Science Daily: A combination of extreme cold temperatures, human-made chemicals and a stagnant atmosphere were behind what became known as the Arctic ozone hole of 2011, a new NASA study finds.
Even when both poles of the planet undergo ozone losses during the winter, the Arctic's ozone depletion tends to be milder and shorter-lived than the Antarctic's. This is because the three key ingredients needed for ozone-destroying chemical reactions -- chlorine from human-made chlorofluorocarbons (CFCs), frigid temperatures...