‘Grandfather of global warming’ won't keep quiet

By Clint Talbott

Jim Hansen has been called the “grandfather of global warming,” a moniker he rejects in part. He is a grandfather, not of a changing climate but rather of children: Sophie and Jake.

Hansen, an outspoken scientist at NASA’s Goddard Institute for Space Sciences who spoke during this year’s Conference on World Affairs, got tagged as the “grandfather of global warming” because he was one of the first scientists to make widely publicized statements about the emerging phenomenon.

After testifying in Congress in the late 1980s, Hansen decided to step out of the public eye. The glare of publicity was intense, and other scientists could do a better job of discussing climate change, he said.

He maintained a lower profile for 15 years afterward. He re-entered the public discourse after the birth of his first grandchild, Sophie. “I decided I didn’t want my grandchildren to say opa understood what was happening, but he didn’t want to make it clear.”

Hansen has tried to make it clear, but his efforts have not been universally appreciated. In 2006, The New York Times reported that the Bush administration tried to stop Hansen from speaking freely about his area of scientific expertise, warning him that there would be “dire consequences” if he continued to make public statements about climate change.

Hansen said he spoke up and continues to speak up (emphasizing along the way that the views he expresses are his own) because of the “huge gap” between what is understood by the scientific community and what is known by the public.

There is also, he said, a huge gap between political rhetoric and political reality. Most politicians, he says, acknowledge that “the planet is in peril.” Meantime, he said, the political reality is a “small perturbation to business as usual.”

Hansen discussed the empirical data from paleoclimatology and from contemporary observations. He noted that the climate is changing much faster than at any time in Earth’s history, and he said human emissions of greenhouse gases were primarily responsible for the rapid climate change observed in the last half-century.

“We do have a crisis, and that’s partly because of the inertia of the climate system,” Hansen said. “There’s about as much warming in the pipeline as has already occurred.”

Hansen argued that the world should aim to stabilize atmospheric concentrations of carbon dioxide somewhere below 350 parts per million. Today, CO2 is about 387 ppm. He said achieving such a reduction would require strong measures, including a carbon tax of, say, $1 per gallon of gas.

He also urged rapid deployment of renewable energy, substantial improvements to the electric grid, and scientific studies of next-generation nuclear power and carbon-capture and sequestration technology for coal-fired electrical plants.

Hansen appeared during the Conference on World Affairs to deliver the Walter Orr Roberts Distinguished Lecture, which memorializes the founder of the National Center for Atmospheric Research in Boulder.