Points and counterpoints

WASHINGTON — Here are some of the studies and data that Michael Crichton cites in his book "State of Fear" and how climate scientists respond:

Crichton: His heroine notes that from 1940 to 1970, carbon-dioxide emissions increased as world temperatures decreased (pgs. 86-7). "So if rising carbon dioxide is the cause of rising temperatures, why didn't it cause temperatures to rise from 1940 to 1970?" she asks.

Response: New York University physics professor Martin Hoffert answers, "Simple. Climate change is caused by several factors: changes in solar radiation, aerosols that scatter sunlight and the buildup of human-emitted greenhouse gases. By the early 1970s, the growing CO2 in the atmosphere (and other human greenhouse gases) overwhelmed the other effects and will continue to do so."

Crichton: His heroine says much of the warming can be attributed to increased heat in growing cities because of reflection by buildings and asphalt. She cites examples of cities warming and towns not (pgs. 368-385). "At least one study suggests that half of the observed temperature change comes from land use alone. If that's true, then global warming in the past century is less than three-tenths of a degree. Not exactly a crisis."

Response: Actually, oceans and rural areas are also warming, said Jeff Severinghaus, a geosciences professor at Scripps Institution of Oceanography in La Jolla, Calif. "The ocean data says it all. Ground temperatures confirm this."

Crichton: His heroine cites satellite data showing that the atmosphere five miles above the ground isn't warming, although global warming says it should be (pgs. 99-100). "The satellite data have been re-analyzed dozens of times. The data from the weather balloons agree with the satellites. They show much less warming than expected by the theory."

Response: At least three groups of scientists have looked at the satellite data Crichton refers to and concluded that it understated temperatures. Longer-term weather balloon data also confirm warming trends, climate researchers say. According to Kevin Trenberth, head of climate analysis at the National Center for Atmospheric Research, "Evidence is mounting that the (original satellite record) is not correct. The (newer) Remote Sensing Systems record is best in my view (but not perfect) and is in full accord with models."

Crichton: Cites numerous locales where warming is not occurring (pgs. 190-4, 368-385). His protagonist says: "As you can see, many places in the United States do not seem to have become warmer since 1930."

Response: Scientists say the global picture over a longer time period is more important.