Stephen Henry Schneider

Stephen Henry Schneider, who understood the full breadth and depth of the climate problem better than anyone else, died on 19 July 2010 at the age of 65 while on travel in Europe. Steve’s research broke new ground in the physics of the climate system and expanded our understanding of climate interactions with natural and social systems; with people; and, in partnership with ornithologist Terry Root—his wife—with other species.

Simultaneously, he exemplified the model of the scientist who engages effectively in the public arena. The scope of his influence is evident in the many online eulogies and other encomiums from colleagues, former students, and acquaintances. Steve led a jam-packed, self-consistent life as a physicist, Earth scientist, and public intellectual, to the benefit of us all.

Steve was born on 11 February 1945 in the New York metropolitan area and was raised there. He received a BS in mechanical engineering and a PhD in plasma physics from Columbia University in 1966 and 1971, respectively. He first encountered the emerging issue of climate change when he got caught up in the scientific and cultural ferment surrounding Earth Day in 1970. While pursuing postdoctoral studies at NASA’s Goddard Institute for Space Studies in New York, he coauthored, with S. Ichtiaque Rasool, a fundamental paper that compared anthropogenic greenhouse warming from carbon dioxide with cooling originating in anthropogenic particulates that, like carbon dioxide, arise from fossil-fuel combustion and enhance planetary albedo. Decades later that groundbreaking paper came to demonstrate the whiplash experienced by “public” scientists: It has been widely cited and irresponsibly distorted by global warming contrarians who charged that Steve switched his mind from cooling to warming. The paper is more accurately cited by climate scientists for its balanced treatment of the large uncertainties in judging the direction of future climate change, and it neatly exemplified the process of scientific discovery and evolution.

But that was only the beginning. In the 1970s and 1980s, Steve pursued a dual intellectual career at the National Center for Atmospheric Research in Boulder, Colorado. On the one hand, he pushed the research frontier forward by explaining the behavior of clouds and other atmospheric components represented by the general circulation models that today project a comprehensive if fuzzy picture of the future climate. His physical intuition was superb. Among his landmark achievements is a description of the ocean’s role in sequestering heat produced by radiative forcing of greenhouse gases, thus retarding and redistributing surface warming. On the other hand, Steve simultaneously began writing a series of books for the general public, including The Genesis Strategy (Springer, 1976), which both broadened and focused concerns for the long-term viability of social and natural systems under stress from growing population density, pollution, and resource exploitation. He emphasized the threat of climate change to food supplies in developing countries; as our understanding of climate has sharpened since then, the salience of his concern has only increased.

The intellectual companion to his popular writings was Steve’s published research, which blasted away the disciplinary walls within climate science and explored the biological, ecological, and socioeconomic implications of the changes projected by physical models of the atmosphere and oceans. His research covered almost the entire scope of the climate problem. In 1977, in an early indication of his deep dedication to a scientific community that he helped establish, Steve initiated Climatic Change, a journal I now coedit, as a model for subsequent efforts to break the disciplinary boundaries that inhibit intellectual progress on complex questions.

In the 1990s, after moving to Stanford University, Steve was one of the first to attempt to formalize probabilistic approaches to the assessment and management of risk from climate change, and again, the two aspects of his intellect—his ability to quantify risk and simultaneously make subjective judgments of the reliability of the quantification—are evident. With colleagues, he developed a comprehensive approach for expressing the uncertainties that are rampant in global warming science and provided a quantitative and qualitative language for participants on the Intergovernmental Panel on Climate Change to use in presenting their expert judgments to their colleagues, to governments, and to the public. At the same time, he never exaggerated the threat of climate change, never stretched his interpretation of science to suit his personal political views, carefully distinguished his expert judgments from his opinions, and held his public pronouncements to the same high standard as his scientific findings.

Above all, Steve was not only deeply humanistic in his concerns but deeply humane in his relations with others. He always shared credit, found time to mentor students at all levels, and treated nonscientists with the same level of respect he accorded members of the profession. His book The Patient From Hell (Da Capo Press, 2005), which recorded his personal and intellectual struggles to come to grips with and ultimately outwit a rare form of lymphoma, helped untold numbers of cancer patients. I have encountered many who drew comfort from his book, and Steve was always generous in sharing his experiences with other patients one-on-one.

Steve was a physicist-in-full, a completely engaged human being. By example, he was a model of scientific genius and unparalleled breadth, public involvement combined with intellectual honesty. I hope at least some budding young scientists aspire to emulate his model of how to be a physicist.