Huge amount of methane could possibly be present beneath the Antarctic ice sheet, a new study suggests.

Methane is one of the greenhouse gases (25 times more potent than carbon dioxide) which cause a significant increase in the global temperatures when released in the atmosphere.

A team of international researchers led by Professor Jemma Wadham from the University of Bristol's School of Geographical Sciences studied the Antarctic ice sheets and suggested that the ancient deposits of organic matter stored beneath the ice sheet might have converted into methane by microorganisms such as microbes.

Microbes produce methane as a byproduct for metabolism when they are in oxygen-deprived conditions.

According to the researchers, an estimate of 50 percent of west Antarctic ice sheet and 25 percent of the east Antarctic ice sheet are lying over sedimentary basins that contains around 21,000 billion tons of organic carbon. "This is an immense amount of organic carbon, more than ten times the size of carbon stocks in northern permafrost regions. Our laboratory experiments tell us that these sub-ice environments are also biologically active, meaning that this organic carbon is probably being metabolised to carbon dioxide and methane gas by microbes," Wadham said in a statement.

Experts warned that the release of methane in case of ice sheet collapse might cause worst impact on the climate change. Using a hydrate model, the experts created a numerical simulation of the amount of methane present below the ice sheet. They found that the conditions favor the formation of a frozen latticelike substance known as methane hydrate.

Based on their calculation, researchers estimated the presence of about 400 billion tons of methane hydrate and methane gas below the Antarctic ice sheet.

"It's not surprising that you might expect to find significant amounts of methane hydrate trapped beneath the ice sheet. Just like in sub-seafloor sediments, it is cold and pressures are high which are important conditions for methane hydrate formation are," Dr Sandra Arndt, a NERC fellow at the University of Bristol and who calculated the numeric modeling, said in a statement.

The findings of the study are published in the Aug. 29 issue of the journal Nature.