July 8, 2007

SCIENCE Magazine Waffles on Warming

By James Lewis

The American scientific establishment is starting to take baby steps away from taking sides in the politics of global warming. It's sad to have to read science articles for political spin, like some announcement by the Kremlin. But climate change has now become so politicized that SCIENCE magazine reflects at least as much politics as honest science. You have to read it for spin.

SCIENCE magazine is the flagship journal of the American Association for the Advancement of Science, which is the professional advocacy group for scientists in the United States. SCIENCE is both the profession's political journal (telling readers how to get government grants, for example), and it also has original findings. So it has an openly political side, as well as a real science side.

The last issue of SCIENCE is waffling like mad on the global warming fad, warning its readers that it may not be so settled a question. Under the headline "Another Global Warming Icon Comes Under Attack," SCIENCE writer Richard Kerr writes:

"...a group of mainstream atmospheric scientists is disputing a rising icon of global warming, and researchers are giving some ground." ...

"Robert Charlson of the University of Washington, Seattle, (is) one of three authors of a commentary published online last week in Nature Reports: Climate Change. ... he and his co-authors argue that the simulation by 14 different climate models of the warming in the 20th century is not the reassuring success IPCC claims it to be."

(IPCC is the supposed international scientific consensus document on global warming - JL).

"... In the run-up to the IPCC climate science report released last February ... 14 groups ran their models under 20th-century conditions of rising greenhouse gases. ... But the group of three atmospheric scientists ... says the close match between models and the actual warming is deceptive. The match "conveys a lot more confidence [in the models] than can be supported in actuality," says Schwartz. [....]

"Greenhouse gas changes are well known, they note, but not so the counteracting cooling of pollutant hazes, called aerosols. Aerosols cool the planet by reflecting away sunlight and increasing the reflectivity of clouds. Somehow, the three researchers say, modelers failed to draw on all the uncertainty inherent in aerosols so that the 20th-century simulations look more certain than they should." [Italics added]

What? "Somehow" they missed the biggest unknown factor in climate prediction?

Highly qualified climate scientists have long warned that warming estimates have at least one giant question mark: Water vapor and other tiny particles in the atmosphere. By failing to include reliable estimates of such "hazes" (not necessarily pollutants, as the article says), global warming models are likely to err wildly on the side of warming. It's the unseen elephant in the living room.

The SCIENCE article therefore finally admits what scientific critics have been saying for years.

Interested readers should also take a good look at the graph in the SCIENCE article, which superficially seems to support the global warming story. But notice the vertical bars at the right side of the graph, which show the "90 percent confidence interval" --- the chances that the graph line is actually where it is shown to be. Turns out that the orange confidence interval includes all the points on the graph between 1930 and 2000... meaning that we can't tell that any of those points are different from each other with even 90 percent certainty. And that's not even including the big Black Hole of water vapor.

Now "90 percent confidence" might sound like a lot. But in standard scientific publications a 95 percent confidence level is the minimum acceptable level. The reason is that one can just run a study 10 times, and achieve a 90 percent confidence level purely by chance. So we normally demand a higher standard of proof --- at least 95 percent confidence. The data in the SCIENCE graph therefore does not meet routine scientific standards.

Many scientists will read this item as a red flag, cautioning that all is not well in the global warming game.

Happy Earth Day - and never forget that telling the truth is the first, indispensible step toward wise management of our resources.

James Lewis blogs at http://www.dangeroustimes.wordpress.com/