william_h_calvin's picture
Theoretical Neurobiologist; Affiliate Professor Emeritus, University of Washington; Author, Global Fever
Greenland changed my mind

Back in 1968, when I first heard about global warming while visiting the Scripps Institute of Oceanography, almost everyone thought that serious problems were several centuries in the future. That's because no one realized how ravenous the world's appetite for coal and oil would become during a mere 40 years. They also thought that problems would develop slowly. Wrong again.
I tuned into abrupt climate change about 1984, when the Greenland ice cores showed big jumps in temperature and snowfall, stepping up and down in a mere decade but lasting centuries. I worried about global warming setting off another flip but I still didn't revise my notions about a slow time scale for the present greenhouse warming.

Greenland changed my mind. About 2004, the speedup of the Greenland glaciers made a lot of climate scientists revise their notions about how fast things were changing. When the summer earthquakes associated with glacial movement doubled and then redoubled in a mere ten years, it made me feel as if I was standing on shaky ground, that bigger things could happen at any time.
Then I saw the data on major floods and fires, steep increases every decade since 1950 and on all continents. That's not trouble moving around. It is called global climate change. It may not be abrupt but it's been fast.

For drought, which had been averaging about 15 percent of the world's land surface at any one time, there was a step up to a new baseline of 25 percent which occurred with the 1982 El Niño. That's not gradual change but an abrupt shift to a new global climate.

But the most sobering realization came when I was going through the Amazon drought data on the big El Niños in 1972, 1982, and 1997. Ten years ago, we nearly lost two of the world's three major tropical rain forests to fires. If that mega Nino had lasted two years instead of one, we could have seen the atmosphere's excess CO2 rise 40 percent over a few years — and likely an even bigger increase in our climate troubles. Furthermore, missing all of those green leaves to remove CO2 from the air, the annual bump up of CO2 concentration would have become half again as large. That's like the movie shifting into fast forward.

And we're not even back paddling as fast as we can, just drifting toward the falls. If I were a student or young professional, seeking my future being trashed, I'd be mad as hell. And hell is a pretty good metaphor for where we are heading if we don't get our act together. Quickly.