Cause Behind Methane Gas Flares Revealed: Global Warming Not to Blame

Off the coast of Svalbard several hundred meters below the surface of the ocean, methane gas flares plume outward from gas hydrate deposits. Now, scientists have taken a closer look at these flares and have found that this outgassing is most likely caused by natural processes and cannot be attributed to global warming.

Methane hydrates are fragile.  At the sea floor, this ice-like solid fuel composed of water and methane is only stable at high pressure and low temperatures. In some areas, in fact, scientists have detected gas flares regularly. The reasons for their occurrence were unclear, but some scientists believed that global warming could be to blame. Yet now, it turns out that this is probably not the case.

"In 2008, when we observed the outgassing of methane for the first time, we were alarmed," said Christian Berndt, one of the researchers, in a news release. "The gas originates from depths where the hydrates should normally be stable. But we knew that a relatively small warming might melt the hydrates."

In order to find out the reason for this outgassing, the scientists examined the area over several expeditions. Using the German research submersible JAGO, the researchers were able to get a close look at the methane hydrates.

"On one hand, we have found that the seasonal variations in temperature in this region are sufficient to push the stability zone of gas hydrates more than a kilometer up and down the slope," said Berndt in a news release.

That's not all they found, though. The researchers also discovered carbonate structures in the vicinity of methane seeps at the seafloor. These were clear indicators that outgassing likely takes place over long periods of time--presumably for several thousand years.

The findings reveal that the causes behind this outgassing are natural. That said, it doesn't mean that this process won't be affected by global warming. Over long periods of time, the deep ocean will also warm up and polar regions will be affected.

"As a powerful greenhouse gas, methane represents a particular risk for our climate," said Berndt in a news release. "A release of large amounts of the gas would further accelerate global warming. Therefore, it is necessary to continue long-term monitoring, particularly in such critical regions as off Svalbard."

The findings are published in the journal Science.