Climate change could trigger more volcanic eruptions, warns scientist

By RTCC Staff

Volcanic eruptions, earthquakes and tsunamis could all be consequences of worsening climate change, a scientist has warned.

McGuire warned of possible impacts of the Greenland Ice Cap melting (source: dsearls/creative commons)

Speaking as part of the Guardian Science Weekly podcast, Bill McGuire, Volcanologist and author of the book ‘Waking the Giant’ explained how past periods of melting ice caps and rising sea levels triggered intensified geological events.

“If we look back over the last 20 thousand years or so we go from a period of full ice age conditions – with great ice sheets covering much of the northern hemisphere down to the situation we have today where we have virtually no ice up there,” he said.

“We can see from looking at that period, when the ice sheets melted and the ocean basins filled with water you had this response in the Earth’s crust…So you had more volcanic eruptions, more earthquakes, sub-marine landslides, all these sorts of things.”

This is caused by the Earth’s crust bouncing and bending in response to the melting of the great ice sheets and the filling of the ocean basins. As ice sheets melted, the Earth below bounced back, while sea basins bended to take the additional water.

For example, in Scandinavia – Norway and Sweden, the earth’s crust bounced back by as much as 300 metres when the ice caps covering the countries melted, causing up to magnitude 8 earthquakes in Lapland, according to McGuire.

Could similar effects be seen today?

“We have seen this happen in the past and the way things are going at the moment with our emissions and the in action on them we can see something like this happening in the future,” explained McGuire.

“There isn’t 3km of ice over northern Canada or over Scandinavia but there is 3km of ice over Greenland and over West Antarctica. The ice is still there and although sea level isn’t going to go up 120 metres, the rate of sea level rise in some of the scenarios is at least comparable to the rate of sea level rise then, so we do have the opportunity to see these effects happening.”

McGuire pointed out that while these changes would not cause geological events to take place that would not have happened anyway at some point in the future, he did warn that these events could become more concentrated with climate change.

Following the agreement made at the UN Climate Conference in Durban last December, McGuire warns that he is very pessimistic about the future.

“I don’t see how we can avoid a two degree temperature rise, which equates to dangerous climate change,” he said. “I can’t see anyway to avoid that now and there are a number of models which say 4°C by 2060-270… [That] means at high latitudes 15°C.

“The Greenland ice sheet is not going to withstand sustained temperature 15°C higher than they are now.”

McGuire’s book, ‘Waking the Giant’ which examines this issue further is currently available in the US, and will be available in the UK from March.

Read more on: Nature |