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No, Volcanoes Are Not the Primary Cause For the Melting Ice Caps

To the possible disappointment of climate change skeptics, warming seas — and not volcanoes — are still the main cause of melting glaciers.
Image via NASA

Climate change skeptics are using a new study about geothermal heating under the world’s ice caps to claim that volcanoes are the real cause of glacial melting, not global warming.

The study was conducted by researchers at the Institute for Geophysics at the University of Texas at Austin (UTIG) and published in the Proceedings of the National Academy of Sciences. It analyzes geothermal heat below the glaciers in West Antarctica and acknowledges that these sources — which include magma movement and volcanic activity — do contribute to some ice cap melting.


Yet, according to the researchers behind the study and other experts in the field, these findings do not actually provide new insight into why the ice is melting.

“It is true that there are active volcanoes in West Antarctica, and so there may have been some local changes, but in most cases, at most times, volcanoes are not erupting under the ice,” Richard Alley, a geologist at Penn State, told VICE News. “This paper is exciting for modelers and geologists who focus on Antarctica, but it doesn’t tell you anything about why the ice is now thinning.”

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Instead, UTIG's research provides more detailed mapping areas of the geothermal heat sources under the Thwaites Glacier, which is one of the most vulnerable parts of the rapidly deteriorating West Antarctic Ice Sheet. Using radar detection, the researchers also pinpointed heating levels at a value of two to three times higher than previously thought and which has been used in previous studies.

With this new data, scientists will be able to plug in more accurate heating values into their calculations while studying the collapse of glaciers in the region.

'People have to be careful when drawing hasty conclusions into how much volcanoes can affect glacial melting.'

Dusty Schroeder, the lead author on the UTIG study, told VICE News that this information gives important insight into how hot the earth is underneath the glaciers and thus how it contributes to certain changes.


“Especially in terms of trying to predict the rate of rising sea levels, this is a factor you need to take into account,” Schroeder said.

While this form of geothermal heating does contribute to glacial melting, it does not necessarily mean "climate alarmism has suffered yet another devastating setback."

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“People have to be careful when drawing hasty conclusions into how much volcanoes can affect glacial melting,” Eric Rignot, an earth science professor at University of California Irvine and a principal scientist at NASA, told VICE News.

Rignot, also the lead author of a study out last month that documented widespread retreat of the West Antarctic Ice Sheet, said geothermal heating contributes to a few millimeters of melting annually, compared to rising sea temperatures which can trigger rates of up to 100 meters each year.

'Geothermal heating is not enough by itself to have caused the observed changes.'

“The studies can be confusing individually, you have to put it in a larger perspective by looking at all the studies together,” Rignot said.

According to Schroeder, Rignot’s paper, and another that came out in May, show that warm oceans are currently the main cause of glacier loss at the edge of the ice.

“The fastest glacial changes are happening where the ocean is warmer,” Schroeder said. “Geothermal heating is not enough by itself to have caused the observed changes.”

In response to those who are using his study to deny climate change, Schroeder confirmed that volcanic activity is not the dominant force of ice loss and rising sea levels.

“If you want to understand how the glaciers are changing, you can’t just look at the ice, you can’t just look at the climate system, you can’t just look at the geology, you have to look at the whole picture,” he said.

Follow Kayla Ruble on Twitter: @RubleKB

Image via Flickr