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.
I didn't have you pegged as a Steve Bell fan. Some of his stuff from the 80's is wonderful.
It's clear to me. Raise temperatures by that amount, and a WAIS "of present size" cannot survive for a century.
Previous thinking has been no significant loss from Antarctica for centuries -- meaning it would stay the "present size" for a long time yet. Isn't that the standard Hansen's doubting if BAU continues?
(Business As Usual)
How can this be read as claiming complete loss?
Confusion with car insurance adjuster usage?
Antarctica is not like your ten year old car, where a crumpled fender causes the insurance adjuster to tell you it's "totaled" -- not worth the cost to repair compared to its resale value -- so you're offered only scrap value.
Or what am I missing?
i agree with cce, it means what it says.
you may portray Hansen as an extremist, but i don't think he is a lonely figure. The president of the AAAS sounded the same alarm bells, in his inaugural address, is he an extremist too?
[Dunno. What did he say? -W]
I'd just recently posted a note in a RC thread on the movie, that I find this "20 feet by 2100" widely repeated recently, usually attributed to something where it doesn't appear.
Dark satanic propaganda mills at work?
February 15 2007 Presidential Address, AAAS annual meeting, article not full text:
" Pliocene is rather vaguely described as +2-3 oC above today ..."
Do you have a number or description for the rate of melt over freezing in the Pliocene?
I'm not a scientist at any level, even grade school. I read the paper and I took him to mean one century of sufficient temp, not a ridiculous one, would eliminate the bergs and their mommy. That's probably totally wrong, so help me if you can.
[Thats probably what he did mean, though "sufficient temp, not a ridiculous one" is even vaguer than 2-3 oC... -W]
I bet it's a lot less vaguer to you than "2-3 oC" is to me!
Seen that way, if that truly reflects what he means, would it alter your state of incredulity?