Scientists have identified thousands of sites in the Arctic where methane that has been stored for many millennia is bubbling into the atmosphere.
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/arctic-melt-releasing-ancient-methane
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/bbc-uk
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/climate-change
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/methane
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/arctic
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/glacial-melt
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/green-house-gases
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/carbon-dioxide
[9] http://admin.indiaenvironmentportal.org.in/category/thesaurus/landfill
[10] http://admin.indiaenvironmentportal.org.in/category/thesaurus/waste-disposal
[11] http://admin.indiaenvironmentportal.org.in/category/thesaurus/global-warming