Carlin Economics and Science

On June 30 I appeared on the Glenn Beck show, where I showed two charts from my Comments on the proposed EPA endangerment finding report. Although these two graphs do not prove or disprove the existence of significant global warming as a result of increasing levels of carbon dioxide in the atmosphere (the principal UN hypothesis), they are readily understandable and suggest that substantial such warming from this cause is implausible.

UN Temperature Projections Compared with Measured Global Temperatures

Comparison of UN Projections with Temperatures (click to enlarge)

The first graph compares some of the United Nations IPCC model projections (in red, orange, and brown) and actual global temperature surface (green) and satellite (blue) measurements. There is also a yellow line representing the UN’s projection of future temperatures if there were no further human caused carbon dioxide (CO2) emissions. The vertical scale shows temperatures and the horizontal scale calendar years.

It is quite evident that there appears to be an increasing divergence between the UN projections and the global temperature measurements. The obvious question is how this could be if the UN projections are correct. We cannot rule out a brief divergence between projections and temperatures, of course, based on other random and unexplained factors.

But the other seemingly more likely possibility is that the UN projections are substantially inaccurate and exaggerate the projected temperature increase on the high side. Subsequent temperature measurements (not shown here) do not resolve this discrepancy.  If the projections are substantially too high, perhaps they do not deserve to be taken as seriously as many people now do.

Decreasing Measured Temperatures and Increasing CO2 Levels

Comparison of Decreasing Temeratures to Increasing CO2 (click to enlarge)

The second graph also shows global temperatures by calendar year for the period 2002 until mid-2008, but superimposes on this chart yearly atmospheric CO2 levels (shown in green) by year. Since there are two principal sources of global temperature data, surface (shown in black) and satellite (shown in red) measurements, both are shown along with trend lines for each. Inspection of the data shows that while temperature data were trending down over this period, CO2 levels were steadily increasing.

This again suggests that either there was a brief, random, divergence from what would be expected if the UN hypothesis concerning the effects of increasing CO2 levels on temperatures are correct, or that the UN models and hypothesis are simply incorrect.   The brief divergence possibility appears implausible because very similar divergences have appeared previously during the periods 1880 to 1910 and 1940 to the mid-1970s. In fact, the changes in global temperatures appear to be cyclical and to be very similar to the pattern of the Pacific Decadal Oscillation (PDO) which has roughly a 60 year cycle (with 30 up years followed by 30 down years). This leaves the other possibility–that something may be wrong with the UN’s basic hypothesis that CO2 levels are the major determinant of global temperatures since the UN models do not show any such cycles and do not explain the down years from 1940 to the mid-1970s or since 1998.

And if their hypothesis is incorrect, their proposed solution, decreasing CO2 emissions into the atmosphere, would not be effective in preventing increases in global temperatures. At the very least there would appear to be other important factors influencing global temperatures besides CO2 levels that the UN has not considered.  It is important that we understand what these other factors might be before committing ourselves to trying to reduce CO2 emissions at the cost of many trillions of dollars.  To proceed now with reducing CO2 emissions would not only be very expensive but possibly largely futile as well.

Some may have wondered how I reconcile my skepticism about the United Nations hypothesis that emissions of CO2 and other greenhouse gases have an important effect on global temperatures fits with my interest in stratospheric geoengineering as an attractive alternative to reductions in CO2 emissions? This interest is shown in four of my previous publications in climate science under publications. If there is no real risk of a significant global temperature rise due to CO2, we may not need geoengineering after all. My view is that we still have much to learn about Earth’s climate and that the history of interglacial periods suggest that we could be faced with global cooling within a few thousand years. It would therefore appear prudent to be prepared for the eventuality that significant global warming or cooling could occur.

For reasons explained in my geoengineering papers, CO2 emissions control is unlikely to be effective in controlling global warming and useless for global cooling. For a comparatively modest cost, however, we could acquire the capability to carry out stratospheric geoengineering. Chances are very good that it would not be advisable to actually use it, but acquiring the capability would appear to be a wise precaution. It might also reassure those who believe in the UN hypothesis that possible potential warming could be stopped if there should ever be agreement that something needed to be done.

So in summary, I believe that significant global warming is unlikely this century, particularly as a result of increasing CO2 levels, but if it should start to occur it might be useful to be prepared to deal with such warming or the slightly more likely global cooling if necessary through stratospheric geoengineering. One other advantage of being prepared to use effective geoengineering techniques is that we would no longer have any need to undertake extremely expensive efforts to reduce CO2 emissions on the chance that there might be damaging global temperature increases or other adverse effects until the effects actually started to occur.

On June 25th the Competitive Enterprise Institute (CEI) released a draft copy of my report critical of the science underlying EPA’s proposed position on Endangerment under the Clean Air Act and the role of CO2 in global warming saying:

“The released report is a draft version, prepared under EPA’s unusually short internal review schedule, and thus may contain inaccuracies which were corrected in the final report. While we hoped that EPA would release the final report, we’re tired of waiting for this agency to become transparent, even though its Administrator has been talking transparency since she took office. So we are releasing a draft version of the report ourselves, today,” said CEI General Counsel Sam Kazman.

CEI noted that: Internal EPA email messages, released by CEI earlier that week, indicate that in their view the report was kept under wraps and that I was silenced because of pressure to support the Administration’s agenda of regulating carbon dioxide. On June 26 I was given permission by EPA management to post the report on my personal website but not on the EPA website.  Instead of posting the earlier draft released by CEI on June 25 I instead posted the last version prepared before the deadline for internal comments modified only to correct a few of the non-substantive problems. On August 5, EPA posted the last version of my Comments prepared prior to the end of the internal EPA comment period on March 16. This does not include the modifications to correct a few of the non-substantive problems. Thus there are now three different versions on the Web to my knowledge:

The early version made public by CEI on June 25
The last version prepared on March 16 completely unchanged and as distributed by EPA in response to FOIA requests.
The non-substantively modified version of the March 16 version which I prepared in late June

The major differences are between the CEI version and the last two, which are substantively identical. Unfortunately, many readers do not realize that the CEI version is an early version rather than the last version. EPA released the original March 16 version on August 5 as a frequently requested record under the Freedom of Information Act.

For further background information on all this, see press coverage including the following: CBSNews, NYTimes, Wall Street Journal news and opinion, and London Telegraph. For commentary on a September NYTimes story see here.

The title page of the last two versions of the report listed above reads as follows:

Comments on Draft Technical Support Document for Endangerment Analysis for Greenhouse Gas Emissions under the Clean Air Act
By Alan Carlin
NCEE/OPEI
Based on TSD Draft of March 9, 2009
March 16, 2009

I prepared an update to this document, which is on page iii of the last version listed above, so that readers can better understand the conditions under which this report was prepared. I’m reproducing it here:

Important Note on the Origins of These Comments

These comments were prepared during the week of March 9-16, 2009 and are based on the March 9 version of the draft EPA Technical Support document for the endangerment analysis for Greenhouse Gases under the Clean Air Act. On March 17, the Director of the National Center for Environmental Economics (NCEE) in the EPA Office of Policy, Economics, and Innovation communicated his decision not to forward these comments along the chain-of-command that would have resulted in their transmission to the Office of Air and Radiation, the authors of the draft TSD.

These comments (dated March 16) represent the last version prepared prior to the close of the internal EPA comment period as modified on June 27 to correct some of the non-substantive problems that could not be corrected at the time. No substantive change has been made from the version actually submitted on March 16. The following example illustrates the type of changes made on June 27. Prior to March 16 the draft comments were prepared as draft comments by NCEE with Alan Carlin and John Davidson listed as authors. In response to internal NCEE comments this was changed on March 16 to single author comments with assistance acknowledged by John Davidson. There was insufficient time, however, because of deadlines imposed by the Office of Air and Radiation, to make the corresponding change in the use of the word “we” to “I” implicit in the change in listed authorship. This change has been made in this version.

It is very important that readers of these comments understand that these comments were prepared under severe time constraints. The actual time available was approximately 4-5 working days. It was therefore impossible to observe normal scholarly standards or even to carefully proofread the comments. As a result there are undoubtedly numerous unresolved inconsistencies and other problems that would normally have been resolved with more normal deadlines. No effort has been made to resolve any possible substantive issues; only a few of the more evident non-substantive ones have been resolved in this version.

It should be noted, of course, that these comments represent the views of the author and not those of the US Environmental Protection Agency or the NCEE.

Alan Carlin
June 27, 2009