NASA’s Jay Zwally not only predicted a possible ice-free Arctic this summer, but his work also formed the basis of Hansen’s five metres of sea level rise .
Hansen still argues 5m 21st C sea level rise possible
This is interesting – here is the latest paper from James Hansen and coauthor Miki Sato Paleoclimate Implications for Human-Made Climate Change. If you are up to reading climate science papers it’s highly recommended (I’m a little slow in getting to it – the press release was Dec 8th 2011 but I just got to reading it yesterday and today).
A little background is in order – one of the serious scientific debates in the climate science community over the last decade has been the implications of the unexpectedly large acceleration of glacier discharge in Greenland and Antarctica and in particular a discovery by Zwally et al in 2002 that surface melt water can get down the base of a glacier and lubricate its motion. Prior to the early 2000s it was assumed that ice sheets would decay mainly by melting on the surface and climate models all assumed that they would decay only very slowly in a warmer world – it was a surprise to realize that the most important breakdown mode was actually basal lubrication and sliding down into the ocean.
I didn’t realize they had serious scientific debates at the nuthouse. I hope they don’t allow these folks to use anything sharper than a crayon.
Hansen in particular became the leading spokesman for the view that the ice sheets on Greenland and parts of Antarctica would prove quite unstable under Anthropocene conditions and might break down in a rapid non-linear manner and cause very large levels of twenty-first century sea level rise.