The IPCC is intending to release its Fourth Assessment Report (AR4) in three parts next year. Part 1 is likely to be launched in early 2007 and focus on the physical basis for climate change. Part 2 is likely to be released mid year and focus on impacts of global warming while Part 3 will be released later in the year and focus on how to mitigate climate change.
In this week's journal Nature (Vol 441, 6-7, 4 May 2006) there is information about the climate change predictions in the current draft of Part 1, including:
"The current draft, which represents the message that the scientific authors want to present to policy-makers, contains few statements that will surprise climate researchers, but its tone is much more confident than that of its predecessor, published in 2001. And that, say researchers, will make it harder for sceptical politicians and lobbyists to attack climate predictions.
"People won't be punching holes in the science," says Jay Gulledge, a senior research fellow at the Pew Center on Global Climate Change in Arlington, Virginia. Emily Shuckburgh, a climate researcher at the University of Cambridge, UK, agrees: "If you're a sceptic, it's difficult to see where to attack on the modelling side."
One critical number in previous reports has been the sensitivity of the climate to increases in greenhouse-gas levels. In 2001, scientists estimated that a doubling of carbon dioxide levels would cause an increase of 1.5–4.5 °C, but acknowledged that this range was little more than a best guess. The draft 2007 WGI report describes how new models and data sets allow the range to be properly quantified. It estimates the effect of doubling carbon dioxide as a rise of 2.0–4.5 °C and, for the first time, suggests a single most likely figure: 3 °C. This estimate is already widely accepted by climate scientists.
Another set of predictions that have become much more robust are those about 'commitment' — the ongoing climatic changes that would be expected even if greenhouse-gas levels could be stabilized. The existence of commitment was acknowledged in the last WGI report, but no number was given in the policy-makers' summary. In contrast, the 2007 summary stresses that even if greenhouse gases level off now, warming will continue at about the current rate for several decades.
The error bars have also shrunk substantially on one of the biggest uncertainties in 2001 — the role of aerosols such as soot from fires, which exert a cooling effect by reflecting sunlight. In addition, certainty over politically important statements about whether climate change has already been observed has increased. Data on twentieth-century changes in precipitation and sea-level rise are now more precise, and the risk of ocean acidification is detailed for the first time. Such assertions are likely to be seized on by environmental groups if they appear in the final document."
If you have a password, you can access the draft here: http://www.climatescience.gov/Library/ipcc/wg14ar-review.htm .
The claim from Ian Castles that we should follow no cost policies only at this time rings hollow. Those of us in the reality based community were advocating such policies ten years ago when the science was less certain. We also said that it was important to move quickly then as the climate system has a lot of momentum. The Ian Cs of the world said, not needed, move on. Increasingly today no cost policies will not be enough, in large part because of the delay. Indeed, if you actually read Hansen, while advocating no cost policies simply to get moving, he states that they will NOT be enough and that stong restrictions on greenhouse gas emissions will be necessary later on.
I am working on a sea level post, but in that regard interested readers might take a look at http://tinyurl.com/pdjr6 for links to original source materials.
Ian,
I have no choice but to and no reason not to accept that that you are "arguing that measures that constrain emissions should make economic sense independent of global warming" and not "insisting on 'complete inaction'."
I am however left wondering what is the point of our whole discussion about consensus and sea level.
Thanks for the economic food for thought, I can not fairly make very much comment as it is not material I am very familiar with. On the subject of cost-benefit analyses, can you tell me by any chance what cost is typically assigned to widespread coral reef death? Also, is ocean acidification and its effects a factor in these kinds of studies?
That should give you a clear idea of the kind of concerns I have with the economic views of climate change I am barely familiar with (and I am not talking about esthetic value here, I really mean the dollar cost of coral reef death). Similarily, what is the cost of losing Miami completely? Does such an assessment include the removal cost for the population? Is an value assigned to the trauma of forced relocation? I know that there are formulae for such things in legal liability cases.
I have such a big problem that I don't know where to start, with this notion that if we accumulate enough wealth we will be able to deal with very severe climate change. To turn a cliche on its head, money doesn't grow on trees, but food does, what good will money be if there is not enough food globally and water is no longer available where huge populations live?
I agree with you and Hansen that there are alot of "no regrets" options available right now and we should take advanatage of them ASAP.
Coby, I’ll be happy to agree that Eli has a good point if he, you or anyone else can cite a prediction of a less-than-50cm rise by 2100 (at the low end) by any recognised institution or individual scientist that was published before 1987. If there was such a prediction, I'm surprised it was not mentioned in either the Titus or Morgenstern papers.
I agree with you that no one has a crystal ball and that as science progresses the predictions are likely to become more reliable.
Your jibe about a 'decision making realm' that supposedly 'insists' on complete inaction presumes that the actions that we should take now if it is certain that the planet will continue to warm and that sea levels will continue to rise are radically different from those that should be taken in the absence of such certainty. I don’t believe that they are.
The subject has been discussed at length on this blog. In response to questions about my preferred action plan, I cited the submission made to the House of Lords Economic Committee by Dr. Indur Goklany, Assistant Director, Science and Technology Policy, Office of Policy Analysis, US Department of the Interior. Dr. Goklany's submission, which was made in a personal capacity, included the following:
'Not only would either focused adaptation or adherence to the [Millennium Development Goals] provide greater benefits at lesser costs through the forseeable future than would any emission reduction scheme, they would help solve today's urgent problems sooner and more certainly. Equally important, they would also increase the ability to deal with tomorrow's problems, whether they are caused by climate change or other factors. None of these claims can be reasonably made on behalf of any mitigation scheme today.
'Accordingly, over the next few decades the focus of climate policy should be to (a) broadly advance sustainable development, particularly in developing countries since that would generally enhance their adaptive capacity to cope with the many urgent problems they currently face, including many that are climate-sensitive; (b) specifically reduce vulnerabilities to climate-sensitive problems that are urgent today and might be exacerbated by future climate change; and (c) implement 'no regrets' emission reduction scenarios, while (d) concurrently trying to expand the universe of no-regrets options through research and development to increase the variety and cost-effectiveness of available mitigation options.'
The detailed argument and proposals are spelled out in Dr. Goklany’s submissions. He has been presenting the case for a response to climate change along these lines for many years. Here, for example, is the abstract of his paper 'Strategies to enhance adaptability: technological change, economic growth and free trade', which was published in 'Climatic Change' 1995, vol. 30: 427-449:
‘This article proposes three broad interrelated strategies - stimulating technological change, sustainable economic growth and free, unsubsidized trade - to enhance future adaptability to global (including climate) change and some principles for developing the social, legal and economic frameworks necessary to effect these strategies. The proposals are based upon an examination of the present and potential contributions of the strategies to sustainability, adaptability, and mitigation (limitation) of environmental changes, and the various synergies between these strategies. The strategies and principles would meet criteria which recognize that climate change is inevitable, that any climate change will occur in the context of already-occurring global change due to other agents of change, and that reducing vulnerability to these other changes will increase the future adaptability to climate change. Specifically, the strategies should: (a) increase the ability to feed, clothe and shelter the world's expanding population regardless of the agent of change; (b) reduce vulnerability of forests, habitats and biological diversity to demographic and other environmental stresses; (c) be compatible with mitigation measures; (d) be independent of results from more detailed and accurate site-specific impacts assessments which will be unavailable for several years; (e) be implementable today; and (f) have clear benefits now and in the future.’
In his paper ‘Understanding Common Climate Claims’ that is to appear in the Proceedings of the 2005 Erice meeting of the World Federation of Scientists on Global Emergencies, Richard Lindzen argues along somewhat similar lines to reach the conclusion that ‘policies promoting the improvement of general welfare throughout the world are also, automatically, the appropriate policies with respect to climate change.’
The ‘automatically’ may be something of an exaggeration, but the IPCC's B1T MESSAGE scenario demonstrates that steep reductions in GHG emissions could well be achieved without assuming the implementation of policies explicitly addressing climate change. James Hansen argued along similar lines in ‘A Brighter Future’, Climatic Change, 2002, vol. 52, no. 4: 435-440 (‘It is possible to achieve a climatically brighter path with actions .. that make economic sense independent of global warming’). I don’t agree that arguing that measures that constrain emissions should make economic sense independent of global warming is the same thing as insisting on 'complete inaction'.
Vincent, you're lying about Zwally 2005 and you know it. Zwally's data didn't include the rapid ice loss at the ice sheet edges shown by contemporaneous papers.
I don't think it is your goal Ian, but you are really weakening your claim that Morgenstern's figure were really a consensus with all these other figures from other agencies. Regardless, Eli has a good point that there are many conferences and many speakers and quoting one speaker at one conference opining about what the consensus is, no matter how expertly, is not a very good comparison to the IPCC process.
If you are merely trying to make the point that scientific findings evolve and/or there is a good deal of uncertainty around sea level rise predictions then you are perfectly correct but I would like to know what specifically you are implying by that.
Before it gets lost in the noise I did want to respond to this a few comments of yours back:
"You say that both predictions are satisfied simultaneously. If the IPCC were now to predict that the sea level change by 2100 will be between -70 cm and + 70 cm, would you claim that the 1987, 2000 and 2006 predictions were all satisfied simultaneously?"
Firstly, any two predictions with overlapping ranges are not in total disagreement, that's just a fact. Secondly, yes I would still correctly tell you that an additional -70 to +70 prediction is not in total disagreement, but I would tell you it is not a very informative prediction.
You really need to think hard about what it is you want, no one has a crystal ball. We are talking about risk mitigation. I also think it is very fair to say that as science progresses the predictions are likely to be more reliable. Could we learn more and change the predictions later? Yes, certainly this is always possible but, seriously, what do you think that implies? I think at this stage it is *extremely* unlikely that the planet will not continue to warm and sea level will therefore inevitably rise. We don't know how much how fast and probably will not until it has happened.
There is no other decision making realm that insists on complete inaction absent absolute certainty of danger.