As the world warms, methane trapped underneath the frozen tundra could be released, increasing the rate of warming in a vicious circle
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/thawing-permafrost-poses-even-greater-global-warming-threat-previously-thought-suggests-study
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/independent-united-kingdom
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/climate-change
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/global-warming
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/methane
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/green-house-gases