In a new study authored by scientists from Harvard and Yale, researchers claimed that the technique, also called “solar engineering” or “solar dimming,” would not only be effective, but relatively cheap compared to state or even national budgets: it would cost roghly $3.5 billion to develop the technology over 15 years, then $2.25 billion to carry out the aerosol spraying each year. Most of the costs aren’t associated with the key chemical involved, sulfur dioxide (which is relatively plentiful), but rather the aircraft used to fly the chemical high into the atmosphere.
based on the paper’s estimates, this kind of solar engineering could reduce global surface temperatures back to ‘normal’ levels, but it wouldn’t deal with some of the climate change effects already in progress, like ocean acidification, or the fact that humans would still be pumping greenhouse gases into the atmosphere. As helpful as the technology might be, the paper’s authors say it’s not a fix for climate change. “I do worry that some fossil fuel company will say exactly that, and the geoengineering community is going to have to figure out how to guard against that infiltration or any association in the public’s mind,” said Wake Smith, a co-author on the paper.
It also might have vast, unforeseen consequences for people around the world. According to Smith: “It may be that we can reduce global surface temperatures overall, relative to where they would be in an un-engineered world, but that doesn’t mean that the climate in every place will go back to the way it was…even a perfectly engineered climate future, which is impossible, will change things all over the world, and that won’t be good for people either.”
According to Kate Ricke, a professor at the University of California, solar engineering may not be the final answer to climate change, but it may be the stop-gap measure we’re looking for. “There’s a lot of scary climate-change impacts, like melting glaciers in Greenland and Antarctica, that are staring us in the face,” Ricke said. “Because [cutting emissions] and CO2 removal will take some time, even if we get serious about implementing them-which I’m not convinced about-I think that solar geoengineering has the potential to be one of the only options left.”