Still open to debate are subsidiary issues such as the role of command-and-control regulations versus market-based approaches like tradable emissions permits. But the Big Issue — humans' harmful effect on the climate and our consequent need to correct the problem — is settled.
Being neither an atmospheric scientist nor a former U.S. vice-president, I haven't the expertise to judge whether or not global warming is a reality or the extent to which humans cause it. Experts who I trust, however, persuade me that science does indeed show that global temperatures are rising and that industrial activity is at least part of the reason. I'm prepared to believe even the possibility that global warming will eventually kill millions of people.
But I nevertheless insist that science does not unambiguously endorse action against global warming. Put differently — and contrary to today's elite opinion — ignoring global warming is not necessarily a sign of scientific illiteracy or of ideologically induced stupidity.
First, human preferences might counsel against tackling global warming. If global warming's ill-effects won't occur for, say, another 150 years, nothing objective says that people today should sacrifice for that distant tomorrow. Such sacrifice might be demanded by ethics — or by human preferences themselves — but not by science.
Second, and more interestingly, sound skepticism of government action to prevent global warming is itself based on science.
Public Choice economics offers objective theory and evidence that political institutions are so prone to malfunctioning that entrusting them with great powers courts great trouble.
Posing the greatest danger is command-and-control regulation, for not only does it aim to achieve goals defined by politicians, it dictates in detail the means to be used by private firms and persons in pursuit of these goals. Such centralized, politicized, and bureaucratized intervention has only weak feedback loops. (For example, how to tell if the mandated method of emissions reduction is better than alternative and now-prohibited methods?) And unsurprisingly, such heavy-handed regulation is especially prone to be hijacked by special-interest groups. When eastern coal producers successfully lobbied for the 1977 Clean Air Act amendment that mandated scrubbers for all coal-burning factory furnaces, the intent (and effect!) had nothing to do with cleaning the air and everything to do with undermining the market for naturally cleaner low-sulfur coal from the west and with creating a market for scrubbers produced by corporations such as Westinghouse.
Even market-based environmental regulation, however, is risky. Tradable emissions permits do give firms flexibility when deciding how much factory output to produce and by what methods, but the overall level of desired emissions is still set politically. This is not because politicians are not scientists, but because the question of what ultimately constitutes an optimal emission level is not a scientific one alone. Neither scientists nor any one else really knows what trade-off individuals are willing to accept in constraining their preferred actions and choices now for the sake of stabilizing carbon dioxide levels in the future. Furthermore, this trade-off will vary from society to society, country to country, company to company, individual to individual. For instance, a poor mother in a Third World country trying to feed her family will have fewer qualms about using cheap, polluting fuels to cook for her children now than the wealthy and environmentally conscious individuals in her own country — not to mention prosperous First World countries — who can forego some immediate material needs for the sake of the psychic benefit of leaving a stable climate to their great-great-grandchildren. Even elected officials with unalloyed devotion to the public good don't have enough information about the particular circumstances and needs of individuals to know where to set emission levels so as to optimize their costs and benefits. Indeed, the 1990 baseline in the Kyoto Treaty was picked not for scientific reasons but political ones.
Nor will it do to argue that democratic voting offers reliable (or even reliable-enough) feedback to elected officials to set optimal limits, as is generally claimed. Geoff Brennan's, Loren Lomasky's, and Bryan Caplan's recent contributions to the theory of "expressive voting," along with Kenneth Arrow's earlier research on the arbitrariness of majoritarian outcomes, provide solid scientific reasons to doubt both the meaningfulness of preferences expressed in voting booths and the legitimacy of electoral outcomes as reflections of these expressed preferences. Not only, as Arrow proved, are the results of majoritarian voting unavoidably sensitive to the specific rules governing elections, but — as Brennan, Lomasky, and Caplan argue — the fact that each voter bears little personal consequence of casting a ballot one way or another means that each voter, effectively, gets to vote for free. A voter gets to express in the voting booth his or her policy preferences without being constrained to reckon seriously the consequences of how he or she votes.
But if democratic decision-making doesn't offer a cure for the real possibility of negative externalities — that the gain pursued by rational individuals might generate an overall outcome in which everyone is worse off than if each person been constrained to follow an available different course of action — what should be done about the kinds of activities that contribute to global warming?
It is hard to admit, but unless solutions are realistically available that do not themselves pose serious risks of unleashing other problems worse than the one sought to be solved, the externality is best left alone. Public Choice reveals the risks of seeking such solutions from government. More general economics reveals yet other risks: stifling, if not killing, the goose laying our golden eggs, namely industrial capitalism.
Political manipulation to encourage investments in the most environmentally correct — as opposed to profitable — energy technologies, for instance, would simply mean less overall investment in the energy sector. Worker productivity in this sector would fall over the long run, as would overall output. Living standards would decline. Indeed, if investors ever come to believe that Al Gore's demand to "drastically change our civilization and our way of thinking" would become a reality, they would surely liquidate much of their stakes in the economy. The resulting destruction of capitalism's capital will throw us all into the dark ages.
We mustn't forget that industrial capitalism is history's greatest life-saver. Over the past two centuries it has more than doubled life-expectancies and made our bodies cleaner, taller, stronger, better clothed, and more disease-resistant. Capitalism has also made available to us rich experiences and knowledge — including most of science itself — that were simply out of reach before the industrial age. Any heavy-handed assault on capitalism might well impair this magnificent institution and lead to human suffering worse than will be wreaked under worst-case global-warming scenarios. As economists J.R. Clark and Dwight Lee argue, "government regulations that undermine both information flows and adjustments of the market process in an effort to reduce greenhouse gases, even if successful, run the serious risk of increasing the long-run damage of any global warming that does occur."
Indeed, until the science of economics, especially that of Public Choice, is brought more fully into the discussion, the science of global warming will remain perilously incomplete.
Donald J. Boudreaux is Chairman of the Department of Economics at George Mason University in Fairfax, Virginia. He can be reached at is firstname.lastname@example.org. This column is part of Reason's Roundtable on policy solutions to global warming.