Hansen has finally done it. He has had to alter his prediction of the end of the world because...well it didn't end. Kind of like that religious fanatic in CA who predicted the end of the world and then issued a correction when it didn't happen. He misread the scriptures you see. Looks like Hansen did the same. What a pathetic excuse for a scientist...
Boy, those natural cycles sure are pesky little bastards aren't they!
"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.
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. See for example this essay from 2005 in which he says:
Consider the situation during past ice sheet disintegrations. In melt-water pulse 1A, about 14,000 years ago, sea level rose about 20 m in approximately 400 years (Kienast et al., 2003). That is an average of 1 m of sea level rise every 20 years. The nature of glacier disintegration required for delivery of that much water from the ice sheets to the ocean would be spectacular (5 cm of sea level, the mean annual change, is about 15,000 cubic kilometers of water). Explosively would be an apt description, if future ice sheet disintegration were to occur at a substantial fraction of the melt-water pulse 1A rate.
Are we on a slippery slope now? Can human-made global warming cause ice sheet melting measured in meters of sea level rise, not centimeters, and can this occur in centuries, not millennia? Can the very inertia of the ice sheets, which protects us from rapid sea level change now, become our bete noire as portions of the ice sheet begin to accelerate, making it practically impossible to avoid disaster for coastal regions?"
Hansen still argues 5m 21st C sea level rise possible | Energy Bulletin
Boy, those natural cycles sure are pesky little bastards aren't they!
"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.
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. See for example this essay from 2005 in which he says:
Consider the situation during past ice sheet disintegrations. In melt-water pulse 1A, about 14,000 years ago, sea level rose about 20 m in approximately 400 years (Kienast et al., 2003). That is an average of 1 m of sea level rise every 20 years. The nature of glacier disintegration required for delivery of that much water from the ice sheets to the ocean would be spectacular (5 cm of sea level, the mean annual change, is about 15,000 cubic kilometers of water). Explosively would be an apt description, if future ice sheet disintegration were to occur at a substantial fraction of the melt-water pulse 1A rate.
Are we on a slippery slope now? Can human-made global warming cause ice sheet melting measured in meters of sea level rise, not centimeters, and can this occur in centuries, not millennia? Can the very inertia of the ice sheets, which protects us from rapid sea level change now, become our bete noire as portions of the ice sheet begin to accelerate, making it practically impossible to avoid disaster for coastal regions?"
Hansen still argues 5m 21st C sea level rise possible | Energy Bulletin