While I was at CRREL, Perovich took me to meet a colleague of his named John Weatherly. Posted on Weatherly’s office door was a bumper sticker designed to be pasted—illicitly—on S.U.V.s. It said, “I’m Changing the Climate! Ask Me How!” For the last several years, Weatherly and Perovich have been working to translate the data gathered on the Des Groseilliers expedition into computer algorithms to be used in climate forecasting.
Weatherly told me that some climate models—worldwide, there are about fifteen major ones in operation—predict that the perennial sea-ice cover in the Arctic will disappear entirely by the year 2080. At that point, although there would continue to be seasonal ice that forms in winter, in summer the Arctic Ocean would be completely ice-free. “That’s not in our lifetime,” he observed. “But it is in the lifetime of our kids.”
Later, back in his office, Perovich and I talked about the long-term prospects for the Arctic. Perovich noted that the earth’s climate system is so vast that it is not easily altered. “On the one hand, you think, It’s the earth’s climate system, it’s big; it’s robust. And, indeed, it has to be somewhat robust or else it would be changing all the time.” On the other hand, the climate record shows that it would be a mistake to assume that change, when it comes, will come slowly. Perovich offered a comparison that he had heard from a glaciologist friend. The friend likened the climate system to a rowboat: “You can tip and then you’ll just go back. You can tip it and just go back. And then you tip it and you get to the other stable state, which is upside down.”
Perovich said that he also liked a regional analogy. “The way I’ve been thinking about it, riding my bike around here, is, You ride by all these pastures and they’ve got these big granite boulders in the middle of them. You’ve got a big boulder sitting there on this rolling hill. You can’t just go by this boulder. You’ve got to try to push it. So you start rocking it, and you get a bunch of friends, and they start rocking it, and finally it starts moving. And then you realize, Maybe this wasn’t the best idea. That’s what we’re doing as a society. This climate, if it starts rolling, we don’t really know where it will stop.”