Kate Mackenzie Geoengineering: you’re probably already doing it

Stephen Chu has been asked about geoengineering before, especially since White House science advisor John Holdren said it ‘had to be looked at’. Yesterday he was asked about it again in London and said there were no plans “at this time”, but he proclaimed the effectiveness of one form of geoengineering: painting roofs white.

“Now you smile, but if you look at all the buildings and make all the roofs white, and if you make the pavement a more concrete-type of colour than a black-type of colour, and you do this uniformly… It’s the equivalent of reducing the carbon emissions due to all the cars in the world by 11 years,” he said.

“It’s like you’ve just taken them off the road for 11 years. It’s actually geoengineering.”

White roofs, and white cars, can reduce carbon emissions by reducing the need to cool cars and buildings during warm times.

It’s a far cry from disturbing scenarios such as giant shields to reflect the sun’s warmth. But geoengineering does cover a whole range of ways of reducing the effect of greenhouse gases on the climate, apart from actually reducing greenhouse gases and other contributing emissions such as soot. So that includes meaures such as carbon capture and storage (CCS), of which several projects are already under way.

The Committee on Science, Engineering, and Public Policy in a report on the policy implications of global warming described geoengineering as “large-scale engineering of our environment in order to combat or counteract the effects of changes in atmospheric chemistry.” They wrote:

Most of these options have to do with the possibility of compensating for a rise in global temperature, caused by an increase in greenhouse gases, by reflecting or scattering back a fraction of the incoming sunlight. Other geoengineering possibilities include reforesting the United States to increase the storage of carbon in vegetation, stimulating an increase in oceanic biomass as a means of increasing the storage and natural sequestering of carbon in the ocean, decreasing CO2 by direct absorption, and decreasing atmospheric halocarbons by direct destruction.

They add:

It is important to recognize that we are at present involved in a large project of inadvertent “geoengineering” by altering atmospheric chemistry, and it does not seem inappropriate to inquire if there are countermeasures that might be implemented to address the adverse impacts.

So whether you knew it or not, you’re probably involved in it.