Clearer skies have brought more rain

2019-04-03 13:03:11

(Image: Malene Thyssen/Wikimedia Commons) FETCH the umbrella – global warming and cleaner skies are making it rain more. Martin Wild of the Swiss Federal Institute of Technology in Zurich and his colleagues analysed global measurements of solar radiation and rainfall taken between 1986 and 2000. On average, surface solar radiation has increased by 0.21 watts per square metre per year over land, and rainfall has increased by 3.5 millimetres per year (Geophysical Research Letters, DOI: 10.1029/2008GL034842). In recent decades, air pollution has dropped, so more sunlight is penetrating the atmosphere, says Wild. Meanwhile,