An old line from Steve Bell, BM of course being Margaret Thatcher (as I recall, this was in the context of “batting for Britain” and Mark Thatcher). Ahem. Anyway. Thatcher, of course, as the destroyer of our coal industry in favour of the dash-for-gas, is responsible for any faint hopes that the UK has of meeting its Kyoto targets, so is an appropriate patron for this post.
What brings this on is “Climate change and trace gases” (Phil. Trans. R. Soc. A (2007) 365, 1925-1954 doi:10.1098/rsta.2007.2052 Published online 18 May 2007) where Hansen goes wild with whipsaws and other related stuff (“Positive feedbacks predominate. This allows the entire planet to be whipsawed between climate states…” and so on; see-also JEB, though he hadn’t read it then).
Its all rather breathless, and seems to read better if you read it quickly, though I’m not at all sure I believe it. Or rather, I don’t believe it. Although some bits are hard to parse: does We find it implausible that BAU scenarios, with climate forcing and global warming exceeding those of the Pliocene, would permit a West Antarctic ice sheet of present size to survive even for a century. mean that they think the WAIS is going to disappear in a century? That sounds extreme, even for Hansen. More likely it means that once GW exceeds Pliocene levels, the WAIS would disappear (or just decline somewhat?). Pliocene is rather vaguely described as +2-3 oC above today, so with the second interpretation that would have the WAIS severely depleted within 2 centuries (one to get up to +2-3, then the one Hansen mentions). Who knows, its not impossible, but nor is it likely, given current understanding (or lack thereof…).
But footnote 5 is wonderful: “The potential of these ‘amber waves of grain‘ and coastal facilities for permanent underground storage ‘from sea to shining sea’ to help restore America’s technical prowess, moral authority and prestige, for the sake of our children and grandchildren, in the course of helping to solve the climate problem, has not escaped our attention.” It would read well in an op-ed, but sits oddly in Phil Trans.