Saturday, May 12, 2007

Rumblings from the icy fields of Greenland

The debate thus far: In An Inconvenient Truth, Al Gore popularized the rather alarming vision of a twenty foot rise in sea level. That's how much rise we'd get if the water tied up in either the West Antarctic Ice Sheet or the Greenland ice went into the oceans (or half of each). It's not easy to forget that graphic showing the water moving inland into Florida, or the idea that millions of senior citizens might have to move back in with their kids.

That picture acted as a great big two-by-four to the skull of America's collective consciousness, summing up in a few seconds the many varied potential devastations our inaction might cause. It was too effective to go unanswered. In the journalistic travesty that was "Exposed: Climate of Fear," Glenn "Prove to us that you're not working with our enemies" Beck tried to stem the damage[1]:

BECK: Now, what about that really cool animation of Florida and Manhattan drowning? Huh, cool, huh? You`ve seen these horrific scenarios everywhere based purely on catastrophic hypotheticals that dramatically exaggerate even what the U.N. says. It`s Al Gore`s best supporting actor, the word "if."

GORE: If we have an increase of five degrees, if Greenland broke up and melted...

... if this were to go, sea level worldwide would go up 20 feet.

MARIO LEWIS, PHD, GOVERNMENT POLICY ANALYST: Where he`s misleading is that he gives the impression that this is something that is likely to happen. The likelihood of this is next to nil.

DAVID LEGATES, PHD, CLIMATOLOGIST, UNIVERSITY OF DELAWARE: The IPCC report is that the upper limit of sea level rise by the year 2100 is going to be about 23 inches.

HORNER: That`s why Al Gore makes up 20 feet. The truth isn`t scary.

BECK: Just look at the difference between Greenland`s ice melt in Al Gore`s scenario when spread out over a century versus what the IPCC projects.

CHRISTY: To come up with 20 feet is really grasping at straws, I think, but it does make a dramatic image.
Indeed, the IPCC report does say that 23 inches of sea rise is the most we can expect, and 2100 seems awful far away. Time doesn't come to a stop at the end of this century, and sea rise would continue over several centuries, eventually leading to the rise that Gore reported in the movie. But twenty feet doesn't sound that dangerous, if we have a millennium to adapt or fix it.

But that's just the question: will it take millennia, or decades? We know that if present warming trends continue, we are eventually going to lose major portions of both ice shelves. The real controversy is exactly how long it will take and how much we will lose.

Enter the reassuring IPCC figures on global sea rise -- the only part of the IPCC report that climate skeptics seem to take seriously. Beck's posse wants us to believe that the twenty foot scenario is laughable to anyone who actually understands the issues. To do that, they fundamentally misrepresent the findings of the report.
(as always) does a great job reporting on this issue. It's especially interesting to see which contributions to overall sea level rise are factored into the IPCC figures.

But let's just focus on the critical weasel words:
Dynamical processes related to ice flow not included in current models but suggested by recent observations could increase the vulnerability of the ice sheets to warming, increasing future sea level rise. Understanding of these processes is limited and there is no consensus on their magnitude. -- IPCC Report (Summary for Policy Makers)
In other words, the IPCC is being very conservative in their sea level estimations. In these words, we see that the IPCC recognizes that the ice shelves are not well understood, and may slide into the ocean far faster than their projections would indicate.

What the global warming deniers are contractually obligated never to acknowledge[2] is that these IPCC reports are very conservative documents. They do not go beyond the evidence available in the published literature, and in fact they have to set a date after which they don't accept new research (to avoid having to rewrite the report). New evidence -- which didn't make it into the report -- suggests that the Greenland shelf is becoming highly unstable.

Recently, geologists discovered an unusual class of earthquake, associated with the movements of ice sheets. In Greenland, they're highly seasonal (occuring mostly in the summer months), and -- more worryingly -- the number of incidents has more than doubled in the last few years.

More information can be found here. It's too soon to say whether the ice will melt gradually or crash into the ocean in a few sudden rushes. The science isn't in yet.

While we're waiting to find out exactly how bad it's going to be, and how quickly we'll have to rush to build twenty foot high walls around our coastal cities, everyone get out there and start shopping. For Hummers. Because the most important thing we can do to prepare for the future is to grow the economy so big that we can pay for any problems that arise. And keep watching Glenn Beck to get "the other side of the story." That boy's a straight shooter.


[1] Beck is far from a neutral source on the issue. Of the nineteen "experts" he's brought on his show to discuss global warming, only two of them supported the consensus position [source]. While he's hardly the first skeptic to take on the topic of sea levels, his approach is representative of the techniques used.

[2] Standard Noncorporeal Essence Transferrence of Ownership Contract, Article IV, subclause 3. Requests for sample copies of this contract can be made to the Legal Affairs Department of the Third Circle of Hell.

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