Monday, August 27, 2007

Readings, 27 August 2007



The text following each item is quoted material, except for editorial comments, which are in color.

Climate change and global warming

Last time around was all about physics and astronomy. This time it's about climate change and global warming, with special emphasis on climate modeling and the politics surrounding these things.


Catching Up With Climate
From the evidence of tree rings, the last 50 years were the warmest half-century in 1,300 years. Eleven of the past 12 years are the hottest on record since reliable record-keeping began in 1850; since 1870, sea level has risen some eight inches worldwide, and the rate is accelerating; since 1900, glaciers have shrunk 80 percent, and polar ice is melting fast; concentrations of carbon dioxide are 35 percent higher than preindustrial levels.

To lead off, we have an article on climate models, some of the people who contribute to them, and the diverse factors that enter into them.

A new dawn for climate prediction
Scientists must develop new, more adaptive approaches to predicting and monitoring climate, say climate modellers from the University of Exeter. In a 'perspectives' article published in leading journal Science, Professor Peter Cox and Professor David Stephenson argue that new prediction tools are required to help us to limit and adapt to climate change.

Here we have a brief overview of a Perspectives article, recently published in Science, about some shortcomings of current climate models with respect to usefulness in making policy decisions. This is the full article, but a subscription is required to read it all.

Cloudy Crystal Balls
Climate models may never produce predictions that agree with one another, even with dramatic improvements in their ability to imitate the physics and chemistry of the atmosphere and oceans. That's the conclusion of a report by James McWilliams, an applied mathematician and earth scientist at the University of California, Los Angeles. The mathematics of complex models guarantees that they will differ from one another, he argues. Therefore, says McWilliams, climate modelers need to change their approach to making predictions.

Julie Rehmeyer weighs in with an excellent summary of McWilliams' report. Although there are well-known shortcomings in current climate models, a key observation is this:

McWilliams says that discrepancies among models do not undermine the most crucial conclusion of climate modeling—the notion that increased levels of greenhouse gases emitted by people are causing the Earth to warm and will continue to do so. He notes that every credible climate model ever made has pointed to that same conclusion. "All sorts of smart climate scientists have tried to produce a model that doesn't show future warming," he says, "and no one has been able to in a credible way."

Happily, McWilliams' report is open access, and can be found here.

The Truth About Denial
If you think those who have long challenged the mainstream scientific findings about global warming recognize that the game is over, think again. Yes, 19 million people watched the "Live Earth" concerts last month, titans of corporate America are calling for laws mandating greenhouse cuts, "green" magazines fill newsstands, and the film based on Al Gore's best-selling book, "An Inconvenient Truth," won an Oscar. But outside Hollywood, Manhattan and other habitats of the chattering classes, the denial machine is running at full throttle—and continuing to shape both government policy and public opinion.

Sharon Begley at Newsweek gives us a detailed and hard-hitting account of the political tactics and strategies that global warming deniers have used over the years in attempting to discredit climate change science and prevent any effective government response. Mentioned in passsing is a review by Congressman Rush Holt (D-NJ), a PhD physicist, of Al Gore's book and movie, An Inconvenient Truth. It appeared in Science last month, and can be found here (subscription rqd).

Heretical Thoughts about Science and Society
My first heresy says that all the fuss about global warming is grossly exaggerated. Here I am opposing the holy brotherhood of climate model experts and the crowd of deluded citizens who believe the numbers predicted by the computer models. Of course, they say, I have no degree in meteorology and I am therefore not qualified to speak. But I have studied the climate models and I know what they can do.

The author of this piece, Freeman Dyson, is (of course) a highly-respected mathematician and theoretical physicist who has frequently in his long career written very intelligently about scientific and cultural subjects far outside his nominal sphere of expertise. Here he expresses skepticism about computer climate models and their general proclivity to support the idea of anthropogenic global warming.

However, his distinguished status does not mean he is correct on this particular issue, any more than, say, Linus Pauling was correct in his championship of the the health benefits of megadoses of vitamin C. As Pauling himself has been quoted as advising "When an old and distinguished person speaks to you, listen to him carefully and with respect – but do not believe him. Never put your trust in anything but your own intellect. Your elder no matter whether he has gray hair or lost his hair, no matter whether he is a Nobel Laureate, may be wrong."


The Changing Arctic: A Response to Dyson's "Heretical Thoughts"
Knowing that Arctic climate models are imperfect, it would be reassuring for me, if not for the scientists, to be able to write that scientists keep making grim predictions that just that don't come true. If that were so, we could follow Dyson's line that the models aren't so good and "the fuss is exaggerated". Scarily, the truth is the other way around. The ice is melting faster than the grimmest of the scientist's predictions, and the predictions keep getting grimmer. Now we are talking about an Arctic free of ice in summer by 2040.

Author Alun Anderson, who has had top-level positions with Nature, Science, and New Scientist, gives a sensible rebuttal to Dyson's essay.

Science vs. politics gets down and dirty
Malicious, vindictive and mean-spirited. These are words that might surface in divorce court.

But they have been lobbed in the course of a different estrangement: the standoff between the Bush administration and the nation's scientific community.

The relationship, which has been troubled since the dawn of the Bush presidency, hit a new low last month when Richard Carmona, surgeon general from 2002 to 2006, lashed out at his former colleagues in testimony before a House committee.

This one isn't, strictly speaking, about climate change. It's more like the political science of contemporary science policy in the U. S. – but climate change is one of two or three leading scientific issues currently under contention. What this is really about is all-out propaganda warfare being waged by a highly ideological administration on behalf of its supporters (mainly in big business and organized religion) against parts of reality-based science that threaten the economic or ideological interests of those supporters. Political scientists will be studying this conflict for years to come, even if it does not further escalate.


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