Asteroid would impact ozone layer

A large asteroid smashing into the Pacific ocean would devastate the ozone layer for years afterwards, report planetary scientists.

The simulations find by experts:

Ocean impacts of 0.6-mile-wide asteroids "can produce a significant, global perturbation of upper atmospheric chemistry."

"Ozone depletion comparable to Antarctic ozone hole records observed in the mid-1980 s and 1990 s, occur worldwide" after such an impact, lasting several years. 

Ozone depletion would cause ultraviolet light levels that can be dangerous for living organisms. "In the Tropics, and in mid-latitude summers immediately after the impact, (ultraviolet levels would ) greatly exceed the highest levels currently experienced anywhere on Earth."

  An ocean impact of a 0.62-mile wide asteroid "would have a long-lasting negative impact on global food production, which, in turn, may affect the sustainability of the current human population."

Effects of a smaller 0.3-mile-wide asteroid would have less far-reaching effects, limited to the hemisphere of the impact and with less duration.