

Sucking carbon from the sky may do little to slow climate change - spenrose
http://news.sciencemag.org/chemistry/2015/08/sucking-carbon-sky-may-not-slow-climate-change

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spenrose
"The Intergovernmental Panel on Climate Change concluded last year that
reaching a key emissions goal—roughly equivalent to limiting warming to 2°C by
2100—would rely on the deployment of one or several CDR technologies.
Deploying them could cost more than a trillion dollars, one expert estimates.

The new study puts the concept of CDR to the test—without getting into the
specifics of which technology to use. The authors used computer simulations to
figure out what would happen if engineers removed a whopping 5 gigatons of
carbon dioxide from the atmosphere each year. Achieving that goal, equivalent
to removing roughly half the amount of CO2 that is now emitted from manmade
sources, would require a gargantuan global effort. (To visualize the scale,
imagine 5000 new facilities each roughly the size of a sports stadium.)

Yet the scientists found the environmental benefits of such a massive
technological campaign were surprisingly small, especially in terms of
protecting the ocean from the impacts of climate change. One key impact of
rising CO2 levels is seen in the pH of ocean waters—the global sea surface has
been acidified by roughly 0.1 units and impacts on marine shells are beginning
to show. But the experiment demonstrated that the CDR campaign had only
limited effect to reverse that trend: Without the CDR the surface pH was
reduced by 0.75 units by 2200; with CDR the acidification was reduced 0.7
units, the team reports online today in Nature Climate Change."

