Commentary

Global Warming: The Scorecard Thus Far

A few weeks ago, the Clinton administration finally got around to signing the Kyoto Protocol, the global warming treaty that obligates the United States to reduce greenhouse gas emissions by 7 percent below 1990 emission levels by the year 2012. Both supporters and opponents of the treaty agree that meeting that goal will require between a 30 and a 40 percent reduction in the greenhouse gas emissions that would otherwise occur about a decade hence. Beyond that, sorting out the scientific and economic argument between the two is difficult for a nonspecialist. Here’s the scorecard to date.

Treaty supporters say that just about all the scientists engaged in global warming research now accept that the problem is real and must be addressed. Well, yes and no. Most (but by no means all) scientists engaged in the field agree that industrial emissions are probably affecting the climate. But the evidence is circumstantial. As the United Nations’ International Panel on Climate Change (IPCC) noted in its most recent (1995) report, the evidence thus far “cannot be considered as compelling evidence of cause-and-effect link between anthropogenic forcing and changes in the Earth’s surface temperature.”

The “balance of evidence suggests” (in the words of the IPCC) that industrial emissions are the culprit, but that’s hardly conclusive. And the consensus about the matter is not as nearly universal as suggested. Seventeen thousand scientists (half of whom are trained in physics, geophysics, climate science, meteorology, oceanography, chemistry, biology or biochemistry) recently signed a petition written by Frederick Seitz, a past president of the National Academy of Sciences, declaring that there is no compelling evidence to justify reducing greenhouse gas emissions at all.

Nor do scientists agree on how hot it would get if we did nothing. The IPCC’s “best guess” back in 1990 was that industrial greenhouse gas emissions would increase average global temperatures by 5.8 degrees (all temperature figures are Fahrenheit) by the end of the next century. In 1995 the IPCC adjusted its “best guess” down to 3.6 degrees. Three studies published this year (by Hansen, Dlogokencky and Myhre) suggest that the present “best guess” stands at about 2.25 degrees of warming by the end of the next century. Most experts doubt that that amount of warming would be particularly worrisome (indeed, we’re already about half way there temperature-wise, and the effect of this “global warming” has thus far proven underwhelming, to say the least).


Killing the coal industry to reduce temperatures 1/7th of 1 degree 50 years hence is justified by treaty advocates as a necessary “first step” of about 30 that must necessarily come. Treaty opponents do a quick cost/benefit analysis and conclude that treaty advocates have lost their grip on reality.


While the Kyoto Protocol envisions significant cuts in greenhouse gas emissions, scientists on all sides of the debate agree that its impact will be virtually undetectable. Tom Wigley, a highly respected senior scientist at the U.S. National Center for Atmospheric Research (and a scientist, moreover, usually thought of as in the alarmist camp), recently calculated that the Kyoto Protocol would only reduce temperatures by 0.13 degrees by 2050 if we accept the IPCC’s 1995 estimate of warming under a business-as-usual scenario. The Kyoto Protocol would have no meaningful impact on future climate change because, as along as we use fossil fuels, the question of global warming is not “if” but “when.”

Finally, advocates of the treaty argue that its costs will be negligible, while opponents warn of a replay of the 1970s energy crises. The best evidence for each argument comes from studies issued by the Clinton administration (the study most optimistic about costs comes from the president’s Council of Economic Advisers (CEA), the most pessimistic from the Energy Information Administration). Both studies make valid projections. The differences are found in the assumptions. But it’s worth noting that the economic models relied on by the CEA reveal that, absent a truly global emissions trading system (a system that was hotly opposed by most nations at the recently concluded talks in Buenos Aires), America would be forced to abandon coal-fired electricity within the next decade to keep compliance costs from skyrocketing.

Killing the coal industry to reduce temperatures 1/7th of 1 degree 50 years hence is justified by treaty advocates as a necessary “first step” of about 30 that must necessarily come. Treaty opponents do a quick cost/benefit analysis and conclude that treaty advocates have lost their grip on reality.

And that, dear readers, is where we stand today. Misleading public characterizations of the global warming debate notwithstanding, the case for the Kyoto Protocol is pretty threadbare. Of course, the Senate is unlikely to ratify the treaty, a fact conceded by the administration in its decision not to send it up for a vote until at least 2001. If the past is any prologue, the case for ratification will continue to weaken. The question is, Will anyone be able to see through the political hot air to notice?

Jerry Taylor is director of natural resource studies at the Cato Institute.