138 The Gray Lecture

    A little digging around and you find that Steve Lyttle’s (not Lytte) story was written for the Charlotte Observer. Gray’s talk was at UNC-Charlotte last week. One of his former students is a meteorology professor there. That explains how he got to Charlotte.

    News stories as you probably know get printed and reprinted and reprinted again. Read the news on Google or Yahoo and then watch the news on TV. In many cases, it’s identical copy taken from the AP or NY Times, etc. That explains how the article wound up in the conservative Australian paper. The Charlotte Observer had already archived the article, so the search engines take you to a page that says article not found.

    Why make William Gray into the default contradictor of Al Gore? Because “the media” needs to show the “other side.” It is actually heartening that Gray was about the only non think tank person they could dredge up to complain about Gore getting the award. Most likely it was just fortuitous he was giving a talk the same day the award was announced.

    Media Matters referencing realclimate, made note of the fact that while Gray may still be regarded as a hurricane predictor, his theories on ocean currents causing warming are not considered credible.

    However, MSNBC seemed to find it necessary to show how “good” Gray’s predictions have been this year, apparently to justify their reference to him as a “top meteorologist.”

    RE: 139 Knocking on Wood, Tierney Credibility

    I think I understand Lowell Wood’s complaint. The bloggers he refers to have pretty much beaten up geo, but they aren’t scientists and have largely drawn upon the-you guessed it- news articles panning the ideas.

    Wood also has some baggage leftover from Star Wars–$62 billion and where are the space lasers, and his connection to a right wing think tank. But that doesn’t make his ideas or geo in general a loser. Evaluate the idea, not the man. I thought it remarkable that the Wall Street Journal would even publish the first paragraph stating that AGW was real.

    The Washington Times ran a short piece about a week ago referencing Dave Schnare’s testimony before the Sen. Envir. and Public Works Committee in which he advocated solar radiation management to prevent destruction of the Chesapeake Bay from AGW.

    So little, by little, the right wing folks, at least the ones with any sense are coming around to the idea that the war against saying AGW is real has been lost. For them, geo is a possible way out of real emissions reductions. But I don’t think it will work out that way. If geo is to be used, either the giant fund I envision will have to be created or other substantive steps will be taken concurrently.

    I don’t understand what John Tierney’s scientific credentials have to do with him raising the issue of geo. The responses came from a variety of people including an NAS member.

    Comment by Alvia Gaskill — 15 Oct 2007 @ 10:45 PM

  143. Re #141: [Almost any other ground cover reflects more than do trees, and of course, anything that obstructs snow cover will actually contribute to global warming.]

    I think I’m missing something in that. Trees obstruct snow cover? How so? What I see is just the opposite: trees break the wind, and cause snow that’s blown off open meadows to be deposited under them. Then in spring the snow remains under trees long after it’s melted from the open meadows.

    Comment by James — 15 Oct 2007 @ 11:22 PM

  144. Re 127 Markus

    All humans added together are a 200-400 GW heat source, and considering that we have reduced the biomass of other heat producing animals, the net effect is negligible. Nevertheless, some fancy highly insulated buildings can be heated purely by the people living in them.

    Comment by Carl

    Carl, wasn’t Markus referring to the extra heat added to the planet’s environment by our burning of fossil fuels? Do we know that number? Is that heat energy used in climate modeling?

    Guesstimating, your figure looks good 100 w/person X 6.5 Billion = 650 Gw

    Comment by catman306 — 16 Oct 2007 @ 7:12 AM

  145. The current estimate is that the world’s population consumes about 400–420 exajoules per year, of which 388 exajoules is from fossil fuels.

    Comment by David B. Benson — 16 Oct 2007 @ 1:43 PM

  146. Thanks, David B. Benson. So, perhaps, 90% of ‘human caused heat’ comes from fossil fuels and the remainder from photosynthesis. That is not encouraging from the standpoint of sustainability for our civilization.

    Comment by catman306 — 16 Oct 2007 @ 3:31 PM

  147. The remainder is from all other sources. The top three are hydropower, nuclear and burning wood or other biomass. Small amounts are obtained from geothermal, wind, tides, etc.

    Comment by David B. Benson — 16 Oct 2007 @ 4:09 PM

  148. James, the main place where trees are replacing snow-covered ground is the Arctic, where warming is letting conifers survive farther and farther north. In an area where there are deciduous trees, the snow melts off about as fast in leafless forest as in open fields. In an area that used to be open tundra that stayed snow-covered, replacement by evergreens reduces the overall longterm albedo significantly. That’s where this change makes a difference that matters.

    Comment by Hank Roberts — 16 Oct 2007 @ 5:16 PM

  149. Re:#143 — James, a more appropriate way of looking at it might be to examine a coniferous forest — how much sun is going to actually reach the snow? Imagine black-and-white photos of a meadow and a forest. In any case, Google “afforestation and albedo” and you’ll find that every entry seems to corroborate the fact that despite all the myriad influences and feedbacks involved, warming results from afforestation due to reduced albedo at any but tropical areas, although temperate forests may be considered neutral. At its crudest evaluation (yes or no), 50 degrees latitude seems to be the line: any afforestation beyond is quite strongly warming, anything nearer to the equater slowly becomes cooling in effect due to a variety of reactions which overcome the reduction in albedo.

    This is not to diminish the other effects of trees and forests which play on biodiversity, different rainfall patterns and water flow, etc.. But as a definite contributor to global cooling, the applicable vegetation is restricted to a pretty narrow band around the equator. Sigh!

    Comment by Dan G — 16 Oct 2007 @ 6:44 PM

  150. [[I’m all in favor of using wind energy, but I suspect that using it for more than a small percentage of the total load is not practical without very expensive energy storage.
    Good sites also seem to be in short supply.

    I understand that Denmark is now getting 16% of its electricity from wind turbines. That might be something to check out. Clearly, they are coping with the problems in some fashion.

    Comment by Barton Paul Levenson — 17 Oct 2007 @ 7:27 AM

  151. #147 David Benson, I’m not trying to be argumentative here, but burning wood and biomass derive their energy from photosynthesis, wind and hydro energy come directly from solar energy.
    Out of the solar radiation loop: nuclear, tidal, geothermal, but tidal and geothermal get at least part of their energy from solar gravitational energy.

    Comment by catman306 — 17 Oct 2007 @ 7:38 AM

  152. Re #149: [At its crudest evaluation (yes or no), 50 degrees latitude seems to be the line: any afforestation beyond is quite strongly warming, anything nearer to the equater slowly becomes cooling…]

    I’ll atmit that most of my experience of forests are of those below 50 degrees. However, I’d argue that most of the area that could be reforested (or revegetated, such as prairie grasslands) does lie below 50 degrees.

    Comment by James — 17 Oct 2007 @ 12:11 PM

  153. catman306 (151) — Geothermal obtains at most an insignificant fraction from anything but the internal (nuclear derived) heat inside the earth.

    I would of said that tidal derives its energy by slowing the earth’s rotation a tiny bit.

    Comment by David B. Benson — 17 Oct 2007 @ 12:45 PM

  154. David B. Benson,
    In addition to the radiogenic energy, the inner regions of Earth also derive a significant amount of energy from condensation of the liquid outer core onto the solid inner core. This energy is very important in generating the geomagnetic field. Not sure how it relates to the geothermal energy flux at the surface.

    Comment by Ray Ladbury — 17 Oct 2007 @ 2:02 PM

  155. Since trees absorb carbon dioxide and give off oxygen, they are essential for combating the global warming effect being created by excess carbon dioxide generation. Since they retain water in the soil and transpire moisture into the air, they are—in part—responsible for the ongoing existence of many springs, the even flow of rivers, and the formation of rain clouds. Since their innumerable roots hold soil in place and their bodies block wind, they are the best of all means for stopping erosion. Indeed, since they continually pull nutrients from the subsoils and drop organic matter to the earth, they are unparalleled soil builders as well.

    But that isn’t all. Consider that:
    A single mature tree absorbs around 13 pounds of carbon dioxide a year, while a younger, actively growing tree may absorb up to 26 pounds of CO 2 , per year—approximately five tons per acre of trees.

    Whether as a family project or an individual one, the point is to plant!

    About half of the weight of any tree is carbon. To maximize the amount of carbon dioxide absorbed, trees should be planted that gain weight the fastest. Depending on the trees’ densities, these may or may not be the same ones that gain diameter the fastest. Some common trees that “bulk up” quickly (in various parts of the country) include river birch, sycamore, tulip poplar, willow oak, red maple (commercial varieties), green ash, and black gum. In the South, try lobolly pine; in the West, Douglas fir; and in the Deep South and the tropics, leucaena. If in doubt, plant any native species that generally do well locally.

    Reducing atmospheric CO 2 , through tree planting costs about 0.3 ¢ to 1.3 ¢ per pound. Doing the same thing, by improving the energy efficiency of appliances costs about 2.5 ¢ for each pound of CO 2 ; and by improving electrical supply efficiency, about 10 ¢ per pound. While tree planting can make a significant contribution to reducing CO 2 buildup, it won’t solve the problem, not unless we all turn into Johnny Appleseeds. For it to do so, we would have to replant all the planet’s deforested areas—or double the growth rate of existing forests—to compensate for humanity’s excess carbon dioxide production. It’s been estimated that a typical family of four would need to plant six acres of trees to offset its CO 2 generation.

    In many locations, the cooling effects of trees can be more important than their ability to absorb carbon. Using landscape trees to shade buildings (and thus decrease the need for air-conditioning) results in CO 2 , emission reductions that are 15 times as great as the amount of the trees alone can absorb. Indeed, shade trees on the south and west sides of a house can lower its air-conditioning bills by up to half.

    Cities are particularly important locales for new tree-planting efforts. All that concrete and asphalt creates a “heat island” that makes cities 5° to 9° warmer than surrounding areas, so the cooling effects of trees can be especially helpful. The American Forestry Association estimates that there are 100 million tree-planting sites available. Planting them all would reduce carbon dioxide emissions from energy production by about 18 million tons per year and save consumers $4 billion each year in energy costs. (
    Perhaps you should all start thinking on a different branch?
    Posted by : the ignored one

    Comment by podwalker — 18 Oct 2007 @ 6:47 AM

  156. Re #155: […trees should be planted that gain weight the fastest.]

    I’d disagree slightly with that, and a couple of other points. I spent this past weekend taking down several of the cottonwood trees planted by a previous owner. They’re a fast-growing tree (some of the annual growth rings are nearly an inch across), but use lots of water. They grow fast, but often die fast, as these did. Slower-growing, less water-hungry species would have been a better choice.

    I’d also suggest broadening the selection of species simply to avoid the problems that come with monocultures.

    I concur with the benefits re A/C and heating. In a climate (east side of the Sierra Nevada mountains) where hot summers are common, a combination of deciduous shade trees and good insulation has meant that I’ve never needed air conditioning, unlike most of my neighbors.

    Comment by James — 18 Oct 2007 @ 10:51 AM

  157. podwalker (155) says, “…A single mature tree absorbs around 13 pounds of carbon dioxide a year… actively growing tree… up to 26 pounds of CO2 a year… ”

    While the thought is good, the problem is that tree absorption is piddly. One gallon of gasoline driving somebody ~20 miles puts out a little less than 20 lbs of CO2, That’s somebody’s short RT commute for one day.

    Others: I fail to see how the reduced albedo from the trees growing in the Arctic is hardly measurable, let alone a problem. A small percentage of the reflecting surface may be going away, but the solar radiation is coming in at a big obtuse angle, and we’re talking about 30watts/m^2 reflecting off the entire surface to begin with. So the reduced Arctic albedo is going to cut it to what, 29.99watts?? That’s magnitudes outside the error of measurement of albedo.

    Which reminds me, I still can’t fathom why a little global warming warms the poles greatly and cools the tropics. Makes no sense, if you omit the Rube Goldberg school of climatology. But I’m working on it.

    Comment by Rod B — 18 Oct 2007 @ 8:22 PM

  158. Re #155: [A single mature tree absorbs around 13 pounds of carbon dioxide a year, while a younger, actively growing tree may absorb up to 26 pounds of CO2…]

    I would think it would have to be quite a bit more than that. For instance, a quick back-of-the-envelope calculation on the ones I had to take down: about 3 ft at the base, roughly 100 ft tall, which gives about 500 cubic ft per tree (remember that the root system is about the same size as the above-ground part). Figure the dry wood is a little less dense than water, say 50 lbs/cubic foot, or 12.5 tons per tree. Wood’s mostly cellulose, C6H10O5, so about 40% of that is carbon, about 5 tons. Since the trees are about 40 years old, that gives about 250 lbs of carbon per tree per year.

    Feel free to check my math, of course :-) Then remember there’s the annual crop of leaves that get raked up and turned to compost…

    Comment by James — 19 Oct 2007 @ 12:47 AM

  159. Rod B. posts:

    [[I still can’t fathom why a little global warming warms the poles greatly and cools the tropics]]

    It doesn’t cool the tropics. It just warms them less than the poles.

    Comment by Barton Paul Levenson — 19 Oct 2007 @ 7:04 AM

  160. Rod B., I hope you have read the discussion of polar amplification here:

    Remember our discussions of thermal radiation. If radiation is not absorbed by the surface, it is reflected back out into space as visible light, to which the atmosphere is transparent/inert. It is only when the light is absorbed and goes into heating the surface that energy is changed into IR and greenhouse mechanisms are accelerated.
    The energy budget in polar regions is so impoverished, that small changes make a big difference. I would imagine that the lower temperatures at the pole decrease energy transport as latent heat and so increase the importance of radiation as a transport mechanism. Somebody pleas correct me if I’m wrong.

    Comment by Ray Ladbury — 19 Oct 2007 @ 9:20 AM

  161. James, here’s a post [edited] from an earlier Friday Roundup thread (I don’t know how to just show the link…).

    Rod B Says:
    16 September 2007 at 5:10 PM
    re 230: Forest Guardians (in the offset business) say the average tree weighs less than a ton at maturity, which they take as 100 years, so has sequestered 1/2ton (300-350kg to use their exact calculus) of carbon over 100 years, though their math seems a bit funny in places.
    [ ]

    [INSERT: that would put the average mature tree at one to 1-1/2 tons total weight. Other sources say about the same thing. That makes your estimate 10x too much. But even at that, the rest of your calculations would put absorbtion of carbon at 25 lbs/yr, or about 100 lbs of CO2 — still piddly though.]

    Makes Ike’s point even more pronounced.

    But something doesn’t seem right. One acre of corn (~10,000 plants) will sequester about 2500kg of carbon in one year, which is ~8 times what the average tree will sequester in 100 years. Seems funny. Any comments or insights?

    Comment by Rod B — 19 Oct 2007 @ 11:33 AM

  162. Re 161: [Forest Guardians (in the offset business) say the average tree weighs less than a ton at maturity, which they take as 100 years…]

    I admit that I’ve never weighed a tree, but I have cut, hauled, and stacked a lot of firewood in my time. If they think an average tree weighs less than a ton, they must have included a lot of bonsai in their calculations :-)

    Likewise with the period to maturity for cottonwoods: I know the previous owner bought this house about 1965, and planted the trees sometime thereafter, which gives about 40 years (and a rough count of growth rings matches) to attain 3+ ft diameter. It’s true that these are cottonwoods, which are among the fastest-growing trees in temperate areas, but still…

    Comment by James — 19 Oct 2007 @ 12:50 PM

  163. I though CO2 reached 380 ppm in 2005 and has been rising ~2 ppm annually. This would suggest about 385 now.

    Comment by Mike Alexander — 19 Oct 2007 @ 1:07 PM

    Looks as though current CO2 level is about 384 ppm

    Comment by Rick Brown — 19 Oct 2007 @ 1:57 PM

  165. :
    “Photosynthesis accounts for 98% of the world’s atmospheric oxygen, while the breakup of water molecules by ultraviolet radiation composes the other 1-2%.
    The sources of atmospheric oxygen through photosynthesis are cyanobacteria and plankton in the ocean, and trees on land. The amount of atmospheric oxygen that each source contributes is under debate: some scientists suggest that over half of the world’s atmospheric oxygen comes from oceans, for example, while others put the number at closer to one third…”

    So – the carbon absorbed by trees is ‘piddly’?(157 Rod B). Is the oxygen they release for us to breathe also ‘piddly’? Or don’t we need that either? Am I missing something here? Am I merely an ignorant treehugger muttering nonsense? If there was 24% forest earth coverage that is now down to 6% – are you telling me this has made no difference, whatsoever to the amount of CO2 in the atmosphere? Is that what you are saying? Please, I would really like to know.
    Have a look at :

    Comment by podwalker — 21 Oct 2007 @ 9:57 AM

  166. And more : from :

    How can trees help fight air pollution?

    * Vegetation purifies the air by removing gaseous pollutants by absorbing them through pores in the leaf surface.
    * Particulate pollution is trapped and filtered by leaves, stems and twigs, and is washed to the ground by rainfall.
    * Trees absorb carbon dioxide – the main greenhouse gas. One acre of trees can absorb as much as 4 tons of carbon dioxide a year, the same amount as a car driven 26,000 miles.
    * Trees save energy. Shade trees reduce air-conditioning needs up to 50%. Reduced energy use means reduced energy production and associated pollution.
    * Trees store carbon dioxide and produce enough oxygen from one acre for 18 people every day. “”

    Are all these people lying ??

    Or are all the scientists ignoring these facts because it too easy a solution??

    Comment by podwalker — 21 Oct 2007 @ 10:09 AM

  167. No, those people aren’t lying, though without cites I can’t say their numbers are right and neither can you. But you can look them up.

    No, all the scientists are not ignoring this.
    No, the scientists are not ignoring ths.
    No, it is not too easy a solution.

    Look, you can be as wrong as a treehugger as you can be as a coalburner. It’s not what you love, it’s how well you do math and read cites and understand footnotes that will advance what you know.

    Have you had a college ecology course? (It’d be an advanced level biology course as an undergrad). Have you had the intro geology course?

    If so you’ve got a basis for reading up on biogeochemical cycling; if you can’t find the text online post back and ask, or ask your local reference librarian.

    Short answer — don’t believe me, look into this. You can look at the total amount of coal, versus the total amount of vegetation, and the amount of CO2 in the atmosphere before the carboniferous period. You can’t plant enough trees to soak up all that carbon if it’s burned, unless you also have a way to put the trees back into deep sediments and make them back into coal.

    Yes it’s very important to reforest, revegetate, restore ecosystems. Topsoil loss exceeds tree loss overall, and may hold more carbon longer if we can get it restored.

    I’m working on restoring a mountain site that had a foot of topsoil a century and more ago. Before it was first logged. Before the big fires after the logging. Before the late 1800s when sheep grazing ate back everything that lived on the topsoil and it started seriously washing away. The river below this site has thirty feet of debris in its bed. All that came off the surrounding mountains. This is nothing unusual. The Midwest lost far more, down to the Gulf of Mexico, and it’s still happening everywhere.

    Plenty of work to do in this regard. Nobody’s ignoring it.

    Comment by Hank Roberts — 21 Oct 2007 @ 10:50 AM

  168. Podwalker, I don’t think that people are against growing trees, but they are emphasizing that it is at best a partial solution. Yes, trees store carbon, but they either grow fairly slowly (e.g. hardwoods) or they have relatively short lifetimes. Moreover, they do give off ghgs–some with a higher potential for warming than CO2–when they decay and at night when they consume rather than store energy. Moreover, the prospect of having to grow gigatons of trees indefinitely is not sustainable.
    As H. L. Mencken said: “Explanations exist: they have existed for all times, for there is always an easy solution to every problem — neat, plausible and wrong.”
    In this case, I would substitute “partial” for “wrong”. Don’t get me wrong, I believe in planting trees. I’ve planted hundreds in the past few years.

    BTW, where in Africa are you from. I spent a couple of years in Togo.

    Comment by Ray Ladbury — 21 Oct 2007 @ 11:09 AM

  169. I can’t verify any of my figures; I was just quoting mostly Forest Guardians who, being in the carbon credit business, you wouldn’t seem would underestimate the carbon that trees absorb. Though, as I said, the numbers seem screwy, especially compared to what corn is estimated to absorb. On the other hand, piddly being a relative term, post #166 was not impressive from this regard: one acre of trees takes care of two average-mileaged cars’ CO2 per year, at your assumed absorption rate (which I can’t refute). This means that a little less than 25% of the US land area needs to be in trees just to absorb the CO2 from passanger vehicles (cars, SUVs, PUs, etc.) Though I’m kinda with you — it just doesn’t sound right.

    I have nothing against trees. Most of your points on their benefits are right on. But, as they say here: math is math and science is science.

    Comment by Rod B — 21 Oct 2007 @ 11:40 AM

  170. Thank you for explanations. By the way – they are not my figures or calculations – these refs are from the quoted websites. I am truly an ignorant, concerned treehugger – I am not being facetious or sarcastic in my questions. Now I know – trees cannot be the only solution. Thanks again.

    Comment by podwalker — 21 Oct 2007 @ 2:47 PM

  171. Podwalker, I’ve worked to conserve forests my whole adult life, think that trees are very fine things indeed and there are lots of reasons to plant more of them. However, they do not provide the oxygen we breathe. Someone can correct me on the fine details, but it goes something like this: The 20% of the atmosphere that is O2 is the result of many millions of years of accumulation of photosynthetic products in sediments and ultimately in geologic formations, mostly as diffuse kerogen, less as fossil fuels. Trees provided some of that photosynthetic product, but aquatic microorganisms provided much more. Relative to the large pool of O2 in the atmosphere, the annual fluxes between the biosphere and atmosphere are tiny and essentially in balance, i.e., as much organic matter is oxidized as is produced. The amount of photosynthate that goes to the sediments is tinier still and it is only the slow accumulation of this material that adds oxygen to the atmosphere. Photosynthesis would have to be shut down for a very, very long time before any reduction in atmospheric O2 could be detected. (See, for instance,

    Rod B, the best estimates I’ve seen are that for the period from about 1952 to 1992, forests in the U.S. sequestered an amount of carbon equal to about 20-25% of U.S. fossil-fuel emissions for that period. Because emissions increased and forest dynamics changed (primarily maturation of forests that began growing on abandoned farms starting in the 1930s), by 2000 the off-set was probably more like 10% and estimates going forward to 2050 are that it will be about 15%. Not nearly enough to solve our problems, but not trivial either. (I think some of this is available online at and I can come up with additional cites if folks want them.)

    Hope this helps.

    Comment by Rick Brown — 21 Oct 2007 @ 3:16 PM

  172. Thanks, Rick. In the context you describe I would agree it is not trivial; nor is it stupendous. But from the context of much ballyhoo like, “Plant a tree and save the planet!” it is much over-hyped.

    Comment by Rod B — 21 Oct 2007 @ 9:35 PM

  173. Thanks again. My concern is that no-one is going to do anything really significant about cutting emissions. Not Mr Citizen, not governments, not industry. My thoughts were if this is the case, perhaps we could do something positively significant to counteract the emissions, even in a small way. I guess not….

    Comment by podwalker — 22 Oct 2007 @ 9:36 AM

  174. podwalker,
    There is a low we can do–and planting trees is probably a part of the equation–just not all of it. At a minimum, trees sequester carbon for a finite time, and buying time may be essential to developing other solutions. I suspect there is no “answer” to our current predicament. It will take effort on a lot of fronts to create a truly sustainable economy.

    Comment by Ray Ladbury — 22 Oct 2007 @ 10:03 AM

  175. Podwalker, you’re talking nonsense. Someone’s fed you discouragement and it’s bogus.

    You can look this stuff up.

    If you’ve believed someone who tells you there’s no hope, most likely you’re reading the PR sites funded by the fossil fuel industry. _They_ leaped from “no proof” to “no problem” to “no hope” without an intervening period of giving a damn about making any effort. That’s advertising puffery public relations.

    Seriously, make an effort. Let me just suggest a few pointers, and you can certainly find more with a minimum of effort. And you can visit any public library, talk to the reference librarian and ask for help finding more.

    From the library:
    Dodging a Warming Bullet — Berardelli 2007 (305): 1 — ScienceNOW
    Dodging a Warming Bullet. By Phil Berardelli ScienceNOW Daily News … 191 countries to curb CFC emissions from sources such as refrigeration, dry cleaning, …

    Comment by Hank Roberts — 22 Oct 2007 @ 10:51 AM

  176. Re # 171 Rick Brown: Trees and photosynthesis

    I think you need to go back and re-read the reference you cited. At the risk of introducting my own errors, let me try to clarify some of your points:

    1. “The 20% of the atmosphere that is O2 is the result of many millions of years of accumulation of photosynthetic products in sediments and ultimately in geologic formations, mostly as diffuse kerogen, less as fossil fuels.”
    Ummm…no. The “accumulation of photosynthetic products” represents the sequestration of phytoplankton biomass in the deep sea sediments. This chemically-bound oxygen is removed from the biogeochemical oxygen cycle. The oxygen gas (O2) in the atmosphere and dissolved in the ocean was produced by early photosynthetic cyanobacteria, starting around 2.4 billion years ago (the so-called the Great Oxidation Event) – oxygen levels rose quickly, until organisms carrying out aerobic cell respiration became abundant, around 1.9 billion years ago.

    2. “Trees provided some of that photosynthetic product, but aquatic microorganisms provided much more. ”
    Mmm…no again. According to the most recent figures I’ve seen (admittedly 10 years old: Field et al. 1998, Science 281: 237-240., trees provide nearly half of the annual terrestrial net primary productivity – i.e., adding oxgen to the atmosphere – with rain forest trees performing the bulk of that; grasslands and cultivated regions provide most of the remainder. Oceanic primary productivity is somewhat less than 50% of the total global net primary production (~ 40-45%), most of that carried out by phytoplankton, primarily cyanobacteria.

    3.”Relative to the large pool of O2 in the atmosphere, the annual fluxes between the biosphere and atmosphere are tiny and essentially in balance, i.e., as much organic matter is oxidized as is produced.”

    I don’t have any data to contradict that, but I think your point is better made by stating that the photosynthetic production of oxygen is essentially in balance with the metabolic consumption of oxygen by aerobic respiration (geochemical oxidation-reduction processes play a minor role in adding or removing oxygen from the ocean-atmosphere pool).

    4. “the amount of photosynthate that goes to the sediments is tinier still and it is only the slow accumulation of this material that adds oxygen to the atmosphere.”
    Again, this process does not add oxygen to the atmosphere – it removes chemically- bound oxygen from the biogeochemical cycle. You need to differentiate between photosynthetic biomass (consisting of carbohydrates, proteins, lipids, etc, all of which contain bound oxygen) and photosynthetic oxygen production (= O2 gas released to the environment).

    5. “Photosynthesis would have to be shut down for a very, very long time before any reduction in atmospheric O2 could be detected.”
    Assume that net primary production adds 105 petagrams of oxygen to the atmosphere each year, and respiration and other oxygen-consuming processes extract an equal quantity of oxygen each year. The pool of oxygen in the atmosphere is about 37,000 petagrams, with another 0.4 petagrams of dissolved oxygen in the atmosphere (according to the web site you cited). Eliminating photosynthesis but keeping respiration rates constant means that the 37,000.4 petagrams of available oxygen would last about 352 years; the enormous quantities of chemically-bound sequestered in sedimentary rocks would likely not change. That is not a particularly long time.

    If I have made some incorrect assumpions, or math errors, please correct me.

    Comment by Chuck Booth — 23 Oct 2007 @ 1:59 PM

  177. > Eliminating photosynthesis but keeping respiration rates constant
    > … available oxygen would last about 352 years …

    See Peter Ward’s “Under a Green Sky” — he’s describing work with sediments across the several ‘great extinction’ periods in terms of changes in the location of downwelling ocean circulation — resulting in changing the temperature, and so the oxygen content, of the deep ocean.

    One abstract here,

    If you’re in New York:
    Monday, November 19, 2007, 7:30 PM Rose Center for Earth and Space

    Comment by Hank Roberts — 23 Oct 2007 @ 2:35 PM

  178. Hank Roberts (#177) wrote:

    See Peter Ward’s “Under a Green Sky” …

    If you’re in New York:
    Monday, November 19, 2007, 7:30 PM Rose Center for Earth and Space

    I can’t get to New York, but maybe he will give something like that in Seattle at some point…

    Comment by Timothy Chase — 23 Oct 2007 @ 3:14 PM

  179. All this talk about trees, reminds me of what one of our leaders had to say about trees several decades ago. Remember this one “trees cause more pollution than automobiles do.”- Ronald Reagan, August 1980-

    Maybe that’s what Dubya was talking about when he said Saddam had WMD. Anyhow, Reagan’s statement emphasizes that the most important thing we can do come next November,regarding AGW is to choose our leadership carefully. We don’t need people at the top who make a mockery of this very serious issue and potential looming crisis.

    Comment by Lawrence Brown — 23 Oct 2007 @ 4:17 PM

  180. Re # 176 My comment about (hypothetically) eliminating photosynthesis:

    In the absence of photsynthetic oxygen production the rates of oxygen consumption by respiration would almost certainly decline exponentially as available oxygen declined, and so oxygen might last for much longer than 352 years. On the other hand, by the time environmental oxygen levels are reduced by ~50% of normal, many aerobic organisms will be suffering,and some will die off. I think the major point here is life on earth depends on the plants, algae, and bacteria carrying out photosynthesis, and we should take great pains to assure their survival.

    Comment by Chuck Booth — 23 Oct 2007 @ 6:07 PM

  181. Timothy, Dr. Ward is at UW and you’ve missed a handful of his presentations locally; I’m sure there will be others. Google …

    Comment by Hank Roberts — 23 Oct 2007 @ 6:50 PM

  182. Chuck wrote
    > rates of oxygen consumption by respiration would almost
    > certainly decline

    This is the mistake that caused Biosphere II to fail. They were in a hurry, so they didn’t take time to build up proper soil profiles by bringing in first mineral soil, then topsoil, then duff and leaf litter.

    They went out and hauled in truckloads of topsoil and filled their entire soil profiles with topsoil that was mostly live, respiring microorganisms.

    Those died. Result, lots and lots of oxygen lost to carbon dioxide as the dying soil organisms oxidized. Level of CO2 went, well, not through the roof since the roof was airtight — it got quite bad.

    This mistake about topsoil came out quite late during the period it was inhabited I recall. Someone wasn’t thinking who ran the dumptrucks and skiploaders.

    So, no, oxygen demand doesn’t go down when life starts to die off.
    Not right away, anyhow.

    Comment by Hank Roberts — 23 Oct 2007 @ 7:31 PM

  183. Chuck —

    It’s true that photosynthesis is the main source of oxygen in Earth’s atmosphere, but it has been allowed to accumulate only because organic matter was constantly being buried. It’s the burial of carbon, not oxygen, that is at issue. Otherwise the oxygen would have combined with the organic matter at its death and there would be no net gain. This is pretty standard geochemistry, I believe, going back to the 1950s at least. I remember it being discussed in Dole’s book, “Habitable Planets for Man,” in 1964, and I think Rubey explored it in 1952.

    Comment by Barton Paul Levenson — 24 Oct 2007 @ 7:49 AM

  184. Re # 182 Hank R. and # 183 Barton P.L.

    I see now that I misinterpreted Rick Brown’s (# 171) comments – I took literally his comments that “The 20% of the atmosphere that is O2 is the result of many millions of years of accumulation of photosynthetic products in sediments” and “The amount of photosynthate that goes to the sediments is tinier still and it is only the slow accumulation of this material that adds oxygen to the atmosphere.” What he meant, I now see, is that because those organisms did not decay, O2 stayed in the atmosphere (instead of being consumed by bacteria and other decomposers).

    Re: Hank’s comment that “oxygen demand doesn’t go down when life starts to die off. Not right away, anyhow.”
    What I wrote (or meant, at least) is that when oxygen levels decline (due to all forms of aerobic respiration, including aerobic decomposition, without replenishment of that oxygen by photosynthesis), rates of oxygen consumption also decline due to the reduced oxygen partial pressure gradient that drives the diffusion of oxygen into the cells – simple physiology (Fick’s Law of Diffusion).

    Re: Hank’s comment that “…lots and lots of oxygen lost to carbon dioxide as the dying soil organisms oxidized…” and Barton’s comment that “Otherwise the oxygen would have combined with the organic matter at its death” – I would point out that during aerobic decomposition the oxygen combines with electrons to form water, not CO2 – the CO2 comes from the removal of carbon from organic substrates in the citric acid (Krebs) cycle – standard biochemistry, complicated a bit, to be sure, by anaerobic decomposition and abiotic redox reactions.

    Anyway, thanks for your clarifications.

    Comment by Chuck Booth — 24 Oct 2007 @ 11:46 PM

  185. Hank Roberts(175). I’m not talking nonsense… I know there is a lot of talk, a lot of articles, a lot of research, a lot of speculation. But is anyone, any govt, any industry, actually REALLY doing anything positive (apart from ‘piddly’ carbon buy backs and sniffles of cutting by 2020 – too late… Perhaps you could enlighten me if there are more positive actions by govts and industry?) Your web refs : Biofuels -the ever-increasing population will starve (because of climate change crop failure and because of using agriculture for fuel) and more forests will be cut down – (my humble opinion); it was encouraging to see graph of reduction in ozone depleting chemicals; could not get into science mag without being a paying subscriber – but did find this – (not encouraging)
    Here, where I live they are about to build more huge power stations which will use dirty coal. China – building the same on a massive scale – vehicles on their roads are increasing daily. India – the same. These are enormous population countries – only just starting on their pollution journey. Air travel increasing daily – Russia buying new fleets of planes.
    Northwest Passage now open for shipping – govts delighted about this – gives them access to oil fields previously icebound and easy transportation of this same oil. Etc, etc, etc. North arctic region melting away this past summer.
    I don’t think I’m talking nonsense. It is very depressing, and I honestly don’t see any hope. And most Mr/s Citizen remark – “well nothing can be done, economies cannot be changed from their reliance on transportation and industry – we don’t want to change our lifestyle…..”

    Comment by podwalker — 25 Oct 2007 @ 9:58 AM

  186. Re 185. I find that I fluctuate between hope and despair on the subject of AGW. I think probably most people who understand the arguments at all do so to some degree. Of course, some people spend more time on the hope side of the swing and others on the despair.

    When I despair, it’s not because I don’t think we can find the fixes that would make a difference or that not enough citizens (worldwide) could be brought on board to change things. Where I despair is, first, the fear that it’s too late, that we have already passed some tipping point of the physical processes that will make any efforts on our part useless. The second fear is that the forces arrayed against doing anything meaningful, not the ordinary people, but the politicians and the corporations who control so much and whose voices ring loudest in the media will manage to block both awareness and action until it is too late.

    But, most of the time, I dwell in hope and even some excitement at the possibilities that could open up out of this crisis.

    Comment by Mary C — 25 Oct 2007 @ 12:48 PM

  187. podwalker (185) — Follow Biopact daily to discover some of the actions being taken by researchers, companies and many govenments.

    Comment by David B. Benson — 25 Oct 2007 @ 1:17 PM

  188. > people are quoting from draft reports that they have
    > neither properly read nor understood and for which
    > better informed opinion is not immediately available.

    Any more on what’s going on with that?

    In other news:
    PNAS finally out today with this one:
    Josep G. Canadell, Corinne Le Quéré, Michael R. Raupach, Christopher B. Field, Erik T. Buitenhuis, Philippe Ciais, Thomas J. Conway, Nathan P. Gillett, R. A. Houghton, and Gregg Marland
    Contributions to accelerating atmospheric CO2 growth from economic activity, carbon intensity, and efficiency of natural sinks
    PNAS published October 25, 2007, 10.1073/pnas.0702737104 ( Sustainability_Science ) [Abstract] [PDF] OPEN ACCESS ARTICLE discussing Science (vol 318, p 582)

    Comment by Hank Roberts — 25 Oct 2007 @ 6:41 PM

  189. Tim Flannery is an expert mammologist and palaeontologist with a big heart who recently won Australian of the Year. He is not a climatologist. He is a brilliant populariser of science with a commitment to the environment, similar to Al Gore, with a similar level of understanding of the issues.

    We are in the middle of an election campaign here and climate-skeptic Prime Minister John Howard is doing badly in the polls. I suspect Tim’s public statements, which I saw live, were an expression of genuine (if slightly mistaken) concern and were intended to make climate change an issue in the campaign, especially to force the opposition to lift its game. It has worked. The government is now internally divided about how to respond.

    I don’t think Flannery intended to mislead, but to admit he made an error now would have the right wing Newscorp press howling “I told you so.” His credibility would become the issue, not climate change. Any subtlety in the issue would be utterly lost and the public would be confused. His technical error has got little air in Australia except among the right wing press, who few believe on this issue anymore.

    The government and much of the press and in Australia have spent years denying climate change or trivialising its significance. The usual staid, measured scientific statements have been easily dismissed and climate change researchers in public organisations have been censored. It takes science popularisers like Flannery to cut through this oppression.

    Comment by Bruce Tabor — 1 Nov 2007 @ 3:07 AM

  190. It would be helpful [and it is anyway good practice] to show the units of ‘forcing’ [ W/m2] in its definition as the concept is still a new one to some who read this most useful web site.

    Comment by Chris Squire — 2 Nov 2007 @ 12:21 PM

  191. Hello, I have just read your original comment about CO2 equivalent, and find the explanation useful. However, my understanding is that although a 375ppmv figure includes carbon black, aerosols etc., it still omits aviation-induced contrails, NOx from transport (particularly aviation), and contrail-induced cirrus clouds. Is this true, and do you know what else it omits? Presumably it is important to include all additional non-greenhouse gas warming and cooling contributions to get to a true figure. My feeling is that we are some way off being able to quantify this, and may never be able to do so, given the very different nature of some of these emissions (e.g. contrails, ship tracks etc). Any thoughts?

    Comment by Alice — 13 Nov 2007 @ 9:39 AM

  192. is India’s 1st Carpool/Rideshare Classifieds. Indimoto’s aim is to enable commuters from over 130 Indian cities to form carpools and reduce harmful CO2 emissions which are increasingly making India into one of the fastest growing contributers to Global Warming. If you are from India, do your bit and try out a carpool. Use of the site is free ofcourse and by carpooling you save money too.

    Comment by Anil Tandon — 2 Dec 2007 @ 2:54 AM

  193. Gavin meant “ln” not “log” in ∆F=5.35 log (C02_e/C02_orig).
    Cf TAR, The Scientific Basis, p.358.
    I.e., he should have written ∆F=5.35 ln(C02_e/C02_orig).

    Comment by Bruce Marshall — 6 Dec 2007 @ 11:06 AM

Sorry, the comment form is closed at this time.

Close this window.

0.317 Powered by WordPress