““The same kind of situation complicates many public debates, like that over global warming. Many scientists predict that altered atmospheric conditions will raise the average global temperature by several degrees. But such changes can also cause extreme weather, which may mean worse snowstorms in the southern United States. Global warming may alter ocean currents like the Gulf Stream and ultimately turn northern Europe into a much colder Siberian-type icebox. Anomalies like this fuel the global warming naysayers: scientists say the world is getting hotter, but you’ve just suffered through the biggest snowstorm in your region’s history. How should you respond? A judicious response is that nature is amazing—rich, varied, complex, and intricately interconnected, with a messy, long history. Anomalies, whether in planetary orbits or North American weather, are not just inconvenient details to brush aside: they are the very essence of understanding what really happened—how things really work. We develop grand and general models of how nature works, and then we use the odd details to refine the original imperfect model (or if the exceptions overwhelm the rule, we regroup around a new model). That’s why good scientists revel in anomalies. If we understood everything, if we could predict everything, there’d be no point in getting up in the morning and heading to the lab.””
