model convergence is “just how science works” might need to be reexamined, and we ignore that possibility at our peril. As we shall see, policies designed to deal with complex systems buck this trend of convergence on a single model, and thus require a novel approach to policy decision-making.
If there is any consensus at all in climate science, it is this: the window for possibly efficacious human intervention is rapidly shrinking, and if we don’t make significant (and effective) policy changes within the next few years, anthropogenic influence on the climate system will take us into uncharted waters, where the best case scenario—complete uncertainty about what might happen—is still rather unsettling. Critics of contemporary climate science argue that the uncertainty endemic to our “best” current models suggests that we should adopt a wait-and-see approach—even if the climate is warming, some argue that the fact that our current models are scattered, multifarious, and imperfect mandates further work before we decide on how (or if) we should respond.
This position, I think, reflects a mistaken assumption about the trajectory of climate science. The most important practical lesson to be drawn here is this: if we wait for climate scientists to agree on a single model before we try to agree on policy, we are likely to be waiting forever. Climate scientists seem interested in diversifying, not narrowing, the field of available models, and complexity-theoretic considerations show that this approach is conceptually on firm ground.
- Again, Isdso & Singer (2009) is perhaps a paradigm case here, given the repeated criticism of climate modeling on the grounds that no single model captures all relevant factors. This argument has also been repeated by many free-market-leaning economists. Dr. David Friedman (personal communication), for instance, argued that “even if we were confident that the net effect was more likely to be negative than positive, it doesn't follow that we should act now. It's true that some actions become more difficult the longer we wait. But it's also true that, the longer we wait, the more relevant information we have.” Reading this charitably (such that it isn’t trivially true), it suggests a tacit belief that climate science will (given enough time) converge on not just more particular information, but a better model, and that the gains in predictive utility in that model will make up for losses in not acting now.