The carbon dioxide generated underground by plants and microbes and released into the atmosphere
Links:
[1] http://admin.indiaenvironmentportal.org.in/feature-article/warm-response-soils
[2] http://admin.indiaenvironmentportal.org.in/category/author/pete-smith
[3] http://admin.indiaenvironmentportal.org.in/category/author/changming-fang
[4] http://admin.indiaenvironmentportal.org.in/category/journal/nature
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/soil-resources
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/carbon-dioxide
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/atmosphere
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/climate-change
[9] http://admin.indiaenvironmentportal.org.in/category/thesaurus/climate-science