Nothing seems more reasonable than the Precautionary Principle, that it is better to be safe than sorry. And it has become the guiding principle of the environmental movement. In the Wingspread Statement, it is defined thus:
When an activity raises threats of harm to human health or the environment, precautionary measures should be taken even if some cause and effect relationships are not fully established scientifically.
In this context the proponent of an activity, rather than the public, should bear the burden of proof.
The process of applying the Precautionary Principle must be open, informed and democratic and must include potentially affected parties. It must also involve an examination of the full range of alternatives, including no action.
All seems well, but as Jonathan Adler writes, in practice it is profoundly incoherent. He quotes Cass Sunstein:
The precautionary principle, for all its rhetorical appeal, is deeply incoherent. It is of course true that we should take precautions against some speculative dangers. But there are always risks on both sides of a decision; inaction can bring danger, but so can action. Precautions, in other words, themselves create risks—and hence the principle bans what it simultaneously requires.
In practice, of course, the Precautionary Principle is a power tool that allows the cultural and political elite to stop stuff they don't like, for it is easier to raise fears about good new ideas than to do something about bad old ideas. Thus, writes Adler, the precautionary principle is used to "burden private actors, most notably corporations, that propose altering the environmental landscape in some way or introducing a new product or technology into the stream of commerce." The problem is that the precautionary principle doesn't address the fact that while there is a risk from doing something, there is also a risk from doing nothing. Elites and governments across the world have insisted that we "do something" about global warming even though it is completely uncertain what the effects of global warming on humans will be, if there is any.
No doubt, the precautionary principle relies on the tendency of people to "dislike losses far more than they like corresponding gains," and there is also the human tendency to wait on a developing problem until it is clearly a serious problem.
But the big problem with the precautionary principle is that it hands government another weapon in its armory of power tools. Any special interest can use the precautionary principle to game the political system. And since the precautionary principle requires artful and articulate people to deploy it, you can understand why the educated elite would like it.
The bottom line is that anything that gives the government more power is questionable on its face. Government is force, and there are some things in the world that can only be done with force. But humans are social animals, not regimental animals, and most things in this world can be done best by persuasion, cooperation, and exchange.
The problem of government is to limit government. There is no pressing need to give governments more ways to deploy force.