According to the IPCC, the global average surface temperature increase from 1850-1899 to 2001-2005 is 0.76
Links:
[1] http://admin.indiaenvironmentportal.org.in/reports-documents/retreat-tibetan-plateau-glaciers-caused-global-warming-threatens-water-supply-and
[2] http://admin.indiaenvironmentportal.org.in/category/publisher/institute-governance-sustainable-development
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/global-warming
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/carbon-dioxide
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/glaciers
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/green-house-gases
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/water-supply
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/food-security
[9] http://admin.indiaenvironmentportal.org.in/category/thesaurus/climate-change