Scientists weigh risks of climate 'techno-fixes'

Schemes from space mirrors to vast algal blooms have sparked debate over the ethics of geoengineering.

from the March 29, 2007 edition

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Others point out that the mere mention of a techno-fix for climate change could have unintended consequences. If people know that someone will bail them out of catastrophe, they're more inclined to engage in risky behavior, says David Keith, director of an energy and environmental systems research group at the University of Calgary. Statistically speaking, those with flood insurance suffer the worst flood damage, he says. And because geoengineering may lead to greater risk-taking – in this case by continuing to emit copious amounts of CO2 – "it's clearly not, in some global sense, economically optimal," says Mr. Keith.

But Mr. Cascio points out that fail-safe technologies could also drive humanity in the other direction. If people understand that these technologies are a terrible last resort, the specter of their deployment may serve as a deterrent the way mutually assured destruction (theoretically) saved the world from a nuclear holocaust during the cold war. The parallel has to be made clear: "You are consciously trying to alter the complex systems that govern how our planet operates," he says. "Do that the wrong way, and you potentially kill everyone."

Not discussing these options could be worse, says Scott Barrett, professor of environmental economics at Johns Hopkins University in Washington, D.C. If scientists don't talk about geoengineering, the institutions and regulations governing its implementation will not be created. "The point may come where countries may experiment and there will be no international arrangements," Professor Barrett says.

We have to "bring this thing out into the open."

Because climate change has winners and losers – one country's breadbasket dries up while another's desert blooms – unilateral change becomes a sticky prospect. Manipulation – even if it's viewed as a corrective measure – will inevitably impinge on another's newfound good fortune. "Even if you're very confident that you can make things better, that doesn't necessarily give you the right to do that if, in fact, you're affecting other people's interests," says Professor Jamieson.

Ken Caldeira posits another possibility: "You could imagine some kind of arms race of geoengineering, where one country is trying to cool the planet and another is trying to warm the planet," he says.

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Click to enlarge SOURCES: INTERGOVERNMENTAL PANEL ON CLIMATE CHANGE; NASA; ROGER ANGEL, UNIVERSITY OF ARIZONA, STEWARD OBSERVATORY; PAUL J. CRUTZEN, SCRIPPS INSTITUTE OF OCEANOGRAPHY, UC SAN DIEGO, AND MAX-PLANK INSTITUE FOR CHEMISTRY; KLAUS LACKNER, COLUMBIA UNIVERSITY/AP