What’s the best way to reduce the chances of climate change wreaking havoc on Earth?
The most obvious answer – one we’ve known for years now – is to reduce the amount of carbon dioxide we’re pumping into the atmosphere. This can be done, for instance, by putting a price on carbon and thus create powerful market incentives for industries to lower their carbon footprint. Or by moving to renewable energy sources. Or by changing people’s behavior so that our collective actions radically reduce the amount of fossil fuel the world needs to power itself.
Despite this knowledge, however, few policies have been put in place to spur any of that. In the United States, the effective price of carbon, as Gernot Wagner and Martin Weitzman point out in their new book, “Climate Shock,” is “about zero” (aside from California). Fossil fuels remain the world’s default energy source, and – despite the impressive growth of global solar capacity over the past decade – that’s likely to be the case for decades to come. A carbon tax on the worst emitters has gotten nowhere.
So maybe we need to start thinking about coming at the climate-change problem from a different direction. Instead of hoping that humans will start reducing their carbon use, maybe it’s time to at least consider using technology to keep climate change at bay.
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The deliberate use of technology to manipulate the environment – usually in the context of fighting climate change – is called geoengineering. One method is carbon capture, traditionally conceived as a process that sucks up carbon from the air and buries it in the ground. A second is called solar radiation management, which uses techniques like shooting sulfate particles into the stratosphere to reflect or divert solar radiation back into space. This very effect was illustrated after the volcanic eruption of Mount Pinatubo in the Philippines in 1991. Spewing 20 million tons of sulfur dioxide in the air, the volcano caused global temperatures to fall, temporarily, by about 0.5 of a degree Celsius, according to Wagner and Weitzman.
Somewhat to my surprise, a good portion of Wagner’s and Weitzman’s book is devoted to the subject of geoengineering, especially solar radiation management, which they describe as relatively inexpensive and technologically feasible, with a serious bang for the buck. The reason I was surprised is that the authors have solid environmental credentials – Weitzman is an environmental economist at Harvard, and Wagner is a senior economist at the Environmental Defense Fund – and many environmental groups object to the very idea of geoengineering. They even object to research into the subject, viewing the desire to manipulate nature as immoral. Ben Schreiber of Friends of the Earth, an advocacy group, recently described discussions about geoengineering as a “dangerous distraction.”
“Geoengineering presumes that we can apply a dramatic technological fix to climate disruption,” he said, “instead of facing the reality that we need to drastically reduce our carbon emissions.”
Schreiber was reacting to two reports by a National Academy of Sciences panel. The reports concluded that, while “climate intervention is no substitute for reductions in carbon dioxide emissions,” the politics around carbon reduction have been so fractious that the day could well come when geoengineering was needed as part of a “portfolio” of responses to global warming. It urged further study for both methods, and, in particular, called for the establishment of a research program to examine the possible risks of solar radiation management.
Wagner and Weitzman do not deny the potential risks; indeed, they write quite cautiously about geoengineering. Wagner told me that it should be thought of as a last resort – something the world could turn to if it had to. He described it as a kind of “chemotherapy for the planet” – something you hope you don’t have to use, but you are ready to use if the need arises. And that requires doing research now to prepare for the future.
David Keith, a scientist who is perhaps the foremost proponent of geoengineering, told me that he believes that solar radiation management should be used even if decent carbon policies became law.
“It has substantial benefits,” he said. “That would be true whether we were cutting emissions or not.”
But he also acknowledged that more research is needed.
“If you put sulfur into the atmosphere, will there be a risk of ozone loss?” he said, as an example of the kind of risk that needed to be studied.
There is another kind of risk, of course: the risk that if people thought a technological solution were available to “solve” climate change, it would make it even less likely that they would collectively agree to do what is needed to be done to reduce carbon emissions. It is yet another reason that many environmentalists object to geoengineering.
Still, if disaster is truly approaching, wouldn’t you rather be safe than sorry?