Wednesday, April 11, 2007

Global Warming Quiz

Russell Roberts:
Suppose we discovered that the earth was cooling rather than warming due to a natural cycle. Would you encourage people to drive more and use more carbon-based energy as a way of warming the earth?
He explains the point of his quiz with:
I suspect that some people's ideal policy towards the earth's climate is that it should be whatever it would be if people didn't exist. Or whatever it would be if people lived in loincloths without fire. That is, the ideal climate is the natural one, because our species is unnatural. In this world view, humans are a poison on the earth and the reason we should put on a carbon tax or discourage fossil fuels is that our use of the earth's resources is somehow immoral. . . . .
I agree that at least some of those concerned about global warming seem to hold this view, or something much like it. A student in one of my past environmental economics courses expressed it something like this: "I think humans are the scourge of the earth; pretty much the same as humans view rats."

It is not clear to me why we would be thought unnatural, or why our choices, our technologies, our economies would be thought unnatural. If the conceptual view that supports efforts at using government to "fix" the global warming problem is whether something is natural or unnatural, then wouldn't the idea have to be that human presence on earth was not the result of evolution of life on earth but because we somehow came from outside the earth system?

I think there is a similar question to the one asked by Roberts which might also be interesting to consider. As I understand it, average global temperature has increased and decreased over a large range of values over the course of the earth's history. You can view a chart of the history of average global temperature here. The brief discussion that accompanies this chart characterizes climate history in these terms:
During the last 2 billion years the Earth's climate has alternated between a frigid "Ice House", like today's world, and a steaming "Hot House", like the world of the dinosaurs.
The chart indicates that "today" the earth is in another cycle of warming. It seems to me the earth would be warming "today" even without the pollutants from our economic activities that are a fundamental part of the concern expressed by those who want government to make some effort to fix the global warming problem. I wonder, if we thought the globe was warming, but we also had not figured out that our economic activities might contribute to the warming today, would there be people calling for government to find some way to stop the warming? Whether the globe is warming for reasons that we think make the warming a "natural" phenomenon, or for reasons that are attributed to our economic activities, the impacts of the global warming would seem pretty much the same. And, given that the policy issue today involves concern for "human induced warming," I wonder if efforts at using public policy to reduce the "human induced warming" are successful, if there would be continued efforts to reduce or slow the warming that is naturally determined?

Oh, and one more note about the global climate chart. Note that in the description of the history presented in the chart, today is characterized as a "frigid ice house" by historical comparison.

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