Ken Caldeira on whether to alter climate on purpose

The Kyoto Protocol – an international climate treaty – expires in 2012. In March 2009, scientists met to prepare policy recommendations for a new treaty to be drawn up in Copenhagen in December 2009. One issue they discussed was geoengineering – intentionally altering the climate. According to Ken Caldeira: I believe that the only realistic way to actually reduce temperatures on this planet, this century, is to intentionally interfere with the climate system.

That’s climate scientist Ken Caldeira, who spoke at the meeting in March. Caldeira told EarthSky that humans might have already failed at cutting emissions in time to prevent a climate crisis. He’s a proponent of conducting scientific research to find ways to turn down the global thermostat through technology.

Ken Caldeira: We could do this by putting dust in the stratosphere. We know this would work because volcanoes do this, and volcanoes cool the Earth.

Caldeira admits this approach could have unforeseen consequences.

Ken Caldeira: So I think it’s imperative that we do the research now so we learn what we can and can not do, and then put it on the shelf and hope we don’t have to use it.

Caldeira hopes to do small-scale field tests to see how geoengineering schemes actually work in the environment.

Caldeira emphasized that he does not see geoengineering as an alternative to reducing greenhouse gas emissions, but as a final line of defense.

Our thanks to:
Ken Caldeira
Department of Global Ecology
Carnegie Institution of Washington

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