Wednesday, April 29, 2009

Climate, Science and Growing Up as a Species

One of the doyens of climate science visited our campus last week and he said something that I can't shake. Steven Schneider has been one of the world leaders in articulating the results of the global study of climate. I met him first as a young man 23 years ago, long before, the greenhouse effect was a household word. He knows of what he speaks.
In his talk Schneider raised an issue, which rarely gets attention in the media or in academic discussions. As a science, the study of climate represents something new, something different and that change matters because it says a lot about what we are up against and how far we have come.

The study of climate not a laboratory science with neat, tidy boundaries between apparatus and subject. It’s not a pure theoretical science where mathematical models can be expected to embrace entire systems and provide single sharp answers that match single sharp data points to within a percent or less. Instead it’s a systems science where many interlocking parts fit together through complicated nonlinear interactions. Atmosphere, hydrosphere, geosphere and biosphere are all complicated enough on their own but together they form a "co-evolutionary" complex that simply does not yield up its secrets in the same way as, say, sulfur ion in a magnetic field does.

Systems science relies on massive multi-variate datasets and equally massive computer simulations. The large sets of coupled linear partial differential equations that govern these systems are inherently chaotic. That means they and the real systems they describe will be sensitive to small changes in how things bump against each other. In a nutshell, the systems represent complexity on a grand scale. Our ability to study such a large and complex system is new and is still developing.

The truth of this bare fact has not really been absorbed by either the scientific or popular culture. While the kind of systems science climate study represents is a beautiful and intellectually exciting thing to behold, its specific link to very specific decisions we need to make about our future is troubling.

If people keep thinking of climate study as a science in the old way they will expect an answer – a single result either proving or disproving the whole shebang. This expectation is exactly the reason why so called “climate skeptics” can publish a single paper focusing on a single aspect of the problem and get major media attention for “proving” climate change wrong. What Schneider was arguing for was a view in which the different communities of study (atmospheric chemistry, glaciers, ocean circulation etc.) form a dialogue in which consensus can be reached on what we think we know and how well we think we know it. Only then can risks associated with different potential outcomes can be assessed. From this view the urgency of acting on the science already “in the bag” can much more readily appreciated.

The really cool and really important point for me here is that our worldview is changing in our encounter with climate change. It is a different kind of science that demands a different approach to the world. Taken as a whole it’s all about growing up as a species and our tools growing with us.