Time's up, CO ₂

Forty years ago this summer, a small group of atmospheric and ocean scientists met in Woods Hole, Massachusetts, to project the future impacts on Earth's climate from atmospheric release of carbon dioxide (CO 2 ) from fossil fuel combustion. Frank Press, head of the United States Office of Science and Technology Policy and Science Adviser to President Carter, requested that the National Academy of Sciences conduct the study for the benefit of policymakers. On the basis of then-current trends, the 1979 committee, led by Jule Charney of the Massachusetts Institute of Technology, assumed that atmospheric CO 2 concentrations would reach double the preindustrial values sometime in the first half of the 21st century. They calculated that as a result, the average global surface temperature would increase by 3° ± 1.5°C, with the greatest warming at high latitudes—the first assessment of its kind. The Charney committee also noted in the models a lag on the order of decades between CO 2 release and the resulting temperature rise. This delay, from disequilibrium effects with the ocean, masks pending temperature increases long before they are apparent.