Over the last month, parts of Europe were hit by intense dust storms. First, a massive dust plume that originated in northeast Algeria caused reddish skies in large parts of Europe. Then, dust deposits tinted the snow-covered Pyrenees and the Alps brown. In late February, a Saharan dust outbreak severely affected the Canary Islands before heading toward continental Europe, reaching as far north as Scandinavia. While such intense and persistent dust activity is unusual, it’s not uncommon for Europe to experience a few large dust outbreaks every year. Why is dust a problem? Desert dust is produced by wind erosion of arid and semi-arid surfaces. It affects weather, climate and atmospheric chemistry, delivers iron and phosphorus to land and ocean ecosystems, and increases photosynthesis and biological productivity.