Methane joins the fray

British and German scientists have discovered 250 plumes of methane gas rising from the thawing seabed off the Spitsbergen archipelago in the Norwegian Arctic, apparently a result of the warming of the West Spitsbergen current. The researchers measured the plumes rising from the seabed at a depth of 150 to 400 meters (500 to 1,300 feet).

The methane — a potent greenhouse gas — is being released by frozen methane hydrates on the sea floor, which are thawing as a result of a 1 degree C (1.8 F) warming of the West Spitsbergen current in the last 30 years, the scientists said.

The data was collected from the royal research ship RRS James Clark Ross, as part of the Natural Environment Research Council’s International Polar Year Initiative. The bubble plumes were detected using sonar and then sampled with a water-bottle sampling system over a range of depths.

Methane hydrate is an ice-like substance composed of water and methane which is stable in conditions of high pressure and low temperature. At present, methane hydrate is stable at water depths greater than 400 metres in the ocean off Spitsbergen. However, thirty years ago it was stable at water depths as shallow as 360 metres.

While most of the methane currently released from the seabed is dissolved in the seawater before it reaches the atmosphere, methane seeps are episodic and unpredictable and periods of more vigorous outflow of methane into the atmosphere are possible.

Furthermore, methane dissolved in the seawater contributes to ocean acididfication, which inhibits the ability of marine creatures to grow shells. Scientists fear that as the world’s oceans warm, huge amounts of methane will be released.

Graham Westbrook Professor of Geophysics at the University of Birmingham, warns: “If this process becomes widespread along Arctic continental margins, tens of megatonnes of methane per year – equivalent to 5-10% of the total amount released globally by natural sources, could be released into the ocean.”

On climate change, a recent report by the Global Humanitarian Forum found that human-induced climate change is already responsible for 300,000 deaths a year and is now affecting 300 million people around the world. (Global Humanitarian Forum, 2009) This report also projects that increasingly severe heat waves, floods, storms and forest fires will be responsible for as many as 500,000 deaths a year by 2030.

So, what do we do? Refuse to accept emission limits with all eyes unblinkered on 'growth'? Come on, let us know your views.