The Vienna Convention for the Protection of the Ozone Layer safeguards human health and the environment.

UN: Secretary-General

Venezuelan environmentalist Erik Quiroga believes the storms could help repair the damaged ozone layer and is campaigning for the entire ecosystem that produces the storms to be recognized as a Unesco World Heritage site.

BBC: In Venezuela, nature��s most electrifying lightning show

This is because it takes years for the compounds to reach the ozone layer's home in the stratosphere, 15-50 kilometres (10-30 miles) above the earth.

ECONOMIST: Phew, the ozone layer may be saved

One reason for rejecting sulphate hazing out of hand might be the damage it could do to the ozone layer.

ECONOMIST: Geoengineering