his is not just a controversy about putting restrictions on scientists who give public speeches or interviews. It is, more deeply, a controversy about the responsibilities of scientists whose technical knowledge gives them enormous authority in modern society. Government scientists, especially—accountable to no electorate, but in positions of public trust—must wield that authority with utmost circumspection.
The Hansen affair is also yet another example of the limits of science to settle policy questions: Knowing the facts, which themselves are often in dispute, does not settle the best course of action. How much economic pain are we willing to endure to prevent the potential dangers of global warming? To what extent are we willing to limit freedom and expand the regulatory power of government to reduce greenhouse gases? How do environmental concerns relate to other urgent problems, whether the looming crisis of entitlements or the threat of a nuclear Iran? Many scientists, experts in their own sub-disciplines, come to think that the “crisis” they know best is the only crisis that matters, and they demand that all “enlightened” politicians govern accordingly. But in reality, democracy, informed by science but not ruled by it, is more enlightened than scientists alone. This fact is often forgotten amid all the endless chatter about “politicizing science.”