Aerosol pollution can raise fresh groundwater supply

Nature : Over the past century, particles such as sulfates emitted by power plants, factories, and agriculture have been clogging the air and reducing the amount of sunlight reaching the ground. According to a recent study published in Nature Geoscience, researchers have found that as less sunlight reaches the ground, less evaporation occurs and more water ends up in rivers. To verify that air pollution really influences land hydrology, the researchers ruled out several other factors that can affect river flow, such as global climate change, atmospheric carbon dioxide, and local vegetation. They estimate that by 1980, aerosol concentrations in the atmosphere “led to an increase in river runoff by up to 25% in the most heavily polluted regions in Europe.” Nevertheless, Earth’s water cycle is complex. Other scientists have pointed out that if the air becomes too polluted, as has happened after major volcanic eruptions, it could also affect rainfall and leave rivers drier than ever.