Saturday, December 5, 2009

AGW: The Quadrant Problem

There are two main axes of belief on the question of anthropogenic global warming. The first is whether or not it is happening. The second is not whether or not we should err on the side of caution. Everyone agrees that we should. The question is what constitutes caution: protecting the environment, or avoiding economically-costly regulation.

The thing is, these beliefs are, or should be, orthogonal. Opinions on one question should not determine or even influence opinions on the second. If people were thinking clearly, public opinion would be arrayed in the quadrants independently. (This is a different matter than evaluating one's own certainty; most wise people would say they are not quite certain if AGW is happening, but if forced to guess would be able to do so without recourse to a coin-toss.)

If we designate:
  • Position A as: "Human activities are warming the environment significantly"
  • Position B as: "Human activities are not warming the environment significantly"
  • Position 1 as: "We should err on the side of protecting the environment"
  • Position 2 as: "We should err on the side of protecting the economy"
then we would quickly find that positions A1 and B2 have many more proponents than A2 and B1.

Compare this to a substantively different, formally similar grid, regarding the opinions of a group of dinner guests as to whether the host should take his leave of the party in order to investigate strange noises emanating from the garage:
  • Position A is: "The noises from the garage are a raccoon robbing the trash cans."
  • Position B is: "The noises from the garage are creaking beams, nothing to worry about."
  • Position 1 is: "We should err on the side of preventing the raccoon from spreading garbage around."
  • Position 2 is: "We should err on the side of avoiding confrontation with a possibly rabid animal."
In this case I believe that the quadrants would be represented independently, i.e., if A2 is three times as popular as A1, then B2 must be three times as popular as B1.

The difference, of course, is scale. Position 1 on the AGW question may involve spending huge sums of economic wealth; I surmise that many who hold Position B avoid Position 1 for this reason. This is a natural enough position, psychologically, but I don't regard it as quite logically defensible. It is reasonable to err on the side of the environment while dismissing AGW as a certain or even plausible phenomenon. In that case the logical way to protect the environment would be some combination of:
  • protecting biodiversity and native habitats of threatened species,
  • minimizing waste, especially of artificial gasses (often halocarbons) with long half-lives,
  • continuing intensive study of climates, coastlines, icebergs, the atmosphere, etc.
This is the responsible, cautious position; the notion that protecting economic growth is a more cautious path than protecting the environment is an error caused by axis confusion.