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House and Senate committee hearings

30 Jan 2007 by group

There are two hearings today from the new congress that are of relevance for RealClimate readers:

The House Oversight Committee is having hearings on the possible suppression of climate change science by the administration (streaming from here). Witnesses include Drew Shindell (NASA GISS), Roger Pielke Jr. and R. Piltz. Update: Full hearing video available at C-SPAN.

The Senate EPW Committee is having an open forum for senators to discuss climate change legislation (streaming from here).

Filed Under: Climate Science, RC Forum

Stern Science

28 Jan 2007 by group

Translations: (Français) (Português)

Halldór Björnsson, William Connolley and Gavin Schmidt

Late last year, the UK Treasury’s Stern Review of the Economics of Climate Change was released to rapturous reception from all sides of the UK political spectrum (i.e. left and right). Since then it has been subject to significant criticism and debate (for a good listing see Rabbett Run). Much of that discussion has revolved around the economic (and ethical) issues associated with ‘discounting’ (how you weight welfare in the future against welfare today) – particularly Nordhaus’s review. We are not qualified to address those issues, and so have not previously commented.

However, as exemplified by interviews on a recent Radio 4 program (including with our own William Connolley), some questions have involved the science that underlies the economics. We will try and address those.

[Read more…] about Stern Science

Filed Under: Climate modelling, Climate Science, Extras, IPCC, Reviews

When the mites go up…

22 Jan 2007 by group

Guest Commentary from Andy Baker, U. of Birmingham

It doesn’t seem obvious really. Going underground into caves, removing stalagmites and analysing their isotopic composition isn’t the first thing you would do to look for past climate information. But for nearly 40 years, there has been an active, and growing research community that investigates the climate records preserved in these archives. Stalagmites have recently received high profile use in climate reconstructions, for example records from China and Norway have featured in Moberg’s last millennium temperature reconstruction; in a northern hemisphere temperature reconstruction of the last 500 years and even been debated here on RealClimate. So it seems timely to review why on (or even under) earth should research go underground to look at surface climate.

[Read more…] about When the mites go up…

Filed Under: Climate Science, Paleoclimate

Calling All Science Teachers

15 Jan 2007 by group

“An Inconvenient Truth,” the Davis Guggenheim documentary on global warming starring Al Gore’s presentation on the subject, provides an accurate, engaging, accessible, thought-provoking and (at times) even humorous introduction to one of the most important scientific issues of our time ( see our review of the movie). In some countries, viewing “An Inconvenient Truth” has actually become a required part of the science curriculum, and with good justification, we think. Given that the DVD is currently selling for $19.99 through Amazon.com, you’d think that the National Science Teachers’ Association ( NSTA) would jump at the chance to quickly get 50,000 free copies quickly into the hands of their members. Yet, when Laurie David, one of the producers of the film, made this offer to NSTA last November, it was summarily turned down on the grounds that the NSTA has a 2001 policy against “product endorsement” (as if Laurie David were trying to shop some new deodorant to high school science teachers). What in the world is going on here?

Before continuing with the history of NSTA’s bizarre decision, let us provide you with the most important information: Up to 50,000 US science teachers can receive a free copy of the DVD by filling out a simple request form here . The deadline for requesting your copy is January 18, so if you want a copy, take a few minutes to put in your request right away.
[Read more…] about Calling All Science Teachers

Filed Under: Climate Science

Arctic Sea Ice decline in the 21st Century

12 Jan 2007 by group

Translations: (Français)

Guest Commentary by Cecilia Bitz, University of Washington

Last month a paper I co-authored received considerable media attention. Headlines read “Experts warn North Pole will be ‘ice free’ by 2040”, “The Big Melt: Loss of Sea Ice Snowballs“, and “Arctic Clear for Summer Sailing by 2040: Models Predict Rapid Decline of Sea Ice”. The story also reached NPR, BBC, CBC, the Discovery channel, and Fox News, among others. Dr. Marika Holland, the first author of the paper, was inundated with media attention. About a dozen journalists contacted me too. I was impressed by the questions they posed — questions that probably reflect what the public most wants to know. However, after giving lengthy interviews, I would read the resulting article and see my explanations boiled down to a few lines. In this essay, I’d like to explain the science in the paper and give my answers to the most often asked questions.

[Read more…] about Arctic Sea Ice decline in the 21st Century

Filed Under: Arctic and Antarctic, Climate Science

Consensus as the New Heresy

3 Jan 2007 by group

Gavin Schmidt, Michael Mann, David Archer, Stefan Rahmstorf, William Connolley, and Raymond Bradley

Andy Revkin, who’s one of the best journalists on the climate beat, wrote a curious piece in the NY Times discussing the ‘middle stance’ of the climate debate. It’s nice to see news pieces on climate that aren’t breathless accounts of a new breakthough and that take the time to point out that the vast majority of relevant scientists take climate change extremely seriously. To that extent, the message of this piece was a welcome one. The curious part, however, was the thread running through the piece that this middle ground is only now emerging, and even curiouser, that this middle ground can be characterized as representing some sort of ‘heresy’.

Heresy, is commonly defined as ‘an opinion or doctrine at variance with the official or orthodox position’. So where does this idea come from, and why is it now ’emerging’?
[Read more…] about Consensus as the New Heresy

Filed Under: Climate Science, RC Forum, Reporting on climate

2006 Year in review

27 Dec 2006 by group

Translations: (Français)

A lighthearted look at the climate science goings-on over the last year:

Best highlight of the gap between the ‘two cultures’:
Justice Scalia: ‘Troposphere, whatever. I told you before I’m not a scientist. That’s why I don’t want to have to deal with global warming’ .

Least effective muzzling of government climate scientist by a junior public affairs political appointee:
George Deutsch met his match in Jim Hansen.

Most puzzling finding that has yet to be replicated:
Methane from plants

Worst reported story and least effectual follow-up press release:
Methane from plants

Best (err… only) climate science documentary on public release:
An Inconvenient Truth.

Most worn out contrarian cliche:
Medieval English vineyards.

Previously prominent contrarian cliche curiously not being used any more:
“The satellites show cooling”

Most bizarre new contrarian claim:
“Global warming stopped in 1998”.
By the same logic, it also stopped in 1973, 1983, and 1990 (only it didn’t).

Most ironic complaint about ‘un-balanced’ climate coverage on CNN:
Pat Michaels (the most interviewed commentator by a factor of two) complaining that he doesn’t get enough exposure.

Most dizzying turn-around of a climate skeptic:
Fred Singer “global warming is not happening” (1998,2000, 2002, 2005) to global warming is “unstoppable” (2006)

Best popular book on the climate change:
Elizabeth Kolbert’s “Field Notes from a Catastrophe”

Least unexpected observations:
(Joint winners) 2006 near-record minima in Arctic sea ice extent, near-record maxima in Northern Hemisphere temperatures, resumed increase in ocean heat content, record increases in CO2 emissions

Best resource for future climate model analyses:
PCMDI database of IPCC AR4 simulations. The gift that will keep on giving.

Best actual good news:
Methane concentrations appear to have stabilised. Maybe they can even be coaxed downward….

Biggest increase in uncertainty as a function of more research:
Anything to do with aerosols.

Least apologetic excuse for getting a climate story wrong:
Newsweek explains its 1975 ‘The Cooling World’ story.

Most promising newcomer on the contrarian comedy circuit:
Viscount Monckton of Brenchley

Least accurate attempted insinuation about RealClimate by a congressional staffer:
‘There’s so much money’: Marc Morano (Senate EPW outgoing majority committee staff, 5:30 into the mp3 file)

Boldest impractical policy idea:
Geo-engineering

Boldest practical policy idea:
Creation of a National Climate Service, which could more effecitvely provide useful climate information to policymakers.

Most revealing insight into the disinformation industry (fiction):
Thank you for smoking

Most revealing insight into the disinformation industry (non-fiction) and year’s best self-parody:
‘CO2 is life’

Feel free to suggest your own categories and winners…

Filed Under: Climate Science, RC Forum

Further comment on the Supreme Court briefs

7 Dec 2006 by group

Comment from Scott Saleska (elevated from previous post). The discussion refers to the brief submitted in support of the EPA position organised by CEI in opposition to the ‘Scientists’ brief‘ that Scott was a party to.

Was there was a reply to CEI brief?

There was no formal venue for a reply, at least not before the court. The general consensus of those of us who discussed it was that the CEI brief was pretty poor anyway. For what it is worth, below are some comments I emailed to my colleagues after I reviewed the CEI brief, followed by comments by Dr. Curt Covey, whose work was cited in the CEI brief:

— begin quoted excerpts of my email —

Our climate scientist brief focused narrowly and conservatively on two questions: (1) whether the state of the science was accurately represented by the EPA and by the lower court, and (2) whether the science is sufficiently compelling to support a judgement that the legal standard for regulation is met (i.e., may greenhouse gas emissions “reasonably be anticipated to endanger public health or welfare”?)

A relevant claim that our scientists brief is wrong or misleading would therefore have to consist of an argument that either (1) the state of the science was in fact accurately characterized by the EPA or the Appeals Court, or (2) that in fact, greenhouse gas emissions may NOT be reasonably anticipated to endanger public health or welfare. The CEI brief does neither, so I suspect it will not have much relevance to the case at hand.

The CEI brief discusses a range of broad questions on which the Climate Scientist’s brief takes no position (e.g. whether the “net” effects of CO2 emissions “will” endanger public health or welfare, or what history would have been like if industrial development had taken a less CO2-intensive trajectory), and quibbles with technical details which have little or no effect on the answer to the overall question no matter how they are resolved (e.g. whether the NRC/NAS statement in 2001 that post-1950 ocean warming was 0.050C is meaningfully different from the Levins et al. 2005, more recent figure of 0.037C).

As far as the technical details, a quick survey convinces me there is not much there. Just to cite a few, taken more or less at random (I have not had time to look at all):

CO2 growth rates (CEI, p. 11): arguments about what growth rates for CO2 emissions that some models use are besides the point of what the science says about the climate sensitivity of the earth system (emissions growth rates are if anything an economic question). It is well-recognized that many of the original emissions scenarios in IPCC overstated the trajectories that were actually realized (indeed, this was a minor point made in the NRC/NAS 2001 report that was picked up on, and misunderstood or misrepresented, by the Appeals Court), but so what? Unless they are arguing that actual BAU emissions will be so low as to prevent CO2 from any further significant build up (or at least stay under a doubling), this is a detail entirely irrelevant to climate science, and almost entirely irrelevant to the question about “reasonable anticipation of endangerment”.

Hurricanes (CEI, p. 16). We barely mention this, as a parenthetical (not as a “prediction” but as a citation of IPCC TAR’s reference to “likely increases” in tropical storm intensities). I am surprised they went after this, with all the recent work showing that the evidence for this has only gotten stronger since 2001. Yes, there is still debate about whether it has reached canonical levels of statistical significance (95% confidence), and there are problems with data quality yet to be fully resolved, but the standard in the law is lower (“may reasonably anticipate” endangerment). Are they arguing, in the light of Emanual 2005, and Webster et al., 2005, that it would be entirely unreasonable to anticipate stronger hurricanes in the future? If not, what is the point?

Satellite and surface temp records (CEI p. 23). The main substantive thing we said with respect to this is that “all available data sets show that both the surface and the troposphere have warmed,” which the CEI brief criticizes. But the quote they criticize is not ours, it is from the U.S. CSSP (2006) re-assessment (the subtitle of which is “understanding and reconciling differences”). An author of the CSSP (and of the Executive Summary, from which our quote is taken) is John Christy, who is an amicus on the CEI brief. Is he arguing against himself? Perhaps he didn’t realize this CEI comment was in there when he signed on.

—- end Saleska quotes —-

With regard to the CO2 scenarios, the CEI brief cited a paper by Curt Covey. My colleague and co-amici David Battisti inquired of Dr. Covey if he had any comments about the way CEI cited his work, and he responded, saying we were free to circulate his comments. Here they are:

— begin quote of Covey email —-

Dear Prof. Battisti,

Part of my job here at LLNL is to accurately communicate the results of my work to scientific colleagues and the public. Accordingly, you should feel free to share the comments below.

Page 11 of the brief begins, “As shown below, computer models predicting future warming must overestimate warming, because they generally use an incorrect increase in carbon dioxide concentration of 1% per year.” It is not true that models “generally use” this rate of increase. Model
simulations of 20th century global warming typically use actual observed amounts of atmospheric carbon dioxide, together with other human (for example chloroflorocarbons or CFCs) and natural (solar brightness variations, volcanic eruptions, …) climate-forcing factors. Model simulations of future global warming use analogous input; of course it is not possible to observe the future, so a variety of scenarios involving possible atmospheric concentrations of carbon dioxide, etc., are employed. These range from stabilization of atmospheric carbon dioxide at twice its pre-industrial value by the end of this century (IPCC SRES B1) to continuously increasing atmospheric carbon dioxide at the rate of a bit less than 1% per year (IPCC SRES A2). Each climate model simulating the future is run several times, with several different scenarios. All of this has been standard practice in climate modeling for the past ten years.

Pages 11-12 quote my 2003 review paper correctly regarding idealized simulations in which atmospheric carbon dioxide is assumed to increase at the precise rate of 1% per year. Note that in the end of the quoted passage, I say that this rate of increase could “perhaps” be considered realistic “as an extreme case in which the world accelerates its consumption of fossil fuels while reducing its production of anthropogenic aerosols.” I’m no expert on scenarios, but from what I hear about China and India I wonder if the world is already on that track. In any case, the purpose of the 1%-per-year scenarios is to compare different models’ responses to identical input — not to produce realistic possibilities of future climate. For the latter purpose, climate model output from the IPCC SRES B1, A2 and other scenarios has been widely used for several years and has been publicly available for
over two years on my group’s Web site at http://www-pcmdi.llnl.gov/ipcc/about_ipcc.php.

Finally it is not true, as implied on Page 12, that “sole reliance on models to the exclusion of observed behavior” is the basis of future climate prediction. As noted above, modern climate models are used to
retrospectively simulate the 20th century as well. Simulation of 20th century global warming is an important confidence-builder for climate models. Indeed, the observed warming during the 20th century cannot be explained other than by assuming that the models are reasonably accurate
in their response to greenhouse gases. This point was clearly made by the IPCC report published in 2001. Pages 12-13 ignore all this and instead use “a constant-rate warming” of 1.8 degrees C per century “based on actual observations.” A constant-rate (i.e. straight-line) extrapolation of global warming from the 20th to the 21st century, as in the brief’s Figure 2, is a favorite technique of one of the authors, Pat Michaels. This technique gives 21st century warming at the low end of the spectrum of possibilities resulting from the different model-input scenarios. It is one possible future, but it’s never been clear to me (or to anyone else I know besides Pat) why the other possibilities — all of which involve more global warming — should be ignored.

Sincerely,
Curt Covey

—- end of Covey email —

Hope that is helpful to you and other interested parties.

Best,
Scott

Filed Under: Climate Science

Supreme Court Amicus Curiae from scientists

29 Nov 2006 by group

In the wake of the NY times editorial yesterday, we’ve been asked to provide a link to the Amicus Curiae (draft) written by David Battisti, Christopher Field, Inez Fung, James E. Hansen, John Harte, Eugenia Kalnay, Daniel Kirk-Davidoff, James C. Mcwilliams, Jonathan T. Overpeck, F. Sherwood Rowland, Joellen Russell, Scott R. Saleska, John M. Wallace and Steven C. Wofsy in the current Supreme Court case (Commonwealth of Massachusetts et al vs. US EPA et al). Some discussion of this statement is also available at Prometheus.

Update: The actual brief (of which the first link was a draft) is available here (see comments below).

Update 2: We also note that on the final brief, Mario Molina, Ed Sarachik, Bill Easterling, and Pam Matson were additional signers.

Filed Under: Climate Science, RC Forum

Global cooling, again

27 Oct 2006 by group

The ice age is coming, the sun’s zooming in / Engines stop running and the wheat is growing thin /A nuclear error, but I have no fear /’Cause London is drowning, and I live by the river (chorus from London’s Calling, by Strummer/Jones, 1979).

[Read more…] about Global cooling, again

Filed Under: Climate Science, Reporting on climate

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