Friday, March 19, 2010

The Four Hurdles of Global Warming

After health care, debate over global warming and the environment has been the most raucous over the past years. Before I go into a full discussion of my views, I do want to mention two points worthy of special mention. The first is whether or not global warming is caused by man. Who cares? Suppose we knew that it global warming was real, but not caused by man. Would that make it any less dangerous? The second point is that even if you don’t believe in global warming, fossil fuels are still pollutants that results in negative externalities. As we all know by now, even the most strident anti-government economists recognize that there is a role for government in the regulation and taxing of negative externalities. (Full disclosure: I consider myself a strident, anti-government economist). With that out of the way, I’ll move on by discussing the four questions that should really guide the debate.

Is global warming really happening? This is the question that has the least to do with economics and the most to do with climate scientists. I’m going to have to say yes on this question based on the climate reports. Admittedly, it is fairly easy to massage data to fit your hypothesis and the models have done a very poor job of forecasting the future. What I mean by this is that it is easy to create a model that explains what happened in the past, but if the model can’t predict the future, it isn’t of much use. So even if the Earth has gotten warmer over the past 100 years, I am not confident that it will continue to get hotter even if there are no actions taken to reduce global warming.
What are the positive and negative effects of global warming? It is possible that global warming may cause the ice sheets to melt and sea levels to rise, but it may also lead to longer growing seasons and more temperate conditions elsewhere. There is no reason to believe that the current climate is the optimal climate. It is entirely possible that a warmer Earth is actually better. Realistically, some people will gain and some will lose. It may suck to be a Polar Bear, but there are areas that will benefit from global warming. I have seen reports that the US would be better off with global warming, and not just because California will be under water.
Can human actions affect it? While I don’t think it matters whether or not humans cause global warming, I do think it is important to know whether or not humans can control it. It doesn’t really matter whether or not man caused global warming, what matters is whether or not we can do something about it. What effect will a reduction in carbon dioxide emissions have? Are there other actions that may affect global warming. The book SuperFreakonomics has a chapter devoted to alternative methods of fighting global warming that includes things like huge ocean mirrors and simulated volcanoes. These might be as effective and cheaper than reducing the use of fossil fuels.
Are the benefits of taking action worth the costs? In economics we talk about tradeoffs, and when I say costs I am not just talking about money, I’m talking about lives. Economics is sometimes known as the Dismal Science because it is concerned with Scarcity. It originally got this name due to the work of Thomas Malthus who basically predicted that population growth would outstrip food supply leading to constant famine. The question became one of forced population control (like China’s one-child policy) or natural population control through starvation. The Earth currently has almost 7 billion people. Many people believe that the Earth is overpopulated and a population of 5 billion may be more manageable. Is this a good thing? I’m not even sure if we can define what is good or bad, and if we can’t define an objective, how can we decide what to do? (Side note: Both Global warming and efforts to fight global warming may cause death). Beyond life and death, there is quality of life. If you could go back 100 years and prevent the development of the car or the discovery of oil, would you? By doing so, you may prevent global warming, but you’d also be eliminating the huge strides in our quality of life.

Frankly, I don’t know what to think. I basically support some taxes on fossil fuels due to the negative externality that results combined with some subsidies for greener forms of energy, but there becomes some point where the taxes and subsidies go too far. Just like the discussion of externalities, the tax should be equal to the marginal social cost – no more and no less. The goal is not to have no pollution (or no global warming) the goal is to have the optimal amount, and your definition of the optimal amount may be different from mine.