In recent decades, historians and sociologists of science have been largely concerned with the social construction of scientific knowledge. This paper examines an important historical episode in the social deconstruction of scientific knowledge. In the early 1980s, a consensus emerged among climate scientists that increased atmospheric carbon dioxide from burning fossil fuels would lead to mean global warming of 2-3°C, probably by the mid-twenty-first century, and would have serious deleterious effects, including sea level rise of at least seventy centimeters. This consensus was challenged, however, by a committee of the U.S. National Academy of Sciences, chaired by physicist William A. (Bill) Nierenberg, whose 1983 report arguably launched the climate change "debate." Drawing on perspectives provided by two economists on his committee, Nierenberg reframed the question not as a matter of climate change per se, but as a matter of the human capacity to adapt to change when it came, a capacity, his report asserted, that was very great. Thus, while accepting the scientific conclusion that warming would occur, Nierenberg rejected the interpretation that it would be a problem. In later years, he would play a major role in political challenges to the scientific conclusions themselves. Reframing was Nierenberg's first step on the road to the deconstruction of scientific knowledge of climate change. © 2008 by the Regents of the University of California. All rights reserved.