Sunday, December 21, 2008

The honest broker quote mine

Ethon, hovering high above the Colorado train wreck has spotted a world class quote mine from the USCCSP chapter on abrupt climate change due to sea level rise. As pointed out first by Mary-Elena Carr at the Columbia Climate Blog, Roger Jr has engaged in Climate Cabala, reading the report to say

So when asked . . . how high will sea levels rise in the 21st century?

. . . the scientifically correct answer, according to this report, is “we don’t know.” It could be large, but it also could be similar to that of the 20th century (and I am implying nothing of probability here). Of course, such a situation lends itself to cherrypicking and political Rorschaching. So the proper response might be “Well, what do you want it to be?”

based on a tasty bit on page 92,
Considerable effort is now underway to improve the models, but it is far from complete, leaving us unable to make reliable predictions of ice-sheet responses to a warming climate if such glacier accelerations were to increase in size and frequency. It should be noted that there is also a large uncertainty in current model predictions of the atmosphere and ocean temperature changes which drive the ice-sheet changes, and this uncertainty could be as large as that on the marginal flow response.
Of course, our honest broker (count your fingers bunnies) doesn't want you to RTFR, because if you did, you might see that the uncertainties all lie in the direction of much higher sea level rise than predicted in the AR4, in other words, the AR4 remains the minimum base for sea level rise and things could be worse, but are unlikely to be better. The report concludes that
Recent rapid changes at the edges of the Greenland and West Antarctic ice sheets show acceleration of flow and thinning, with the velocity of some glaciers increasing more than twofold. Glacier accelerations causing this imbalance have been related to enhanced surface meltwater production penetrating to the bed to lubricate glacier motion, and to ice-shelf removal, ice-front retreat, and glacier ungrounding that reduce resistance to flow. The present generation of models does not capture these processes. It is unclear whether this imbalance is a short-term natural adjustment or a response to recent climate change, but processes causing accelerations are enabled by warming, so these adjustments will very likely become more frequent in a warmer climate. The regions likely to experience future rapid changes in ice volume are those where ice is grounded well below sea level such as the West Antarctic Ice Sheet or large glaciers in Greenland like the Jakobshavn Isbrae that flow into the sea through a deep channel reaching far inland. Inclusion of these processes in models will likely lead to sea-level projections for the end of the 21st century that substantially exceed the projections presented in the IPCC AR4 report (0.28 ± 0.10 m to 0.42 ± 0.16 m rise).
Even better, in the comments RP uses his misrepresentation to bash Joe Romm for actually having read the report, and accepts the acclimation of the crowd for his honest broker act.

Hat tip to the Columbia Climate blog

PS - if you wonder what Ethon has been up to

7 comments:

Anonymous said...

the scientifically correct answer, according to this report, is “we don’t know.” It could be large, but it also could be similar to that of the 20th century (and I am implying nothing of probability here). "

In other words, if we don't know 100%, "we don't know" at all.

Probability means everything in science because one can never "know" anything for certain.

RP Jr aparently never learned that.

Dano said...

Roger is just mad that so many have discovered his tricks. It might make him less interesting to the public, lead to less work, his influence wanes....waaaaaah.

Best,

D

Steve Bloom said...

The science advances quickly, as we see in this article on fresh results finding that the rate of Greenland ice loss tripled this year relative to 2007 (quoting the now very unreticent Jason Box):

"We now know that the climate doesn't have to warm any more for Greenland to continue losing ice," Box said. "It has probably passed the point where it could maintain the mass of ice that we remember.

"But that doesn't mean that Greenland's ice will all disappear. It's likely that it will probably adjust to a new 'equilibrium' but before it reaches the equilibrium, it will shed a lot more ice.

"Greenland is deglaciating and actually has been doing so for most of the past half-century."

I'm fairly confident that the new equilibrium to which he refers is the much smaller North Greenland ice sheet that existed toward the end of the last interglacial. IIRC this means four to five meters SLR.

Hank Roberts said...

I wish I knew of an interesting political science blog somewhere.

Stuff like this
http://csc.sagepub.com/cgi/content/abstract/8/2/159
pops up all the time when I do searches, but I don't find discussions of it.

Where _are_ all the interesting political scientists? Do they do nothing but write publishable academic papers and speak to one another at universities, and avoid the press entirely, and not blog aobut their field?

EliRabett said...

crooked timber (a mix), daniel drezner, feel free to add

EliRabett said...

and the d-squared digest, although that is an acquired taste.

John Mashey said...

Really, sea level issues are of little concern to residents of Colorado.

On the other hand, more directly relevant to Colorado is:

From Saturday Dec 17, 2008, there's a nice Wall Street Journal story by Stephanie Simon, Tiny Beetle Chews Way Through Millions of Trees".

"The beetle is expected to kill virtually every lodgepole pine in Colorado, or five million of the state's 22 million forested acres."

Fires, trees crashing onto power lines, etc, trouble finding volunteers, efforts to figure out what to do with dead wood.

Why: temperatures too warm to kill beetles, drought (weakens trees), bad forest management.

If you like her article, think about sending her email, as the WSJ OpEd folks might not be as supportive.

===
We ski in British Columbia, and the beetles are up there in force as well. These beetles are the ones that generate their own antifreeze.

This is a good example where *averages* are way less important than extremes. In particular, to kill the beetles, all you need is a quick surprise cold snap early in the season (before much antifreeze), or a longer/deeper cold spell later ...

Of course, any climate trend that clips off the minimum winter temperature swings is just what the beetles ordered!

Of course, none of this does forest carbon sequestration much good.

And one wonders if CO residents know who to talk to about the joys of adaptation, as it seems likely that they will now live with these beetles for a very long time, unless we get a lot of volcanoes.