One of the layers of atmosphere that protects all life on our planet is the width of two pennies, and hangs out six to ten miles above the Earth’s in an environment that human activity made extremely hostile. Every year when winter ends and warmer weather returns to Antarctica, chemicals that we put into the air rip a hole in the layer. But this year, that hole is smaller than usual.
This week, NASA and NOAA announced that 2017’s ozone hole, at 7.6 million square miles, was the smallest since 1988.
Ozone is a molecule made of three oxygen atoms bonded together. On the ground, it can form harmful smog. But above the Earth, it acts like sunscreen, protecting life from harmful solar radiation. When elements like chlorine and bromine undergo a particular chemical reaction in clouds, ozone takes a beating.
This year it was warmer than usual in Antarctica’s lower stratosphere, with …