On 13 July 1971, world-leading researchers gathered in Stockholm, Sweden, concluded their presentations about human influence on climate, and opened the meeting to questions from the press. But rather than asking about the most important climate meeting yet, the assembled reporters first looked to the meeting’s 26-year old secretary. “Where is Dr. Schneider? When is the ice age coming?” they asked.
The journalists sought out Stephen Schneider about a paper by him and his NASA Goddard Institute for Space Studies (GISS) boss, S. Ichtiaque Rasool, published just four days before. Using early computer models, they warned of a scenario where enough dusty aerosol pollution could be ‘sufficient to trigger an ice age’. For Steve, this would be the first encounter of many with the media’s interest in climate, leading him ultimately to help define how scientists influence the wider world.
As a PhD student at Columbia University in New York in the late 1960s, Steve came into contact with some of the world’s leading experts on climate. Wally Broecker, who at that time was helping establish the timing of the ice ages, lectured him on oceanography. A talk by Joe Smagorinsky from the US National Oceanic and Atmospheric Administration (NOAA), who was establishing some of the first computer climate models with Suki Manabe, played on Steve’s childhood fascination with hurricanes. And when he took a seminar by Ichtiaque talking about planets’ atmospheres – why Mars was too cold, Venus too hot, and Earth just right – he was hooked.
While writing up his PhD thesis he got a part-time job with Ichtiaque, tackling a key question at the time. Burning fossil fuels creates two types of pollution that influence climate – warming CO2 and cooling aerosols. But which one would win out? On the advice of fellow GISS scientist Jim Hansen, Steve used a method partly developed by astronomer Carl Sagan to calculate the aerosol effect. He put this into a model of warming from CO2 Ichtiaque gave him. They found that doubling CO2 levels in the air would raise temperatures by about 0.7°C – much lower than Suki’s earlier estimate of 2°C for this ‘climate sensitivity’ figure. But models where aerosols were spread everywhere experienced 3-5°C cooling, prompting Ichtiaque to write the ice age comment, referring to other controversial research of the time.
Ichtiaque had asked Steve to handle criticism of the study, but in the meantime Steve had managed to get an invite to the Stockholm gathering of leading climate scientists. Being a ‘rapporteur’ he was supposed to only be taking notes at the three week Study of Man’s Impact on Climate (SMIC) meeting, organised by Bert Bolin. But Steve couldn’t resist showing Suki some of his modelling work on clouds’ role in climate – and then the aerosol study was published. Ichtiaque had mischievously told a reporter that Steve was presenting the work at SMIC, forcing his young colleague to give a brief seminar, and face the press. Read the rest of this entry »