By Barbara Kessler
Green Right Now
As inventors of all varieties race to develop the magic eco-fuel, the best ion battery or the most effective solar collection system, geologists are quietly exploring how certain types of rocks absorb our human carbon emissions.
The phenomenon is not unique. Trees and plants absorb some carbon. The ocean absorbs carbon. But trees can only do so much, and when they die, they release the carbon back into the atmosphere. The ocean has limits as well; it is already becoming acidic as gobbles our thickening stream of pollution.
Rocks, though, can capture carbon and render it into a solid, where it is virtually inert.
There’s a teeny problem. The rocks that are most effective at capturing carbon do so over thousands of years, naturally.
Researchers at the Columbia University’s Earth Institute are working on a process to speed that up a bit. It’s called mineral carbonation and involves dissolving carbon dioxide in water, injecting it into the rock and using the heat generated by the reaction to accelerate the mineralization.
Aside from tinkering with nature’s process. Certain rocks, called ultramafic, are required. They, unlike some other stone cousins, interact with carbon dioxide to form minerals. Fortunately, in the United States, thousands of square miles of these rocks – which include peridotite, dunite, lherzholite and others — can be found along the west and east coasts, beneath the earth and popping through the surface in places. The Columbia team has mapped these suddenly valuable formations in in a new report.
Now with the rock inventory identified, researchers should be ready to rock and roll.
If they’re able to perect the technology (making the chemical absorption work faster), they will have pieced together the granddaddy of closed-loop systems in the fight against global warming: Taking the fossil fuel pollution that we humans have created with oil and coal from deep in the earth and stashing it back into the earth.