Vast methane plumes spotted bubbling up from the Arctic Ocean floor

       

Methane bubbles rise up through the waters of the Arctic Ocean, in this photograph from the SWERUS-C3 program. Credit: Pete Hill

   

   Thursday, July 31, 2014, 1:01 -    An international team of scientists, who are studying the vast deposits of methane trapped on the floor of the Arctic Ocean, have captured their first look at plumes of this powerful greenhouse gas bubbling up through water. This discovery could lead to better forecasting, but it also has serious implications for Earth's climate in the years to come.    

Much of the science of global warming has been focused on the study of carbon dioxide (CO₂) as the main culprit in the current trend of rising global temperatures and resulting climate disruption we're seeing today. This is only appropriate, since CO₂ is, by far, the largest contributor to the problem - at least by total amount of gas that's added to the atmosphere on a yearly basis. However, methane (chemical formula CH₄) is another greenhouse gas that's been 'on the radar' for climate scientists, because it is much better than carbon dioxide at trapping heat in our atmosphere. Over a 20 year span of time, kg for kg, methane traps over 85 times more heat than carbon dioxide. Over a 100 year period, that ratio drops, but even averaged over that long methane is still over 20 times more potent a greenhouse gas than CO₂. Methane is only a small contributor to the overall climate change we're seeing now, but there are fears that this could change in the years to come.

Credit: Pete Hill, SWERUS-C3

Although there are natural sources of methane in the atmosphere, according to the US EPA, over 60 per cent comes from human activities - industry, agriculture and garbage. Scientists have also discovered large deposits of methane in the Arctic, where it has been locked away in a slushy frozen form on the sea floor called methane hydrates, which has also been called 'fire ice' due to the fact that it readily burns, even in its frozen form. These hydrates are kept frozen by the extreme low temperature and crushing pressure at the bottom of the ocean, but with our oceans accumulating more heat all the time now, these hydrates could 'melt' and release the methane in gas form. If that were to happen, all that methane bubbling up to the ocean surface and into the atmosphere would likely result in the accelerated rate of climate change we're seeing now turning into catastrophic abrupt climate change.

Since these methane hydrate deposits were discovered, scientists have been doing what they can to monitor and study them, and now a team from SWERUS-C3 - the Swedish–Russian–US Arctic Ocean Investigation of Climate-Cryosphere-Carbon Interactions program - have actually spotted methane bubbling up through the water, while measuring a concentration of methane dissolved in the water that's 10-50 times higher than background levels.

”This was somewhat of a surprise,” SWERUS-C3 chief scientist Örjan Gustafsson, from Stockholm University, wrote in his blog. “While there has been much speculation about the vulnerability of regular marine hydrates along the continental slopes of the Arctic rim, very few actual observations of methane releases due to collapsing marine hydrates on the Arctic slope have been made."

The short, 3-second video below actually shows the bubbles they caught rising through the water:

According to Gustafsson, scientists have noted that the 'end' of the Gulf Stream in the Atlantic Ocean, which is a relatively warm 'tongue' of water that flows past northern Europe and through the Arctic Ocean towards East Siberia, may have been warming up in recent years. "ur SWERUS-C3 program is hypothesizing that this heating may lead to destabilization of upper portion of the slope methane hydrates," he wrote. "This may be what we now for the first time are observing."

Does this mean that the disaster scenario is now developing? Unfortunately, at the moment, that's an unknown. The SWERUS-C3 team will be continuing to monitor the location as long as the weather holds out for their expedition. However, as the Stockholm University press release stated: "These early glimpses of what may be in store for a warming Arctic Ocean could help scientists project the future releases of the strong greenhouse gas methane from the Arctic Ocean."