The concept is called geoengineering, and in the past few years, it has gone from being dismissed as a fringe idea to the subject of intense debates in the halls of power. Many of us who have been watching this subject closely have gone from being skeptics to advocates. Very reluctant advocates, to be sure, but advocates nonetheless.

What has changed? Quite simply, as the effects of global warming have worsened, policy makers have failed to meet the challenge. As a result, if we want to avoid an unprecedented global catastrophe, we may have no other choice but to reduce the impact of global warning, alongside focusing on the factors that are causing it in the first place. That is, while we continue to work aggressively to reduce the amount of carbon released into the atmosphere, we also need to consider lowering the temperature of the Earth itself.

To be clear, geoengineering won’t solve global warming. It’s not a “techno-fix.” It would be enormously risky and almost certainly lead to troubling unforeseen consequences. And without a doubt, the deployment of geoengineering would lead to international tension. Who decides what the ideal temperature would be? Russia? India? The U.S.? Who’s to blame if Country A’s geoengineering efforts cause a drought in Country B?

Also let’s be clear about one other thing: We will still have to radically reduce carbon emissions, and do so quickly. We will still have to eliminate the use of fossil fuels, and adopt substantially more sustainable agricultural methods. We will still have to deal with the effects of ecosystems damaged by carbon overload.

http://online.wsj.com/article/SB1000142405...