A SLIPPERY SLOPE: HOW MUCH GLOBAL WARMING CONSTITUTES “DANGEROUS ANTHROPOGENIC INTERFERENCE”?
In a recent article (Hansen, 2004) I included a photograph taken by Roger Braithwaite with a rushing stream pouring into a hole in the Greenland ice sheet. The photo relates to my contention that disintegration of ice sheets is a wet, potentially rapid, process, and consequent sea level rise sets a...
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| Language: | English |
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.186.9068 http://www.columbia.edu/%7Ejeh1/hansen_slippery.pdf |
| Summary: | In a recent article (Hansen, 2004) I included a photograph taken by Roger Braithwaite with a rushing stream pouring into a hole in the Greenland ice sheet. The photo relates to my contention that disintegration of ice sheets is a wet, potentially rapid, process, and consequent sea level rise sets a low limit on the global warming that can be tolerated without risking dangerous anthropogenic interference with climate. I asked glaciologist Jay Zwally if I would be crucified for a caption such as: “On a slippery slope to Hell, a stream of snowmelt cascades down a moulin on the Greenland ice sheet. The moulin, a near-vertical shaft worn in the ice by surface water, carries water to the base of the ice sheet. There the water is a lubricating fluid that speeds motion and disintegration of the ice sheet. Ice sheet growth is a slow dry process, inherently limited by the snowfall rate, but disintegration is a wet process, spurred by positive feedbacks, and once well underway it can be explosively rapid.” Zwally replied “Well, you have been crucified before, and March is the right |
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