Monday, June 29, 2009

The Catastrophist

Elizabeth Kolbert has an article about the cap and trade legislation and Jim Hansen. It's behind a paywall, but the New Yorker is one of those things you should subscribe to ($50/yr) so don't expect sympathy. Particularly interesting is Kolbert's description of how Hansen moved from space science (modeling Venus) to Earth science. After the discovery that CFC were killing off the ozone layer Hansen

"realized that we had a planet that was changing before our eyes, and that's more interesting," Hansen told me. The topic attracted him for much the same reason that Venus's coulds had: there were new research questions to be answered. He decided to try to adapt a computer program that had been designed to forecast the weather to see if it could be used to look further into the future. What would happen to the earth if, for example, greenhouse gas levels were to double.

"He never worked on any topic thinking it might be any use for the world," Anniek told me. "He just wanted to figure out the scientific meaning of it."

When Hansen began his modeling work, there were good theoretical reasons for blieving that increasing CO2 levels would cause the world to warm, but little empirical evidence. Average global temperatures had risen in the nineteen thirties and forties; then they had declined in some regions, in the nineteen fifties and sixties. A few years into his project, Hansen concluded that a new pattern was about to emerge. In 1981, he became the director of GISS. In a paper published that year in Science, he forecast that the following decade would be unusually warm. (That turned out to be the case). In the same paper, he predicted that the nineteen nineties would be warmer still. (That also turned out to be true.) Finally he forecast that by the end of the twentieth century a global warming signal would emerge from the "noise" of natural climate variability. (This too proved to be correct.)

Later, Hansen became even more specific. In 1990, he bet a roomful of scientists that that year, or one of the following two, would be the warmest on record. (Within nine months, he had won the bet. ) In 1991, he predicted that, owing to the eruption of Mt. Pinatubo, in the Philippines, average global temperatures would drop, and then, a few years later, recommence their upward climb, which was precisely what happened.

From early on, the significance of Hansen's insights was recognized by the scientific community. "The work that he did in the seventies, eighties and nineties was absolutely groundbreaking," Spencer Weart, a physicist turned historian who has studies the efforts to understand climate change told me. He added, "It does help to be right."

"I have a whole folder in my drawer labelled 'Canonical Papers,' Michael Oppenheimer, a climate scientist at Princeton, said. "About half of them are Jim's"
Comments?

13 comments:

Anonymous said...

Sinclair is also troubling a good man's humility

http://www.youtube.com/user/greenman3610#play/all/uploads-all/0/D6Un69RMNSw

Hank Roberts said...

http://www.seattlepi.com/dayart/20090630/cartoon20090630.jpg

TimC said...

It is beginning to look like Hansen will have another prediction that's panned out.

ASA: 2007 Second Warmest Year Ever, with Record Warmth Likely by 2010
December 11th, 2007
http://climateprogress.org/2007/12/11/nasa-hansen-2007-second-warmest-year-ever-warmest-year-likely-by-2010/

To see why:

The following graph and table show forecasts made by dynamical and statistical models for SST in the Nino 3.4 region for nine overlapping 3-month periods. Note that the expected skills of the models, based on historical performance, are not equal to one another…
Summary of ENSO Model Forecasts
17 June 2009
http://iri.columbia.edu/climate/ENSO/currentinfo/SST_table.html

If -- as nearly all of the dynamical models are now predicting -- we have an El Nino before the end of this year, there is a very good chance that 2010 break the previous record of 1998/2005.

Magnus Westerstrand said...

Nobel prize?
http://nobelprize.org/nomination/physics/process.html

Horatio Algeranon said...

Hansen should be taken seriously precisely because many of his insights/predictions have been borne out.

I don't think most people appreciate how rare such correct predictions (even general ones like "by the end of the twentieth century a global warming signal would emerge from the "noise" of natural climate variability") actually are in science.

There are actually a couple reasons for this. First, it takes real insight to see what is happening when one has relatively little actual data to go on (as Hansen did back in the 80's).

Second, most scientists are not willing to stick out their necks and make predictions on significant matters because it can be a career ender if they are wrong. This is particularly true in the case of sparse data.

For what it's worth, Hansen seems to have a very good "intuition" about what is going on with the climate.

Physical "intuition" may be dismissed by some as "unscientific" or even mystical, but it is something that seems to be possessed by all good scientists ( certainly all the great ones.

thingsbreak said...

It's behind a paywall, but the New Yorker is one of those things you should subscribe to ($50/yr) so don't expect sympathy.

Or alternatively, they can read a PDFed version here.

Steve Bloom said...

Thanks, Things!

joe1 said...

Eli:

Is there any proof about all these bets and stuff. Frankly I would like to see a little bit of evidence that Hansen was such an amazing forecaster that it would be good it was verified.

Sorry, but you would be asking the same of Lindzen wouldn't you?

joe1 said...

Hansen should be taken seriously precisely because many of his insights/predictions have been borne out.

Yea, that's how some of the big fund managers felt when the posted gains in a 25 year bull market.

I don't think most people appreciate how rare such correct predictions (even general ones like "by the end of the twentieth century a global warming signal would emerge from the "noise" of natural climate variability") actually are in science.

Not true as walls street traders know what flukes are.

Horatio Algeranon said...

walls [sic] street traders know what flukes are.

Horatio was talking about "science", not voodoo (or doo-doo).

EliRabett said...

You could read his congressional testimony from 1988 (there are about three times that he testified), or the papers that were published shortly before and after. Here is a link with more links

Horatio Algeranon said...

Horatio also wrote something about Hansen's 88 "predictions" and on the propensity of some to use argumentum ad Hansenem instead of discussing Hansen's scientific findings.

mndean said...

The New Yorker USED to be worth subscribing to, until they decided to back the Iraq invasion. Now they're on par with The Atlantic, another rag on the downswing of it's existence. William Shawn would have wept at what happened, Harold Ross would have cursed.