We don’t know exactly how climate change affects the frequency and intensity of hurricanes. But, from the historical data, we do know that the frequency and intensity of hurricanes is linked with higher ocean temperatures. If we could reduce the temperature of the water, therefore, there’s a chance we could reduce the number of Sandys and Katrinas we see in the coming years.
This is something entirely feasible to do, according to a radical geoengineering proposal published in the journal PNAS. By pumping millions of tons of sulfur dioxide 12 miles up into the atmosphere, we could significantly alter the Atlantic Ocean conditions that give rise to superstorms, says the analysis.
But there’s a catch, or three: We’d have to put out 10 billion tons of SO2 every year to make a serious impact. The stuff won’t stay in the sky but gradually fall to the ground as particulate pollution. And, worst of all, all that sulfur would exacerbate ozone depletion. We would have to keep increasing the sulfur dump to have the same temperate-dampening effect.
Scientists have long considered sulfur for geoengineering, or “hacking climate change.” The idea of using sulfur comes from major volcanic eruptions, like Mount Pinatubo’s in 1991, which blocked out the sun and caused significant drops in temperatures. Also, volcanic events seem to reduce the incidence of hurricanes, says the study:
The explosive volcanic eruptions of Katmai (Alaska, June 1912) and El Chichón (Mexico, April 1982) preferentially loaded the Northern Hemisphere with aerosol, and they were followed by the least active hurricane season on record in 1914 and the least active hurricane season in the satellite observation period in 1983 [HURDAT2 (25)]. These observations suggest that injecting stratospheric aerosols into the Northern Hemisphere may mitigate Atlantic hurricanes.
The paper models various scenarios for greenhouse gas buildup and sulfur use. For example, if we ramp up the sulfur to 10 billion tons a year by 2070, we could keep the incidence of hurricanes at the current level, but reduce their surge impact by as much as 50%. Which is obviously a big deal: For one thing, we wouldn’t have to build up New York’s flood protection barrier so much.
Still, the practicality and uncertain side effects of the intervention are probably too dangerous to contemplate seriously. Lead author John Moore told Popular Mechanics: “No one is really seriously looking at implementing this type of geoengineering project with sulfates.”
But that’s not to say the research isn’t useful. For example, it could lead scientists to come up with less toxic materials than sulfur that do a similar job. Also, the method could be worth considering in an emergency–say, if hurricanes increased to such frequency and intensity that we really had to do something, however drastic.
“We pretty much know we won’t use sulfate aerosols, but we shouldn’t dismiss the whole concept while it’s still in the [infancy] of research,” the researcher says.