Michael Gerson

In the field of environmentalism -- where brows tend to be frozen in furrow and despair is a professional credential -- Gregg Easterbrook of the Brookings Institution is notable for his optimism. And one cause of his sunniness is smog in Los Angeles.

In 1975, Los Angeles exceeded the ozone standard 192 days out of the year -- meaning the choking smog was so bad that children, the elderly and the infirm were better off avoiding the risky practice of outdoor breathing. In 2005, the ozone standard was exceeded on just 27 days. Los Angeles has had 30 years of consistent improvement in reducing smog.

As conservatives would expect, these gains were largely the result of technology -- the catalytic converter in automobiles and reformulated gasoline -- and not by pedaling to work or undoing the Industrial Revolution. Smog was reduced mainly by innovation, not austerity.

But liberals are correct about something else: This technological progress would not have taken place as a result of the free market alone. Easterbrook argues that as long as producing pollution is a free good -- without cost to the polluter -- there is little economic incentive to produce new methods to restrict it. Federal and state regulations on auto emissions and air quality created an environment in which the invention of new technologies was economically necessary.

There are lessons here in the controversy over global warming. The debate is less and less about the existence of the problem itself. A consensus has hardened and broadened that global temperatures are increasing, that humans have contributed to the rise and that this is eventually a bad thing for the planet -- views held by the environmental movement and publicly affirmed by the current president. The differences come on whether these environmental changes are likely to be gradual and manageable or swift and apocalyptic. Here, the scientific computer simulations are complex and speculative, and their conclusions are sometimes wildly overplayed.

Hysteria on the environment is a liberal temptation. Prudence, however, remains a conservative virtue, and it requires the issue of warming to be addressed.

Michael Gerson

Michael Gerson writes a twice-weekly column for The Post on issues that include politics, global health, development, religion and foreign policy. Michael Gerson is the author of the book "Heroic Conservatism" and a contributor to Newsweek magazine.
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