November 1, 2012 9:00AM

Response to Federal Critics of our Report on Climate Change Impacts in the U.S.

The Cato Institute’s Center for the Study of Science has released the author’s proof version of its major report examining the potential impacts of climate change in the United States. It’s called Addendum: Global Climate Change Impacts in the United States (the final copy will be available shortly).

Our document grew from our desire to show how the government report upon which ours is based could have/should have looked if the original scientists involved had included a more thorough (less narrow) review of the scientific literature, and had not been obviously predisposed towards climate change doom and gloom.

Our report refers to itself as an “Addendum” to draw attention to the fact that the original 2009 report from the U.S. Global Climate Change Research Program (USGCRP) was incomplete, insufficient and badly in need of an update to include both scientific results published since its release and to include scientific research that was overlooked or ignored in that original document.

In general, our report, while pointing out that the earth’s temperature is rising and that human activities play a role, paints a more modest picture of climate change and its effects in the U.S. and emphasizes our adaptive capacity to handle a large amount of change in virtually all aspects of society. The overall tone of the Cato report is an optimistic one—a stark contrast to the pessimism that pervades the USGCRP report.

USGCRP Authors React

Our report has drawn ire from climate change alarmists, as well as from a subset of the group of scientists which authored the original USGCRP report.  We note that those who signed the group note make up barely a third of the 31 scientists who authored the USGCRP report. Eleven USGCRP co-authors released a statement airing their discontent in which they said:

As authors of [the USGCRP] report, we are dismayed that the report of the Cato Institute, ADDENDUM: Global Climate Change Impacts in the United States, expropriates the title and style of our report in such a deceptive and misleading way. The Cato report is in no way an addendum to our 2009 report. It is not an update, explanation, or supplement by the authors of the original report. Rather, it is a completely separate document lacking rigorous scientific analysis and review.

In fact, one of the primary ways that our report intended to make its point was by mimicking the style of the USGCRP report (in this case, imitation is not a form of flattery).  It is what the government report would have looked like had the authors been more open-minded and inclusive of the scientific literature.  In places where it was determined the original authors had done an adequate job, those sections were included verbatim, which we were certainly explicit about! This was all clearly explained in the “About this Report” section of our report (p. 8; analogous to their p. 7):

This Addendum is similar in format to the 2009 USGCRP report, allowing a facile reference for science that was omitted. In some places, we have moved text verbatim from the 2009 report to this Addendum.

That’s “deceptive or misleading?” The front cover of our report, smack in the middle of the page it says “Center for the Study of Science, Cato Institute.” That’s deceptive or misleading? The back cover is completely blank except for the prominent Cato Institute logo. There is a letter of introduction (p. 3 in both documents) written and signed by (then) Cato President Edward Crane. And “The Cato Institute” is included in the running header of every left-hand page in the document.

Deceptive or misleading? All of this led the world’s most prominent and popular climate blogger Anthony Watts to state “How anyone with even limited intelligence could get the idea that the report is from the US Government/NOAA is truly laughable, because if they can’t read “Cato Institute” clearly printed on the front and back cover, then they probably aren’t capable of reading and interpreting the original report either.”

As to the USGCRP co-authors statement that the Cato report is not “an update, explanation, or supplement by the authors of the original report” this is certainly true. The original authors had nothing whatsoever to do with our report. In fact, the original authors substantively ignored virtually every comment in a 77-page single-spaced (24,958 word) review of their draft document that we submitted in August, 2008—which is why they are now seething over our Addendum, which is partially based on that review.   It is their very poor job, which is so misleading in spots that it appears intentional, that required a subsequent addendum, update, explanation, and supplement, or whatever you chose to call it.

And as to their claim that our report is “lacking rigorous scientific analysis and review,” any reader of our report will find the text to be well documented and derived primarily from the well-accepted material.  Our report describes its source material this way:

This Addendum is primarily based upon the peer-reviewed scientific literature, peer-screened professional presentations, and publicly-available climate data. We include literature through the beginning of 2012, which of course could not be in the 2009 [original USGCRP] report. But there are also a plethora of citations from 2008 or earlier that were not included in the US­GCRP document. Why that is the case is for others to determine.

These sources are no less rigorous (and certainly more inclusive) than those assessed/included by the original USGCRP authors.

The co-authors of the group letter go on to note four other points that they wish to emphasize.

Quality References

The first has to do with the number/quality of references included in the USGRCP report vs. our report. Both reports draw primarily from the peer-reviewed scientific literature. That our report includes a large number of peer-reviewed studies directly relevant to climate change impacts in the United States that were not included in the USGCRP report, and which support a more modest impact, in and of itself speaks volumes. Instead of quibbling over the number of references, the USGCRP co-authors ought to be apologizing profusely for producing such an incomplete and one-sided report on the taxpayers’ dime.

Effectiveness of Public Comment

Another bone of contention is that the USGCRP report was open to public comment while our report was not. But, as Ed Crane described in his introductory remarks in the report, the public comment process for the USGCRP report left a lot to be desired:

This effort grew out of the recognition that the original [USGCRP] document was lacking in scope and relevant scientific detail. A Cato review of a draft noted that it was among the worst summary documents on climate change ever written, and that literally every paragraph was missing critical information from the refereed scientific literature. While that review was extensive, the restricted timeframe for commentary necessarily limited any effort. The following document completes that effort.

And, of course, our Addendum is a public comment.  As is the letter signed by 11 of the USGCRP report’s original authors.

Modest Climate Change

Here is the third point made by the USGCRP author team:

The authors of the Cato Institute report agree with our Committee’s conclusions that global warming is unequivocal and consistent with a change in greenhouse gas effects attributable to human activities. They also conclude that climate change will continue to occur as greenhouse gas concentrations increase. However, their conclusions that future climate change will be benign, if not beneficial, and easily adapted to, diverge markedly from our Committee’s view regarding the seriousness of the risks. This is because the Cato Institute authors assume—based on their own analysis and contrary to peer-reviewed, contemporary science—that warming, intensification of weather extremes, polar ice cap melting, and sea-level rise will all be at the lowest end of the ranges projected in the Fourth Assessment of the Intergovernmental Panel of Climate Change.

I largely agree with all of this except the phrase “based on their own analysis and contrary to peer-reviewed, contemporary science”—in fact, our entire report is largely built upon the peer-reviewed, contemporary science.  And our “conclusions that future climate change will be benign, if not beneficial, and easily adapted to” are well-supported by the literature (and, as we point out, common sense). That the USGCRP co-authors find otherwise, or at least fail to even consider this very strong possibility, is the primary fault in their report that we address.

NAS Reports

The fourth and last point made by the USGCRP author team is that the USGCRP findings are backed by recent National Academy of Sciences reports. To me this is a hollow claim, as the NAS reports are about as selective in their science as the USGCRP report. Most of the NAS reports mentioned by the USGCRP authors in support of their report have been taken apart by the Cato Center for the Study of Science staff (see here and here, for example).

Future Update

And finally, the USGCRP co-authors note:

The next U.S. National Climate Assessment is underway under the auspices of the U.S. Global Change Research Program, with draft sections of its report to be released in December and completed in 2013. We are confident that this new assessment will reinforce and extend the findings of Global Climate Change Impacts in the United States.

Well that last line sure sounds like a bummer. My guess is that there will soon be another Addendum report from the Center for the Study of Science in the making.  In fact, the last substantive section of their document is titled “A vision for future U.S. assessments.”  Ours is titled “Future federal science assessments,” and says:

Future assessments of climate change are likely to be as poor in quality as Global Climate Change Impacts in the United States...However...each  new federal assessment is likely to be answered like the USGCRP report was—with more science than our federal government chooses to recognize.

Note: This is post is a substantial modification of one that originally appeared at