In the article, true believers warned that the end was near. The magazine cited climate models as if they were peer-reviewed fact. "I don't think anybody down here looks at the sea-level-rise problem and puts their heads in the sand," it quoted Windell Curole, the manager of a Louisiana levee district. To back up the sea-level argument, a chart shows the sea level rising 4 inches over 100 years. The problem is, the earliest data is from 2000, so the chart doesn't show actual increases; it plots "projections." A best-case scenario shows the 4-inch rise by 2100; a worst-case scenario shows a rise closer to 3 feet. Guesstimates aren't hard science.

 The libertarian-leaning Cato Institute's Pat Michaels, who wrote his book on global warming, "Meltdown," took on the National Geographic piece in an op-ed published in the Washington Times. Michaels chided the magazine for showing a flooded rice field in Bangladesh, cautioning that rising global temperatures and sea levels threaten rice farming. "In the last 50 years," he wrote, the sea level at Bangladesh has risen "an infinitesimal seven-tenths of an inch, far too little for anyone to notice."

 National Geographic editor William L. Allen responded just as Crichton's characters would -- by attacking Michaels personally for writing a report funded by "the Western Fuels Association, an association of coal-burning utility companies." The letter didn't take on Michaels' facts.

 On Dec. 29, National Geographic's Web site reported that while media accounts "frequently assert that climate change is uncertain," a University of California at San Diego professor read 928 scientific papers and found, "Not one of the papers refuted the claim that human activities are affecting the Earth's climate." (Funny, Crichton's 20-page bibliography found contrary opinions.)

 But as Crichton and Michaels both argue, some global-warming true believers argue things that they know aren't true. And that makes them dangerous.