Volcanic eruptions once caused mass extinctions in the oceans – could climate change do the same?
Posted by admin on 13th November 2018

All animals, whether they live on land or in the water, require oxygen to breathe. But today the world’s oceans are losing oxygen, due to a combination of rising temperatures and changing ocean currents. Both factors are driven by human-induced climate change.

This process has the potential to disrupt marine food chains. We already know that large hypoxic, or low-oxygen, zones can be deadly. If hypoxia expands in both size and duration, it is possible to cause widespread extinction of marine life, which has happened previously in Earth’s history.

We investigate natural, ancient changes in ocean oxygenation and the biological effects as a way of understanding the natural response to potential future climate scenarios. In a recent study, we examined links between a major volcanic event that occurred millions of years ago and changes in ocean oxygen levels. Like human activities today, this event released massive amounts of carbon dioxide and other greenhouse gases into the atmosphere.

We found that this episode appeared to trigger significant oxygen losses in the world’s ocean that lasted over one million years. Our research adds to growing evidence that marine oxygen contents are dramatically affected by warming temperatures and other climate-related feedbacks caused by the release of greenhouse gases.