As the ravages of climate change become ever more apparent, some scientists are contemplating an array of possible technological fixes — most of which would have sounded like science fiction just a few years ago (and in many cases still seem pretty far-fetched). But drastic times may call for drastic measures, and the time may have come to tinker with the climate in order to keep the planet livable.
"Geoengineering" is the catch-all term for attempts to alter Earth's climate in order to mitigate the effects of global warming. And, not surprisingly, it's been controversial from the start. Critics have derided it as "playing God" with the environment, and the potential risks are almost too many to tally — even its proponents stress that the consequences of large-scale climate intervention are impossible to foresee. But as the signs of global warming multiply, geoengineering is beginning to seem like a plausible solution — or at least part of a solution — to today's climate woes.
Many different strategies for geoengineering have been put forward. Most of them confront some aspect of the "greenhouse effect" — the warming of the planet that results from heat getting trapped by the atmosphere. Earth has always experienced some degree of greenhouse warming, but the problem has accelerated since the Industrial Revolution, when we began releasing artificially produced greenhouse gases, especially carbon dioxide, into the atmosphere. The result — global warming — is now one of the greatest threats to life on Earth.
One way to reduce greenhouse heating would be to curb carbon emissions — something that, collectively, we've pretty much failed to do. The next best thing would be to neutralize the effect of the carbon we're releasing. Several ways to do that have been proposed: planting trees on a massive scale; burying carbon at sea; even sprinkling iron filings over the ocean to simulate the effect of carbon-neutralizing plankton.
Any sort of tinkering with the planet's climate is "a very controversial topic, for good reasons," Keutsch says. "Even in the best-case scenario, geoengineering through albedo modification is not a solution to the problem." Solar geoengineering would do nothing to lower the concentration of atmospheric carbon dioxide and other greenhouse gases, which means the atmosphere would continue heating up the moment the intervention was over. It also wouldn't slow the acidification of the oceans, a result of the buildup of carbon dioxide in the atmosphere.
"You're really not addressing the cause of the problem; you're only addressing the symptoms," Keutsch says. Drawing an analogy, he adds, "Sometimes there's a reason to take painkillers. But painkillers have all kinds of consequences." And with the pain under control, he explains, the patient may end up doing things that exacerbate the original condition, making the patient more reliant on medication and eventually making the underlying problem even worse.
"This is a very real risk," he says.
In other words, the public might be lulled into believing that a "technological quick fix" is at hand — and that no other measures are needed to save Earth from potentially catastrophic climate change.