An \"economic time bomb\" of methane emissions caused by shrinking sea ice in the arctic could come with a global price tag of $60 trillion, scientists say. That figure is equal to the size of the total world economy in 2012, they said. An analysis of the likely cost of methane emissions in the region by British and Dutch researchers suggests a significant release of methane from thawing permafrost in the arctic could have dire implications for the world\'s economy, Britain\'s Cambridge University reported Wednesday. A release of even a fraction of the vast reservoirs of methane in the arctic could trigger potentially catastrophic climate change, they said. \"The imminent disappearance of the summer sea ice in the arctic will have enormous implications for both the acceleration of climate change and the release of methane from offshore waters, which are now able to warm up in the summer,\" Cambridge scientist Peter Wadhams said. \"This massive methane boost will have major implications for global economies and societies.\" The researchers calculated the global consequences of the release of 50 gigatons of methane over a decade from thawing permafrost beneath the East Siberian Sea. \"The methane release would bring forward the date at which the global mean temperature rise exceeds 2 degrees C (3.5 degrees F) by between 15 and 35 years,\" Cambridge\'s Chris Hope said. \"The global impact of a warming arctic is an economic time bomb,\" said Gail Whiteman, a professor of sustainability, management and climate change at the Rotterdam School of Management.