London, Sep 2 (): Antarctic researchers have found large volumes of methane locked beneath Antarctic ice sheet that could have been produced over millions of years. Researchers estimated the potent greenhouse gas hidden to be as much as 400 billion metric tons.
It states this methane could be released into the atmosphere as ice melts, contributing to global warming. The researches in the survey state that ancient deposits of organic matter may have been converted to methane by microbes living in low-oxygen conditions.
Plants flourished on Antarctica before the continent was covered by ice some 35 million years ago when the Antarctica was much warmer than it is today and teeming with life. These carbon-rich sediments containing up to 4 billion metric tons of methane in the form of methane hydrates is estimated under the ice sheet. These are ice-like substances formed when methane and water combine.
As temperatures increase, the hydrate breaks down and methane is released from the sea bed, mostly dissolving into the seawater. But, if stuck methane under the ice broke sea surfaces and escaped into the atmosphere, it would intensify global warming.
Scientists have already found thousands of sites in the Arctic where methane is bubbling into the atmosphere, but the potential for methane formation under the Antarctic Ice Sheet has been less well-studied.
The experts estimated that 0.5 megatonnes of methane are released per year and at least 1,400 gigatonnes of carbon is trapped as methane and methane hydrates under the Arctic permafrost.
International team study leader Jemima Wadham, from Bristol University, said: “This is an immense amount of organic carbon, more than ten times the size of carbon stocks in northern permafrost regions.”
The amount of methane in the atmosphere rose 0.28 percent to 1,808 parts per billion in 2010, the highest since records began, the UN said in November.
Methane is a powerful greenhouse gas amounting around 14 per cent of the global warming effect of current man-made greenhouse gas emissions.