Science and politics of global climate change

Dessler e-mail to Lindzen on 1/17/11

2011-01-17T14:47:00.001-08:00

Dick-

First, I’d like to comment on your statement that, “The issue of
whether clouds can cause El Nino is a red herring.” I agree, and I
assume from this that you also have no physical evidence that clouds
are causing surface temperature changes. If you did, you would be
advancing it as a fatal flaw in my paper.

What’s puzzling is that I just re-read the comment you submitted to
Science about my paper. In it, your first and main point is: “These
results imply that [Dessler’s results are] ... not indicative of the
cloud feedback, but is largely a consequence of the temperature
changes induced by non-feedback cloud variations.” That sure sounds
like “clouds cause ENSO” to me.

So have you concluded that your comment to Science is now a “red
herring”? Are you going to withdraw it?

OK, now on to the meat of your e-mail. You make the argument that
there are certain time scales over which the feedback must be
calculated.

To be honest, I simply don’t follow the logic of your argument.
Luckily, it sounds like this is really point number 2 from your
Science comment, which is reasonably clear: “A second problem arises
from the use of regression over the whole record. The problem here
stems from the fact that feedbacks introduce temporary imbalances to
the radiative budget (over time scales of hours to months), but over
longer periods (years to decades depending on climate sensitivity),
the system equilibrates so as to eliminate these imbalances (6). Using
the whole record acts to distort the feedback estimates by including
equilibration as well as feedback. More accurate estimation of
feedback requires the isolation of the specific feedback signals (5,
6).”

I have two responses. First, as I wrote in my response to the Science
comment, “Their second criticism indicates confusion between forcing
and feedbacks. It is forcing (e.g., an increase in greenhouse gases,
a brightening Sun) that generates imbalances in the Earth’s radiative
budget. This radiative imbalance then causes the planet to warm,
restoring equilibrium. Feedbacks do not create a radiative imbalance
— they simply change the magnitude of the warming necessary to restore
radiative balance. When estimating the magnitude of a feedback, there
is no requirement that the Earth’s surface temperature be either in or
not in equilibrium.” Clearly, as articulated in your Science comment,
this argument is fundamentally wrong.

Second, I wonder what the source is of the claim that we must consider
equilibrium time scales in our analyses of feedbacks. It appears to
be reference 6, which is Lindzen and Choi 2009. But the claim is not
proven in that paper --- it is simply assumed (in paragraph 5 of that
paper). Can you provide a reference where some evidence is presented
in support of this claim?

Thanks!

Dessler e-mail to Spencer on 1/17/11

2011-01-17T14:46:00.000-08:00

Roy-

Correlation does not prove causality. Period. I honestly cannot
believe you want to argue this point. The fact that you do lays bare
the intellectual bankruptcy of your “clouds cause climate change”
hypothesis. It’s now evident that there really is no actual physical
evidence to support it.

In science, correlations allow you to construct hypotheses, which then
must be tested with physical arguments. The history of science is
littered with the corpses of high r squared correlations that fooled
people into assuming causality. I’m afraid you’re another victim.

I would NEVER assume correlation proves causality. My cloud feedback
calculation is supported by a firm causal link: ENSO causes surface
temperature variations which causes cloud changes. This is supported
by the iron triangle of observations, theory, and climate models.

As to your comment:
“After all, the Southern Oscillation Index is an ATMOSPHERIC index,
and for you to claim that changes in the trade winds DON'T cause a
change in cloud cover, which can in turn affect ocean temperatures, is
treading on thin ice.”

Of course changes in trade winds can change clouds.

But what causes changes in the trade winds during ENSO?

It’s the changing SST distribution. Get it? Surface temps drive clouds. QED.

Thanks for this interesting discussion. Believe it or not, I think
we’ve actually reached closure. I have no more questions for you.

To the reporters/bloggers on this list: I would encourage you to
write/blog about this exchange. I think that this was an unusual and
frank exchange of views that people would be interested in. FYI, I’m
also archiving these e-mails on my previously dead blog,
http://sciencepoliticsclimatechange.blogspot.com/.

Thanks!

Lindzen e-mail to Dessler on 1/14/11

2011-01-17T11:24:00.001-08:00

Dear Andy,

It is clear where you are going wrong. You are confusing changes over long periods during which equilibration can occur with fluctuations from which feedbacks can be determined. Note that in order to measure feedbacks from outgoing radiation, one must look at time scales that are short compared to equilibration times (years) but long compared to the action of feedback processes (days). That fluctuations in clouds, volcanos, etc. occur over the relevant time scales is obvious as is the fact that such fluctuations must, of necessity, cause changes in surface temperature. The issue of whether clouds can cause El Nino is a red herring. Incidentally, we have looked at your data. If you restrict yourself to relevant time segments, your r-square goes up greatly, and if you perform an analysis of leads and lags, you too get a negative feedback from fluctuations in outgoing radiation that lag SST (whether you choose segments or your entire record -- though again, r square is much larger for segments). The ambiguities in the choice of segments in Lindzen-Choi 2009 disappear when one uses 2 or 3 month smoothing.

Best wishes,

Dick

Spencer e-mail to Dessler on 1/14/11

2011-01-17T11:22:00.000-08:00

Andy,

I cannot believe you keep saying "correlations do not prove causality", when you yourself have used a (near-zero!) correlation in your paper to support causality in only one direction!

But we (including Lindzen) are claiming that relatively LARGE correlations, with a clear lead-lag relationship, DO strongly suggest causation.

I do not know how you can, in all honesty, continue this mantra of yours...oversimplifying our position into something like "clouds cause El Nino", or some such thing.

After all, the Southern Oscillation Index is an ATMOSPHERIC index, and for you to claim that changes in the trade winds DON'T cause a change in cloud cover, which can in turn affect ocean temperatures, is treading on thin ice.

And if, perchance, Kevin Trenberth is coaching you on these talking points, I wish he would just come out and defend them himself.

-Roy

Dessler e-mail to Lindzen on 1/14/11

2011-01-14T06:35:00.000-08:00

Dick-

Your question gets to the same issue that I am after: what is the
cause of the temperature variations over the last 10 years. If it
turns out that clouds are responsible, then that would indeed
challenge my feedback estimate.

However, I suggest that ENSO is responsible for the temperature
variations. I've repeatedly asked Roy for evidence that clouds are
responsible, and he cannot provide anything beyond some ambiguous
correlations. The problem with that of course is that correlations do
not tell us causality.

If you have evidence that the variations over the last decade are
caused by clouds, then please let me know what that evidence is.

Thanks!

Lindzen e-mail to Dessler on 1/11/11

2011-01-14T06:34:00.000-08:00

Dear Andy,

I find this exchange a little peculiar in that you never seem to address what I understand Roy's main points to be.

First, Roy notes that outgoing radiation (especially in the visible) varies for many reasons of which feedback to surface temperature is but one. Other obvious examples range from volcanic aerosol production to cloud triggering by Kelvin-Helmholtz instabilities. I know of no one who really questions that surface temperature is not the only or even the main source of fluctuations in visible radiation.

Second, any changes in outgoing radiation will also cause changes in surface temperature. This is simply a matter of elementary thermodynamics. For non-feedback changes in radiation, the temperature changes will follow rather than lead temperature changes.

Third, because of the first two points, simple regressions of outgoing radiation on surface temperature will not be a useful measure of feedback. Spencer and Braswell illustrated this in their paper. There are, of course, other problems with the use of simple regressions as well.

It would be interesting to see your response to these points.

Best wishes,

Dick

Dessler e-mail to Spencer on 1/10/11

2011-01-14T06:33:00.000-08:00

Hello, Roy.

If you don't mind, I'm going to keep after you on one important point.

In these e-mails, we have discussed two hypotheses for the observed
lead/lag relation and decorrelation. My hypothesis is that all of the
observations are due to canonical ENSO physics --- not clouds causing
temperature changes. The fact that climate models get these relations
supports this, and it is consistent with the surface energy budget.

Your hypothesis --- clouds cause temperature changes --- has no
supporting data (beyond just the correlation & decorrelation) and it
is not consistent with the surface energy budget.

Here's my question: Why would anyone (including you) accept your
hypothesis when the mainstream view fits the data better.

I'm interested in your thoughts.

Thanks!

Spencer e-mail to Dessler on 1/7/11

2011-01-07T19:24:00.000-08:00

Happy New Year Andy,

I've been catching up this week after having last week off for the holidays.

The evidence I presented you was NOT just the decorrelation of the data, as you claim...as I mentioned in my previous e-mail , it was TWO-fold: It is also the lagged relationship, with radiative flux changes preceding the temperature response, then the temperature changes either simultaneous with (os as we will see with ENSO, preceding) the radiative feedback response. The phase space plots we published are one way of revealing the lagged relationship.

Without taking this time lag into account, you will get correlations -- and thus regression slopes-- close to zero...as you do, even in the climate model regression.....no matter what the feedbacks are. We demonstrated this in Spencer & Braswell (2010).

Now, let's look at the oceans, since you want to emphasize the signature of ENSO during the period of record....

By far the most precise measurements of global SST variations come from AMSR-E on NASA's Aqua satellite and, as you know, a CERES radiation budget instrument also flies on that satellite. I did a calculation with these data somewhat similar to the one you did.

Attached find a plot somewhat analogous to yours, but from Aqua SST versus radiative flux....As you can see, the radiative feedback response occurring AFTER the temperature changes suggest strongly negative feedback. Also shown in the same plot AR4 climate model results from their 20th Century runs on the same plot.

The peak correlation of the satellite data in the plot was 0.68, at 11 months lag. At zero lag, the correlation is only 0.27. (What was the correlation of the data you showed in Fig. 2 of your Science paper? I did not see one listed.)

Clearly, there are cause-effect things going on here that cannot be revealed in plots like your Fig. 2, unless these time lags are taken into account.

As a result of our discussion, I've decided that we should do another publication, focusing on the lag relationships seen in the Aqua data and what they might mean for feedback and climate model validation.

-Roy

Dessler e-mail to Spencer 1/3/11

2011-01-04T18:08:00.000-08:00

Roy-

Happy new year!

Thanks for your response. I do think we are making progress now.

In your last message, you confirm that the only evidence supporting your hypothesis is the observed correlation between surface temperature and cloud radiative forcing as well as what you refer to as "decorrelation" of the data.

Because of the complexity of the Earth, there are always multiple hypotheses for every correlation. For the observed correlations you note, I have a competing hypothesis which I think explains the data better than yours.

Here is mine: the heating the surface is caused by energy stored in the ocean. This drives changes in atmospheric circulation, which change clouds. Clouds play a very small role in the surface energy budget during ENSO.

There are several strong pieces of evidence that support my point of view:
(1) Climate models successfully simulate the same lead/lag relationship -- see my attached figure. This suggests that correlation you identified is just normal ENSO physics.
(2) Energy budgets of the surface also suggest virtually no role for clouds during ENSO (e.g., see Trenberth publications).
(3) As far as the decorrelation of the data goes, I have not looked at this in the climate models. However, I think you sent a figure a few e-mails ago showing a climate model that reproduced that. Again, this suggests that it's normal ENSO physics. In addition, I note that the models generate about the same r^2 as the data.

Finally, you have no evidence supporting your hypothesis beyond the mere existence of the correlation. Because of that, your theory explains nothing (e.g., you cannot tell me what percentage of all of the variability is due to "forcing" versus "feedback") and makes no testable hypotheses.

So here are my questions for you:
(a) Do you have any evidence that my proposed hypothesis is wrong?
(b) Does your hypothesis make any testable predictions that would
allow it to be falsified? If so, what are they?
(c) Does your hypothesis explain anything that my theory does not?

Thanks!

[Figure caption: The slope of the regression of energy trapped by
clouds vs. surface temperature, as a function of the lag between the
time series. Negative values indicate that changes in clouds lead
changes in surface temperature. The black line is calculated from
observations cited in Dessler [2010] and the red lines are the climate
models from that same paper.]

The blog is back ... at least temporarily

2011-01-04T18:01:00.000-08:00

Roy Spencer and I have been having an interesting and useful exchange of ideas on the cloud feedback. The goal is not just for us to hear contrasting views, but for the interested public to listen in on the conversation. My goal is to publish our correspondence as it occurs, rather than have a big dump of e-mails periodically. Roy published the first bunch on his blog, and you can read it here. Subsequent e-mails will be posted here as they arrive.

Thanks and welcome to the conversation.

Scientific hubris?

2007-06-25T15:33:00.000-07:00

Link to grist story here.

On another note, I've finally decided to shut down this blog. For those dedicated readers out there, you can get an RSS feed for my blog entries on grist here. My apologies to those of you who don't like grist ...

Should the IPCC be more extreme?

2007-06-08T14:58:00.000-07:00

Link to grist story here.

Powering cars with hydrogen

2007-06-04T09:33:00.000-07:00

Link to grist story here.

What is the optimal climate?

2007-06-02T10:43:00.000-07:00

Link to grist story here.

Scientists and alarmism

2007-05-29T11:24:00.001-07:00

Link to grist story here.

A few random notes

2007-05-25T16:46:00.000-07:00

Link to grist story here.

Who's that good-lookin' guy in the commercial?

2007-05-14T22:00:00.000-07:00

Link to grist story here.

Uh oh!

2007-05-10T13:24:00.001-07:00

Link to grist story here.

Is the science of climate change settled?

2007-05-09T11:41:00.000-07:00

Link to grist story here.

Testifying before the Texas Legislature on climate change

2007-05-02T08:27:00.000-07:00

Link to grist story here.

Conspiracy uncovered!

2007-04-24T11:46:00.000-07:00

Link to grist story here.

Bush vs. Clinton on climate change

2007-04-19T19:27:00.000-07:00

Link to grist story here.

Betting on global warming

2007-04-13T13:52:00.001-07:00

Link to grist story here.

Coming soon to a skeptic near you ... MARS WARMS!

2007-04-12T13:55:00.000-07:00

Link to grist story here.

A unique insight into the IPCC process

2007-04-07T17:54:00.000-07:00

Link to grist story here.

In climate science, small changes matter

2007-04-04T14:24:00.000-07:00

Link to grist story here.

The power of "verification" in science

2007-04-01T11:46:00.000-07:00

Link to grist post here.

Carbon trading vs. carbon taxes on Science Friday

2007-03-25T16:05:00.000-07:00

Link to grist story here.

Another op-ed on climate change

2007-03-18T12:58:00.000-07:00

Link to grist story here.

Hang the bastards!

2007-03-15T14:33:00.001-07:00

Link to grist story here.

Why is climate change not taken seriously in the U.S.?

2007-03-14T11:33:00.000-07:00

Link to grist story here.

More on the 'reasonable middle'

2007-03-13T12:17:00.000-07:00

Everyone and their dog are blogging about today's NYT article on overselling climate change. (Yes, my dogs are working on their entry)

Link to my analysis on grist here.

Biofuels on Science Friday

2007-03-11T20:25:00.000-07:00

Link to grist story here.

Texas: Climate's anti-canary

2007-03-09T14:16:00.001-08:00

Link to grist post here

Elements of an effective response to global warming

2007-02-22T13:47:00.001-08:00

Link to grist story here.

The $10,000 question

2007-02-13T15:04:00.001-08:00

Link to grist story here.

This story highlights the AEI/AR4 saga, which I've blogged about extensively (e.g., here). The most important message is at the end:

Those who favor action on climate change can learn something from this episode as well, and not just the wisdom of bringing heightened skepticism to favorably biased news stories. Too many activists and commentators are fighting the last war, pounding away on any sign of doubt about basic climate science, even where no such doubt exists. The debate over the existence of anthropogenic climate change, despite some noisy rear-guard skirmishes, is largely over.

The policy debate is going to be more messy and politicized than the science debate ever was -- after all, science will not be there to settle it. It will turn on risk assessment and the untidy art of balancing competing interests. Many conservatives who have abandoned their contrarianism on the science will likely now turn to carving out a policy position that downplays the risks of climate change, exaggerates the costs of addressing it, and above all discourages any response that relies too heavily on government regulation or investment.

Those who favor immediate, substantial action to address climate change would do well to prepare for that debate. Bashing climate denialists still makes good copy, but it is increasingly beside the point.

A new round of attacks on the IPCC

2007-02-11T11:45:00.000-08:00

Link to grist story here.

Op Ed in the Fort Worth Star-Telegram

2007-02-11T10:29:00.000-08:00

An op-ed I authored with my colleague Katharine Hayhoe of Texas Tech be found here.

There is also an accompanying editorial here. Oddly, it continues their support for allowing TXU to build 11 new coal-fired power plants. But they also advocate for a carbon tax. Combining these two positions seems problematic to me: with a carbon tax in place, the coal plants don't make nearly as much sense as they do without a tax. In fact, they might make no sense at all, when considering the entire 50-year life of the plant.

Colbert on scientific uncertainty

2007-02-10T12:52:00.000-08:00

More update on the AEI and AR/4 brouhaha

2007-02-08T12:00:00.000-08:00

Link to grist story here.

AEI and the AR/4 --- update

2007-02-07T08:14:00.000-08:00

The "AEI vs. AR/4" story has gotten a surprising amount of play in the mainstream press over the last few days. I initially blogged about it last summer here. I suspect that blog entry was the actual genesis of all of the stories in the mainstream press (e.g., here or here).

Today I received an e-mail from AEI's Steve Hayward:

Dear Prof. Dessler:

I wonder if, as a courtesy and in the spirit of fairness, you would post on your blog both the statement from AEI's president Chris DeMuth and our most recent letter approaching participants our project, which speaks for itself (and was sent out in mid-January before l'affaire Guardian occurred). I attach both documents.

I hope to find time between endless letters to the editor and other responses correcting the gross distortions over this matter to have more to discuss with you directly; for the moment, know that Ken and I have a long magazine article coming out in the next few days where we characterize your original blog post from last July as "critical but fair-minded." I wish I could say the same for the press coverage and commentary in the blogosphere.

Cordially,

Steve Hayward
AEI

So, as requested, here are their statements.

The first is a statement by AEI President Chris DeMuth.

Many of us have received telephone calls and emails prompted by a shoddy article on the front page of today’s Guardian, the British newspaper, headlined “Scientists offered cash to dispute climate study” (posted here).

The article uses several garden-variety journalistic tricks to create the impression of a story where none exists. Thus, AEI is described as a “lobby group” (we are a research group that does no lobbying and takes no institutional positions on policy issues); ExxonMobil’s donations to AEI are either bulked up by adding donations over many years, or simply made up (the firm’s annual AEI support is generous and valued but is a fraction of the amount reported—no corporation accounts for more than 1 percent of our annual budget); and AEI is characterized as the Bush administration’s “intellectual Cosa Nostra” and “White House surrogates” (AEI scholars criticize or praise Bush administration policies— every day, on the merits). All of this could have been gleaned from a brief visit to the AEI website.

But the article’s specific charge (announced in the headline) is a very serious one. Although most of you will appreciate the truth on your own, I thought it would be useful to provide a few details.

First, AEI has published a large volume of books and papers on climate change issues over the past decade and has held numerous conferences on the subject. A wide range of views on the scientific and policy issues have been presented in these publications and conferences. All of them are posted on our website. It would be easy to find policy arguments in our publications and conferences that people at ExxonMobil (or other corporations that support AEI) disagree with—as well as those they agree with and, I hope, some they hadn’t thought of until we presented them. Our latest book on the subject, Lee Lane’s Strategic Options for Bush Administration Climate Policy, advocates a carbon tax, which I’m pretty sure ExxonMobil opposes (the book also dares to criticize some of the Bush administration’s climate-change policies!).

Second, attempting to disentangle science from politics on the question of climate change causation, and to fashion policies that take account of the uncertainties concerning causation, are longstanding AEI interests. Several recent issues of our “Environmental Policy Outlook” address these issues, as does Ken Green’s “Q & A” article in the November-December issue of The American. The new research project that Ken and Steve Hayward have been organizing is a continuation of these interests. I am attaching the two letters that Steve and Ken have sent out to climate change scientists and policy experts (the first one emphasizing the scientific and climate-modeling issues addressed by the Intergovernmental Panel on Climate Change; the second, more recent one covering broader policy issues as well)—and invite you to read them and compare them with the characterization in the Guardian article. The first letter, sent last summer to Professor Steve Schroeder of Texas A&M (and also to his colleague Gerald North), is the one quoted by the Guardian. Ken and Steve canvassed scholars with a range of views on the scientific and policy issues, with an eye to the intrinsic quality and interest of their work rather than to whether partisans might characterize them as climate change “skeptics” or “advocates.” They certainly did not avoid those with a favorable view of the IPCC reports—such as Professor Schroeder himself.

Third, what the Guardian essentially characterizes as a bribe is the conventional practice of AEI—and Brookings, Harvard, and the University of Manchester—to pay individuals at other research institutions for commissioned work, and to cover their travel expenses when they come to the sponsoring institution to present their papers. The levels of authors’ honoraria vary from case to case, but a $10,000 fee for a research project involving the review of a large amount of dense scientific material, and the synthesis of that material into an original, footnoted and rigorous article is hardly exorbitant or unusual; many academics would call it modest.

We should all be aware that political attacks such as the Guardian‘s are more than sloppy or sensation-seeking journalism: they are efforts to throttle debate, and therefore aim at the heart of AEI’s purposes and methods. The successive IPCC climate change reports contain a wealth of valuable information, but there has been a longstanding effort to characterize them as representing more of a “scientific consensus” than they probably are, and to gloss over uncertainties and disagreements within the IPCC documents themselves. Consensus plays an important role in science and scientific progress, but so does disputation—reasoned argument is essential to good science, and competition of ideas is essential to scientific progress. AEI is strongly opposed to the politicization of science, just as it is to the politicization of economics and other disciplines. On climate change as on other issues, we try to sort out the areas of genuine consensus from the areas of reasonable debate and uncertainty. Ken and Steve’s letter to Professor Schroeder was clear about this: “we are looking for . . . a well-supported but accessible discussion of which elements of climate modeling have demonstrated predictive value that might make them policy-relevant and which elements of climate modeling have less levels of predictive utility, and hence, less utility in developing climate policy.”

The effort to anathematize opposing views is the standard recourse of the ideologue; one of AEI’s highest purposes, here as in many other contentious areas, is to ensure that such efforts do not succeed.

Chris DeMuth

The second is a revised letter approaching participants of their project:

Dear-----

This is Steven Hayward and Ken Green writing from the American Enterprise Institute in Washington. We are writing to solicit your thoughts about, and hopefully your participation in, an AEI project on climate change policy. Between the forthcoming Fourth Assessment Report of the IPCC due later this year, the Stern Review, and the close of the Kyoto Protocol’s first commitment period on the intermediate horizon, the time seems propitious for a fresh round of discussion of climate policy. AEI would like to commission a series of essays from a broad range of experts on various general and specific aspects of the issue, around which we should like to organize several conferences in Washington and ultimately a book.

Two general thoughts dominate our thinking about the structure of a useful project. First, in the public mind at least (which is to say, the news media) climate change has tended to be caught in a straightjacket between so-called “skeptics” and so-called “alarmists,” with seemingly little room left in the middle for people who may have reasonable doubts or heterodox views about the range of policy prescriptions that should be considered for climate change of uncertain dimension. This perception is mistaken, of course, as Andrew Revkin’s recent New York Times article on “an emerging middle ground” on climate change made evident. Nonetheless, we would like to attempt to break out of this straightjacket and see if it is possible to create a space for an identifiable “third way” of thinking about the problem that is similar to the various “third way” approaches to other social policy problems that were popular in the 1990s.

Our second general thought is that the chief difficulty of carving out a “third way” on climate change is due to the unwieldy size and complexity of both the scientific inquiry and policy approaches to the problem. We had thought to produce a series of essays to review and critique the forthcoming IPCC FAR, early drafts of which are circulating, but have been persuaded that an IPCC-focused project is too limited. Although some commentary on the IPCC FAR is in order, our latest thinking is broaden our scope. One idea is to solicit essays in two categories. The first category would be along the lines of a blue-sky essay on “What Climate Policies Would I Implement If I Was King for a Day.” The second category would be specific critiques of existing or proposed policy responses such as will appear in Working Group III or have been put forward in reports such as the Stern Review. (Such essays might take as their focus a single chapter from Working Group III, or an aspect of the Stern Review.)

Above all we want to have a diverse collection of pre-eminent thinkers on this subject, which is why we are keen to include you in the project. AEI is willing to offer honoraria of up to $10,000 for participating authors, for essays in the range of 7,500 to 10,000 words, to be completed by September 1, and we are keen to work with you to refine an appropriate topic.

Highlights of the new IPCC report

2007-02-02T17:36:00.000-08:00

Link to grist story here.

Hurricanes --- A new and improved hockey stick

2007-02-01T14:17:00.000-08:00

Link to the grist story here.

This explains a lot about Texas

2007-01-28T11:02:00.000-08:00

Link to grist story here.

Interesting article on peer review

2007-01-26T08:18:00.000-08:00

The CS Monitor had an interesting article on peer review.

My view is that peer review is a highly effective filter. But one should not expect too much from it. While it stops most errors from being published, it cannot catch every problem. Reviewers occasionally fail to notice an obvious mistake, and there are some types of error that reviewers usually cannot catch. They cannot tell if the author misread observations of an instrument, or wrote a number down wrong, or if chemical samples used in an experiment were contaminated. Moreover, peer review often cannot identify clever fraud, such as the rare cases where the scientific work being reported was not really done at all.

But peer review is only the first of many levels of testing and quality control applied to scientific claims. When an important or novel claim is published in a journal, other scientists test the result by trying to replicate it, often using different data sets, experimental designs, or analytic techniques. While one scientist might make a mistake, do a sloppy experiment, or misinterpret their results (and peer reviewers might fail to catch it), it is unlikely that several independent groups will make the same mistake. Consequently, as other scientists repeat an observation, or examine a question using different approaches and get the same answer, the community increasingly comes to accept the claim as correct.

Peer review is also important for evaluating proposals to funding agencies as well as for things like tenure and promotion. It seems difficult to imagine how an alternative system for those things would work. I suspect that changes in the peer review system will eventually occur as our ways of communicating changes, but those changes will be slow.

More polling data on climate change

2007-01-25T13:52:00.001-08:00

Link to grist story here.

For those that read The Onion

2007-01-25T09:07:00.001-08:00

You'll enjoy this.

Front page in today's WSJ

2007-01-23T11:32:00.000-08:00

A front page story in today's Wall Street Journal (I don't have a link, sorry) begins:

The global warming debate is shifting from science to economics.

For years, the fight over the Earth's rising temperature has been mostly over what's causing it: fossil-fuel emissions or natural factors beyond man's control. Now, some of the country's biggest industrial companies are acknowledging that fossil fuels are a major culprit whose emissions should be cut significantly over time.

...

The broadening, if incomplete, consensus that fossil fuels are at least a big part of the global-warming problem signals real change in the environmental debate. The biggest question going forward no longer is whether fossil fuel emissions should be curbed. It's who will foot the bill for the cleanup --- and that battle is heating up.

I sincerely hope that the WSJ editorial page reads this article.

We are now experiencing a tectonic shift in the political landscape on the issue of climate change. The skeptics are disappearing --- both in numbers and in influence. At the same time, the debate is shifting from "should we do something" to "what should we do?"

Another op-ed on climate change and Texas

2007-01-22T18:47:00.001-08:00

Link to grist story here.

Climate change with Al Gore, II

2007-01-20T21:20:00.000-08:00

For those interested in Al Gore's climate project training (which I blogged about here), here are news stories of Climate Project Presenters:

Miss Rhode Island spreads the word

Wisconsin resident and businessman

Grammy-winner Kathy Mattea gives presentation in Utah

Oregon's Secretary of State presents across the State

Canadian banker reaches investment community

Cincinnati's climate messenger

Allentown messenger

New Yorkers head to Nashville to become messengers

Fort Smith Arkansas messenger

Should we burn climate skeptics at the stake?

2007-01-19T12:15:00.001-08:00

Link to grist story here.

Capitol Hill briefing on science and politics

2007-01-17T14:31:00.000-08:00

Link to grist story here.

Climate change with Al Gore

2007-01-11T19:13:00.000-08:00

Link to grist story here.

Least surprising headlines of the day

2007-01-03T19:40:00.000-08:00

ExxonMobil paid to mislead public Article here

ExxonMobil cultivates global warming doubt Article here

My problem with Revkin's article

2007-01-03T18:27:00.000-08:00

Link to grist story here.

Overestimating the cost of emissions reductions

2006-12-31T12:15:00.000-08:00

Link to grist story here.

Video podcasts on climate change

2006-12-27T09:50:00.001-08:00

Link to grist story here.

Have we oversold climate science?

2006-12-26T09:39:00.001-08:00

Link to grist story here.

What does 'politicization of science' mean to you?

2006-12-22T11:04:00.001-08:00

Link to grist story here.

Nature ends public peer-review trial

2006-12-21T13:51:00.000-08:00

According to this story, Nature is scrapping its attempt to open up the peer review system.

As the article says,

In the Nature experiment, authors whose manuscripts were selected for traditional peer review could also opt to have them simultaneously posted on the Internet for feedback by rank-and-file scientists. Journal editors then weighed both sides when deciding whether a paper gets published.
The experiment generated high online traffic, about 5,600 page views a week, according to Nature. But it was ultimately canceled because few authors participated and many of the online comments were nothing more than "nice work."

My experience with open peer review (through the journal Atmospheric Chemistry and Physics) is similar. While it seems like a good idea, few articles get any public comments. I suspect this is true for a few reasons. First, it can be dangerous to make negative comments without anonymity (and on ACP comments must be attributed) --- which is why most journals implement anonymous reviewers. Second, it takes a lot of time to write a comment, and most people are simply too busy. Another reason the Nature experiment failed was that they did a terrible job publicizing it.

As a dedicated blogger, I see great value in an open comment system and I suspect that some kind of open system will eventually be adopted. However, I don't think any journal has yet stumbled upon the winning model.

New polling data on global warming ...

2006-12-20T08:18:00.000-08:00

Link to grist story here.

Snowe and Rockefeller on the 'uncertainty' agenda

2006-12-04T19:33:00.000-08:00

Link to grist story here.

The climate change insurgency

2006-12-04T10:55:00.000-08:00

Link to grist story here.

The "uncertainty" agenda

2006-11-30T10:12:00.000-08:00

Link to grist story here.

Why the Supreme Court case is not a really big deal

2006-11-27T11:14:00.000-08:00

Link to grist story here.

Could the Sun be causing climate change?

2006-11-25T11:43:00.000-08:00

Link to grist story here.

The CO2-temperature correlation

2006-11-22T12:22:00.000-08:00

Hello, gentle readers. I'm back --- sort of. I've decided that I'm going to post on this blog links to my blog entries on grist.

I'm doing this because there's no way to get an RSS feed from grist for just my articles, and as a result it's easy to miss my posts. You can get an RSS feed from this page, and that will alert you to my new grist posts.

Also, some former readers have expressed some reticence about posting on grist. Feel free to post comments here or on grist.

My most recent post is on the well-known CO2-temperature correlation. You can find it here.

I'm going to Disney World!

2006-10-24T22:49:00.000-07:00

OK, not really. Turns out I'm afraid of people in giant mouse suits.

But what IS happening is that this blog is moving to grist.org. Check out my blog page. Other than the host, everything else about the blog should remain the same. I hope you head over there and keep reading my stuff!

This web site will remain up, but I don't plan on posting here anymore.

[NOTE added in proof: the grist.org site requires an e-mail address to sign up. Here's a tip for those who don't want to give out their real e-mail: use the dodgeit.com e-mail avoider service. Check out their FAQ here. It's a great and free service that I use all the time.]

The "house of cards" analogy

2006-10-22T23:17:00.000-07:00

In a comment to the "puzzle analogy" post, Bill Chameides points out an alternative analogy that climate skeptics like to push:

Science skeptics often try to undercut established science (be it global warming or something else) by portraying the knowledge-base as a house of cards. They hope by identifying one weak link, they can bring the whole house down (i.e., create the illusion of uncertainty in the entire subject.)

Examples of this strategy are easy to find. After the NRC hockey stick report concluded that we really don't know what the temperature was 1000 years ago, many skeptics used this to argue that this repudiated all climate science. This is, of course, nonsense. Important conclusions in science are all subject to multiple tests and verifications, and scientists do not accept a conclusion until it has been multiply verified. As Bill concluded:

In fact, most science is like a jigsaw - lots of interlocking pieces based on multiple, independent lines of inquiry. Even if you take away one piece, the picture is still apparent.

Canada's new greenhouse gas targets

2006-10-20T07:56:00.000-07:00

A recent news article described a proposed greenhouse gas target for Canada:

Canada will aim to reduce its greenhouse gas emissions that cause global warming by 45-65 percent by 2050, ... The bill introduced Thursday in the House of Commons would also apply intensity-based targets until 2020, allowing emissions to continue to rise until then.

There're actually a lot of advantages of this target over something like Kyoto. First, it sets a definite long-term target, which Kyoto does not. This provides a more stable environment for people and companies to make investments in emissions reducing technology. Second, it allows emissions to grow in the near term, i.e., does not require sharp near-term cuts in emissions, as Kyoto does. Most economists agree that allowing some near-term growth followed by steeper cuts later provides the lowest cost trajectory to get to your preferred emissions level.

The downside of a longer term target is that it can be used as a stalling tactic if the administration really doesn't want to do anything about the problem. However, one need not wait long to find out if that's the case. While some emissions growth can be tolerated near-term, deviations from business-as-usual need to occur within a few years to hit the target in 2050 at minimum cost. Thus, if Canada is serious about this, we need to see some near-term actions relatively soon.

Finally, the target is not quite ambitious enough. In order to stabilize the climate at around 550 ppmv (i.e., double pre-industrial CO2), we need to reduce world emissions to about 2 GtC/yr, about 80% less than we're emittiong today. Their target, 45-65% reductions, would not be sufficient to do this if applied to the entire world.

Values in the climate change debate

2006-10-17T22:48:00.000-07:00

An interesting editorial can be found here. One particularly interesting point they make is about the moral dimension to the problem:

Without mitigation, rising global temperatures are expected to cause ferocious hurricanes, tornadoes and floods; spawn heat waves, drought and famine; and prompt the spread of disease-carrying insects.

Middle- and upper-class families will hop in their cars to seek refuge from storms. They'll vaccinate their children and find good health care. They'll buy air conditioners. The poor, lacking resources to adapt, will disproportionately suffer and die.

Global warming isn't just an environmental debate. It's also about social and racial justice.

If you read the various blogs, many opposed to action will make the argument that addressing AGW is too economically damaging. My experience is that many of these people are so married to the economics of the problem that they don't even recognize that there exist different ways to look at the problem. In fact, the decision to take a cost-benefit view is itself a moral choices --- and one that is debatable.

My view is that some balance needs to be achieved: costs and benefits need to be considered, but so do the issues of social justice and fairness. Only by doing this can we obtain a socially and economically optimal solution to this problem.

The puzzle analogy

2006-10-16T10:25:00.000-07:00

I recently heard a good analogy about climate science from Bill Chameides, chief scientist for Environmental Defense.

The state of science of climate change today is like a partially completed jigsaw puzzle. There are lots of pieces in place --- things we know quite well (like the water vapor feedback) --- and lots of areas where there are no pieces --- things we don't know particularly well (like cloud feedbacks). The point here is that you don't have to have every piece in place in order to know what the picture looks like. Consider the image above. While many pieces are missing, one can easily observe that it's an image of fruit.

Climate science is like that. While there's a lot we don't know, the big picture is still clear. We know the climate is warming, humans are contributing, and there's a risk of significant warming over the next century. The missing pieces don't change any of that.

The "uncertainty" argument would have you believe that, if even one piece is not in place, that we have no idea what the big picture is. That's simply not true.

Climate models vs weather models

2006-10-12T08:55:00.000-07:00

You can find a lot of discussion on the net with arguments like:

If we cannot predict the weather next week, how can we predict the climate over the next century?

While this sounds like a reasonable argument, there are in fact good reasons to accept 100-year climate forecasts even though we cannot predict the weather more than a few days out.

Predicting the weather is hard because you have to get the exact details of a weather system right. If your prediction of a storm track is 100 km off, then a giant snowstorm predicted to bury a city might fall harmlessly offshore. If your temperature is 3 deg C off, then what you predicted as rain turns into snow. If your initial conditions are off, then precipitation predicted to fall during rush hour falls at midnight. All of these things mean that you've blown the forecast, and people will mumble about how weather forecasters don't know what they're doing.

For the climate, these things generally don't matter. What matters is that, in the long run, one gets the statistics of the weather right. If one storm in a climate model is 100 km too far East, that won't matter if the long-term statistics of the storm track is right. This is quite a different problem than predicting the EXACT evolution of a single atmospheric disturbance.

One simple way to think about the difference in predicting weather and climate is to think about rolling a six-sided die. Predicting the weather is like predicting what the next roll will be. Predicting the cliamte is like predicting what the average and standard deviation of 1000 rolls will be. The ability to predict the statistics of the next 1000 rolls does not hinge on the ability to predict the next roll. Thus, one should not dismiss climate forecasts simply because weather forecasts are only good for a few days.

One should not take from this that climate modeling is easier than weather forecasting. There are several aspects of the problem that make climate modeling more difficult than weather forecasting: climate models need to also predict the evolution of long time-constant domains like the oceans, cryosphere, and biosphere. Weather models don't have to worry about these things because oceans conditions, etc. don't change over a few weeks. Climate models also use uncertain predictions of future emissions, from which the atmospheric concentration of CO2 and other greenhouse gases will be determined.

Another statement you hear is that:

Because climate models do not predict next year's climate, why should you believe a prediction in 100 years?

Here's why: short-term forecasts (e.g., over the next few years) require accurate simulation of the magnitude and phase of short-term climate variability like El Nino. Over much longer time scales, however, one does not need to accurately simulate these short-term climate variability. I discussed that here. The upshot is again that one should not dismiss the long-term climate forecasts because short-term forecasts are problematic.

Report from the G8 meeting on climate

2006-10-10T10:57:00.000-07:00

An interesting article about the recent G8 meeting on climate can be found here.

A few quotes of note:

Several said they had never known such a positive atmosphere. Nobody doubted the reality of climate science anymore.

This continues a trend that I've noticed recently. Those opposed to action now rarely attack the science. Their arguments tend to be more diffuse, with more of a focus on economic and fairness issues.

The Under-Secretary of State for Global Affairs, Paula Dobriansky, told the BBC that the US was now acting urgently to tackle greenhouse gases - then later admitted that the country's emissions would continue to rise.

The statement that the U.S. is working hard on climate change is as accurate as the statements "We will be greeted as liberators" and "The insurgency is in it's last throes". The U.S. is, of course, doing essentially nothing.

So, for all the positive mood of the meeting in this spectacular northern Mexican city, surrounded by towering limestone mountains, it is hard to be optimistic.

The UK Environment Secretary David Miliband said there had been real and practical progress but warned that the pace of action had to be much faster or CO2 emissions by 2050 would be 137% higher than in 2003.

"Business as usual", he said, was not an option.

One delegate told me he thought the pace of political ambition on emissions was so slow that we had a 1,000-1 chance of avoiding dangerous climate change.

He later sent me a text message to assert that he had been overly pessimistic. The odds, he said, were only 100-1.

The chances were bad, he said, but it was still worth fighting on.

I'm not as pessimistic as this delegate, but I agree that we are at present far away from any workable program to stabilize atmospheric CO2. Perhaps the 2009 inauguration of a new President will change that.

The build-up of CO2 in our atmosphere will be good!

2006-10-08T11:06:00.000-07:00

A common argument you hear goes like this:

because increased CO2 will lead to increased plant growth, the build-up of CO2 must therefore be a net benefit rather than a net harm to our society

Does this type of argument make sense? To understand why it doesn't, realize that in any environmental disaster, some groups always benefit. Consider the destruction of New Orleans by Katrina. Few people consider this event to be a net benefit to our society. However, it is easy to pick out small groups that greatly benefitted from it. The owners of demolition companies, construction companies, construction material companies, etc., are all making money hand over fist.

Thus, one could make the argument:

Katrina's destruction of New Orleans was a highly beneficial event because it greatly stimulated the construction industry on the Gulf Coast.

This is, of course, extremely misleading and most people would agree is wrong. While some benefitted from the destruction of New Orleans, the net result, considering all harms and benefits, was clearly negative.

So when people argue that climate change must be good because plants grow better at higher CO2, think about the Katrina example. Plants might indeed do better(*), but that tells us nothing about all of the other harms and benefits. As I discussed in a previous post:

Clearly, some people will benefit from warming, while others will suffer. There are a lot of dimensions to this (economic, moral, etc.), but I'll just give the broadest answer. For small warming (e.g., 1 deg C over the next 100 years), current thinking is that harms and benefits are largely comparable, although it is estimated that harms still outweigh the benefits. As the warming increases, the harms get much bigger, and begin dominating over benefits somewhere around 2-3 deg C of warming. That's why 2-3 deg C is often referred to as a tipping point or threshold for dangerous anthropogenic interference. Warmings much greater, say 5 deg C, would be a calamity of Biblical proportions ... real Wrath of God stuff.

Make no mistake. Estimates of harms and benefits are highly uncertain. However, there is clearly a significant risk of serious net harms over the next century as the climate warms. People arguing that there is no risk of serious harms are either dishonest or disconnected from reality.

* For the record: While most plants do grow better as atmospheric CO2 increases, there's dispute about whether this means that plants will grow better under global warming scenarios. While CO2 is definitely going up, which will help plant productivity, there are other changes that might not benefit plants, like changes in precipitation patterns, soil moisture, migration of invasive species, etc. Overall, it's unclear how much plant productivity will actually increase.

Answers to a few questions

2006-10-05T22:38:00.000-07:00

Although I've answered these in various posts, I think it's useful to repeat this material. Recent commenters continue to bring these questions up.

Is the Earth warming?

Are humans to blame?

here

likely

most

Will the effects of climate change be beneficial or disastrous?

tipping point

Can we do anything about it?

Alternatives to peer review

2006-10-05T07:29:00.000-07:00

For those interested in the process of peer review, take a look at this interesting article.

For those not familiar with the concept of "peer review," here's a short explanation. Scientific journals will not publish a paper until it has been critically scrutinized by other scientists (usually two or three) who are experts on its subject. In this process, called peer review, the reviewers’ job is to look for any errors or weaknesses – in data used, calculations, experimental methods, or interpretation of results – that might cast doubt on the conclusions of the paper. The process is usually anonymous, so reviewers are free to give their honest professional opinion without fear of embarrassment or retribution.

Peer review is one of the cornerstones of modern science. And succeeding at peer review counts for everything in a scientific career. For scientific work to attract attention and respect, it has to be published in peer-reviewed journals. Proposals for research funding must also go through peer review. For scientists to get and keep jobs and achieve all other forms of professional reward and status, they must succeed at getting their work through peer review.

Because of its central place in science, I'm quite skeptical that non-peer-reviewed journals will be successful. It seems like likely that non-peer-reviewed journal publications will simply not count the same as peer-reviewed publications for things that matter, like tenure decisions, and that people will not publish first-rate work there. Rather, it will be second-rate work that has been rejected from peer-reviewed journals that will end up in the non-peer-reviewed literature.

One of the complaints against peer review is that good science is sometimes held up or even rejected by stubborn or biased reviewers, thus hurting both the authors and the scientific community. My experience is that this is rarely a real problem: if your paper gets rejected by one journal, you can always submit it to another. And an author can always request that a particular person (or two) not serve as peer reviewer. If a paper gets rejected by several groups of reviewers picked by several journals, then it probably doesn't deserve to be published anywhere.

In addition, implementing a non-peer-reviewed journal simply trades one problem for another. While legitimate science might sometimes be delayed or rejected by peer review, a lot of really bad science is correctly filtered by peer review. By eliminating peer review, you will unleash all of the bad science on the community. This seems to me to be a bad idea.

In any event, it looks like the experiment is going to be run, so we'll all see how this turns out.

Lindzen class on global warming

2006-10-03T12:40:00.000-07:00

This class should be entertaining, particularly for those with a well-tuned sense of irony.

"An Inconvenient Truth" blitzkrieg

2006-10-01T18:17:00.000-07:00

I've noticed something interesting going on. SciGuy reports that more than 20 Houston-area churches will show Gore's film on climate change next week. Over on Prometheus, Roger Pielke Jr. blogged that the film will be shown at the University of Colorado, and then there'd be a panel discussion following. I have been invited to attend a screening of the film at SMU, and then be part of a panel discussion there.

It seems obvious that there's a concerted effort to get this movie out there. I'm not sure who's behind it (if any of you know, please let me know), but I think that these showings of the movie and panel discussions will definitely benefit the debate. While I might quibble with a statement here or there in the movie, overall I think the movie is pretty accurate. Much more accurate, in fact, than recent Wall Street Journal editorials on the subject. I think that most people come out of the movie better informed than when they went in.

Climate change and tobacco, part II

2006-10-01T11:55:00.000-07:00

A while back, I blogged about the connection between denialists on climate and tobacco. Here is an interesting BBC report on the same subject:
(tip 'o the hat to random variable blog via deltoid)

When the history of climate change is written ...

2006-09-29T14:54:00.000-07:00

I'm quite convinced that the citizens of the Earth will at some point band together and attempt to stabilize atmospheric CO2 abundances . If I were a betting man (and I am), I would bet that an international agreement will be reached during he first term of the next U.S. President (2009-2013). Let's hope it's sensible and successful.

When the history of AGW is written, I believe that three occurrences will have been crucial in setting the stage for CO2 emissions reductions:

Hurrican Katrina - we can argue about the effect of AGW on hurricanes, but there's no question in my mind that Katrina had an affect on how many view AGW
Drowning polar bears - images play a key role in policy debates, and images of so-called charismatic megafauna can quickly become iconic. These images appeal to the obligation many feel for stewardship of the planet.
Al Gore - Love him or hate him, his movie has had a huge effect on the debate --- not on the hard-core Gore haters, nor on the AGW believers, but on the undecided middle of the debate. And not necessarily because they went to see his movie, but because his movie has kept AGW in the news and on the public's radar.

Together, these three events have been crucial in generating the growing wave of awareness on the issue. In fact, I think we've recently passed a tipping point, where the question has changed from whether to take action to what form that action will take.

Has the climate warmed since 1998?

2006-09-27T13:58:00.000-07:00

No.

1998 was a blistering hot year, caused primarily by an enormous El Nino that year. 2005 was hot, too, and while some claim it was hotter than '98, my view is that it was a statistical tie.

Does this mean that global warming stopped in '98? (as argued in places like this) The answer is no. To illustrate, let's consider some synthetic data I made up.

First, let's assume that the human contribution to globally averaged temperatures looks like this:

This is 0.2 deg C per decade, similar to measurements over the past few decades. But as we all know, other things also affect our climate. A particularly good example is El Nino. During an El Nino, the globe warms considerably compared to non-El Nino years. El Nino's occur every few years, so let's assume that El Nino's contribution to global temperature looks like this:

Now let's sum them.

As one can see, the El Nino signal in our little example (and in reality) totally dominates the human-induced signal.

So if one wants to know how much "global warming" has occurred since 1998, one has to subtract out the influence of El Nino. If one does that, then 2005 is much hotter than 1998, and global warming is alive and well.

The important lesson to learn here is one of time scales. Looking at the temperatures from 1998 to 2005 means you have about 8 years of data. This is comparable to the El Nino cycle time. If one looked at much longer times (e.g., a few hundred years), the effect of El Nino would be less important and more obvious. To illustrate that, here's the same two time series extended out 200 years.
As you can see, the upward 0.2 deg per decade signal is quite obvious in this plot.

The same is true if the time series is much shorter than the time scale of the variation. That's why we don't have to worry about ice age/interglacial variations in our analysis of the warming of this century. But by picking a time scale that is comparable, it maximizes the confounding effects on any trend calculation.

People who argue that global warming stopped in 1998 are 1) clever advocates who are willing to mislead to win the argument or 2) don't understand much about the climate system.

Good new FAQ on global warming

2006-09-26T22:02:00.000-07:00

My colleague Steve Sherwood has a good FAQ on global warming here. It's another resource you can show your Aunt Petunia ... you know, the one that still doesn't believe that atmospheric CO2 is increasing!

Still more Bush on global warming

2006-09-25T15:36:00.000-07:00

Following on my series of blogs on Bush, SciGuy had a link to this video. A little comedy to lighten your day!

Are scientists biased?

2006-09-24T14:25:00.000-07:00

One of the parts of the Wegman report that I objected to was his characterization that scientists are biased towards getting results that confirm the underlying paradigm of AGW:

there is a tightly knit group of individuals who passionately believe in their thesis. However, our perception is that this group has a self-reinforcing feedback mechanism and, moreover, the work has been sufficiently politicized that they can hardly reassess their public positions without losing credibility.

What this idea overlooks is that one gets ahead in science not by agreeing with previous work, but by advancing new ideas. The bigger the new idea, and the bigger the old idea that it replaces, the more fame and success accrue to the scientist. Look at famous scientists through history and you won't find a single one that got there by agreeing with the prevailing wisdom.

If you're a member of the so-called "hockey team," you're not going to get much credit or respect from the community if all you do is agree with hockey stick. Rather, an individual scientist will do much, much better if he can show that his competitors' (aka colleagues) work is faulty or biased. And that same individual scientist will do much worse if his or her work is viewed as faulty or biased. This incentive to destroy previous work explains why, in any group of a few scientists, there will be at least two that hate each other.

Scientists are human and all of us have personal biases. But because scientists know that important ideas they advance will be re-tested by other scientists, there is a strong incentive to be careful and conservative in their claims.

People that argue that there's some type of "conspiracy" among climate scientists to increase funding by producing "alarmist" science are either a) a clever advocates trying to obstruct AGW policy by attacking the science or b) someone who doesn't understand science.

My thoughts on the hockey stick

2006-09-21T14:35:00.000-07:00

A few people have asked me what I think about the hockey-stick debate. Here are a few thoughts.

(1) I never say whether the hockey stick is "right" or "wrong". Labels like that are ambiguous and misleading. I actually don't know whether it was wrong or not, but I do know that some of the best research has turned out, in the end, to be wrong; it's value was in pointing the community towards an interesting question.

(2) I adopt the NRC's party line that we simply cannot say whether the MWP was warmer or not than the present. I've seen a lot of people misinterpret this to mean that we can now say that the MWP was warmer than present. That's incorrect --- the uncertainty cuts both ways. We cannot say today is warmer than the MWP or that the MWP is warmer than today. We just do not know.

(3) The hockey stick plays little or no role in attribution of the recent rise in temperatures to human activities. For example, see this blog entry where I talk about why we think much of today's warming is caused by man. Note the absence of any reference to the hockey stick. Thus, the statement that humans are contributing to the present day warming remains unscathed.

(4) The scientific community should provide code and data to any interested party. Not being forthcoming with these things seems to me to violate the ethos of science, well summed up by the AGU's motto: "unselfish cooperation in research." And it makes us look bad.

Speech by Boehlert

2006-09-20T13:10:00.000-07:00

(thanks to a tip from a reader)

I'm really going to miss Sherwood Boehlert, who's retiring at the end of the term. Here's why:

FOR IMMEDIATE RELEASE
September 20, 2006
Science Committee Press Office: 202-225-4275
Joe Pouliot, joe.pouliot@mail.house.gov
Zachary Kurz, zachary.kurz@mail.house.gov

BOEHLERT DISCUSSES CLIMATE ISSUES

WASHINGTON - House Science Committee Chairman Sherwood Boehlert (R-NY) today delivered the following speech at the Climate Institute's Washington Summit on Climate Stabilization:

I know that yesterday you heard from some of the world's leading scientists about the frightening possibility that the earth's climate may change more quickly and abruptly than expected, and whether there's anything that can be done to avoid that.

Well, this morning's session should offer a break from all of that. Instead, I'm going to talk about the frightening possibility that Washington's political climate may not change more quickly and abruptly than expected, and whether there's anything that can be done to avoid that.

Certainly, without abrupt political climate change, it's going to be next to impossible to do anything about global climate change.

Let me hasten to add that by calling for "political climate change," I'm not covertly advocating a change in political party control. There are segments of both parties that support action to address climate change, and segments in both parties that don't.

But right now, those of us who seek action are confronted by ideology, by fear, by a reluctance to lead, by apathy, by comfort with the status quo. All of that has to change, and I think it is beginning to change.

But before I get to some of the better news, let me give you one illustration of how hard it is to make progress right now. One of the simplest steps we could take to reduce greenhouse gas emissions would be to increase the mileage of our auto and light truck fleet.

It just so happens that increasing mileage would also enhance our national security, bolster our economy, and save consumers money.

And, according to the National Academy of Sciences, we could increase mileage substantially, using technology that already exists, without any reduction in safety. So to exaggerate only a little, this should be a no-brainer - even without taking climate into account, but especially when climate concerns are added to the mix.
So has Congress voted to increase mileage requirements, known as Corporate Average Fuel Economy, or CAFE standards? No.

The proposal has been defeated repeatedly in both the House and the Senate by a mixture of conservative ideologues, and Republicans and Democrats who are lobbied by automakers and/or the United Auto Workers. And I should know because I'm the guy who offers the amendment in the House each time.

Now in the House at least, we do a little better each time. We got 160 votes in favor in 2001, 162 in 2003, and 177 in 2005, and we know we would do better still this year because Members have declared publicly that they've changed their position.

Unfortunately, we can't seem to get a vote scheduled this year, despite high gasoline prices, perhaps because we're on the cusp of victory, at least in the House.
But my point is a more sober one: if we can't make a relatively simple change in mileage regulations - a change to an existing regulation that doesn't even require new technology and that would have numerous benefits aside from the climate implications, then what does that say about our ability to reduce greenhouse gas emissions? It certainly doesn't say anything good.

So all of us who want to see some action on climate change have our work cut out for us.

In the House, many, perhaps even most Members, still question whether climate change is a genuine phenomenon. The scientific consensus has simply not pierced through the ideological barriers. And there are briefings almost weekly sponsored by groups that argue that climate change science is some kind of environmental conspiracy, and they bring seemingly credentialed people forward to make their claims.

We've even had to confront the situation where Members of Congress have tried to investigate scientists whose views made them uncomfortable.

In July 2005, the Energy and Commerce Committee initiated an investigation of Michael Mann and his colleagues who wrote the so-called "hockey stick" article. I took that Committee to task, arguing that raising questions about scientific methods and conclusions was fine, but intimidating scientists was not.

As I wrote to that Committee, "The only conceivable explanation for the investigation is to attempt to intimidate a prominent scientist and to have Congress put its thumbs on the scales of a scientific debate. This is at best foolhardy; when it comes to scientific debates, Congress is 'all thumbs.'"

Eventually, I asked the National Academy of Sciences to convene a panel to look at the historic temperature record. That panel came up with what I think just about everyone views as a balanced and thoughtful report.

It took issue with some of Dr. Mann's initial methods and specific conclusions, but it confirmed that the past few decades have been hotter than any time in at least the last 400 years and probably longer.

This July, the Energy and Commerce Committee had a hearing on that report, which was a legitimate Congressional step to take.

We'll have to wait and see how the testimony at that hearing will influence the future thinking of the Members of that Committee.

I should say that the White House position has been far more nuanced than that of most House Members. The President has stayed within the bounds laid out in the 2001 National Academy of Sciences report on climate change that he requested.

The emphasis of the White House view changes a little depending on who is speaking, but the White House has not been in the camp of those who deny climate change, although it has shied away from mandatory action to combat climate change - unfortunately, in my view.

Now, we're seeing rumors in the media that the White House may be planning a major climate announcement in the next few weeks. I have no idea if that is true.
I'm more concerned about how the Administration is implementing its existing climate plans and programs. Our Science Committee's Energy Subcommittee has a hearing later today, for example, on the Administration's strategic plan for the Climate Change Technology Program, or CCTP.

I have the highest regard for Energy Secretary Bodman, an alumnus of Cornell and MIT, who is a true advocate for science and a candid and creative thinker. But I am not a big fan of the strategic plan, which is more of an inventory of existing programs and a wish list of possible future ones, than a planning document with clear priorities.
Moreover, as is often the case with this Administration, the plan is silent on what policies might be necessary to actually get new or improved technologies into the marketplace.

"If someone builds it, they will come" is not much of a technology deployment strategy, especially when the immediate and significant benefits of new technologies may accrue more to the public as a whole than to the individual consumer.

The example of hydrogen illustrates my point. Hydrogen has a long, long way to go to be a useful energy source, but its potential is enormous and worth pursuing. But we're not going to be driven to a hydrogen economy simply through market forces.
Every transportation revolution in American history - canals, railroads, turnpikes, air travel, interstate highways - has been underwritten by the government.

It's folly to think that that wouldn't be true of a hydrogen revolution, especially since a hydrogen "revolution" would require displacing our current infrastructure, an infrastructure that works just fine from an individual perspective.

But the good news is that the Administration understands that we need new technologies to address climate change, and that the government has a role in developing them.

The third federal player is the Senate, and Senator Bingaman can focus on them. But the Senate, thought it pains me to say it, has been the leader on climate change policy, albeit with minimal results.

Legislation that is explicitly designed to address climate change has at least come up for a vote in the Senate - something that is almost inconceivable in the House. And bills like the McCain-Lieberman cap-and-trade proposal have done respectably, although they have not been passed.

One of the most hopeful events in Washington related to climate change all year was the all-day session that Senator Domenici and Senator Bingaman held back in April to have serious discussions about how greenhouse gas emissions might be regulated.
At that session, not only the senators, but also key business leaders, expressed openness to finding ways to control emissions.

And an even more hopeful sign is what's been happening in the states. California and the northeastern states are trying to take concrete action to reduce greenhouse gas emissions. And many other states and localities have expressed interest in reducing their emissions.

Given the way states compete for jobs and the fact that the impacts of greenhouse gases are felt internationally, not locally, this state interest is not what one would expect. But it's a sign that the public is beginning to sense that this is a problem that must be addressed.

And, of course, the key to creating abrupt political change will be to further engage, educate and inspire the public. Politicians are responsive to public opinion, even in this day and age of political manipulation and multinational corporations.

In fact, in this era of the Internet and constant polling, politicians may be, if anything, too responsive to momentary shifts in public opinion.

So what's needed is for scientists and politicians and concerned business leaders to redouble our efforts to reach out to the public through as many different forums as possible. Complacent satisfaction with our own right beliefs won't carry the day.

The abolitionist Wendell Phillips famously said, "One man on the side of God is a majority." But while that no doubt got Phillips through some lonely times, the anti-slavery advocates didn't gain political influence until they won more converts.

So scientists have to engage. And what scientists say needs to be clear and accurate and modulated and persuasive. Hyperbolic claims will only diminish scientific credibility over time.

Scientists have to be clear about what we know, and about what we don't. They need to be "up front" about uncertainties - and about the potential costs of waiting until all uncertainties are resolved.

(I always quote former Governor Tom Kean's line about acid rain. He said that if all we do is continue to study acid rain, "we'll have the best documented environmental disaster in history.")

We need to lay out an argument for action, but we won't win by mimicking the opposition's tendencies toward rhetorical excess.

And we need to keep in mind that if we win - if the political environment changes so that a desire for action takes root - then our hardest tasks will be ahead of us.

We may end up longing for the days of debate over whether climate change is real - because the intellectual and political decisions we will have to make to confront climate change - whether through mitigation or adaptation or, more likely, both - are going to make today's debates seem like child's play.

I don't think there's anything about the European experience post-Kyoto, for example, that should make us think that this is going to be easy.

So, like abrupt climate change, abrupt political change will present us with a different and problematic world with new and uncomfortable choices. But unlike abrupt climate change, a changed Washington should give us reason for hope, despite all its attendant difficulties.

Climate change discussions can be consumed by gloom. They can remind me of the opening of Woody Allen's classic essay, "My Address to the Graduates." It starts: "Today, we are at a crossroad. One road leads to hopelessness and despair; the other to total extinction. Let us pray we choose wisely."

I think our choices are a little better than that, and if they're not, we'll never win over the wider public.

We have had successes in the recent past in winning over skeptics and taking action. We have controlled the CFCs that created the ozone hole. The Bush Administration has imposed strict new regulations to control fine particles - the health effects of which were still the subject of angry debate not so long ago.

These problems were easier to tackle than climate change, but they didn't seem very easy at the time. The public and policy makers had to be convinced of the science so that difficult concrete steps could be taken.

So I look forward to working with all of you, to continuing to learn with all of you, so that we can create a political climate in which action is possible on climate change.

That's going to take a lot of tough and honest discussion. But it can be done. If we break through the current apathy and cynicism, we can revive American politics, and our environment will be the beneficiary.

Thank you.

What is the Earth's ideal climate?

2006-09-20T08:27:00.000-07:00

In another thread, a commenter asked an interesting question: what is the Earth's ideal temperature? This question is often used as a version of the "AGW might be good argument": the point was that perhaps the ideal temperature was warmer than today's, so climate change might actually be beneficial.

Given everything else equal, one might be able to make an argument that a warmer world might be better. However, everything else is NOT equal. Rather, we have adapted to our present climate and made significant investments in these adaptations. We build cities in places where it makes sense to put them (with the notable exception of New Orleans), we build infrastructure where it makes sense to put infrastructure, we perform economic activity where such activity makes sense. If the climate changes significantly, it might take enormous investments to adapt to our new climate. Our previous investments in infrastructure might become worthless.

Consider this example. You build a sawmill next to a roaring river, using the river as a power source for the mill. Now AGW causes the precipitation pattern to change and the river moves miles away. In this new world, the river might have higher flow rates, which would provide MORE energy to the mill, which would be a good thing --- if the mill were still on the river. But the mill is no longer anywhere near the river. So you have to build a new mill on the banks of the new river. This investment in new infrastructure is potentially expensive, and some countries will not be able to afford it.

My point here is that any question about suitability of future climates has to take into account our investment and adaptation to our present climate.

More on Bush climate u-turn

2006-09-18T10:51:00.000-07:00

I received an e-mail from a distinguished scientist (member of the Academy) saying:

A few months ago I heard from a friend that Karl Rove had met privately with a small group of global warming luminaries that included Bob Corell, and that Rove was listening intently and sympathetically to what they were saying. The article at this link predicts that something big is about to happen, perhaps at Rove's direction. Bizarre as it sounds, I'm inclined to believe it.

I blogged on this recently here. I don't normally put too much faith in hearsay, but I also believe there's a grain of truth here. My current theory is that this is a "trial balloon" put out by the administration to see how much screaming and howling there is.

Overall, however, this is not necessarily inconsistent with an evolution in Bush's rhetoric over the past few years. In 2001, he emphasized the uncertainties in our science. As that position moved from shaky to downright untenable, however, his rhetoric shifted to fairness (China hasn't signed on, etc.) and economic (we'll put people out of work). He really doesn't argue the science anymore.

Stay tuned for more!

Important news

2006-09-14T10:25:00.000-07:00

An interesting news report is circulating around the blogosphere today. Allegedly, the Bush administration is going to propose we limit CO2 to 450 ppmv by the year 2106.

If true, this as an incredibly important event --- it will move the debate from "should we take action?" to "what action should we take?" In other words, the debate will evolve into a discussion of what the target should be --- and this is (in my opinion) exactly what we should be talking about.

The long lifetime of CO2 in the atmosphere means that we cannot wait for 50 years to start reducing emissions if we want to hit 450 ppmv. In fact, we need to start deviating from our baseline in the next 10 years or so in order to avoid having to make large and disruptive cuts later. And the near-term actions required are pretty much the same for a wide range CO2 targets and timelines. Thus, while some will critize the target date of 2106, it will be one or several decades before actions in pursuit of this target preclude more ambitious targets.

ps: I've turned on "comment moderation" on the blog as a test, so your comments might take a few hours to appear. Your patience is appreciated.

[Note added later: The more I think of this alleged proposal, the more puzzled I am about it. The target (450 ppmv) and the time period (2106) are not really consistent. It is almost certainly the case that in order to stabilize CO2 at 450 ppmv at the beginning of the 22nd century, one has to be close to or at that target in the middle of the 21st century. So why put the target date 50 years later? Perhaps this is a cynical election year ploy, as suggested by several commenters. Or maybe there's something I'm not considering. Any thoughts on this are welcome.]

Op-ed on TV's view of scientists

2006-09-13T13:24:00.000-07:00

Interesting editorial by my friend Chris Reddy in the Seattle Post-Intelligencer. Check it out here.

How do you define success?

2006-09-12T10:52:00.000-07:00

Some people define it in terms of Nobel Prizes or election to the National Academy. But I define success as being interviewed by The Houston Chronicle's SciGuy, Eric Berger.

At any rate, I've made it!!! You can check out the interview here and listen to a recording of the entire interview here.

Editorial in the Economist

2006-09-10T10:43:00.000-07:00

Check out this excellent editorial in the Economist. I have a few nits here and there with it, but overall it is what I would have written if I were a much better writer. I think it makes the essential points with great precision.

Three caveats

2006-09-08T18:52:00.000-07:00

Not everyone appreciates the carefully caveated statement in the IPCC's TAR about the attribution to humans of the current warming. Let's take a closer look at the exact statement:

In the light of new evidence and taking into account the remaining uncertainties, most of the observed warming over the last 50 years is likely to have been due to the increase in greenhouse gas concentrations.

There are three important caveats in this statement, which are often ignored by strawman-toting advocates.

"most of the observed warming": this says that humans contributed > 50% of the warming, but it leaves the door open for a significant amount to be due to non-human influences.
"last 50 years": this says that we can identify the hand of humans in only the recent warming; before that, the data are too poor to unambiguously assign the cause of the warming.
"likely": in the carefully nuanced language of the IPCC, "likely" denotes a confidence of about 75%. Thus, there is a possibility that this statement is wrong. This reflects the fact that our knowledge of the climate is imperfect, and it is possible though unlikely that new research could significantly revise our understanding of the climate system.

The main problem is that when advocates use the IPCC in their policy arguments, the carefully crafted language is abandoned for much stronger statements that support the advocates position. When these positions turn out to be false, the blame falls (unfairly) on the IPCC. Clearly, I think we all need to read the IPCC with the scientific precision with which it was written.

Recovery from the little ice age?

2006-09-07T08:44:00.000-07:00

One argument often heard in the AGW debate goes something like this:

The Earth may be warming, but human activities are not responsible: Even if the Earth is warming, it is obviously part of the continuing recovery from the “little ice age,” the cool period from the fifteenth to eighteenth centuries.

This argument tacitly assumes that the Earth’s climate system has a “normal” state that it pushes back to after unusually warm or cold periods, like a stretched spring returning to its normal length. While this might appear commonsensical, it has no foundation in either the record of how climate has varied or the fundamental physics of the atmosphere. The Earth’s climate has no “normal” state to which the climate seeks to return, so there is no reason to expect that an unusually cool period will be followed naturally by a return to warmer conditions.

Rather, when interpreting cause-and-effect in the temperature record, one has to consider the forcings. One can make a strong argument based on solar proxies (like sunspots) that the increasing temperature between the 17th century to about the middle of the 20th century was due to increasing solar forcing.

However, for the particularly rapid warming of the late 20th century, we have a good knowledge of the forcings of the climate. As I described here, we can eliminate solar variability as a primary driver. In fact, the only forcing that explains the warming is the increase in greenhouse gases.

In summary, there is no evidence that today’s particularly rapid warming is caused by the same thing as caused most of the warming over the last few centuries. By considering the forcings, we can conclude that most of the recent warming can be attrbituted to human activities. Thus, the argument that today's warming is simply a continuation of some natural trend is unsupported by any science.

A sensible position

2006-09-04T08:56:00.000-07:00

Can be found here. I might have re-written the title, if I were the editor, but I generally agree with the sentiment expressed that both adaptation and mitigation will be necessary to deal with the climate change problem.

North on the hockey stick

2006-09-04T08:29:00.000-07:00

My colleague Jerry North was the chair of the National Academy panel that investigated the hockey stick. Last week he gave an interesting seminar to our department about the experience. You can view the seminar here.

[Techincal details: it's a 40 MB file, so it'll take some bandwidth. It's in mp4 format --- if you have a recent version of quicktime on your computer, you should be able to view this. It runs just over an hour, so grab some popcorn and enjoy!]

Fill in the blanks

2006-09-02T11:05:00.000-07:00

Consider the following diatribe against the system that I found on the web:

If a contest were held to award the most scientifically baseless, politically oppressive, morally bankrupt, economically destructive environmental farce, the hands-down winner would be the theory of global warming.

Whenever a major action is being dictated, especially at the national level, you should ask yourself, "Who benefits?" If your answer includes arrogant "scientists," trendy politicians & faceless corporate bureaucrats, you can safely assume that scandal is not far behind. Obviously these do-gooders will proclaim that you are going to benefit because they are doing you a big favor; one you don't remember requesting. If you're starting to feel queasy, good.

When I began studying the theory that greenhouse gases were affecting the climate, I found less & less, not more, credibility. What I did find however is that people who will make money on this scandal support it, & choose to deny or ignore the facts. This trend continues at an accelerating pace.

This sounds like pretty routine stuff, right? Actually, I've edited a few words: the bold words have been replaced as follows:

"theory of global warming" was really "the banning of CFCs."
"greenhouse gases" was really "CFCs"
"climate" was "ozone layer"

The point here is that the arguments you hear about climate change are just a re-run of the arguments over ozone depletion. And when the next environmental issues comes up, just replace the bold words with whatever is necessary to attack the science of that issue. You see ... it's easy to be a "skeptic"!

Science and politics of global climate change

Dessler e-mail to Lindzen on 1/17/11

Dessler e-mail to Spencer on 1/17/11

Lindzen e-mail to Dessler on 1/14/11

Spencer e-mail to Dessler on 1/14/11

Dessler e-mail to Lindzen on 1/14/11

Lindzen e-mail to Dessler on 1/11/11

Dessler e-mail to Spencer on 1/10/11

Spencer e-mail to Dessler on 1/7/11

Dessler e-mail to Spencer 1/3/11

The blog is back ... at least temporarily

Scientific hubris?

Should the IPCC be more extreme?

Powering cars with hydrogen

What is the optimal climate?

Scientists and alarmism

A few random notes

Who's that good-lookin' guy in the commercial?

Uh oh!

Is the science of climate change settled?

Testifying before the Texas Legislature on climate change

Conspiracy uncovered!

Bush vs. Clinton on climate change

Betting on global warming

Coming soon to a skeptic near you ... MARS WARMS!

A unique insight into the IPCC process

In climate science, small changes matter

The power of "verification" in science

Carbon trading vs. carbon taxes on Science Friday

Another op-ed on climate change

Hang the bastards!

Why is climate change not taken seriously in the U.S.?

More on the 'reasonable middle'

Biofuels on Science Friday

Texas: Climate's anti-canary

Elements of an effective response to global warming

The $10,000 question

A new round of attacks on the IPCC

Op Ed in the Fort Worth Star-Telegram

Colbert on scientific uncertainty

More update on the AEI and AR/4 brouhaha

AEI and the AR/4 --- update

Highlights of the new IPCC report

Hurricanes --- A new and improved hockey stick

This explains a lot about Texas

Interesting article on peer review

More polling data on climate change

For those that read The Onion

Front page in today's WSJ

Another op-ed on climate change and Texas

Climate change with Al Gore, II

Should we burn climate skeptics at the stake?

Capitol Hill briefing on science and politics

Climate change with Al Gore

Least surprising headlines of the day

My problem with Revkin's article

Overestimating the cost of emissions reductions

Video podcasts on climate change

Have we oversold climate science?

What does 'politicization of science' mean to you?

Nature ends public peer-review trial

New polling data on global warming ...

Top 10 climate stories of 2006, part II

Top 10 climate stories of 2006, part I

Snowe and Rockefeller on the 'uncertainty' agenda

The climate change insurgency

The "uncertainty" agenda

Why the Supreme Court case is not a really big deal

Could the Sun be causing climate change?

The CO2-temperature correlation

I'm going to Disney World!

The "house of cards" analogy

Canada's new greenhouse gas targets

Values in the climate change debate

The puzzle analogy

Climate models vs weather models

Report from the G8 meeting on climate

The build-up of CO2 in our atmosphere will be good!

Answers to a few questions

Alternatives to peer review