So long as governments and industry are unwilling or unable to reduce the use of greenhouse gas-emitting energy sources, climate change will continue unabated.
Unless, of course, there might be ways of preventing carbon dioxide from entering the atmosphere after it has been generated. As this article from yesterday’s New York Times reports, geoengineering options generally fall into two categories: capturing and storing some of the carbon dioxide that has already been emitted so that the atmosphere traps less heat, or reflecting more sunlight away from the earth so there is less heat to start with.
The first option, called carbon dioxide removal, is relatively low risk, but it is expensive, and even if it was pursued on a planet-wide scale, it would take many decades to have a significant impact on the climate. The second option, called solar radiation management, is far more controversial. Most discussions of the concept focus on the idea of dispersing sulfates or other chemicals high in the atmosphere, where they would reflect sunlight, in some ways mimicking the effect of a large volcanic eruption. Although the process would be relatively inexpensive and should quickly lower temperatures, it would have to be repeated indefinitely and would do nothing about another carbon dioxide-related problem: the acidification of oceans.
Meanwhile, researchers in Iceland are working on turning gaseous carbon dioxide into stone. Unlike conventional carbon sequestration (which, itself, is only in its nascent stages), by turning the carbon dioxide into stone, there is no chance that the carbon may ultimately leak back into the atmosphere at a later time.
Whether this approach will prove to be commercially viable and lead to wider adoption of carbon storage, particularly on the huge scale that will be required to help stem the forces of climate change, remains uncertain. But time is of the essence, and no reasonable measures should be rejected.
On Tuesday, in two widely anticipated reports, a National Academy of Sciences panel — which was supported by NASA and other federal agencies, including what the reports described as the “U.S. intelligence community” — noted that drastically reducing emissions of carbon dioxide and other greenhouse gases was by far the best way to mitigate the effects of a warming planet. Unless and until, however, governments and businesses get serious about those reductions, geoengineering may be the planet’s only chance.