A long climate record reveals abrupt hydrological variations during past interglacials in southwestern North America. These data set a natural benchmark for detecting human effects on regional climates.
Links:
[1] http://admin.indiaenvironmentportal.org.in/feature-article/old-droughts-new-mexico
[2] http://admin.indiaenvironmentportal.org.in/category/author/john-williams
[3] http://admin.indiaenvironmentportal.org.in/category/journal/nature
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/drought
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/mexico
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/climate-change
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/climate-science
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/hydrology
[9] http://admin.indiaenvironmentportal.org.in/category/thesaurus/n-c-america
[10] http://admin.indiaenvironmentportal.org.in/category/thesaurus/monsoons
[11] http://admin.indiaenvironmentportal.org.in/category/thesaurus/rainfall