Take a look at the clouds, if there are any in your sky right now. If not, here are a few examples. Watch the billows, the white lofty tufts set against the blue sky. Or, depending on your weather, watch the soft grey edges smear together into blended tones that drag down through the air […]

In 1870, explorer Adolf Erik Nordenskiöld, trekking across the barren and remote ice cap of Greenland, saw something most people wouldn’t expect in such an empty, inhospitable landscape: haze. Nordenskiöld’s record of the haze was among the first evidence that air pollution around the northern hemisphere can travel toward the pole and degrade air quality […]