Global warming may have started far earlier than anyone has so far imagined.
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/humans-sparked-warming-nearly-200-years-ago
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/eco-business
[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/scientists
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/carbon-dioxide
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/green-house-gases