Climate Change

There are so many perspectives and angles of approach one can take when trying to think clearly about the issue of global warming, or as it is currently being referred to: “climate change”. There’s the scientific perspective (what is the evidence for climate change and how rigorous is the science?) and the public policy perspective (what regulations should be in place to deal with climate change?). There is also a social science perspective (why is climate change controversial and seemingly divided along ideological lines?) and even a religious perspective (did God give man stewardship over the earth, or is the earth to be venerated by man?)

My thinking on this subject tends to be drawn to the structure of the relationship between the claim that the effects of climate change demand a response by governments on a massive scale, and the nature of that response. The French philosopher, Blaise Pascal, once proposed an approach to decision making that has come to be known as “Pascal’s wager”. The question for Pascal was the relationship between the existence of God and the state of his own belief in God. Should he believe in God or not? He suggested that there were two possible “states of nature” with respect to the existence of God: Either God existed, or he did not. There were also two possible responses Pascal could take with respect to these states of nature: Believe in God, or don’t believe in God. So Pascal created four possible outcomes based on these states of nature and his responses to them:

1. God exists/I believe in God – therefore a positive outcome
2. God exists/I don’t believe in God – most likely a very negative outcome!
3. God does not exist/I believe in God – a less negative outcome than (2)
4. God does not exist/I don’t believe in God – a rather neutral outcome

As in the case of climate change, there are also two basic “states of nature”: either the planet is warming or it is not. But unlike Pascal’s simple decision aid, our problem is more complicated (it is actually a decision tree, and if this were not a blog post, I’d probably try and show an illustration of that at this point). But I think you can get an idea of the complexity of the decision problem by examining the table below:

The potential states of nature range from no global warming to significant increases in world temperatures in a relatively short period of time. The potential responses can be grouped into three categories: 1) do nothing, 2) take defensive measures (that is, assume that global temperature increases are incapable of being reversed, so we must protect civilization from the inevitable effects – rising sea levels, increasing areas of arid land, etc.), 3) take pro-active measures (reverse the effects of global warming).

The problem is that there is a great deal of uncertainty surrounding the actual “state of nature” of planetary warming. All of the scenarios describing the projected effects of planetary warming are based on computer modeling. The ability to forecast the local weather (also based on computer models) over the next week is not a certain science, yet predictions of specific global temperature increases over a period of 50 to 100 years are viewed as certain. So we really don’t know how dire the situation is.

If global warming is a reality and is unstoppable (that is, will not yield to efforts by humans to reverse it) then the best recourse for public policy makers would be to take defensive measures; e.g., divert resources to protecting civilization from its effects. Sea walls and dikes should be constructed around vulnerable coastal communities like New York and New Orleans to protect these cities from the inevitable rising sea levels caused by melting polar ice.

On the other hand, if we know what causes global warming, and can reverse its effects, we should do so. But here is the problem: scientists are not certain what causes global warming. There is no “scientific consensus” about climate change. A number of distinguished researchers in this area have studied the evidence and have found that if we are in a planetary warming period, it may simply be cyclical (due to activity by the sun or other causes). In addition, they have noted that, while increases in carbon dioxide in the atmosphere have been associated with temperature increases, such a correlation may not infer causation; that is carbon dioxide may not actually be causing atmospheric warming, but may actually be a “lagging” indicator of it.

From a public policy standpoint, then, we really do not have enough information about the extent to which human beings actually cause global warming (if, in fact, it is taking place) to commit our nation to policies and treaties that would have immediate and dire economic effects such as placing caps on carbon dioxide emissions.

To return to our decision matrix, it appears our government and society in general has decided on the solution before the problem is really defined. Continued repetition in the media of a particular theme is not a substitute for scientific rigor and evidence. Global warming may be real, but much more work needs to be done to clarify the true state of nature before committing public resources to politically acceptable “solutions”.