The world's decision to fix the ozone hole is paying off 30 years later

The ozone hole over the Antarctic has begun to heal, according to a new study, more than 30 years after its discovery. The findings suggest that global efforts to phase out ozone-depleting chemicals have been effective, though scientists still aren't entirely sure about what's driving the ozone hole's recovery.

The study, published in the journal Science, combines data gathered from balloons and satellites to measure the area of the ozone layer over Antarctica from 2000 to 2015. Since 2000, the paper reports, the size of the ozone hole over Antarctica shrank by about 4 million square miles — an area equivalent to about half of the contiguous United States. Using computer simulations to account for changes in wind and temperature, the...