Large volumes of the greenhouse gas methane could have been produced under the Antarctic Ice Sheet over millions of years, which could add to global warming if released into the atmosphere by a thaw, a study said. Scientists from the universities of Bristol, Utrecht, California and Alberta simulated the accumulation of methane in Antarctic sedimentary basins using models and calculations. They found it was likely there were micro-organisms there that would have been able to convert the ice sheet’s large deposits of organic carbon into the potent gas.

If present, methane would most likely be trapped under the ice.m But it could be released into the atmosphere as rising global temperatures melt the ice sheet, fuelling even more global warming, the scientists said in the paper published in the journal Nature.