There are any number of crazy, last ditch efforts that scientists have proposed to counteract climate change, if simply reducing our carbon doesn’t pan out (outlook currently not so good). But spraying aerosols into the atmosphere, one of the more commonly suggested geoengineering schemes, may actually work.
Researchers studying the phenomenon found that a 2% reduction in the amount of the sun’s light hitting Earth would offset a doubling of atmospheric concentrations of carbon dioxide from historical levels. That reduction could be achieved by spewing tiny airborne particles that scatter light–aerosols–into the atmosphere, similar to what happens during a massive volcanic eruption. It would also wipe out blue skies as we know them, making the sky three to five times brighter, as well as whiter. Imagine the urban haze in many cities: that would be the sky everywhere.
“These results give people one more thing to consider before deciding whether we really want to go down this road,” says the Carnegie Institution for Science’s Ben Kravitz, a lead author of the study (published in Geophysical Research Letters ) in a statement. “Although our study did not address the potential psychological impact of these changes to the sky, they are important to consider as well.”
Whether this is a good idea is another matter. Scientists say preventing the problem is the first line of defense. But those hopes are dimming as GHG emissions soar past 400 parts per million, while a safe threshold may be as low as 350 PPM (PDF).
“This is one study where I am not eager to have our predictions proven right by a global stratospheric aerosol layer in the real world,” says Kravitz.