Hacking the Climate

The idea of geoengineering — tampering with the Earth’s climate to fit our needs — has been a favorite trope of science fiction since the 1920s. In the 1970s, Carl Sagan speculated that we could terraform Mars to make it into a second Earth. That inspired novelist Kim Stanley Robinson to write his Mars trilogy — Red Mars, Green Mars, and Blue Mars — in which he imagines how that scenario would play out. Robinson relied on actual science — and there’s plenty on this subject.

As the dangers of climate change become imminently clear, some scientists believe that geoengineering’s time has come — not on Mars, but on Earth. Yale professor and atmospheric scientist Trude Storelvmo studies cirrus clouds, which tend to trap heat in the atmosphere. She analyzes what would happen if the clouds were seeded with ice crystals that would thin them. “If you don’t put enough of these seeding particles into the upper atmosphere, you would get no effect at all,” Storelvmo says. “But if you put too much, you could actually have the opposite effect, which would obviously be disastrous.”

Another plan, dating back to the early 1980s, proposes cooling the climate by spreading sulfur dioxide particles into the upper atmosphere. “You can think of them as tiny mirrors that would reflect sunlight back to space,” Storelvmo explains, mimicking the effects of major volcanic eruptions. That plan is particularly controversial because the particles are much longer-lasting, and their effects harder to predict.  And some view it as a band-aid that would not limit carbon emissions and the resulting acidification of the oceans. 

Storelvmo says we shouldn’t think of her colleagues as “a group of mad scientists that want to play God.” They’re cautious in their analysis and they don’t make policy recommendations. But she admits simply studying what’s possible could have real-world effects. “Individual states can simply go ahead and implement geoengineering, particularly if they feel like they are suffering more than the rest of the globe,” she says. “Even wealthy individuals, they could simply decide that they wanted to do something about global warming.” 

Video: Engineering the Atmosphere