A recent panel of the National Academy of Sciences called for increased research into geoengineering. The announcement drew a variety of reactions, ranging from “this is proof that mankind is doomed!” to “uh, what is geoengineering?” So in the spirit of science, I’ve prepared a brief “explainer” on this fascinating and complicated subject.
What is geoengineering?
Geoengineering, or climate engineering, is the attempt to alter the earth’s climate on a large scale via deliberate human intervention. Specifically, geoengineering aims to counteract the effects of global warming. Remember in old movies or kids’ television shows when a mad genius creates a weather-control device? Well, weather is not climate, so it’s nothing like that. But basically.
How would it work?
A lot of geoengineering proposals do sound like something out of a science-fiction movie. The most popular version involves pumping aerosols into the upper atmosphere to block some of the incoming sunlight. The idea is based on the fact that, just as there are greenhouse gases that trap sunlight and make the earth warmer, so there are others (such as sulfuric aerosols) that have a cooling effect. An unplanned demonstration of this strategy occurred in 1991, when Mount Pinatubo erupted, spewing tons of sulfur dioxide into the air. Over the following 18 months, global temperatures declined by nearly a degree Fahrenheit.
Other less-common proposals include dumping iron into the oceans (to stimulate plankton growth), increasing the reflectivity of surfaces and deploying giant space umbrellas to block out the sun (not even kidding). Needless to say, the practicality of some of these plans is doubtful.
Who wants to do this?
Right now, nobody. But a variety of people have argued that geoengineering could be a much cheaper solution to global warming than cutting greenhouse-gas emissions. Most geoengineering proposals would cost a few billion to implement, and would not require painful government-mandated emissions reductions. For example, the economist Robert P. Murphy has written that “[t]he option of geo-engineering makes it much safer to continue using fossil fuels and thereby pass on extra trillions of dollars of wealth to the next generation at possibly little or even no cost.” Similarly, Jim Manzi has advocated for “the development of geo-engineering technology that would be available on a ‘break-the-glass-in-case-of-emergency’ basis” in case warming were to reach dangerous levels.
Is there a downside?
Oh, yes. Milton Friedman famously noted that if you put the government in charge of the Sahara Desert, in five years there’d be a shortage of sand. Geoengineering would give the government control over the planet’s thermostat.
Consider an analogy: For the past hundred years, control over the money supply has been given to the Federal Reserve. Led by a group of experts in economics and business, the Federal Reserve is justified as a means of tempering the boom and bust cycle of the pre-central bank period. But the economy, it turns out, is really complicated, and nobody’s perfect, so occasionally the Fed makes mistakes that plunge the globe into a crippling depression.
Now imagine the equivalent of the Federal Reserve, but for global temperature. Maybe it would be based in Washington (shudder); maybe at the United Nations (double shudder). No doubt, it would be staffed by the world’s most eminent experts who made it through the political vetting process. Yet one wrong move, one over-reaction or under-correction, and the planet could turn into a hothouse or be headed into a new ice age. That could be really bad. When the earth’s temperature dropped a couple of degrees during the “Little Ice Age,” this led to crop failures, wars, revolutions, and other nastiness that may have killed off upwards of a third of humanity.
And that’s not the worst-case scenario. Because there is no world government (thank God), setting a single target temperature for the planet would be very difficult. Some countries might prefer a warming world. Others might want it chilly. The resulting conflict could lead to a new Cold War (pun intended). Because geoengineering is so cheap, planet-changing programs are well within the reach of poorer nations and even some wealthy individuals. That’s a lot of chances to screw things up royally.
Are we all going to die?
So we shouldn’t research geoengineering?
Just the opposite. In my view, the dangers inherent in geoengineering are precisely why we need to prepare for it. The United States has spent a lot of time and effort trying to limit the proliferation of nuclear weapons. Geoengineering has just as much destructive potential, but is potentially far easier to get (unlike uranium, aerosols are readily available). Even if we don’t have to worry about a criminal organization trying to blackmail the world, we should worry about the possibility of environmentalists who take matters into their own hands, or of a dozen countries launching secret geoengineering programs that accidentally multiply their efforts. To guard against this, we need to know as much as possible about how the different options work (or if they work at all). We also need to figure out how to reverse whatever we do quickly, if necessary. In short, we cannot allow a geoengineering gap.
Also, Manzi isn’t wrong. Given the possibility that global warming could turn out really, really badly, it makes sense to have geoengineering as an option just in case. At least until President Gingrich establishes our Mars colony, this is the only planet where we can keep all our stuff. Geoengineering may seem like science fiction, but it could end up being better than the alternative.