Alam: Perbedaan antara revisi

Kehidupan telah mengubah keadaan [[atmosfer]] Bumi,<ref>{{cite web|date=2005-09-11|url=http://www.sciencedaily.com/releases/2005/09/050911103921.htm|title=Calculations favor reducing atmosphere for early Earth|publisher=Science Daily|accessdate=2007-01-06}}</ref> yang menciptakan keseimbangan ekologi yang menstabilkan kondisi permukaan. Meskipun ada variasi iklim regional akibat posisi lintang dan faktor geografis lainnya, iklim global jangka panjang rata-rata cukup stabil selama periode interglasial,<ref>{{cite web|url=http://www.epa.gov/climatechange/science/pastcc.html|title=Past Climate Change|publisher=U.S. Environmental Protection Agency|accessdate=2007-01-07}}</ref> dan variasi satu atau dua derajat dari suhu global rata-rata secara historis memiliki efek besar pada keseimbangan ekologis, dan pada kondisi aktual geografi Bumi.<ref>{{cite web|author=Hugh Anderson, Bernard Walter|date=March 28, 1997|url=http://vathena.arc.nasa.gov/curric/land/global/climchng.html|title=History of Climate Change|publisher=NASA|accessdate=2007-01-07|archiveurl=https://web.archive.org/web/20080123130745/http://vathena.arc.nasa.gov/curric/land/global/climchng.html|archivedate=2008-01-23|dead-url=yes}} {{Webarchive|url=https://web.archive.org/web/20080123130745/http://vathena.arc.nasa.gov/curric/land/global/climchng.html |date=2008-01-23 }}</ref><ref>{{cite web|last=Weart|first=Spencer|month=June|year=2006|url=http://www.aip.org/history/climate/|title=The Discovery of Global Warming|publisher=American Institute of Physics|accessdate=2007-01-07|archive-date=2011-08-04|archive-url=https://web.archive.org/web/20110804232058/http://www.aip.org/history/climate/|dead-url=yes}}</ref>