Ozone-depleting gases from an eruption in a volcanically active region of Central America could thin Earth’s ozone layer for several years, scientists say. Current levels of the chemicals bromine and chlorine in the stratosphere – where ozone protects life on Earth from harmful ultraviolet radiation – could double or even triple with an eruption, German researchers said.

By studying chemicals in rock layers deposited before and after historic eruptions, the researchers determined the average eruption released two to three times the quantity of human-produced bromine and chlorine currently in the stratosphere.