Greenhouse gas beneath the ice

A VAST reservoir of the potent greenhouse gas methane may be locked beneath the Antarctic ice sheet, a US study suggests.

Scientists say the gas could be released into the atmosphere if enough of the ice melts away, adding to global warming.

Research indicates that ancient deposits of organic matter may have been converted to methane by microbes living in low-oxygen conditions. The organic material dates from a period 35 million years ago when the Antarctic was much warmer and teeming with life.

Frozen and free methane gas beneath the ice sheets could amount to four billion tonnes, the researchers estimate.

Disappearing ice could free enough of the gas to have an impact on future global climate change, scientists believe.