I’ve got to admit I’m not the world’s biggest fan of geoengineering, and I’ve said so quite publicly. The idea is that if we fail to cut back greenhouse gas emissions and the planet’s temperature soars to potentially dangerous levels, we’ll have to do something.
Since greenhouse gases trap heat from the sun, that something could be finding a way to block sunlight — by lofting particles of reflective sulfur dioxide up into the stratosphere, for example, or by “seeding” clouds with a fine spray of seawater to make them whiter, or even, in one of the more farfetched schemes I’ve heard about, by sending little mirrors into space.
Or, since CO2 stays in the atmosphere for hundreds of years after it’s emitted, the something could be a new technology, like “artificial trees,” which would suck that most important greenhouse gas back out of the air.
There’s a long list of geoengineering ideas, but they all make me think of Edward Tenner’s classic work: Why Things Bite Back: Technology and the Revenge of Unintended Consequences. Technological breakthroughs that solve one environmental problem all too often lead to new problems that are even worse (my favorite example is the advent of the automobile, which solved the great Horse Manure Crisis of the late 1800s). Nobody really knows what unexpected disasters could arise from geoengineering, and it could be very, very unpleasant to find out.
That’s one legitimate rap against geoengineering. Another is that focusing too much attention on solving the climate problem after the fact can divert us from trying to prevent the climate problem from happening in the first place. It’s somewhat analogous to maladies like coronary artery disease. The best way to reduce your risk as you get older is to eat right and get plenty of exercise when you’re younger.
But guess what? Lots of people aren’t willing to do those things. You might argue that we should ban coronary bypass surgery and stents and cholesterol-lowering drugs on the theory that they let people get away with bad behavior — and they have plenty of pretty unpleasant side effects, just as geoengineering might have.
You wouldn’t get very far with that argument though: sure, it’s better to practice healthy habits in the first place, but it would be reckless not to have a plan B, just in case. And given that no meaningful action has yet been taken to cut greenhouse gas emissions despite a decade and a half of good intentions (the International Energy Agency just reported that emissions for 2011 were the highest on record), it would be even crazier to ignore geoengineering than it would be to embrace it.
That doesn’t mean rushing into full-scale experiments. It means proceeding really, really carefully, and creating a set of rules to govern how those experiments play out. In fact, a group of scientists began hammering out those rules at a conference in 2010.
But there are all sorts of other issues besides the riskiness of rushing into large-scale geoengineering experiments. One of them has to do with intellectual property. A preliminary test of technology that could send reflective particles into the air (the test itself would have sent up only water droplets) was cancelled recently when it turned out two of the scientists had submitted patents for the process without telling the others.
Another issue is who gets to decide whether a project actually goes forward. There’s nothing to prevent a nation from launching a geoengineering scheme tomorrow — not just an experiment, but a full-fledged project — all on its own, without any evidence that it’s safe.
So there are plenty of reasons why the world needs to proceed with extreme caution on geoengineering. But there are also plenty of reasons why the world can’t afford to ignore it.