September 01, 2006
Posted to Author: Pielke Jr., R. | Climate Change
Can this be a correct reporting of the IPCC's forthcoming report?
THE world's top climate scientists have cut their worst-case forecast for global warming over the next 100 years.
Is the climate policy debate really about the difference between a global average temperature change of 2+ and 3 degrees C over the next 93 years?Posted on September 1, 2006 10:50 PM
Well, time will tell, but I wonder if this is not just a garbled reporting of climate sensitivity to 2x CO2.
I hope that this report looks harder at possible carbon cycle feedbacks, these are very dangerous possibilities even if they are highly uncertain. There is a hell of a lot of methane in permafrost and ocean sediments and there is the possibility of a "composting" effect as soils warm.
Posted by: coby at September 1, 2006 11:45 PM
Obviously garbled. As Coby points out, the confusion is over the refinement of climate sensitivity to 2xCO2. This is probably going to be given a 'most likely' value of near 3 deg C and range from 2 to 4.5. This is emphatically not the same as the projected range for 2100 - which is unlikely to be much different from TAR. (Note that the revisions after the second order review have not yet been released, let alone approved, so it's a little premature still for comments).
Posted by: Gavin at September 2, 2006 03:40 AM
To borrow my favorite new word from a blogging science policy scholar of my acquaintence, this is pretty clearly undertermined. Trying to guess what the IPCC report says based on a somewhat confused newspaper story and then discussing that doesn't seem terribly fruitful.
Posted by: jfleck at September 2, 2006 11:33 AM
John- I agree! I am fishing for clarity from someone who might know fisthand what is actually being referred to . . . the circle of people with access to the IPCC who might leak a draft to the Weekend Australian has got to be pretty small ;-)
Posted by: Roger Pielke, Jr. at September 2, 2006 11:46 AM
Probably one of those guys from the New Zealand Climate Science Coalition. And they probably (mis)interpreted it for the report too.
Posted by: coby at September 2, 2006 12:17 PM
Thinking that the IPCC might do issue an honest scientific assessment of possible temperature increases during the 21st century in AR4 is like thinking that a chimp might win the World Chess Championship in 2007.
They've gotten away with being blatantly dishonest for more than 5 years...why in the world would they change now?
Posted by: Mark Bahner at September 2, 2006 05:45 PM
Coby - if you check on the website of the New Zealand Climate Science Coalition (www.climatescience.org.nz) you will find that there are links to two articles directly from the "Australian" newspaper. We are just the messenger dodging your bullets!
Posted by: Terry Dunleavy at September 2, 2006 10:42 PM
Here's another (paraphrased) line from the report:
Draft report, do not cite, do not quote.
Posted by: Scott at September 3, 2006 11:17 AM
Seams that media is picking up just parts of this, wondering about the leak to the Weekend Australian...
Posted by: Eric at September 3, 2006 10:36 PM
Thanks to a number of folks who emailed me from Australia (and elsewhere) I am convinced that:
a) The story in The Australian is not an accurate description of the forthcoming IPCC report, and
b) That The Australian may not be a disinterested party in this debate, and thus may not be a reliable source of information.
These are my current views, however, if anyone at The Australian would like to reply we'll print it.
Thanks to those who have written in!
Posted by: Roger Pielke, Jr. at September 4, 2006 05:42 AM
Roger. I amf fascinated by this sentance:
"The Australian may not be a disinterested party in this debate, and thus may not be a reliable source of information."
Posted by: Paul at September 4, 2006 08:58 AM
Just following up on my last note after doing a bit of blog surfing. Now I understand. The integrity of the journalist is being questioned. I thought you were above such tripe Roger.
Posted by: Paul at September 4, 2006 09:21 AM
Well, at least lets hope that the IPCC this time prepares a Summary for Policymakers that more closely reflects the body of the report than happened with TAR. In that case, it is quite evident that "someone" saw fit to edit the original Summary to remove nuance, qualification, and a generally more moderate assessment.
Of course, that someone was merely following the strategy advocated and acknowledged by Stephen Schneider, Al Gore (and it seems Michael Mann and the folks at RC) that it is OK to exaggerate the problems since it is necessary to frighten the public in order to get them to support action to prevent AGW. The end justifies the means.
Posted by: mtb at September 4, 2006 03:27 PM
Paul D.- Thanks for your comments. But where were you when,e.g., I was questioning whether Rajendra Pachauri was not a disinterested party on climate policy? We ought to call the game the same way no matter what team is at bat, no?
Posted by: Roger Pielke, Jr. at September 4, 2006 03:38 PM
RealClimate appears to agree with our views on this subject and the importance of setting things straight:
We agree with their thoughts on when to comment on the IPCC forthcoming report.
Posted by: Roger Pielke, Jr. at September 4, 2006 04:05 PM
"We agree with their thoughts on when to comment on the IPCC forthcoming report."
which explains why you opened your post with "Can this be a correct reporting of the IPCC's forthcoming report?" and have left undeleted a comment which purports to be a direct quote from some version of it...
Posted by: James Annan at September 4, 2006 06:49 PM
James- Thanks for your comment. As RC says, " we are prepared to correct obvious errors" [in reporting of IPCC], and that is what we have done here.
Posted by: Roger Pielke, Jr. at September 5, 2006 01:36 AM
Isn't this part of the statement very incorrect, " ... contained to 2C by 2100 if greenhouse gas emissions are held at current levels." in that it is impossible that emissions can be held to current levels. It's a very false premise. Emissions might be reduced back to current levels at some time in the future, but they cannot under any conditions whatsoever be held at current levels.
Posted by: Dan Hughes at September 5, 2006 07:01 AM
Hi there -
Does anyone know which draft is being bandied about in the news? I have the "government/expert review" draft that I am assiduously not citing, but I've assumed there's already a later draft, like a near final, or second government review, or what have you.
Does anyone know which draft is being cited on the narrowed projection range?
Posted by: KenGreen at September 5, 2006 01:25 PM
The draft is widely available and the position of the IPCC is clear.
There is no change in the "projections" for 2100 from those published in "Climate Change 2001", namely 1.5-5.8°C depending on the scenario and the model used. These do not consider possible "mitigation" measures
The measures that are reported are from a section which considers the reduction in these "projections" when "stabilization" commitments are made at various levels.
It should always be realised that several of the "scenarios" make absurd assumptions about the future and none of the models that are used to derive temperatures have ever been shown to be capable of a reliable climate forecast
Posted by: Vince Gray at September 5, 2006 03:03 PM
For the sake of argument, assume that the business as usual, or do nothing, scenario does in fact give an expected 3C rise in global temperature by 2100 and a do something effective scenario, whatever it is, will produce a rise of 2C by 2100. What difference will it make to wait ten years, say, before starting to do something? Would it be in the ball park of 0.05, 0.2 or 0.5C?
Posted by: DeWitt Payne at September 5, 2006 06:49 PM
We are trying to avoid a discussion "for the sake of argument." We are trying, here, to include reality. Therefore, your question is precluded by Vincent's previous statement:
"It should always be realised that several of the "scenarios" make absurd assumptions about the future and none of the models that are used to derive temperatures have ever been shown to be capable of a reliable climate forecast."
Posted by: Steve Hemphill at September 5, 2006 08:40 PM
"Paul D.- Thanks for your comments. But where were you when,e.g., I was questioning whether Rajendra Pachauri was not a disinterested party on climate policy? We ought to call the game the same way no matter what team is at bat, no?"
Can you point to the specific elements of the report in question that would cause you to dismiss either the article, the author or the publicaton as compromised? All we seem to have is a mistake in one part of the report stemming out of niaiviety. Apart fomr that it seems relatively balanced, with the last word going to someone warning against the potential severe consequences of anthropegenic climat change.
Where I come from here is a saying "play the ball, not the man"
Posted by: Paul at September 6, 2006 06:10 AM
If a doctor said that he had a pill that had been computer modelled to show that it was perfectly safe, would you take it?
Posted by: chrisl at September 6, 2006 06:52 AM
DeWitt Payne writes, "For the sake of argument, assume that the business as usual, or do nothing, scenario does in fact give an expected 3C rise in global temperature by 2100..."
Steve Hemphill responds, "We are trying to avoid a discussion 'for the sake of argument.' We are trying, here, to include reality."
I agree that there is no need to assume that "business as usual" results in a 3C rise in global temperature "by 2100"...especially if the starting point in 2006.
The IPCC "projected" a rise of "1.4 to 5.8C" from 1990 to 2100. The evidence since then is overwhelming that the expected warming will be less than 2C by 2100...particularly if we take 2006 as the starting point (rather than 1990).
In fact, the evidence is approximately 50/50 that the warming from now until 2100 will be 1C or less. See slide 43 (page 57 of 64) of James Hansen's Keeling Lecture:
Posted by: Mark Bahner at September 6, 2006 08:53 AM