Methane levels up -but why?

There is a useful information article on the Carbon Commentary web site on rising methane levels.

Methane is a potent greenhouse gas and recent research has shown that it is rising in concentration in the atmosphere.

Research from Royal Holloway College indicated that methane levels were higher over the Arctic leading to the hypothesis that the rising levels were being caused by rotting biological matter in the tundra arising from melting ice.

However more recent work from MIT has shown that methane levels have rising across the globe and not just in the Arctic.

This is important because methane plays a key role in the climate change models and at the moment we don't know exactly why concentrations are increasing. Lets hope its not the start of the positive feedback loop - rising temperatures melt the tundra which releases methane and the eruption of methane from the deep oceans (the clathrate gun hypothesis)

For more details see here. Methane graph copyright of the NOAA