Good morning and welcome to the AEI conference, "Return to Rio: Reexamining Climate Change Science, Economics, and Policy." I am grateful to my colleagues James Glassman and Samuel Thernstrom for conceiving and organizing the conference and to the several natural and social scientists, policy experts, and government officials who have joined us for what promises to be a lively and productive series of discussions.

I am very reluctant to put the views of participants in AEI conferences into political cubbyholes--especially when we are dealing with a subject such as climate change, a matter of heated political contention where many serious scholars hold views more nuanced than those of political partisans. But today I would like to offer special thanks to our panel participants who hold the view that recent warming trends are largely or entirely the result of man-made increases in emissions of carbon dioxide and other greenhouse gases, and to offer an apology and explanation to our audience for the fact that these views are not more thoroughly represented on our panels.

The American Enterprise Institute does not take positions on policy or political questions, but individual AEI scholars do, and there is a broad consistency to these views: we are a "school" in the original sense of the word, and our school is that of limited-government, free-market, constitutional conservatism. At the same time, we are serious academics and empiricists: we regard open, reasoned debate as essential for the search for truth and the improvement of practical policy, and we want to keep the conversation going among contending viewpoints in the face of political efforts to gang up on or vilify inconvenient views. Our longtime motto is, "Competition of ideas is fundamental to a free society," and in organizing conferences we go out of our way to see that important competing views are vigorously represented. I daresay that AEI economists are at one in strongly opposing the quotas on Chinese imports imposed yesterday by the Bush administration, but if we hold a conference on the subject we will look for the most forceful advocate of the quotas we can find. We also like to devote ourselves to harder questions where the intellectual merits are less clear cut; it we were to hold a conference today on the Medicare reform bill currently before the Congress, we would not need to look beyond our own research staff for sharply differing views.

On climate change issues, AEI scholars have been adamant critics of the Kyoto Protocol, for reasons having nothing to do with the underlying science; on the issue of policy response, we have not been mere critics and nay-sayers, but have produced and published important studies proposing robust institutional alternatives to Kyoto should they be necessary or prudent. On the science, several AEI scholars have been very skeptical about the propositions that warming is largely man-made and is for that reason is likely to increase, and that it is likely to cause massive harms. On the science we regard ourselves as consumers rather than producers, but sophisticated consumers--we are not natural scientists but are social scientists or are well grounded in empirical technique and inference. Our primary position on the science has been that inquiry and debate should remain open and that alternative views of causation and consequences should be seriously entertained.

In planning today’s conference, we went well beyond our usual careful procedures for identifying vigorous proponents of all viewpoints, and invited a very large number of eminent global warming proponents to participate. Almost all of those invitations were turned down, sometimes quite heatedly, and in one case a highly regarded physicist active in the climate change debates accepted and then withdrew at the last minute under circumstances that made it clear he was bowing to political pressure.

It has long been the position of Kyoto advocates such as former Vice President Gore, and many membership-driven environmental organizations, that debate over the causes of climate change has become illegitimate--nothing but the cat’s-paw of unseemly corporate interests--and must cease. That is unfortunate but not unusual in cases where science and politics meet. What is more disturbing is that this posture has recently been adopted by many scientists themselves. One would think that scientists, above everyone else, would insist that all theoretical and empirical propositions remain continuously subject to challenge and discussion. There are limits of course; most scientists would not be much interested in dwelling on challenges to the fundamental laws of gravity or thermodynamics or biological evolution. But we are not dealing with such a case here, and the effort to pretend that we are is dangerous. As the National Academy of Sciences’ Committee on the Science of Climate change wrote in its 2001 report:

"The most valuable contribution U.S. scientists can make is to continually question basic assumptions and conclusions, promote clear and careful appraisal and presentation of the uncertainties about climate change as well as those areas in which science is leading to robust conclusions, and to work toward a significant improvement in the ability to predict the future."

In these circumstances, and particularly because of the momentous social, economic, and political stakes presented by the climate change issue, I am very proud that AEI is attempting to uphold the principle of reasoned, on-the-merits, non-politicized inquiry and debate, and very grateful to today’s panelists for offering us a sterling example of that principle in action.