2010 has been a bad year for climate, and an even worse year for climate policy. But for that very reason, it’s been a good year for geoengineering—the notion that humans can deliberately manipulate the climate and cool the earth.

Official Washington is starting to take geoengineering seriously: The Government Accountability Office and a bipartisan task force of experts convened by the New America Foundation will soon report on geoengineering. Bill Gates has invested in geoengineering research. Environmental groups–notably Steven Hamburg, the chief scientist of Environmental Defense Fund–have engaged in the conversation. On a parochial note, at FORTUNE’s Brainstorm Green conference last spring, Stewart Brand talked about why geoengineering is important, to a rapt audience that included Bill Ford and Lee Scott.

David Keith

David Keith, a leading scholar of geoengineering who administers Gates’ $4.6 million grant with  with Stanford climate scientist Ken Caldeira, also spoke at Brainstorm Green. So I was pleased to have a chance to reconnect with him at the excellent annual conference run by the Society of Environmental Journalists at the University of Montana in Missoula.  I expected him to be pleased by the momentum gathering behind  geoengineering lately, but I was wrong.

“I think things are moving too fast,” David told me. “Research programs can be killed by spending too much money too fast.” Besides, he said, people need time to wrap their head around geoenginnering. (Juliet Eilperin of The Washington Post recently described it as playing God with the weather. ) “This is a topic—the first time people hear about it, they have wild ideas,” he said.

As I’ve written before – see this, this and this – geoengineering raises a host of thorny ethical, political and governance issues. Who gets to control the earth’s thermostat? Who decides if and when to deploy geoengineering techniques? Which should be used?

At SEJ, David was on a panel with Dane Scott, director of the center for ethics at the University of Montana, and journalist Eli Kintisch, author of a recent book about geoengineering called Hack the Planet. They all seemed to agree that the technology to cool the earth now exists—either by reflecting sunlight back into the sky, an approach known as solar radiation management, or by capturing carbon dioxide from the air. (Keith has a for-profit startup called Carbon Engineering designed to do just that.) They also agreed that the moral ethical issues surrounding geoengineering are daunting. [click to continue...]