Plan B for global warming

In October 2001, Keith was among 25 bureaucrats and academics quietly brought together by the U.S. Department of Energy to brainstorm about technological responses to “rapid or severe climate change.” An odd assignment given George W. Bush’s public questioning of whether climate change was even happening, and his controversial decision to abandon the Kyoto Protocol just months before. “If they had broadcast that meeting live to people in Europe, there would have been riots,” Keith has said. Which surely explains why the white paper that flowed from the discussions—a research agenda not dissimilar to what geoengineering backers want today—never saw the light of day.

It’s not that the climate change community was unaware of the schemes. But there was a general consensus that publicly airing them was somehow irresponsible, if not downright dangerous. Environmental groups and many senior scientists viewed the very idea as a “moral hazard,” and were not keen to provide governments and business with an excuse to turn away from the tough work of emission cuts. In 2006, NASA organized a hush-hush conference at its Ames Research Center in San Francisco (Keith was in attendance); it was billed as a meeting on “managing solar radiation.”

When you ask geoengineering supporters what finally pushed them out of the closet, all point to one event: an article on sulphur injections by the Dutch chemist Paul J. Crutzen, winner of a 1995 Nobel Prize for his work on the degrading ozone layer. His cautious endorsement of more research gave the schemes instant scientific credibility.

In 2007, Keith and Dan Schrag, a Harvard climate scientist, organized a conference in Cambridge, Mass., that brought together not just the usual enthusiasts, but climate modellers, oceanographers, and political heavyweights like Larry Summers, now President Obama’s chief economic adviser. According to some participants, the off-the-record two-day session was wrenching, as scientists clashed, grappling with the implications. “A lot of people when they hear this topic for the first time think it’s horrible,” says Schrag. “What arrogance to think we can control such a complex system.” But the meeting marked another turning point. Geoengineering was now undeniably on the climate change agenda. “I talk about this as a tourniquet. It’s not a fix and it’s not a Band-Aid. It’s only to be used when you think you are going to bleed to death,” says Schrag. “It’s the worst possible solution in the world. Except for the alternative.”

Ask Ray Pierrehumbert, a University of Chicago climate dynamicist, about geoengineering, and he doesn’t mince words. “It’s like taking Aspirin when you’ve got a brain tumour.” For people who have spent their careers trying to get the world to take global warming seriously, the abrupt shift toward a quick fix is galling. “The science is really cool. It’s a way that some people can get their names in the newspapers as the saviours of the globe,” he says. “But we will never know how dangerous it is until we try it on a large scale. It could be like throwing gasoline on the fire.”

A handful of recent papers are raising similar concerns. Last spring, scientists at the Livermore Labs predicted that “sunshade” geoengineering projects like stratospheric particles or space-based lenses will slow the global water cycle and lessen rainfall. Another study from the National Center for Atmospheric Research in Colorado suggested that adding sulphates will destroy a quarter to three-quarters of the ozone layer over the Arctic. And in December, Richard Turco, a UCLA professor, estimated the “preposterous” stratospheric spraying being talked about would require thousands of high-altitude jet flights every day.

Pierrehumbert says he sympathizes with his colleagues’ despair over the bleak new climate change data, but that their “sincere panic” isn’t helping. Geoengineering will do nothing about the root problem—growing CO2 concentrations—and once started would have to be maintained almost indefinitely. “It would become addictive,” he says. “It would just result in people putting off the hard decisions because some of the most obvious problems in the First World would be mitigated.”

James Fleming, the science historian, likens proponents to the “loonies, charlatans and pathological scientists” of the past who promised governments and the public that they could control the weather, with negligible results. One of the few outsiders in attendance at the NASA conference (Keith invited him), he describes the vibe as chilling. “This is an odd bunch of people that really, truly believe there is a planetary emergency,” he says. “It’s post-Al Gore. Gore believes we’ll be all right if everybody brushes their teeth. These guys are into severe restorative dentistry.”