10 Apr 2015

Ocean acidity caused extinction - scientist

10:27 pm on 10 April 2015

International research led by a New Zealand scientist shows soaring ocean acidity was a key factor in the greatest mass extinction of life on Earth.

Otago University researcher Matthew Clarkson co-ordinated a just-published international study which has found direct evidence in Middle Eastern rocks that ocean acidification triggered by massive volcanic eruptions helped cause the mass extinction 252 million years ago.

It wiped out more than 90 percent of marine species and more than two-thirds of land species.

Dr Clarkson said this was a worrying finding, considering that we were now seeing an increase in ocean acidity as a result of carbon emissions caused by human activity.

A high tide across Ejit Island in Majuro Atoll, Marshall Islands on March 3, 2014, causing widespread flooding. Officials in the Marshall Islands blamed climate change for severe flooding in the Pacific nation's capital Majuro.

Flooding caused by huge spring tides which Marshall Islands officials have blamed on climate change. Photo: AFP