Leaked IPCC report triggers false alarm

Published December 1, 2000

Every five years, the United Nations Intergovernmental Panel on Climate Change (IPCC) gives its assessment of the state of global warming science. In the Fall of both 1995 and 2000, the New York Times published dramatic revelations from a draft version that had yet to receive final approval.

This time, the main story is that the United Nations has dramatically increased the upper limit of its forecast of this century’s climate change, from 4.5°C to 6.0°C.

The document that was sent out for scientific peer review contained no such number. After the scientists reviewed it, the maximum value was 4.8°C. In a sad repetition of the fiasco of the 1995 assessment—in which the key phrase “the balance of evidence suggests a discernible human influence on global climate” was inserted after peer review—again, the most important aspect of the report has been changed.

Not peer reviewed

IPCC reports go through several stages. First, a team of scientists selected by the United Nations writes a “zeroth order draft.” This version makes sure that as many of the environmentally correct hot buttons as possible are fleshed out, and research indicating that global warming is overblown is buried, if it is mentioned at all.

That makes the next step, the scientific review, biased in one direction. Criticism against the relatively gloomy zeroth draft must argue both against extant text and for a 180-degree revision.

This really isn’t peer review in the classic sense. Here, the original authors review the comments and decide which to keep and which to ignore. As an example, you’ll find little in the new IPCC report about an important paper published in January in the refereed journal Climate Research, which proved that the warming of the late twentieth century is inordinately limited to the coldest, deadliest air masses of Siberia and North America.

After this form of scientific review, the document goes for a “Government Review.” It was at this stage that the 6°C figure was inserted, after the scientists were done. In this process, national governments send their comments to the same original authors–99 percent of whom either work for or are funded by their governments.

This daisy-chain has a propensity to produce very strange offspring.

Illogical storylines

The 6°C figure is based upon a socioclimatological model. For sociology, it relies upon a number of illogical scenarios, called “storylines,” first generated at the Center for International Earth Science Information Network (CIESIN) at Columbia University. The “storylines” then generate profiles for the emissions of warming greenhouse gases such as carbon dioxide, and purported cooling agents, called sulfate aerosols.

The “storylines” can be senseless. “Storyline A1,” according to CIESIN, is “a future world of very rapid economic growth. . . . [I]n this world people pursue personal wealth rather than environmental quality.” CIESIN and the IPCC apparently do not understand that there is a logical and strong correlation between personal wealth and environmental quality, as excess capital is required for investment in increasingly clean infrastructure.

These and other “storylines” were first published in a non-peer-reviewed report by Tom Wigley, a government climatologist at the U.S. National Center for Atmospheric Research. The report was produced by the Pew Foundation Center on Global Climatic Change, which itself has nakedly advocated for passage of the Kyoto Protocol on climate change.

In his Times article, reporter Andrew Revkin noted that the leaked copy of the IPCC document was supplied by “someone who was eager to have the findings disseminated at the meetings in The Hague” that are supposed to implement the Kyoto Protocol. Between now and The Hague meetings lies Election Day.

When the Pew Foundation published Wigley’s pamphlet, it produced a press release stating that his scenarios (the original “storylines”) would be incorporated into the IPCC’s new assessment of climate change. In other words, what was then an un-peer-reviewed, illogical series of assumptions was slated to become the basis for the self-appointed “consensus of scientists” comprising the IPCC.

Dubious sulfate cooling theory

The 6°C warming prediction hangs upon the slim thread of the sulfate cooling theory, which holds that man-made emissions called sulfate aerosols are masking the effects of rising greenhouse gases, which explains why we have observed so much less warming than global warming models predict. The theory further holds that these sulfates will be dramatically cleansed from the atmosphere in the next few decades (resulting in enhanced warming).

But, at the time the IPCC report was being finalized, a paper appeared in the September 15, 2000 issue of Geophysical Research Letters demonstrating that climate models using sulfate cooling and greenhouse warming simply cannot explain why integrated warming of the troposphere (the bottom layer of the atmosphere) is ten times less than what was forecast for the last quarter-century.

Another test of the sulfate hypothesis can be gained by looking at northern vs. southern hemisphere temperatures in the lower troposphere. As shown in a landmark paper by Benjamin Santer et al. in 1996, sulfate cooling should have been more pronounced in recent decades in the northern hemisphere, so that the difference between the hemispheres (northern minus southern) should be dropping significantly.

In fact, this differential is, beyond a doubt, changing in the direction opposite to what was predicted. As a result of this and other work, many atmospheric scientists, including the esteemed Gerry North of Texas A&M University, now believe that sulfate cooling has been drastically overestimated.

The high CIESIN/Wigley/Pew estimates assume not only that sulfates are important, but that they are rapidly removed from the atmosphere in coming decades and are replaced by dramatically increasing greenhouse emissions. In fact, no one at all knows how our energy structure will evolve in the next 100 years.

Consider the transitions of the last 100 years–from horses to jet planes, from wood heating to nuclear power, and myriad others–that simply could not be predicted. It is fair to say that what was not predicted to occur had a much greater impact on society that what was. A similar thought experiment can be run between 1800 and 1900, with similar results. Yet the IPCC confidently feels it can anticipate the next 100 years of technological change.

Other models differ

The same draft version of the IPCC report contains a summary of the dozens of computer models for climate change that do not use the silly CIESIN storylines. Instead, they use a (probably overestimated) exponential increase in greenhouse gases, and still a central tendency of all of the models is around 2°C of warming for this century, or very near the bottom limit of warming (1.5°C) given by the IPCC.

The Times cites a broad consensus of scientists who believe human warming has been going on for some time now. This is very likely to be correct because of the propensity for recent warming to be in the winter and in frigid air–which is where greenhouse theory predicts the largest changes. But the IPCC climate models also show the average prediction is a straight-line warming, and that once it starts (at the surface it has been going on for decades) it continues at a constant rate.

As a result, if the warming of recent decades is largely a human product, then we know the rate of warming for this century, barring any major decreases in greenhouse emissions. That works out to right below 1.5°C. Further, the winter/summer differentials between models also remain quite constant, which means this century is likely to experience a considerable warming of the coldest winter temperatures and relatively little change in the summer.

On the other hand, in order to reach the inflammatory and alarming projections described in the document leaked to the Times, one has to assume illogical social behavior, an ability to see the technology of the next 100 years better than anyone in human history, an argument about sulfate cooling that does not stand the test of reality, and a text changed by governments after the normal scientific review process.

According to Nature magazine, University of Virginia environmental sciences professor Patrick J. Michaels is probably the nation’s most popular lecturer on the subject of climate change. Michaels is coauthor of The Satanic Gases: Clearing the Air About Global Warming.


Michaels, P.J., and P.C. Knappenberger, 2000. Natural Signals in the MSU Lower Tropospheric Temperature Record. Geophysical Research Letters 27, 2905-2908.

Michaels, P.J., Knappenberger, P.C., Balling, R.C., and R. E. Davis, 2000. Observed Warming in Cold Anticyclones. Climate Research 14, 1-6.

Santer, B.D., et al., 1996. A Search for Human Influenced on the Thermal Structure of the Atmosphere. Nature, 382, 36-45.