A (Somewhat) Curmudgeonly Take on Geoengineering

by Michael D. Lemonick

Geoengineering: It’s currently one of the hotter topics in climate change—or at least, it has that flavor. This is largely thanks to a pair of new books: “Hack the Planet,” by Science Magazine reporter Eli Kintisch and “How to Cool the Planet,” by Jeff Goodell of Rolling Stone, both published in recent weeks (the coincidence might suggest some sort of collusion, but having worked at TIME for many years, which often had the same cover story as our arch-rival Newsweek, I strongly suspect it has more to do with an effort by both parties to be first).

As both books explain quite clearly and thoroughly, geoengineering is a kind of Plan B for addressing climate change, based on the idea that we might not be able to curb carbon emissions enough to prevent dangerous global warming. If that turns out to be the case, we might be forced to reduce the warming in other ways—by spewing reflective particles of sulfur dioxide into the atmosphere, for example, or using salt spray to make clouds brighter, both of which would reflect sunlight back into space. Or we might launch huge sunshades into orbit, to act as giant parasols. Or dump iron dust into the ocean, stimulating the bloom of iron-needing plankton that would suck CO2 out of the air (pilot projects involving this technique have been discouraging). There are several more schemes, which both books go into.

Despite the recent flurry of interest, though, geoengineering isn’t new. The New York Times ran a story in 2006 titled “How to Cool a Planet (Maybe).” And way back in 1998, the Stanford Environmental Law Journal published a paper titled “Geoengineering: A Climate Change Manhattan Project.” Last year, the authors of SuperFreakonomics were widely castigated for being too credulous in their enthusiasm for geoengineering (the RealClimate blog is just one of many critiques).

Nevertheless, both Goodell and Kintisch argue that something fundamental has changed. Climate scientists and others (including some veterans of the Cold War-era Star Wars program) are talking more seriously, and in greater numbers, about taking a hard look at how you’d actually implement these schemes, what it would cost—and, what sort of unintended consequences might result.

That last point is vitally important. History is full of examples where humans have come up with a clever way of improving nature, only to make things worse. The American South is being slowly overrun with kudzu, a vine imported to prevent erosion in highway roadcuts. Killer bees have established themselves throughout South America because a clever biologist thought he could get better honey production by crossbreeding two species. The hybrid escaped, and started moving north. For a great read about how technology, in particular, can backfire, check out Edward Tenner’s classic Why Things Bite Back: Technology and the Revenge of Unintended Consequences.

In an effort to anticipate what some of the surprises might be, climate scientists have been studying the potential effects of geoengineering schemes. One study, published in 2008 in the Proceedings of the National Academy of Sciences, raised concerns that plans to reflect more incoming solar radiation would unintentionally reduce global precipitation.

Just last month, some 200 scientists, ethicists and other interested parties met at the Asilomar conference center in northern California, to ponder the rules that should govern geoengineering experiments in an effort to prevent things from going wrong (Goodell and Kintisch both attended; Kintisch wrote about the meeting in Slate). It was here, in 1975, that molecular biologists began to work out the ground rules for genetic engineering—and both Kintisch and Goodell argue that this demonstrates that the topic is being taken much more seriously.

But there’s a big difference between geo- and genetic engineering. In the latter case, the pressure to move ahead was enormous—the potential economic, agricultural and medical payoffs were huge. If the scientists hadn’t laid down ground rules, the whole thing could have gone very badly very fast.

But with geoengineering, there’s much less pressure to figure things out, because there’s at least a theoretical alternative: cut back on greenhouse gas emissions. So while it’s clear that scientists are thinking more about geoengineering, that doesn’t necessarily mean the field is really about to take off. Compared with genetic engineering, experiments are likely to be very expensive, hard to do in any sort of limited manner, and could themselves lead to unpleasant consequences. Furthermore, many scientists are still hesitant to talk seriously about geoengineering; because they worry it would divert attention from the priority of reducing greenhouse gas emissions.

On the other hand, it will take huge and rapid CO2 emissions reductions in order to prevent significant warming. This would have taken a mammoth effort even if we’d started last year. Every year we wait, the harder it will be. So while the interest in geoengineering among scientists and policymakers may not be growing as fast as the recent flurry of books and stories might have it, it’s probably a good thing that they’re thinking about it at all. If geoengineering really does become necessary, there won’t be a lot of time to figure out how to do it.