Clear skies? Not for long, according to research from the University of California, Riverside. The future, say scientists, is hazy.
In the new study, published in Nature Climate Change, researchers used computer models of the Earth’s atmosphere to fast-forward changes in air quality over the next century. They found that climate change caused by greenhouse gases (GHGs) increases the concentration of atmospheric ‘aerosols’ - air-based mists, including natural aerosols like fog and human-made air pollutants like sulfates. The result? A lot of haze.
“Our work on the models shows that nearly all aerosol species will increase under GHG-induced climate change," said Robert J. Allen, first author on the paper and assistant professor in the Department of Earth Sciences at Riverside. "The surprising finding is the consistency of the increase in aerosols over all the different models.”
While some previous studies have suggested climate change might decrease the concentration of aerosols by increasing the volume of rain, the state-of-the-art models used here showed the opposite effect. According to Allen, it’s not just about how much rain you get, it’s where that rain occurs and how often it falls.
"The models show that GHG warming will lead to more global-mean precipitation, which should reduce aerosol burden because the aerosols are rained out,” said Allen. “However, GHG warming will also lead to a decrease in precipitation in certain regions, as well as a global mean decrease in the frequency of precipitation. These latter two changes, which would be expected to increase the burden of atmospheric aerosols, outweigh the former change."
Projected consequences include poorer air quality and a shift in how much of the sun’s energy reaches the surface of the Earth over the next few decades.
“Stricter reductions in aerosol emissions will be necessary for attaining a desired level of air quality through the 21st century,” said Allen.
Better enjoy those blue skies while you can.