Climate warning, 50 years later

Abstract

Long before geophysicist Michael Mann's hockeystick graph became the icon for anthropogenic global warming, the U.S. President's Science Advisory Committee [now known as the President's Council of Advisors on Science and Technology (PCAST)] cautioned President Lyndon B. Johnson that the continued release of CO 2 to the atmosphere from burning fossil fuels would “almost certainly cause significant changes” and “could be deleterious from the point of view of human beings.” The committee's report concluded that there could be “marked changes in climate, not controllable through local or even national efforts.” In recognition of the 50th anniversary of that first official warning from scientists to policy-makers, the American Association for the Advancement of Science (AAAS), the Carnegie Institution for Science, the American Meteorological Society, and the Linden Trust for Conservation sponsored a 1-day climate symposium on 29 October.