Wednesday, January 13, 2010

Ultimately we must accept climate change

Too much social discourse is directed at magnifying disagreement and disparaging the motives and intellect of others. In Why We Disagree about Climate Change: Understanding Controversey, Inaction and Opportunity (Cambridge University Press, 2009), Mike Hulme takes the position that reasonable people can and do disagree; he then sets off to examine the disagreements and the reasons.

Hulme explores numerous areas of disagreement and organizes his chapters around specific areas. He begins with three mostly (though not entirely) science-oriented sources of disagreement, which involve our conceptualization of climates and climate change, the development of scientific thought regarding climate change, and what science can and cannot tell us. From there, he moves onto disagreements regarding economics, religion, fears, communication strategies, development, and government action. The book ends with a provocative chapter about rethinking climate change.

My own nerdy biases initially drew me into the first chapters, especially the history of scientific thought regarding climate change. Hulme points out that scientific acceptance of the notion that climates change is relatively recent, dating only to the 19th century. Widespread scientific acceptance of the theory of anthropogenic climate change on human time scales is newer still. Although components of the theory, such as the greenhouse effect, were developed in the late 19th and early 20th centuries, it wasn't until the last quarter of the century that broad elements of the scientific began to broadly accept anthropogenic global warming.

However, accepting the likelihood of anthropogenic global warming is only a scientific preliminary. For effective public policy, we need to know much more, including how strong the link between human activities and climate change is, when and how fast systemic changes are likely to occur, how the effects will be distributed, and what the possibilities are for catastrophic changes. As we move into these important areas, the scientific disagreements become larger, and the opportunities for other sources of disagreement to influence scientific discourse also grow.

At a first reading, I was initially disappointed with most of the follow-on, non-scientific "disagreement" chapters. The chapters work well enough in listing and explaining many ways that people can disagree about things. However, they do not explain which disagreements really matter and whether there are fundamental and connecting sources to the disagreements. There are interesting arguments and insights along the way, but much of the material reads like a middle-of-the-road undergraduate term paper--"it could be this (source A), it could be that (source B)," and so on.

Different readers will nonetheless appreciate different things in these chapters. As an economist, I enjoyed an outsider's take on my profession's disagreements. The discussion of development challenges was also very good, especially in reminding us of how many times smart, careful, and concerned people from Malthus to the Club of Rome have predicted doom only to discover that humans have innovated, adapted, and prospered within the then-existing environmental constraints.

The deeper rationale behind these chapters, though, became clearer after reading the final chapter. A central point of that chapter and ultimately of the book is that climate change is here, and the notion of climate change can't be undone. Climate has changed and will change, and humans, to some extent, are affecting this change. Once we accept this, we cannot "unknow" anthropogenic climate change.

Another crucial point in the chapter is that we are unlikely to "solve" the climate change "problem" in any conventional sense in our lifetimes. "Solving a problem" implies meeting a particular objective; in the case, of climate change, what would that be? Suppose that science could give us the magic key to setting the planet's climate--where would we set it? Do we want a pre-industrial climate, a 20th century climate, something warmer, something cooler. Also, (and this is the part where the non-science chapters come in) which objectives do we adopt?

Hulme instead advocates for the more sensible position of living with climate change. To be clear, he does not mean this in a fatalistic sense or as a call for a "do nothing approach." Hulme does mean that we must accept that human activities affect the global climate and that those activities have consequences that impede other objectives. He reminds us that our behavior and policy setting should focus on those objectives rather than the fact of climate change.