Charles David Keeling, 77; Scientist Linked Humans to Increase in Greenhouse Gas
Charles David Keeling, the climate scientist whose precise, meticulous measurements of carbon dioxide in the atmosphere for nearly half a century warned humans that we are changing the composition of the global atmosphere, has died. He was 77.
Keeling suffered a heart attack Monday while hiking with one of his sons near the family's summer home in Montana, according to a spokesman for the Scripps Institution of Oceanography, where he spent virtually his entire professional career.
Keeling's studies showed that the atmospheric concentration of carbon dioxide -- a so-called greenhouse gas that traps energy from sunlight and prevents it from radiating back into space -- has been rising steadily since the onset of the Industrial Age, and he linked that growth conclusively to the increased consumption of fossil fuels, which release carbon dioxide when they are burned.
The graph showing that increase, known as the Keeling curve, is one of the best-known anywhere. "During the early 1990s, it was said that the only scientific data on display at the White House was [the Keeling curve]," said Ralph Cicerone, president of the National Academy of Sciences.
Politicians and scientists may disagree over whether the increased carbon dioxide concentrations are causing the planet to heat up, but no one questions the accuracy of Keeling's data and its link to human activities.
Even President George W. Bush, who has repeatedly discounted the possibility of global warming, recognized the importance of Keeling's work by awarding him the National Medal of Science in 2002. In April, Keeling received the Tyler Prize for Environmental Achievement, the most prestigious award for environmental research.
Keeling's records of carbon dioxide concentrations "are the single most important environmental data set taken in the 20th century," said Charles F. Kennel, the director of Scripps. "Dave Keeling was living proof that a scientist could, by sticking close to his laboratory bench, change the world."
Keeling began his career as a postdoctoral fellow at Caltech, where he conceived and built the first instrument to measure the concentration of carbon dioxide in atmospheric samples. He was entering uncharted territory. Estimates of the amount of the gas in the air ranged from 150 parts per million to 450 ppm. Most researchers, moreover, assumed that because the atmosphere was well mixed, the concentration showed little variance, even from year to year.
