Graphic: U.S. Government Accountability Office
There are several approaches to how climate engineering could work, but the technology isn't nearly ready, the GAO found.

Geoengineering: The GAO Assesses ‘Plan B’

August 29, 2011
6 min read

The idea that the only way to deal with how humans are changing the climate is to have scientists and engineers figure out a way to change it back again has attracted some clever monikers over the last few years. Journalists and bloggers have called geoengineering everything from “the MacGyver-ish solution” to “Plan B” to “the panic button.”

Last year, The New America Foundation held a conference that asked whether it was “the horrifying idea whose time has come.” When Stephen Dubner and Steven Levitt devoted a chapter to geoengineering in their book SuperFreakonomics, they ended up having to defend themselves from accusations that they were climate deniers. As Dubner wrote in response: “If we weren’t convinced that global warming was worth worrying about, we wouldn’t have written a chapter about proposed solutions.”

For a scientific question, the idea of geoengineering (and it is mainly an idea at this point) has been a kind of emotional litmus test. Whether you think it’s as clever as MacGyver or as dumb as his easily distracted Saturday Night Live parody, MacGruber seems to depend more on whether you consider yourself an environmentalist or in the “drill baby drill” camp.

Now the U.S. Government Accountability Office has issued a report assessing the state of “climate engineering technologies, focusing on their technical status, future directions for research on them, and potential responses.” The analysts at the GAO combed through the scientific literature and convened panels of top scientists, engineers, and policymakers to help them appraise whether geoengineering proposals are workable and safe. The report looks at the two main strands of work:

• ideas for removing carbon dioxide from the atmosphere—basically, we put it up there, so we need to figure out how to take it out.
• ideas for “solar radiation management” to “scatter or reflect sunlight.” Here, the suggestions range from injecting “sulfate aerosols into the stratosphere to scatter incoming solar radiation” to painting rooftops and pavement light colors to reflect sunlight.

(Related National Geographic Stories: “The Quest to Capture Carbon Dioxide” and “Carbon Recycling: Mining the Air for Fuel”)

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The GAO’s conclusions? None of these ideas is anywhere near ready for prime time—or to use the GAO’s more measured phrasing, they are “currently immature, many with potentially negative consequences.” In fact, many of the experts the GAO consulted warned that risk management should be built into future studies, since there are both political and environmental issues if anything goes wrong. What’s needed now, the report suggests, is research to determine whether ideas like these are really feasible and whether the risks and unknowns can be reduced.

One of us participated in one of the review panels (to help the GAO team consider public opinion on the issue) and was struck by how thorny and complicated these proposals would be and why more research is so necessary. Take the idea of cloud brightening, or injecting material into the clouds to help reflect the strength of the sun. There’s the question of whether the idea actually works to help cool the Earth. There’s the question of whether it could have negative consequences along with the intended ones. Some of the current research suggests that doing this might “greatly reduce summer precipitation in places such as India and northern China.”

Then there are a whole range of practical questions. How would you get countries around the world to agree on this strategy? What do you do if some country decided to go ahead on its own, even though others don’t agree? How often would you have to do it? Do we even have enough planes to conduct the sorties that would be required to get it done?

But given the potential devastation unchecked global warming could unleash on humanity (and given the likelihood that someone, somewhere will probably act on one of these ideas, even though it hasn’t been well-vetted), the GAO’s advice that we need to know more about how they would work and what the risks are seems undeniably sensible.

We also applaud the GAO for including an assessment of public opinion in their study. Most Americans don’t know much about geoengineering, and many are quick to wonder about the downsides. But most are also remarkably open to the idea that we need to know more about it before we decide to accept it or reject it.

For us, the GAO report raises another important point for environmental and energy issues overall. We need more impartial, “let’s take a look at what we know and don’t know” work in other areas too. There is a lot of hyperventilating about nuclear power, clean coal, using “fracking” to drill for natural gas, and the real prospects for much wider use of wind and solar. In all these areas, having an independent group sift through the research and describe the options, risks, and trade-offs for the rest of us would be a public service.

Of course, there are some human beings who reject any information that doesn’t support their pre-existing point of view, but based on what we’ve seen in the public opinion research, most Americans aren’t in that camp. Despite all the hoopla about climate science denial, only 19 percent of Americans say global warming is “not a problem at all,” and 7 in 10 (including 55 percent of Republicans) say they want the federal government to “regulate the release of greenhouse gases from sources like power plants, cars and factories in an effort to reduce global warming.”

In fact, we’re convinced that most Americans might welcome a pause in the fire-breathing rhetoric on this issue and others. There is a huge swath of the public that is eager to have fair-minded experts help them understand what’s at stake. And on geoengineering, there is plenty at stake—far too much to risk anything less than careful thought.

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