Chemotherapy For The Planet: Geoengineering As A Solution Of Last Resort

Stanford scientist Ken Caldeira is busy working out models for a system to pump the atmosphere so full of sulfur that it cools the planet. It could have disastrous consequences—but would they be worse than total planetary destruction?

Interesting fact about geoengineering, the idea of large-scale climate intervention. It has a longer history than you might think. As far back as 1965, President Johnson’s scientific advisers were considering whitening the oceans to deflect sunlight back to the atmosphere. As Ken Caldeira, a Stanford climate scientist, told an audience at NYU: "The idea of geoengineering precedes the idea of emissions reductions."

Many people have since dismissed geoengineering as unworkable, unpredictable, or unnecessary. Or crazy. But that hasn’t stopped serious research into the topic over the last few years. Scientists have written papers modeling different methods, and convened conferences to discuss the effects. Caldeira has come up with what is widely thought to be the most feasible idea: the "Pinatubo Option."

Mount Pinatubo is a volcano in the Philippines that erupted in 1991, spreading 10 million tons of sulfur into the atmosphere. The impact on the local environment was horrific. But scientists later noticed that the acrid cloud deflected 2% of normal sunlight, and reduced worldwide temperatures by 0.5 degrees Celsius (0.9 degrees Fahrenheit). The thinking behind the "Pinatubo Option" is basically to re-enact this natural event: to put thousands of tons of particles into the atmosphere to deflect sunlight, and cool the Earth’s surface.

Caldeira says it would be possible to stop most of the global warming each year by releasing tens of kilograms a second into the air. The cost would be low, probably in the few millions of dollars. And the operation could be carried out by an airline-sized fleet of aircraft.

According to his models, it would be possible to offset 90% of the warming change from increased CO2 concentrations, and 70% of the precipitation change, even if emissions doubled. "The basic story is that climate models indicate that the deflection of sunlight will offset most climate change in most of the places, most of the time," Caldeira says.

Caldeira doesn’t actually endorse the Pinatubo Option, saying it is more like chemotherapy for a cancer patient than a painless cure. But he said it should be considered in an emergency, and that research should continue so that we’re ready if we need it.

The reasons not to mess with the atmospheric system are numerous. There would probably be lots of unforeseen consequences. There would likely be arguments between countries about when to employ the solution. Releasing large amounts of sulfur could further deplete the ozone, as happened with the 1991 eruption. And, it could be used as an excuse by emitters to carry on as usual.

Still, the advantage of geoengineering is that it gets round the "collective action" problem of other climate solutions, and it’s a lot less expensive than redesigning the whole energy system. It also potentially gets temperatures down faster than switching away from fossil fuels. Every model produced by the UN IPCC shows global temperatures rising—the question is just by how much.

The big unknown is whether the Pinatubo Option, or something like it, would work as the scientists say. Caldeira admits: "Where I am right now is that there is certain potential for risk reduction. But whether these things are going to reduce risks in the real world? I don’t think we really have any idea."

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  • Jim Fleming

    Nothing new here, and it dates way before President Johnson. 

    See Flixing the Sky: The Checkered History of Weather and Climate Control (2010, paper 2012).

    "The advantage of geoengineering is that it gets round the "collective action" problem..." The disadvantage is that it is unilateral planetary tinkering by Rube Goldberg or worse, Dr. Strangelove types.

  • Leon Tate

    "Climate models indicate that the deflection of sunlight will offset most climate change in most of the places, most of the time."  And that's the root of all "climate change" hoaxes.  In the 70's it was pollution - but that was too local nobody cared.  In the 80's we were worried about the hole in the ozone layer - but that kept closing and opening and closing and cycling naturally.  The the 90's it was global warming - except it was also cooling.  Now it's CLIMATE CHANGE.  Ahh - great term - now we don't have to worry about which direction the trend heads and EVERYONE gets affected too. Madison Avenue advertising meets bunk science is what this is.  The earth has experiences shifts in climate through its history - nothing new.  Temperatures are correlated to solar activity greater and more convincingly that it is to CO2 content or any other man-made effect.  Let's call a hoax a hoax and start following the money that motivates these goofy claims.

  • Andrew Redman

    Leon: Really? Do you seriously think it's ok to state "truths" without bothering to understand the science or even how things are named? "Hole in the ozone opening closing, opening closing - yadda, whatever - Nothing bad is going to happen because it's all fine today isn't it?... " 

    Of course there are variations and cycles - the climate is a vastly complex system. All the scientists can say for sure is it's warming up and the weather is becoming more extreme. The scary thing is we don't actually know what's going to happen. At one end of the scale it could be a simple blip caused by the sun's current cycle. At the other end of the scale we could reach a tipping point where the current finely balanced conditions we need to sustain life dramatically destabilises, wiping us out. There is evidence that this kind of thing has happened before. 

    In these circumstances it seems pretty logical to compare the worst case and costs either way. So if we do something about it "just in case, but it turns out to be a load of hot air (sic), then we might have wasted some money, although ended up with new clean energy technology that free'd us from dependence on oil (and the Middle East). Alternatively we could just ignore the evidence and hope it goes away, with the possibility this might leave us all dead.

    I know which option I'd bet on.

  • George

    Geo-engineering is a joke. This instead of reducing emissions? Its utter psychopathy. The act of Geo-engineering itself increases air emissions by having hundreds more airplanes flying around. More likely it's for military purposes or just to fuck everything up. Why aren't questions being asked for find out exactly why it's being done. Instead morons are going along with with what some dipshit said basically. Sites and other media outlets just want views and hits. Fuck you all. Do some real investigation.