Full IPCC AR4 report now available
The complete WG1 IPCC 4th Assessment report (AR4) is now available online. It's missing the index and some supplemental data, but all should be available by May 7.
Over the next few weeks we'll try and go through the report chapter by chapter, but since this is likely to the key reference for a number of years, we can take a little time to do it properly. Happy reading!
29 April 2007 at 12:20 PM
Thanks, I am looking forward for your comments to the chapters.
29 April 2007 at 2:00 PM
IPCC missed the opportunity again! What is Climate? A question which should not be ignored when going through the full Report. It is interesting to see what IPCC can do with the term: CLIMATE. That the term climate is used demonstrates the new Technical Summary, AR4WG1_TS, which states on page 21, that: “The Earth’s global mean climate is determined by incoming energy from the Sun and by properties from the Earth”. But IPCC has never even tried to define the term. As part of WMO and UNEP it is also responsible for the UN Framework Convention on Climate Change, which did not define the term at all, but referes instead to: Climate Change, and Climate System. While one can only wonder to read in the FCCC that: Climate change means the change of climate…; the new Policy Summary is just introducing its own understanding: Climate change in IPCC usage refers to any change in climate over time, whether due to natural variability or as a result of human activity. (see Footnote 1, of the SPM-Report).
It should to be not so difficult for IPCC to realise that one can not define climate change if climate has not been defined in the first place. Further papers discussing this question since 1992, e.g. Sea Law Inst., 1994, or Nature 360, p.292 (1992) on: http://www.oceanclimate.de. Many thanks for making the TS available so quickly.
29 April 2007 at 2:14 PM
Thanks, just like to mentione that a WIKI as a quick reference is always more handy than those pdf’s. Also the content is even more accessable.
A quick summary maybe even a speaken youtube video would be great for educational purpose.
Cheers
29 April 2007 at 2:21 PM
Gavin, your approach is sound. The only cautionary would be that where there is not incontrovertible evidence for conclusions reached, that you bring forward, exhaustively, counter-arguments, and when, having done that, you also state, in non-technical language, why you think that particular conclusion may have over-reached and try, in effect, not to negate that majority conclusion but to raise some reasonable doubt about it no matter how many scientists in your area of expertise may disagree with you. Doubt, after all, is the beginning of knowledge. I look forward to your discussions. Thanks for your efforts. My approach, basically, is the medical one, because even if there may be uncertainty, we must take care to always err on the side of caution as the planet itself is the patient.
29 April 2007 at 2:35 PM
I believe that there is a entire document dedicated to how to mitigate climate change and I personally would like Scientists to comment on this subject. I know that RC are not energy scientists but maybe they can get a few of them to write an article for RC because from what I can tell and from what I have read the entire situation is a big mess strategically and a lot of the technology being pushed seems premature anc could even make climate change worse. We need some clarity on the matter. Maybe RC will comment on these matters now that the debate on climate change is becomming old and worn.
29 April 2007 at 3:16 PM
Well, if you are going to be covering this in depth, I will be sure to set aside some time for it. I would certainly like to learn more, particularly if you take it slow so that I can digest. And what the heck - it will give some more purpose to my life. The first moral obligation of anyone human is to understand. We will see what happens after that.
Thank you!
29 April 2007 at 3:33 PM
RE#5, pete we can at least try and break the complicated topic of enegy supply and energy technologies down into a couple of categories:
1. Already existing technology: Wind turbines, solar thermal systems, solar photovoltaic systems, fuel-efficient hybrids, ethanol and biodiesel from crops (which can be used in existing diesel and gasoline engines).
2. “Dead-end” carbon-neutral technology - for example, nuclear and hydropower. Dams silt up and nuclear is not a long term soultion (waste disposal, limited fuel, and high cost of dealing with aging nuclear power plants).
3. Future technologies that need R&D: high-efficiency photovoltaics (say, 50% conversion) (as well as lowering the cost of PV), energy storage systems for intermittent sources like solar and wind (hydrogen storage, other methods), advances in biofuel technology (for example, hydrogen production from algae, cellulosic ethanol, etc.)
4. Identifying where fossil fuel reductions can be made - #1 is in agricultural production. Massive amounts of fossil fuel are used in industrial agriculture, from diesel for machinery to natural gas for fertilizers and herbicides to the fuel used for long-distance transport and refrigeration. #2 is in transportation, from airlines to cars to ships to trains. Electric vehicles that use solar and wind for energy are one example. One airline company is experimenting with new biofuels for airplanes (biodiesel won’t work as it freezes at altitude).
The important thing is to convince governments to get behind such plans, and to convince individuals to use less energy. The existing value of fossil fuel infrastructure is estimated at something like $10 trillion dollars, and that needs to be replaced by renewable energy infrastructure. That does seem like a very large amount of money, but in comparison to other recent expenditures it isn’t so large.
Still, there’s a huge gap that needs to be filled. For example, the amount of renewable energy research that is carried out in US universities is miniscule compared to the amount of pharmaceutical research that goes on (i.e. the entire NIH budget, more or less). A 1000-fold increase in funding for renewable energy research would be a good first step.
29 April 2007 at 5:35 PM
Re #5 & #7, I also feel this is becoming a critical part of the whole debate, though we still need to advance the climate science.
Much of the fear uncertainty & doubt (and downright bullshit) that has mainly left the climate arena is well entrenched in the energy debate, and is more likely to stay there due to the much greater commercial interest.
We very definitely need a partisan but scientific viewpoint expressed by experts in the field (as RC has been doing - thank you).
29 April 2007 at 6:46 PM
Re #5, #7 & #8: Perhaps we need a sister website called RealClimateSolutions that is run by energy engineers. I for one am watching the various low-emission energy solutions with the will of a football fan desperately hoping to win the grand final - ” c’mon, score a goal, score a goal “. The greenhouse science is fascinating, but sooo depressing.
My favorite teams at the moment are:
* hot dry rock geothermal
* solar tower technology (see animated rendition here )
* Pelamis wave energy generators
And of course all the energy efficiency technologies such as LED bulbs, and the various intelligent policy options that will be critical to driving down energy use.
Don’t forget to boo the umpire when he unfairly favors opposition teams.
29 April 2007 at 6:46 PM
Re: #2
From the Third Assessment Report, Appendix I - Glossary:
“Climate in a narrow sense is usually defined as the â��average weatherâ��, or more rigorously, as the statistical description in terms of the mean and variability of relevant quantities over a period of time ranging from months to thousands or millions of years. The classical period is 30 years, as defined by the World Meteorological Organization (WMO). These quantities are most often surface variables such as temperature, precipitation, and wind. Climate in a wider sense is the state, including a statistical description, of the climate system.”
A definition is clearly stated.
29 April 2007 at 7:04 PM
Re #5, #7 & #8,
Note that existing nuclear power plants in this country are lasting much longer than had been expected and new designs could be even better. They aren’t the ultimate solution, but they can be an important part of it for some time.
While looking at the other energy sources and increasing efficiency in energy use, don’t ignore really creative solutions such as what the Heat Island Group at Berkeley have been working on: http://eetd.lbl.gov/HeatIsland/ . Better roofing materials can greatly reduce energy usage while directly reflecting more energy into space. They have many other ideas that are worth looking into.
29 April 2007 at 8:45 PM
Could you please respond to a news report from Dab Elliott of Denver, quoting William Gray, a Colorado State University researcher and hurricane forecaster, who has said that global warming is all down to ocean currents and will reverse itself within 10 years.
The news article was headlined “Ocean currents to blame for warming: expert”.
Has he submitted a paper on the subject for peer review by climate scientists? I’m actually assuming that the answer to my question is, No!
29 April 2007 at 10:10 PM
Is there any chance that the new IPCC reports will be put into html, like the 2001 reports are currently? (The pdfs are so slow - not that it isn’t worth the wait, but…)
29 April 2007 at 10:25 PM
Re # 4 [bring forward… counter-arguments, and…state…why you think that particular conclusion may have over-reached …to raise some reasonable doubt about it]
Hmmm…sounds like you are already convinced that the report presents incorrect conclusions, and you want Gavin to do the skeptics’ work for them?
What if Gavin agrees with the conclusions of the report?
29 April 2007 at 11:21 PM
Why am I tempted to respond to Chuck by asking if he wants to bet on that? Unless you can find a countervailing forcing opposite in sign to that of CO2, and Gray cannot (nor can Lindzen and he has been trying to decades) you cannot handwave accelerating global warming away. Increased greenhouse gases, principally CO2, are by far the largest forcing in the climate system today and are getting larger. It is the elephant in the room.
29 April 2007 at 11:34 PM
Re: #12
William Gray’s wiki entry answers your questions. He has a hypothesis about thermohaline circulation being responsible for recent warming, and forecasts future cooling.
Has has no peer reviewed papers on this ideas re GW (no surprise there) but claims to be ‘working on it’. He was renowned for his earlier work on hurricanes but seems to have gone off the rails a bit.
Gray’s ideas have already been given the realclimate treatment.
30 April 2007 at 1:23 AM
RE #4 & 14, I’d like to see some mention of scientific studies and articles that didn’t make the cut off date for the IPCC (or were excluded on technicalities or the politics of trying to get everyone to agree), and how they might be showing things are even worse than the IPCC portrays.
It’s not that I want it to be worse; I pray everyday GW is not real, or is not as serious as they say. It’s just that I have this niggling feeling that it may actually be or could be worse, and we need to know.
30 April 2007 at 2:20 AM
There is now a public understanding that global warming is real, and man-made, at least here in Italy. I suppose the reason is this IPCC report is so sound that objections are unreasonable. This does not imply, however, that average people understand all of what is going on.
So I have a proposal for oceanographers and atmospheric scientists (and geologists, for that matter) who wish to do some spreading of recent scientific achievements. The proposal is to start contribute to the Citizendium ( http://en.citizendium.org/wiki/Main_Page ), which is sort of a wikipedia with an editorial system. Or, post in wikipedia.
Think about that: when you look for a definition in Google, wikipedia or other wikis are almost always in the first page. People knowing nothing of, e.g., global warming, will end up learning about it from wikis, most probably. I believe posting in such wikis is a primary way to do scientific culture.
30 April 2007 at 2:51 AM
Re # 12 - Ron, see if this section from April last year helps.
http://www.realclimate.org/index.php/archives/2006/04/gray-on-agw/
30 April 2007 at 3:21 AM
#12: roughly speaking, you can have two kinds of temperature variations: in one version the global heat content keeps unchanged, but the heat is redistributed differently, leading to changed temperature patterns. This is what happens when you have a very cold winter in, say, Russia. It is then warmer somewhere else, and the global average temperature doesn’t change.
The other version shows an increase in the global heat content, due to greenhouse gases. There we have globally increasing average temperatures, including the oceans AND the atmosphere. This is what happens right now under the conditions of global warming.
If global warming was due to warmer ocean currents, then this energy has to come from somewhere. Therefore, we should be able to find it in in the form of lower temperatures somewhere else (the deep ocean??), but we don’t. Therefore Gray should come up with some REALLY good explanation regarding his claim, but I doubt it will be convincing. As Eli said: Ask Gray to bet a few thousand dollars, and you’ll see whether he’s up to it.
30 April 2007 at 4:22 AM
Re 18, The USA produces 25% of all global emissions and has a relatively small population (5%) and it is here that real climate and others are making their case because in the USA they are having trouble getting the whole idea through to their people and politicians. I believe that the way that the US political system is set up and works means that the greens nees money to lobby and seduce politicians just like the ultra rich fossil fuel lobby does. Alaska will be a waste land and the middle east a war zone before this argument is ended.
30 April 2007 at 5:51 AM
#5 - I’m sitting in the ‘Mitigation’ chapter closing negotiations now. Obviously I can’t say what’s going on, but I think it’s safe to say that the final report will offer some new insights on how we move from where we are today to where we need to be in a few decades time.
It would be /extremely/ interesting to see some discussion on mitigation on RealClimate. I realise it’s not Climate Science per se, but it’s as hotly debated an area and as important.
30 April 2007 at 5:56 AM
How would you change your private life to protect the environment?
30 April 2007 at 6:00 AM
Re #21, I would hope that there is emphasis on how to get there rather than just the end product. For instance the UK has committed itself to a 60% reduction from 1990 levels by 2050 but as yet the document on how it is going to get there is missing, in other words they can make progress during the early years (obvious reductions) and get a 1/3 or CO2 removed but then it gets progressively harder to remove the other 2/3rds as that requires greater and greater strategic planning and it is this that becomes politically unsettling. The worlds population is increasing, the worlds most populous countries want what we have and have the means to get it now that the the west in preapred to invest and as yet there is no technology solutions currently available to either remove CO2 or not produce it at all that are mature and commercially available. We all know that we have to reduce demand and not increase supply so much.
I reckon that it cannot be done and presently I side with James Lovelock. Some of the changes required need new energy infrastructures like a new decentralised grid, things have to be redesigned and that will cost trillions.
30 April 2007 at 6:46 AM
Typo!
A lot of good reading ahead. I read chapter 6 on paleo climate. Too bad there is not more about the Miocene climate (would love to see an article on RC about this one day). I could not help myself to point out this typo: page 464 :’A likely cause for the 8.2 ka event is an outburst flood during which pro-glacial Lake Agassiz drained about 1,014 m3 of freshwater into Hudson Bay extremely rapidly (possibly 5 Sv over 0.5 year; Clarke et al., 2004).’
Lake Agassiz was larger than the average fish pond??
30 April 2007 at 8:05 AM
In the Summary for Policymakers on page 10:
The figure shows computer model output with and without anthropogenic effects for all continents except Antarctica. Does this mean that the models can’t account for the data there, or that such data isn’t sufficient to make a judgment? It seems like the omission needs more explanation.
30 April 2007 at 8:23 AM
nuclear is not a long term soultion (waste disposal, limited fuel, and high cost of dealing with aging nuclear power plants).
The first is not a difficult problem (indefinite surface storage is acceptable), the second is very likely surmountable (for example, by extraction of uranium dissolved in seawater), and the third is demonstrably not a problem at all.
What has held nuclear back is capital cost of the plants themselves, but the renewable alternatives face this problem in an even stronger form.
30 April 2007 at 8:28 AM
#24 - Mostly it is because there are very few observations of what the climate is doing on Antarctica, due to the fact that the continent is only inhabited by a small number of scientists (and penguins and possibly whalers in the past?). There simply isn’t the observational data to compare the models with.
Remember that the Summary for Policymakers is just that: a summary. I expect there is a reference to the full chapter, where you would expect this to be discussed.
Indeed, 3.2 is referenced and I can now find the sentence in that section of the full report: “..substantial gaps in data coverage remain, especially in the tropics and the SH, particularly Antarctica.”
30 April 2007 at 10:18 AM
#23 - The implication of that question seems to be “how much pain are you willing to incur to leave a smaller GW footprint?” Correct me if I misinterpreted.
My personal answer: it’s a question of cost. I stretch one high-tech income to cover me, my wife, our 5 children and our two cats. I buy energy efficient appliances and flourescent light bulbs, I insulate my doors and windows, and I keep electric devices which are not in use turned off. I still drive to work, mainly because biking in this hilly area would get me to work sweaty. I do not own a hybrid, because I cannot afford a new car at all and they are too new to be readily available in the used car market.
If ‘renting’ solar (a la CitizenRe) becomes feasible, I will jump on that. If my utility offers me the option to ‘purchase’ energy from renewable sources, and is within 10% of my current costs, I will do it.
I strongly believe that innovation will lead mankind away from spewing CO2 into the atmosphere. What will lead to better management of land use, and what will lead to less impact from livestock? These answers are less clear and will be more complex to manage.
At a personal level, however, if we all make changes which, for example, average 10% better energy efficiency, we won’t notice much pain, we will lower our energy expenses, and the cumulative impact will be quite meaningful.
30 April 2007 at 11:24 AM
I wonder if RealClimate could help me with the key logic components that generate rising temperature forecasts. There’s a disparity between the temperature increases that Hansen and others predict, and the numbers I get from two of the core formulas that are said to be at the heart of this issue.
One formula links radiative increases to rising greenhouse gases. For rising CO2, delta R = 5.35 * log(new PPM/original PPM). [This formula from NOAA’s AGGI webpage.] With new PPM = 382, original PPM = 280, this CO2 formula implies radiative forcing of 1.66 watts/meter^2.
The second links temperature to rising radiative energy. Roughly, R = constant * T^4, where T is degrees Kelvin. I use 235 watts/meter^2 as the starting R, and 286 Kelvin as the starting T. Probably not exactly right, but pretty close I think.
To go from PPM to rising temperature, I first calculate the radiative forcing. Then I add the radiative forcing value to the R in the second formula, and solve for T.
When I do this, I don’t get a very fast increase in Temperature Kelvin. In fact, I’m surprised at how slowly the T value seems to rise as a function of rising PPM for CO2.
Here’s what I do get:
382 PPM –> +1.66 watts/meter^2 –> +0.50 Kelvin.
450 PPM –> +2.54 watts/meter^2 –> +0.77 Kelvin.
560 PPM –> +3.70 watts/meter^2 –> +1.12 Kelvin.
740 PPM –> +5.20 watts/meter^2 –> +1.57 Kelvin.
Each of these new Kelvin values are delta values from the starting number, 286 Kelvin (13 Celsius). Though 740 PPM vs 280 PPM represents a tripling of atmospheric CO2, the formulas cited imply an overall temperature increase of 1.57 Celsius, from 13 C to 14.57 C. Not an earthshaking result, I shouldn’t think.
Are these formulas wrong? Am I using them improperly?
I’d like to be able to make the case - for those of my friends who don’t believe GW is a priority - in as mathematical a way as possible. The math I’ve just cited, though, doesn’t seem especially compelling. Thanks for any help you can provide.
[Response: Steven–those formulas provide the radiative forcing from co2 alone, i.e. they assume no feedbacks! It is the positive feedbacks, primarily water vapor feedback and ice-albedo feedback, that lead to significantly greater warming than would be predicted by the radiative forcing from co2 alone. Indeed, it is precisely the role of these positive feedbacks that is at the heart of discussions of climate sensitivity. A good primer is Gavin’s recent article Learning from a simple model. -mike]
30 April 2007 at 11:41 AM
in the mid 1970s we where told that the earth is cooling down. know we are told its warming up who do we, or what do we belive..?
The governments of the world have put money in research into “global warming” co2 levels etc, could it be something else but this. I must admit the evidence point towards higher co2 levels in future. But if that’s all you’re paying the scientist to find that what they will find. If your in a court of law what’s the evidence on the opposing side …?
Could it be the earth is in a “natural cycle” could it be sun spots.
All the computer models are based on human in put and not fact based on history. But what if the records don’t go far enough for the information that needs to be generated and is that accurate …. Questions questions questions
30 April 2007 at 12:09 PM
Jamie, I’m gonna go way out on a limb and guess that maybe you aren’t a scientist. Am I right. First, climate scientists do not just look at CO2. They look at solar output. They look at water vapor. They look at cloud formation. They don’t look much at galactic cosmic rays because, frankly, nobody can come up with a coherent theory of how this mechanism might work.
Your court of law in this case is the scientific community. Anybody who has relevant evidence is welcome to present it to that community and see if it holds up. So far, no alternative explanation has even come close to being able to explain what we’re seeing.
As to the climate models, yes, they are the product of human beings, but they are constrained by the best data we have–both historical and current. Moreover they work very well. And the records–they go back 650000 years with fair accuracy, or if you want to include fossil evidence, even further. We KNOW humans are causing climate change. We KNOW it with as much certainty as we know that Einstein’s General Theory of Relativity is a good description of gravity. If you have “questions, questions, questions,” then go find “answers, answers, answers”, but go to a reasonable source of information or you won’t know anything more than you do right now. Misinformation does not fill the void of lack of information.
30 April 2007 at 12:12 PM
Re: #31 (Jamie)
Told by whom?
30 April 2007 at 1:27 PM
RE#27, Paul - to repeat, it still seems to be that if you have $4 billion to spend on non-CO2 producing energy sources, the better investment would be to build 40 solar-cell manufacturing facilities at $100 million apiece; for example see Honda Solar Factory; this would result in some 1,100 megawatts of solar cell capacity being produced per year, in comparison to a single nuclear power plant (typical power level: 600-1200 MW) being built.
While some may claim that nuclear power is far cheaper, if you look at the history of nuclear power cost overuns, you see that $4 billion for a single plant is an underestimate; for example the Shoreham Nuclear Power station came in at $6 billion. At the end of the lifetime of a nuclear plant, you have a huge, toxic mess to clean up; after 30 years of comparable solar cell manufacturing, you have 30 MW of installed solar power (assuming good PV panel lifetimes). Solar PV is a far better approach, with immediate payoffs.
30 April 2007 at 1:35 PM
RE#31 - The IPCC report addresses that in chapter one, pg 98:
Not all theories or early results are verified by later analysis. In the mid-1970s, several articles about possible global cooling appeared in the popular press, primarily motivated by analyses indicating that Northern Hemisphere (NH) temperatures had decreased during the previous three decades (e.g., Gwynne, 1975). In the peer-reviewed literature, a paper by Bryson and Dittberner (1976) reported that increases in carbon dioxide (CO2) should be associated with a decrease in global temperatures. When challenged by Woronko (1977), Bryson and Dittberner (1977) explained that the cooling projected by their model was due to aerosols (small particles in the atmosphere) produced by the same combustion that caused the increase in CO2. However, because aerosols remain in the atmosphere only a short time compared to CO2, the results were not applicable for long-term climate change projections. This example of a prediction of global cooling is a classic illustration of the self-correcting nature of Earth science.
This just shows the lengths some people will go to - repeatedly citing a few papers from the 1970’s as evidence that no one understands climate… can you imagine a similar claim regarding, say, HIV and AIDs? “In the 1970s, scientists didn’t know about HIV and AIDs, so why should we believe them now?”
30 April 2007 at 1:46 PM
Re #31
Jamie,
In the 1970s the earth was cooling down, now it is warming up. Is that so hard to believe?
In the 1970s it was discovered that when the climate changes it usually does so abruptly, and so a rapid cooling was thought to be the main danger. Now, however, no one seems to have worked out that a rapid warming is the most likely catastrophe!
30 April 2007 at 2:52 PM
Let’s dispel this myth once and for all.
Analyzing GISTEMP data for the 1970s gives a positive rate of global temperature change — warming! — of 0.05 deg.C/decade. But the error bars are +/- 0.19 deg.C/decade, so the trend is not statistically significant.
In fact the much-vaunted “global cooling 1940 to 1970″ is not real either. Then trend for that time period is -0.25 +/- 0.3, again not statistically significant. The cooling is from about 1944 to 1951, the rest of that time shows no sign of any significant change.
The only isolated decades which have statistically significant trends are (all in deg.C/decade):
1930s: warming +1.8 +/- 1.2
1940s: cooling -1.6 +/- 1.0
2000s: warming +3.1 +/- 2.1
The much higher error range for the 2000s is mainly due to the fact that we have less data (the 2000s aren’t over yet).
30 April 2007 at 2:58 PM
My favorite recent source on mitigation is ‘Heat’ by George Monbiot. While it is very UK centric and, I believe, wrong about a few issues, it is the only work I’ve seen that specifies changes to create an industrial society with vastly (90%) less carbon emissions. I’d like to know what folks here think.
30 April 2007 at 2:59 PM
Re: #37 (tamino)
Correction to my previous post: all the numbers are deg.C/century, not deg.C/decade
30 April 2007 at 4:40 PM
Typo - re#34, that should be 30,000 MW installed after 30yrs, not 30!
You can take a look at the temp record here, which supports tamino’s conclusions.
It’s also now well understood that large volcanic eruptions have a short-term cooling effect, see GW FAQ: effect of volcanic activity (short-term being the key phrase, after Church et al Nature 2005, and also http://www.llnl.gov/str/JulAug02/Santer.html )
Thus, a large volcanic explosion this year would result in cooling temperatures for a few years… but the long-term trend would soon override this. This illustrates the natural variability - who wants to bet that there will be a large volcanic explosion this year? Noone can assign a realistic probability to that one, but 1 in 10 is the recent historical average.
30 April 2007 at 4:41 PM
re #30 and Mike’s response to my post. As you suggested Mike, I have re-read Gavin’s earlier post. I think it ends up about where I do. Gavin suggests a sensitivity of 0.3C/(W/m^2) with no feedback, and in an albedo feedback example shows that rising to 0.33C/(W/m^2). Those results are similar to my back of the envelop scratchings in Excel.
In other words, it takes a forcing increase of approximately 3 W/(m^2) to produce an increase of 1 degree Celsius.
The simple incremental CO2 forcing that comes from 380 PPM rising to 450 PPM - if NOAA’s formula is right - is only 0.27 W/(m^2). Before any feedbacks are added in. Not much of a Temperature gain in that, is there?
Even the baseline forcing - 280 PPM to 450 PPM - implies a rise in temperature of only 0.77 degrees Celsius. Before feedbacks are taken into account. Still not much of an implied temperature gain, especially not if the sensitivity is 0.33C/(W/m^2).
You’ve said you’d be summarizing the IPCC analyses, including, of course, the IPCC temperature forecasts. May I sugggest adding to your summary a table that lines up the variables?
- CO2 PPM changes expected in coming decades
- Other GHG changes expected over the same time period
- Anticipated W/(m^2) from GHG forcings
- Anticipated W/(m^2) from albedo forcings
- Anticipated W/(m^2) from water vapor forcings
- Temperature changes implied by these forcings
The point is simple. If Temperature change is a function of a forcing change, and a forcing change is a function of a Greenhouse Gas change plus a feedback loop, then it would be cool to have a table that connects the dots. GHG changes + Feedback changes –> Total forcing changes –> Total temperature changes.
I assume the IPCC estimates will include some forecasts that show temperatures rising by as much as 3 to 4 C. If Gavin is roughly right, that the temperature sensitivity is somewhere around 0.33C/(W/m^2), then it’ll be interesting to see where the forcings come from that yield those predicted temperature increases.
One last thought. Blackbody temperature changes are interesting. But climate is ultimately about atmosphere, isn’t it? Is it at all likely that temperatures rise first in the atmosphere? That ocean and land temperatures lag the atmosphere? Is it possible for climate effects to outpace ocean & land warming rates?
Thanks so much for your patience and the teaching you do with this website!
[Response: I think you’ve misunderstood Mike’s point. My calculations for the simple model are not representative of the real world (as I think I stated multiple times). They are illustrative of the kind of calculations that go on, but they are not a replacement for the more complicated ones. The most likely sensitivity is around 0.75 C/(W/m2), not 0.33. See http://www.realclimate.org/index.php/archives/2006/03/climate-sensitivity-plus-a-change/ for observationally based reasons for that conclusion. - gavin]
30 April 2007 at 5:25 PM
RE #34 IKE.
Before we go off quoting the costs and troubles of a nuclear power plant built over 20 years ago we might have a look around at other more up to date stuff. I figure these guys might have learned something in 25 years. Kinda like GW scientists learned stuff.Just a hunch.
Not a settled matter you know.. but I found this. again, it’s just one data point, but it’s not 25 years old.
http://www.nei.org/index.asp?catnum=3&catid=186
Now, the IRONIC thing I found was in your very next post, you are JUSTIFIABLY critical of somebody for reaching back to to the 70s for scientific papers. That was FUNNY as hell, but ironic. First( in #34) you reach back to the same period to pull up example to strengthen your case against Nukes and then you slam somebody for doing essentially the same thing. I thought you would find this as humerous as I did. Kind of like running with scissors .
Finally, go check the honda numbers again. The plant looks like it is sited on existing corporate property ( so those costs are probably not included), capitalization is 4B Yen. Total investment is 7B Yen. Finally, I’m seeing PV lifespans guaranteed at 10-20 years. I’m not critical of solar, but I would take a bit more care in comparing alternatives.
Anyways, I always enjoy your posts.
30 April 2007 at 6:48 PM
Seabrook NH is more recent than that (completed late 80s or early 90s I believe) and United Illuminating Customers in Connecticut are still paying it off.
There has been almost no reactor construction since the 1970s in the US, so all the domestic datapoints are old.
30 April 2007 at 7:44 PM
It appears (as usual) the IPCC reports are way out of date before they are published. A new paper “Arctic Sea Ice declines - faster than forecast” in Geophysical Research Letters by researchers at NCAR and the U of Colorado National Snow and Ice Data Center show that the Arctic may be ice free by 2020, 30 years ahead of the forecasts by the models. As I stated in an earlier post several months ago, Dr. David Barber (a sea-ice specialist at the University of Manitoba), predicted the Arctic could be ice free in 15 years (Feb 15, 2006). Looks like more people are agreeing with him. Looks like again the models come up real short. Another surprise (and I think more are coming).
Wish I could remember which paper I read several months ago where the average age of the sea ice in the Arctic is now less than 3 years old (memory fading with age). So apparently the ice is turning over a lot faster than originally thought.
Also, the models were way off on the melting of the Greenland ice sheet. I can be critical of models since I am a computer scientist (retired) who has done some modeling.
As I learned in my marine science courses many years ago, the Arctic is our thermostat for the northern hemisphere. Once it is broken, we had better hang on for a wild ride.
30 April 2007 at 8:06 PM
Re: faster than expected
Official memorandum by directors of NOAA/NWS and NWS North Central River Forecast Center (NCRFC) states:
(2000,2001).
30 April 2007 at 8:17 PM
Re #44: Here’s the link to the press release on the new Arctic sea ice paper. I don’t recall seeing your prior comment on the prediction from Barber, but IIRC Wieslaw Maslowski (the U.S. Navy’s sea ice expert) was saying something similar at least two years, and in a recent AMS presentation noted that simply eyeballing the trend led to the conclusion that the summer sea ice is not long for the world (my phrasing).
30 April 2007 at 8:22 PM
Re #44 “Arctic Sea Ice declines faster than expected”
Those that can’t access GRL can check out this recent poster on the same topic by the authors (from the 2nd CIRES Symposium a few weeks ago).
30 April 2007 at 8:27 PM
Re #41 and Gavin’s reply. Thanks Gavin. I followed the link and read the observations. Also your reply to the first post following, in which you say the forcing for a doubling of CO2 is roughly 5.3 * LN(560/280), or 3.7 W/(m^2). This is the calculation I’ve already been guided by.
I must be making an amateur’s mistake of some kind, though. On the assumption that a doubling of CO2 yields a forcing value of 3.7 W/(m^2), I add 3.7 to the value of G in your Stefan-Boltzmann formula, and I solve for Temperature. The increase in T is only a shade over 1 degree C, not the 2+ degrees that you say is the likely minimum.
What am I doing wrong? Is it a mistake simply to increase the value of G by 3.7 W/(m^2), and then solve? Or am I wildly off in the value of sigma? (I’m using a sigma that I derived from your numbers, with G ~ 390 and T ~ 288.) Thanks again.
30 April 2007 at 9:20 PM
While I was reading Ch 6 of the IPCC report on Paleoclimate I came across the description of the Paleocene Eocene Thermal Maximum 55Ma. They describe a very large step input of carbon into the atmosphere and the ocean. Both Atmospheric CO2 and Ocean Carbon content increased in magnitude similar to what we are seeing today. How do we know that we are not seeing a repeat of the PETM?
30 April 2007 at 9:22 PM
“Alaska will be a waste land and the middle east a war zone before this argument is ended. ”
I don’t get your point, pete. Save for its oil, I thought Alaska is a wasteland (scenic to be sure…), and the Middle East is a war zone…
30 April 2007 at 9:45 PM
Re 31,
http://www.denialism.com/2007/03/what-is-denialism.htm
“We believe there are five simple guidelines for identifying denialist arguments. Most denialist arguments will incorporate more than one of the following tactics: Conspiracy, Selectivity, False Experts, Impossible Expectations/Moving Goalposts, and Argument from Metaphor/violations of informal logic.”
You have an almost perfect score, congratulations!
30 April 2007 at 9:51 PM
The included link in the my previous post seems to be broken it is found on this page:
http://scienceblogs.com/denialism/2007/04/hello_to_scienceblogs.php
30 April 2007 at 10:11 PM
#31 and #36 TROLL. re, “global cooling predicted in 1970s… now they predict global warming … so scientists should not be believed.”
This is covered several times on this site and you know it.
Alastair, these are senseless trolls.
I present hard evidence below, including papers, that show your post is completely ignorant and blatent progaganda…now, where is your evidence?????
There was no scientific consensus on cooling in the 1970s in the scientific journals (not including pop mags, like Time or National Geographic), however there is now a strong consensus that it is warming in the journals. This is the difference between night and day.
This site covers has covered it pretty well as any honest person knows.
“The point to remember, says Connolley, is that predictions of global cooling never approached the kind of widespread scientific consensus that supports the greenhouse effect today. And for good reason: the tools scientists have at their disposal nowâ??vastly more data, incomparably faster computers and infinitely more sophisticated mathematical modelsâ??render any forecasts from 1975 as inoperative as the predictions being made around the same time about the inevitable triumph of communism.” Newsweek
“Least apologetic excuse for getting a climate story wrong:
Newsweek explains its 1975 ‘The Cooling World’ story.”
http://realclimate.org/index.php?s=cooling&submit=Search&qt=&q=&cx=009744842749537478185%3Ahwbuiarvsbo&client=google-coop-np&cof=GALT%3A808080%3BGL%3A1%3BDIV%3A34374A%3BVLC%3AAA8610%3BAH%3Aleft%3BBGC%3AFFFFFF%3BLBGC%3AFFFFFF%3BALC%3A66AA55%3BLC%3A66AA55%3BT%3
http://www.realclimate.org/index.php/archives/2006/10/global-cooling-again/
“I should clarify that I’m talking about predictions in the scientific press. There were some regrettable things published in the popular press (e.g. Newsweek; though National Geographic did better). But we’re only responsible for the scientific press. If you want to look at an analysis of various papers that mention the subject, then try
http://www.wmconnolley.org.uk/sci/iceage/.”
http://www.realclimate.org/index.php/archives/2005/01/the-global-cooling-myth/
30 April 2007 at 10:19 PM
RE #29, Walt, you may be interested in NATURAL CAPITALISM by Paul Hawkin and Amory Lovins, see www.natcap.org
They figure we can reduce our GHG emissions by more than half cost-effectively, even by 75% or more. And I heard Hunter lovins say something like, “The poor cannot afford not to become energy efficient & conservative” & “The national energy policy comes down to the cracks around our windows.”
There are also some other hidden savings in “doing the right thing” — the EC (environmentally correct) thing. For instance, offsetting some driving with walking & cycling, and eating lower on the food chain could improve health & lower medical bills.
So re your questions “What will lead to better management of land use, and what will lead to less impact from livestock?” Eating less meat! Which is also good for the health. And when you consider that many toxins bioaccummulate up the food chain (toxins on plants get more concentrated in livestock, and still more concentrated in people who eat the livestock), well, there’s even more reason to reduce meat consumption. Going green is a win-win-win-win situation. Not doing so is a lose-lose-lose-lose situation.
Then people ask, if it makes sense to do all these things anyway (without considering global warming), then why haven’t they done them already? The answer may be that economists are wrong about man being rational and maximizing. Maybe there’s something disturbing and perhaps Freudian going on deep in our psyches — some thanatos death wish. Or, we’re just crazy.
30 April 2007 at 10:26 PM
Re: gavin’s response to 41> “The most likely sensitivity is around 0.75 C/(W/m2), not 0.33. See http://www.realclimate.org/index.php/archives/2006/03/climate-sensitivity-plus-a-change/ for observationally based reasons for that conclusion.”
Most of the observations seem to be based on changes in insolation (such as volcanic dimming). How do we know that sensitivity in C/(W/m2) is the same for GHG forcing as for insolation forcing?
The two sources of forcing have different ‘fingerprints’ and cause different distributions (vertically and geographicly) of temperature change. How do we know that those distributions do not cause different feedback effects?
[Response: They do - slightly. Read this paper for a full discussion of the issue. The bottom line is that the concept works pretty well for almost all forcings (otherwise we wouldn’t use it). You can use the simple model discussed before to show why it works in the simplest case. - gavin]
30 April 2007 at 10:41 PM
Re # 15 Eli,
I don’t understand your comment. I was responding to Vern’s (#4) request that Gavin to savage any conclusion in the IPCC report that is not based on incontrovertible evidence. How do you interpret that request?
Bet on what? I’m quite familiar with the major evidence for AGW, and I’ve learned from this site the serious flaws in Gray’s and Lindzen’s arguments.
Perhaps you misread my comment, or Vern’s?
1 May 2007 at 12:26 AM
This is a bit off topic, but does anyone have recommendations for a good, general book (for the “educated layman”) covering the science of global warming? I read and enjoyed “Field Notes From a Catastrophe” but it left me wanting more.
Thanks!
1 May 2007 at 1:22 AM
Intresting discussion regarding global cooling in the 60’s, 70’s. It gets quite emotional. Key reasons it didn’t become a scientific concensus are (i) that the trend didn’t last long enough for the hysgteria to set in and (ii) that an international body to study the issue was not established. The concern for global warming started in a similar way. People watched the trend for a few years and started to make a few noises about it, some media stories. One or two well-known scientists made some strong statements. The IPCC was formed and the snowball started to role. It will role until the its realised we are no longer in a rising trend. What I am sure about is that when we move again into a cooling trend, no AGW advocates of today will admit any error. What will be blamed is aerosols and that this other form of man-made pollution is taking over - and so it will still be our fault. You heard it here first.
[Response: Sadly no, I didn’t hear it first here, its been said many times before. For GC, you can look at http://en.wikipedia.org/wiki/Global_cooling . The key reason it didn’t become a sci cons was that the science didn’t support it - William]
1 May 2007 at 2:18 AM
#36 Alastair, I was around in the 70’s, and I must say that it didn’t feel like a cooling then, but now all over the world there is a warming felt by billions. The difference: it was a media prediction (perhaps inspired by Milankovitch theory) compared to the media reacting with no shortage of people in awe of deadly heat waves “la canicule 2003″ , not having any winter in Europe amongst other myriad warming stories, many not heard from every place on Earth. The IPCC meets from common knowledge created by temperature change.
1 May 2007 at 2:23 AM
As a non-scientist I look forward to your step by step progression through IPCC report. I also appreciate the comment entries.
Several years ago,
I bought a copy of Natural Capitalism by Hawkins and Lovins. GREAT BOOK!
1 May 2007 at 4:59 AM
Try Global Warming : The Complete Briefing by John Houghton. It is intended for a nontechnical audience and is detailed and thorough. You can check out the table of contents and some sample pages via the above amazon link.
1 May 2007 at 5:03 AM
CLIMATE SENSIVITITY ISSUE
The issue of how sensitive climate is appears to be the real issue in regards to how far humankind should go in mtigating carbon release into the atmosphere. Lubos Motl (who is probably well known to real climate and tends to have an opinion on anything that is controversial in science) writes this blog http://motls.blogspot.com/2006/05/climate-sensitivity-and-editorial.html on the subject and quotes well known climate detractors like Lindzen at MIT.
He agrees that there cannot be a runaway effect but he then takes the posiiton that the current 1.5 to 4.5 IPCC projections of temperature are incorrect citing the fact that 560 ppmv would mean no more than 1.5 C of warming through CO2 alone. So what is the issue here, I know from realclimate that he must be incorrect but I am no mathematician and hence I cannot vouch for his equation or his conclusions he draws from it (although I do know that the formual is exponential in nature and that we get more warming from the early CO2 increase than we do for even more) so he could be right for all I really know.
So what can I say that might reveal his depection: Is he only using CO2 and not greenhouse gases? Has he taken into account the albedo and aerosols to ?
Can realclimate answer this one for me please. Is he being economical with the truth or disengenuous to science and hence scientists?
1 May 2007 at 5:35 AM
#57 #60
After that one try “The Last Generation” by Fred Pearce. It mercifully breaks GW up into small chapters and gives Stephen King a run for his money.
http://www.amazon.co.uk/Last-Generation-Nature-Revenge-Climate/dp/1903919878
Keep up the good work chaps and Tamino - ta for the cooling info.
1 May 2007 at 5:39 AM
I was disappointed that Eric shut down the discussion on the carbon cycle just as I was about to post. My question relates to just how well we understand the carbon cycle actually. I have reviewed the Wikipedia entry on this topic (I know, I should read the literature) and remain unsatisfied. For example, the Wikipedia entry fails, so far as I can see, to consider the impact of rising atmospheric CO2 levels on the biomass. We know that rising CO2 levels will stimulate plant growth. In effect, that sequesters CO2 in vegetative matter, and in a fashion that increases the biomass as atmospheric CO2 levels increase.
There may well be other aspects of the cycle that are poorly understood. For example, I seriously doubt that we really understand the CO2 issues with the ocean.
So my question in regard to the CO2 cycle is - just what level of confidence do we put on our understanding of the CO2 cycle. IPCC, Algore, RC and Hockey Team all suggest that we have a very clear understanding of this (Very Likely probably), but I seriously don’t see how this conclusion can be substantiated.
1 May 2007 at 6:45 AM
I have a question about arctic sea ice that I’ve yet to see addressed, and it won’t get out of my brain and just leave me alone –
While it’s true that sea ice lowers the albedo of the arctic region, we’re talking about a region that is a net heat loser on an annual basis. I’m not caffinated well enough this morning to calculate the annual watt-hours per square meter received at the north pole, but I’m guessing it isn’t a big number.
How does heat loss in the north polar region change with and without sea ice cover?
1 May 2007 at 6:54 AM
Re #48, having struggled through the simple model article recently, maybe I can clarify. If you double CO2 today, then forcing is 3.7W/m^2. However, as the atmosphere warms, other things change. For example, warmer air holds more water vapour which adds more forcing.
Both observations (of a more than 0.6C rise with only 380ppm CO2 level), and models show that the net effect of feedbacks is positive.
Hope I’ve got that about right.
One thing that really confused me till I got my head around it was the way papers talk about forcing (W/m^2/K) and then slip smoothly into sensitivity C/(W/m2) once they start talking about feedbacks.
1 May 2007 at 7:13 AM
Jamie and Alastair and PHE, your eagerness to abandon the conservation of energy tells me you don’t have much scientific background. The energy of a system–such as climate–does not change without something changing it. In the 1970s, yes, there were some observations of cooling, and even at the time, many researchers understood the cause to be blocking of sunlight by aerosols from the burning of fossil fuels. By the late 1990s the climate models had evolved sufficiently that this could be demonstrated. So, not only did scientists understand the cause of warming from the start of the industrial revolution into the early 1900s, they also understood the cause of the cooling observed from ~1940 to ~1975, and when emissions were controled, the warming re-emerged. Rather than undermining the credibility of climate science, this confirms it.
Your assertion that climate can change as a result of a “natural cycle” is as unscientific as the claim of a creationist that “GODDIDIT” unless you have some hypothesis as to what the forcing function of that “natural cycle” may be. Science works. Learn some of it.
1 May 2007 at 8:02 AM
I’ll keep saying it: there is not cooling from ~1940 to ~1975.
Trend analysis of GISTEMP data from 1940 to 1975 indicates a temperature change rate of -0.15 +/- 0.25 deg.C/century. Note the error range is larger than the value, so the indicated trend is not statistically signficant.
The only real “global cooling” is from 1944 to 1951. Seven years. That’s all, folks. For the remaining period in question, from 1951 to 1975, the indicated trend is +0.07 +/- 0.5 deg.C/century. This indicates warming, not cooling, although again the trend is not statistically significant.
1 May 2007 at 8:21 AM
Just a quick question. Why wasn’t this released in February along with the summary? I know of no other field where a summary document is released months before the paper that it is supposed to summarize.
1 May 2007 at 8:24 AM
The “global cooling” talked about in a couple of glossy magazines (And Rob Reiner. We can’t forget his pivotal role.) was about the fact that we were in an interglacial period which could end. Which is true: interglacial periods do end. Since we had fairly bitter winters from 76-77 through 78-79, there was the spice of memory added to the mix.
There wasn’t any discussion in the scientific literature about it.
1 May 2007 at 8:25 AM
Trevor, CO2 stimulates plant growth only to the extent that there are no other limiting factors. I believe Hank posted on this several posts back. The short answer is that it’s mixed. Some plants do better and some do worse. As I recall, weeds thrive. So, yes, this has been looked at.
The other misunderstanding reflected by your post is that unless the plant growth involved is dominated by long-lived woody plants, there isn’t much increase in long-term sequestration of carbon. Indeed, as the plants die and decay, a lot of the carbon goes back into the system as CH4, and so actually increases greenhouse efficiency. This straw has been grasped at repeatedly, and hasn’t supplied much bouyancy so far.
1 May 2007 at 8:26 AM
Trevor, you’re right, you should read in the current science.
Beware assumptions; “we’re sure more CO2 is good, it fertilizes life, and we’re sure the uncertainty is great, and we’re sure that there’s no need to worry” is the PR from the denial sources.
Try your own words as a search term:
http://scholar.google.com/scholar?hl=en&lr=&scoring=r&q=rising+atmospheric+CO2+levels+on+the+biomass.+We+know+that+rising+CO2+levels+will+stimulate+plant+growth.&as_ylo=2006&btnG=Search
You’ll need to visit a library, talk to the reference desk, and borrow most of the journals; the abstracts will get you started.
Example:
“Conclusions drawn from experimental works differ when the data are grouped in a way such that the relative frequency of test conditions does not determine the emerging trends, for instance unrealistically strong CO2-’fertilization’ effects, which are in conflict with some basic ecological principles. I suggest separating three test conditions: uncoupled systems (plants not depending in a natural nutrient cycle) (I); expanding systems, in which plants are given ample space and time to explore otherwise limited resources (II); and fully coupled systems in which the natural nutrient cycling governs growth at steady-state leaf area index (LAI) and fine root renewal (III). Data for 10 type III experiments yield rather moderate effects of elevated CO2 on plant biomass production, if any. In steady-state grassland, the effects are water-related; in closed tree stands, initial effects decline rapidly with time. Plant-soil coupling (soil conditions) deserves far greater attention than plant-atmosphere coupling (CO2 enrichment technology).”
New Phytologist (2006) 172: 393-411
1 May 2007 at 8:36 AM
A modest suggestion. Hank Roberts (whom I’ve learned a great deal from) often asks posters where they are getting their information about climate–especially when that information appears suspect. It occurs to me that it might be helpful in general if posters shared their sources of information–particularly the reliable ones, along with any biases they have observed. Realclimate remains my main source of scientific information about climate change. It is a goldmine. However, I also follow releases from NASA, NOAA and other sources. I do try to look at the IPCC reports, but I’m afraid that the politics here have a tendency to try to dilute the science (though in quite the opposite direction that the denialists imply). I try to flip through the stack of Science and Nature that accumulate over time. Unfortunately, I rarely make it to the library to read GRL anymore. Popular sources I use are Yahoo news. And I find the comments on the blogs at Scientific American an excellent source on the most popular denialist arguments of the day. I also try to keep in touch with colleagues at Physics Today, who actually still get to read this stuff as part of their day jobs. Nothing too novel or helpful, I’m afraid. But it’s a start.
1 May 2007 at 9:34 AM
I have a question about the much cited in the MSM phrase - “Longer growing seasons”
To me this sounds like the “Healthy Forests Initiative” or “No Child Left Behind” - who comes up with these phrases?
It is really too bad that the 2 messages most widely received from the IPPC II is the (mmmm, sounds good) “longer growing season”, and that AGW will “only happen to poor people far away from us.”
You scientists really need a Jeffrey Feldman type to control the message better. You can rely on the MSM to distort this.
1 May 2007 at 9:41 AM
Re: 43 “Seabrook NH is more recent than that (completed late 80s or early 90s I believe) and United Illuminating Customers in Connecticut are still paying it off.”
Even more current, look at the truly huge overrun costs for Ontario Hydro’s Darlington plant on Lake Onatrio. For overruns on overhaul costs check for Ont Hydro’s Pickering plant, also on L. Ontario. The Bruce plant (on L. Huron) is currently being overhauled, but by a private firm, so figures will not likely be available.
1 May 2007 at 10:29 AM
Just because a climate sceptics and trolls say that there was cooling from the 40s to the 70s does not mean that is not true. You only have to look at http://www.cru.uea.ac.uk/cru/info/warming/ to see that. Moreover, there were worries by reputable scientists that a rapid cooling could happen, See G.J. Kukla & R.K. Matthews, Science, 178, 190-1, 1972. Moreover, they were worried enough for it to reach the press, and for a letter to be penned to the President of the USA.
Of course the worries now are far greater than those then, but it is wrong to deny that they existed. One might accuse those deniers of being dishonest, but it is clear to me now that it is their firm belief in the infallibility of scientists that is leading them astray, and that they find it difficult to accept that scientists could ever have been wrong.
The problem is that they also believe that they too are infallible. When they are told the Arctic ice may be gone within 10 years, and as Jim Crabtree says “… the Arctic is our thermostat for the northern hemisphere. Once it is broken, we had better hang on for a wild ride” they are not afraid. For them, the IPCC consensus says that the ice will last until 2070 so that must be true.
If even the scientist cannot face up to the facts, then what hope is there for the rest of us?
1 May 2007 at 10:54 AM
Earth’s Climate Is Seesawing, According To Climate Researchers
During the last 10,000 years climate has been seesawing between the North and South Atlantic Oceans. As revealed by findings presented by Quaternary scientists at Lund University, Sweden, cold periods in the north have corresponded to warmth in the south and vice verse. These results imply that Europe may face a slightly cooler future than predicted by IPCC, the Intergovernmental Panel on Climate Change.
http://www.sciencedaily.com/releases/2007/04/070428170229.htm
1 May 2007 at 11:05 AM
Jim Crabtree (#44) wrote:
State of the Arctic (NOAA)
October 2006
http://www.arctic.noaa.gov/soa2006/
http://www.pmel.noaa.gov/pubs/PDF/rich2952/rich2952.pdf
pg 16 Difference in Ice Extent (1979-2005)
pg 18 Change in the age of ice on the Arctic Ocean (September 1988, 1990, 2001, 2005)
pg 26 Changes in Permafrost temperatures at a depth of 20 m (Alaska Permafrost Observatory, 1977-2003)
I believe pg 18 most closely corresponds to what you are thinking of.
For something a little earlier:
A rapidly declining perennial sea ice cover in the Arctic
Josefino C. Comiso (NASA, 2002)
http://neptune.gsfc.nasa.gov/publications/pdf/pubs2002/2_rapidly_decling_perennial.pdf
I worked with highway traffic modeling a while back myself.
Now this isn’t modeling, but as far as glaciers go, you might also be interested in:
State of the Cryosphere
National Snow and Ice Data Center
http://nsidc.org/sotc
In particular:
SOTC: Glaciers
http://nsidc.org/sotc/glacier_balance.html
“SOTC: Glaciers” includes Chart of Global Glacier Mass Balance from 1961-2003
State of the Cryosphere is meant for the general public. It uses Google Maps, images, etc. It might be worth getting the word out about.
1 May 2007 at 11:29 AM
Ike Solem (#35) wrote:
Aerosols have in fact masked the effects of global warming through “global dimming” during the latter part of the twentieth century. However, some of their effects (e.g., sulfates lowering the albedo of clouds) contribute to global warming. There have been a number of posts on the subject of “global dimming” here in the past. One of Real Climate’s guest posters (Beate Liepert) was involved in some of the earlier modeling of its affects, including how it affects the formation of clouds, how sulfates decrease the albedo of clouds, how such polution can reduce the solar energy we receive on cloudless days, and how aerosols resulted in observed reduction of sunlight from the 1961-1990.
Here are a few of the posts Real Climate has had on this:
18 Jan 2005
Global Dimming?
Gavin Schmidt
climate modeller at the NASA Goddard Institute for Space Studies in New York
http://www.realclimate.org/index.php?p=105
19 Jan 2005
Global Dimming II
Guest posting from Beate Liepert (Lamont-Doherty Earth Observatory)
http://www.realclimate.org/index.php?p=110
Anyway, for those who are interested:
17 Apr 2006
Global Dimming and climate models
Guest posting from Beate Liepert (Lamont-Doherty Earth Observatory)
http://www.realclimate.org/index.php/archives/2006/04/global-dimming-and-climate-models/
1 May 2007 at 11:42 AM
I agree that the fact that denialists claim it, doesn’t make it false. But it is still false.
Indeed. Look very closely at that graph. Look at the period 1951 to 1970. Does that look like cooling to you?
Rather than trust what it “looks like,” I ran the numbers. I’m a professional mathematician specializing in the statistical analysis of time series. The numbers say: no cooling 1951 to 1970, or 1951 to 1975, or 1940 to 1970, or 1940 to 1975. The only verifiable global cooling is from 1944 to 1951. Seven years. That’s all, folks.
Let’s all face the truth: global cooling from the 40s to the 70s is a myth.
1 May 2007 at 11:56 AM
Here is one angle I am interested in: the more temperate regions are experiencing warmer winters and fewer freezing nights which kill mosquitos. Consequently, mosquitos are having extended seasons, and mosquito-borne illnesses are moving to more temperate zones and are at risk of becoming endemic.
A hemorrhagic type of dengue fever in Mexico:
Lethal type of dengue fever hits Mexico
By Mark Stevenson
Sunday, April 1, 2007 - Page updated at 02:04 AM
http://seattletimes.nwsource.com/html/nationworld/2003645837_dengue31.html
Hemorrhagic dengue is also in the process of becoming endogenous to Taiwan due to warmer winters.
Second dengue fever patient dies in Taiwan
(November 1, 2006)
http://www.sciencedaily.com/upi/index.php?feed=Science&article=UPI-1-20061101-13131500-bc-taiwan-dengue.xml
More dengue fever cases reported in India
(October 17, 2006)
http://www.sciencedaily.com/upi/index.php?feed=Science&article=UPI-1-20061017-10114900-bc-india-dengue.xml
Dengue Surveillance in Florida, 1997â??98
Julia Gill,* Lillian M. Stark,* and Gary G. Clark
Emerging Infectious Diseases, Vol. 6, No. 1, Januaryâ??February 2000, pp 30-35
http://www.cdc.gov/ncidod/eid/vol6no1/pdf/v6n1.pdf
1 May 2007 at 12:18 PM
Incidently, there was a story a while back regarding the production of methane by plants. Real Climate had a couple of posts on it, first because it was puzzling, then because it got misrepresented in the press.
Turns out that we have learned a little more in this regard:
1 May 2007 at 12:27 PM
Hello, is there any evidence that co2 in the paleo record causes catastrophic warming. Is there any evidence that co2 amplifies?
Thanks
1 May 2007 at 12:54 PM
Tamino wrote “The only verifiable global cooling is from 1944 to 1951.”
I apologize for adding scifi to the talk, but I was asked to ask you good people whether you think the Hiroshima/Nagasaki/above ground A-bomb tests might have generated enough airborne debris to contribute significantly to the cooling effect Tamino cited (and I suppose whether general wartime activity elevated fossil fuel use enough to accelerate post-war AGW some). This question I gather comes from musing about Dr. Sagan’s nuke winter idea. I also have been asked to say that the meaningful contributors to RC are simply brilliant
1 May 2007 at 12:58 PM
Re #65: Probably the key relationship to bear in mind regarding Arctic sea ice is that the heat absorption will be through the open water in the summer, but that winter sea ice will still develop and greatly reduce the amount of heat lost then. While summer insolation is obviously much less than farther south, it’s still large enough to do the job (although not by itself at present, since encroaching warm currents have been found to be a big part of it). Another aspect (IIRC) is that the persistence of the Arctic sea ice is related to the presence of a surface layer of relatively fresh water that will be progressively disrupted (by mixing) as the warming proceeds, so the summer ice-free state will itself acquire persistence as that layer dissipates. NSIDC has good non-technical explanations of all of this.
1 May 2007 at 12:59 PM
Ray Ladbury - In #67, you state that scientists now understand the effect of aerosols on global mean temperatures in the 20th century and that the current models confirm the credibility of climate science regarding this issue. The IPCC AR4 report does not appear to share your confidence, as shown in Table 2.11. For the four types of aerosols, the report indicates a level of scientific understanding ranging from low, to low to medium; along with a low grade of consensus.
In #71 you discuss stimulated plant growth and the lack of long-term sequestation of carbon that results from the increased growth. There is actually quite a bit of information to the contrary. The article below is a good place to start.
http://www.co2science.org/scripts/CO2scienceB2C/articles/V10/N18/EDIT.jsp
Thanks
B Buckner
1 May 2007 at 1:28 PM
I would like to commend to everyone’s attention this article by British journalist George Monbiot, author of the book Heat: How to Stop the Planet from Burning:
It is a pretty sobering assessment of the efforts of developed countries to reduce GHG emissions. Monbiot argues that even the most aggressive GHG reduction targets currently being proposed (e.g. by the EU, Britain and Sweden) fall short of what current science says will be needed to prevent “dangerous” global warming of 2 degrees Centigrade above pre-industrial levels.
1 May 2007 at 1:39 PM
M. Buckner —
You’ve been misled by a PR “advocacy” site. Don’t take what you find there as accurate. You _always_ should look at the original paper, not rely on other people’s statements.
You can check your sources with sourcewatch, to find out if they’re PR sites or not:
http://www.google.com/search?q=co2science+sourcewatch
Look them up:
http://www.sourcewatch.org/index.php?title=Center_for_the_Study_of_Carbon_Dioxide_and_Global_Change
In any area where you have some expertise, look for references you know something about and evaluate what they tell you against what you know, for example:
http://scienceblogs.com/deltoid/2006/11/chinese_navy_disproves_global.php#comment-257716
1 May 2007 at 1:47 PM
B. Buckner, I couldn’t get your link to work, but I did spend some time poking around co2science. I recommend it to anybody who needs a good laugh. Must be nice having a job where all you have to do all day is cherrypick the latest studies that provide even minimal support to your position. Oh, and did I say support–Ex-Mob is providing a lot of it to co2science.org.
So, you think all we have to do is plant trees? Then I suppose you’re fine with Al Gore’s carbon offsets, right?
Yes CO2 does promote growth in some plants under some conditions. However, really long-term sequestration requires a continual increase in the amount of carbon stored in plants. Redwoods are a good carbon sink. Brussel sprouts (as anybody who has eaten them knows) are not. Short-lived plants die and decay, returning their carbon to the cycle fairly quickly, not just as CO2, but also a CH4–a more potent greenhouse gas. And long-lived trees grow slowly, and when they reach maturity, the growth stops. What is more, they stop growth under the canopy. So, while forests can act as carbon sinks, the potential is limited. And the assertion that CO2 is a benefit to agriculture is without merit–weeds like CO2 even more than crops do.
As to aerosols, yes, they remain an area of uncertainty. They are certain enough that we know that if you dump soot into the air, you get cooling (or at least a slowdown in warming). They are also certain enough to nail the effect of a volcanic eruption such as Mt. Pinatubo nuts on. In other words, they are certain enough that we know they won’t change the answer dramatically.
1 May 2007 at 1:54 PM
Recent studies looked at increased CO2 and other climate effects on plant growth. Remember, plants need more than CO2 and warmth to grow. Nitrogen and other nutrients in the soil, water levels, and light levels all play important roles. Merely increasing one or two of these factors may not give the expected results. For instance, increasing CO2 may not encourage the plants you would like to grow, but instead encourage “weeds.”
Perspective with links to relevant articles:
http://www.sciencemag.org/cgi/content/full/315/5812/606
Also remember the rate at which this change is happening is faster than a natural climate shift rate, and desirable plants may not be able to move quickly enough. Also, the areas into which plants might migrate may not be suitable for their growth.
1 May 2007 at 1:55 PM
Re: #84 (ghost)
I thought of that idea a little over a year ago; it does seem quite a coincidence that 1945 marked the first A-bomb explosions and several were tested throughout the remainder of the 40s. So I investigated the number of above-ground nuclear explosions, and found that they continued throughout the 50s, but the nuclear test ban treaty reduced the number greatly in the 60s. If I recall correctly, the last above-ground test was in 1970. Global cooling doesn’t match this pattern.
Another idea is that the massive firestorms from conventional bombing late in world war II may have contributed to the global cooling 1944-1951. Moderators — any comments?
1 May 2007 at 2:04 PM
Regarding plant growth…
The Chinese have been doing studies where they vent rice in the field with CO2 which simulates projected levels from 2050. Rice grows more quickly, but has considerably diminished nutritional value. Additionally, the does not take into account the increased temperature (rice is especially sensative to heat) or the effects of drought.
Please see:
Rising carbon dioxide could make crops less nutritious
Jia Hepeng
4 March 2005
http://www.scidev.net/News/index.cfm?fuseaction=readNews&itemid=1969&language=1
1 May 2007 at 2:30 PM
Hank Roberts (#88) wrote:
CO2Science is the name of the online newsletter. The organization is:
Center for the Study of Carbon Dioxide and Global Change
http://www.sourcewatch.org/index.php?title=Center_for_the_Study_of_Carbon_Dioxide_and_Global_Change
Family-owned and strong ties to the fuel industry. Some background in agriculture, too, which might help to explain the cherry-picking.
1 May 2007 at 3:31 PM
Re #90 (TM): This new paper in PNAS discusses the role of nitrogen availability as the limiting factor in forest growth.
1 May 2007 at 4:14 PM
About mitigation, I posted a set of recommendations at:
http://www.realclimate.org/index.php/archives/2007/03/the-ipcc-sea-level-numbers/#more-427, comment #308.
These are radical, holistic re-visions of how we feel and behave toward Earth and how we relate to one another. They may seem too radical, in the sense of going to the roots of the problem, but the alternative is the Lovelockian Earth ridding itself of human pathogens, which is elegant as theory but mind-numbingly brutal in practice. At least let’s try to talk about some fundamental reformations in human society and relationships.
1 May 2007 at 4:28 PM
#66 Mr. Buckner wrote: [There is actually quite a bit of information to the contrary. The article below is a good place to start.]
[http://www.co2science.org/scripts/CO2scienceB2C/articles/V10/N18/EDIT.jsp]
You have indeed been duped by the fossil fuel industry.
They have taken a legititmate scientific paper and selectively edited it so that you will think and act the way they want you to.
This is an old trick of theirs (and the left’s and the right’s as well on global warming) and it has helped stop any action on global warming/climate change for ten years….time that we might or might not have.
Read the original paper at your library or from the origional source and not what someone wants you to believe.
The Union of Concerned Scientists has this to say about the co2science.org website.
http://www.ucsusa.org/ssi/archive/climate-misinformation.html
and
http://www.ucsusa.org/global_warming/science/skeptic-organizations.html
1 May 2007 at 7:14 PM
Timothy Chase (#78):
Thanks for the additional info. Still not the paper I was looking for. I will do some more searching in the next few days.
#92.
The drop in nutrition value is true for wheat and other grains when CO2 passes a certain point. I would have to find a reference, but one of the Universities found that the caterpillars would not go into pupae stage.
1 May 2007 at 7:21 PM
stormboy (#95) wrote:
OK there…
Maybe before we get around to discussing your manifesto, we could cover the IPCC AR4 Report.
I was thinking, we all have topics that we might want to touch on, whether it happens to be how well the plants might do with increased carbon dioxide, the projected intensities of storms, the spread of diseases, global dimming, etc. But rather than trying to discuss all of these things all at once, maybe we could discuss them as they come up which covering the report.
In addition, rather than asking Gavin and the rest of the good people at Real Climate to play Cartesian doubt with it, maybe we can ask that they give their realistic assessments of it, or better yet, maybe let them figure out what they want to cover since they’ve got the degrees and seem to be pretty good at figuring that out all for themselves - and we can raise other points relevant to what is being discussed at the time. But in any case, I think going over the report chapter by chapter, as they intend, will provide the discussion with some structure - and it may even give us the chance to examine what the report actually states. Any critique can be done in relation to its actual content at the time that we are actually going over the relevant part. Then if we think there are other important topics which didn’t fit into the structured discussion, maybe we can turn to them at the end.
Just my two cents…
1 May 2007 at 7:26 PM
Timoothy Chase (#78 again):
Here are two links on sea ice age:
http://ieeexplore.ieee.org/Xplore/login.jsp?url=/iel5/8859/28759/01291384.pdf?arnumber=1291384
http://seaice.apl.washington.edu/IceAge&Extent/
I may have seen a brief article about the first one in IEEE Spectrum.
1 May 2007 at 9:06 PM
Well low and behold, section 7.3.2.2.3 of the IPCC AR4 Report “Residual Land Sink” cites the same paper and comes to the same conclusions as the misleading, laughable, PR advocacy, cherry picking, Exxon-Mobil funded, fossil fuel duping CO2Science site.
Rather than making ad hominem attacks on the authors, perhaps we can deal directly with the science involved.
1 May 2007 at 9:17 PM
The Second Draft for WG1 from several months ago said the following in Chapter 8 (Climate Models and Their Evaluation), Question 8.1: “As a consequence, models continue to display a substantial range of global temperature change in response to specified greenhouse gas forcing (refer Chapter 10), To date it has not been possible to quantify how errors in a model’s simulation of specific climate observations impact on errors in its future climate projections, but a few studies suggest this may be possible in the future. Despite such uncertainties,…”
In the final version that was just released this was changed to the following:
“Consequently, models continue to display a substantial range of global temperature change in response to specified greenhouse gas forcing (see Chapter 10). Despite such uncertainties,…”
The key phrase eliminated here is “it has not been possible to quantify how errors in a model’s simulation of specific climate observations impact on errors in its future climate projections.” In effect, didn’t the Second Draft said that we can’t quantitatively bound errors in climate forecasts generated by global climate models?
Why was this eliminated? Did some new research become available or better understood?
[Response: I’d guess it was because it just didn’t fit. The previous sentence says there are uncertainties, and the next explains what is robust. The missing sentence is related to a distinct issue which is to what extent errors in climatology lead to errors in projections, or even if they do to any significant extent. That is dealt with more comprehensively in Chapter 10. Your rephrasing of the sentence is not the same thing at all. - gavin]
1 May 2007 at 10:14 PM
RE#42, stephen - current estimates are still for a nuclear plant to take some 5-10 years to construct, and the point is that it’s better to invest in solar cell manufacturing (which produce sources of power, not just power) than in new nuclear facilities. As far as the 70’s versus today, there is nuclear construction going on in India, and individual plant investments are still around 3.5 billion $US. This is still better than using coal for electricity generation, but in the long run nuclear fission is a dead-end technology. The solar resource is far larger and mostly untapped, in contrast to nuclear (~20% of current US electricity generation). Why doesn’t it make sense to boost solar to the same level as nuclear?
RE#78 - Timothy, I have to admit that that was a quote lifted from the IPCC report. The issue is very complicated what with black carbon and the effects of stratospheric vs. tropospheric aerosols, as you point out.
RE#100 - CO2 effects on plant growth are well studied and the fact is that there is no evidence that a warming, high CO2 world will result in higher crop yields for a number of reasons: drought, heat waves, nitrogen and phosphorous limitation, etc. It was thought that the increase in CO2 would offset crop losses due to climate change, resulting in a zero-sum effect, but that’s not supported by real-world experiments: Food for Thought: Lower-Than-Expected Crop Yield Stimulation with Rising CO2 Concentrations, Long et al Sci 2006.
To quote from the science magazine summary: “Although rising CO2 levels may reduce global crop yields through the effects of higher temperatures and decreased soil moisture, arguments have been made that direct fertilization effects will more than offset these losses. Long et al. (p. 1918; see the Perspective by Schimel) present a critical analysis of data on which the Intergovernmental Panel for Climate Change base their projections that elevated CO2 will have a fertilizing effect. The original estimates came from experiments conducted in the 1980s in greenhouses and sheltered enclosures. More sobering figures are derived from open-field studies in which increased CO2 levels enhanced crop yields ~50% less than in enclosure studies.”
Keep in mind that the IPCC report doesn’t include recent research, and is a valuable reference but not the last word on the topic of climate change.
1 May 2007 at 10:46 PM
IPCC AR4 Report. Ok.
In #71, Ray Landbury states,
Comment by ray ladbury â?? 1 May 2007 @ 8:25 am
In #86, B. Buckner states,
Later, in #100, B. Buckner states,
Looking at section 7.3.2.2.3, it states:
As such, plants may act as a sink for the sequestration of carbon - just as CO2Science claims.
However, looking at the following paragraph, section 7.3.2.2.3 also states:
(Emphasis added.)
This would seem to be precisely the point that Ray Landbury was making in #71.
Cherry-picking.
1 May 2007 at 10:48 PM
Re: 101
Gavin,
Thanks for your immediate response.
If the issue being addresses in this point was “a distinct issue which is to what extent errors in climatology lead to errors in projections, or even if they do to any significant extent”, is there some known bound on this error, or is it an undefined potential error?
Can you point me to the portion of Chapter 10 where it is addressed?
Thanks in advance.
Best,
Jim
1 May 2007 at 11:56 PM
Ike Solem wrote (#102 in response to #100):
I completely agree.
However, judging from what I uncovered in #103, they seem to have done a very good job of anticipating the more recent research.
Nice.
Thank you for bringing the article to our attention - it is good to see that sort of confirmation.
2 May 2007 at 1:21 AM
Jim wrote (#104):
I would recommend “10.5 Quantifying the Range of Climate Change Projections.” In essence, what we are dealing with are a hierarchy of models, some wider, yet coarser (due to limitations on computational power), others narrower and more detailed. Then with parametrization it is possible to make probablistic projections, compare these against the evidence by means of Bayesian analysis, fine-tune the narrower, more detailed theories by adjusting their parameters and use these to adjust the wider, less detailed theories. Or so it would appear from my first skimming of the first section.
2 May 2007 at 3:46 AM
Re #80 Where