by Richard T. Stuebi
The challenges associated with climate change are so daunting — so much emission reductions to achieve, so much money to invest in energy efficiency and low/zero-carbon energy technologies and infrastructure, and so little time to do it — that we’re going to have to be awfully creative.
In the past, I’ve blogged about geoengineering the planet, putting stuff up in the atmosphere to block incoming solar radiation, thereby reducing the energetic input to the planet from the sun. This week, I take note of an article entitled “Eating Carbon” in the November 15 issue of The Economist.
It appears that the Earth is endowed with massive reserves of a particular type of rock called peridotite, which seems to be able to react quickly with carbon dioxide to produce carbonates. One thought is to grind up the peridotite and expose it to exhaust streams, but a new approach profiled in a paper (see abstract) in Proceedings of the National Academy of Sciences by Peter Kelemen and Juerg Matter of Columbia University involves injecting carbon dioxide in mass quantities (e.g., from powerplants) into the peridotite strata, leaving inert byproducts in-situ underground.
The big challenge appears to be depth: the peridotite is 20 km down. But, the upside appears to be substantial, with seemingly much more carbon dioxide sequestration capacity than the caverns and reservoirs mainly being considered in the carbon capture/sequestration (CCS) community — and with no potential for leakage.
Apparently, peridotite is not the only rock that “eats” carbon, as researchers are now investigating volcanic basalt as well. With luck, perhaps geologists can find a good rock type that is both quickly reactive, highly plentiful and dispersed on the planet, and relatively cheap/easy to access.