Researchers at the University of Southampton have shown that an extinction event 360 million years ago, that killed much of the Earth’s plant and freshwater aquatic life, was caused by a brief breakdown of the ozone layer that shields the Earth from damaging ultraviolet (UV) radiation.
Only one was caused by an asteroid hitting the Earth, which was 66 million years ago when the dinosaurs became extinct.
The ozone collapse occurred as the climate rapidly warmed following an intense ice age and the researchers suggest that the Earth today could reach comparable temperatures, possibly triggering a similar event.
Credit: John Marshall.
The scientists concluded that, during a time of rapid global warming, the ozone layer collapsed for a short period, exposing life on Earth to harmful levels of UV radiation and triggering a mass extinction event on land and in shallow water at the Devonian-Carboniferous boundary.
Credit: John Marshall.
Lead researcher Professor John Marshall, of the University of Southampton’s School of Ocean and Earth Science, who is a National Geographic Explorer, comments: “Our ozone shield vanished for a short time in this ancient period, coinciding with a brief and quick warming of the Earth.
Camp site in East Greenland.
Credit: John Marshall.
Professor Marshall says his team’s findings have startling implications for life on Earth today: “Current estimates suggest we will reach similar global temperatures to those of 360 million years ago, with the possibility that a similar collapse of the ozone layer could occur again, exposing surface and shallow sea life to deadly radiation.
The remote locations visited in East Greenland are very difficult to access, with travel involving light aircraft capable of landing directly on the tundra.
May 25, 2020
May 25, 2020
May 25, 2020
May 25, 2020
May 25, 2020
May 25, 2020
May 24, 2020
UK
Australia
France
Germany
Russia
India
Canada