Commentary

Another October Climate Surprise

Every five years, the U. N. Intergovernmental Panel on Climate Change (IPCC) releases its assessment of global warming science. In the fall of 1995, The New York Times published dramatic revelations from a draft version of the assessment that had yet to receive final approval. Last week the report was leaked again, and this time the big story is that the IPCC has increased the upper limit of its forecast for this century’s climate change from 4.5 C to 6.0 C, or 8.1 F to 10.8 F.

Predictably, Vice President Gore was quick to use the assessment to frighten people. “Instead of just going up a few degrees in the lifetimes of these kids, unless we act, the average temperature is going to go up ten or eleven degrees,” he charged. But the document sent out for scientific peer review contained no such numbers. Even after the scientists reviewed it, the maximum value was 4.8 C. In a sad repetition of the 1995 fiasco (in which the key phrase, “the balance of evidence suggests a discernible human influence on global climate,” was inserted after peer review), the most important aspect of the report has been changed after scientific review.

Before IPCC reports are released, they progress through several stages. First, a team of scientists selected by the United Nations writes a “zeroth order draft.” This draft tends to press as many environmental hot buttons as possible, and to bury research indicating that global warming is overblown. That ensures that during the next stage — the scientific review – dissenting experts will argue that the text be revised to achieve balance. But this isn’t peer review in the standard sense, so the original authors review comments and decide which to keep and which to ignore.

Then the document is submitted for “Government Review.” It was at this stage that the 6 C figure was inserted, after the scientists had finished their work. During this stage, comments are received from representatives of various governments — 99 percent of whom either work for or are funded by their government.

This daisy-chain has a propensity to produce very strange offspring. The 6 C figure is based on a socioclimatological model. For sociology, it relies on an array of largely improbable scenarios, called “storylines,” which predict the emissions of greenhouse gases and purported cooling agents, called sulfate aerosols.

For example, “storyline A1,” is “a future world of very rapid economic growth…[in which] people pursue personal wealth rather than environmental quality.” Of course, the socioclimatologists don’t consider the strong correlation between personal wealth and environmental quality, as capital is required for investment in clean technology and infrastructure.

That 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 underwritten by the Pew Foundation Center on Global Climatic Change, which has nakedly advocated passage of the Kyoto Protocol.

When the Pew Foundation published Wigley’s report, it sent a press release stating that his storylines would be incorporated into IPCC’s new assessment of climate change. In other words, a non-peer-reviewed series of illogical assumptions was slated to become the document from which the IPCC’s “consensus of scientists” would predict global warming for the next 100 years.

The 6 C warming claim depends on the declining prevalence of sulfate aerosols, which are supposed to be cleansed from the atmosphere during the next few decades (causing increased warming). But, at the time the IPCC report was being finalized, a troubling article was published that demonstrates why climate models heavily concerned with sulfate cooling and greenhouse warming simply cannot explain why warming of the troposphere (the bottom layer of the atmosphere) has been 10 times less than what had been forecast for the past quarter-century. As a result of this and other work, many atmospheric scientists, including the esteemed Gerry North of Texas A&M University, now believe that the importance of sulfate cooling has been drastically overstated.

The intense global warming predictions of the new U.N. assessment assume not only that sulfates are important, but that they will be rapidly removed from the atmosphere in coming decades, to be replaced by dramatically increasing greenhouse gas emissions. In fact, no one can predict how energy use will evolve over the next 100 years. Consider the transitions of the past 100 years — from horses to jet planes, from wood heating to nuclear power, and a myriad of other technological changes — all of which simply could not have been predicted. It is fair to say that what was not predicted to occur had a much greater impact on society that what was. Yet the IPCC is confident that it can forecast the next 100 years of technological change.

The fact is, there are dozens of computer models for climate change that do not use silly “storylines” and other gimmicks. Those models predict warming of about 2 C over the coming century, a number very near the bottom limit of warming (1.5 C) predicted by the IPCC (they can be found in Chapter 9 of the same IPCC report).

On the other hand, to reach the alarming projections described in the report leaked to the Times, one has to be able to predict technological change better than anyone in human history, believe an argument about sulfate cooling that does not stand the test of reality, and trust a text altered after scientific review was complete.

Patrick J. Michaels is senior fellow in environmental studies at the Cato Institute.