Gernot Wagner and Martin Weitzman on the "allure of geoengineering" as a solution to global warming, and the temptation for individual countries to act on their own:
Playing God: ... All it takes is a single actor willing to focus on the purported benefits to his country or her region to pull the geoengineering trigger. The task with geoengineering is to coordinate international inaction while the international community considers what steps should be taken. The fate of the planet cannot be left in the hands of one leader, one nation, one billionaire.
Fortunately, we are still many years off from the full "free driver" effect taking hold. There's some time to engage in a serious global governance debate and careful research: building coalitions, guiding countries and perhaps even individuals lest they take global matters into their own hands. In fact, that is where the discussion stands at the moment, with a governance initiative convened by the British Royal Society, the Academy of Sciences for the Developing World, and the Environmental Defense Fund, among other deliberations guiding how geoengineering research should be pursued.
With time come the "free drivers"
The clock, however, is ticking. A single dramatic climate-related event anywhere in the world - think Hurricane Katrina on steroids - could trigger the "free driver" effect. That event need not be global and it need not even be conclusively linked to global warming. A nervous leader of a frightened nation might well race past the point of debate to deployment. The "free driver" effect will all but guarantee that we will face this choice at some point.
"Free riding" and "free driving" occupy opposite poles of the spectrum of climate action: One ensures that individuals won't supply enough of a public good. The other creates an incentive to engage in potentially reckless geoengineering and supply a global bad. It's tough to say which one is more dangerous. Together, these powerful forces could push the globe to the brink.