Climate change: a warning from the past

It is not generally realized that, through rising atmospheric CO2 levels since ~8000 years ago due to fires and deforestation, and rising methane since ~5000 years due to rice cultivation and animal husbandry, civilization has subconsciously postponed climate cooling toward the next ice age by near-2.7 degrees Celsius [7]. Judicious science-based injection of greenhouse gases into the atmosphere would have been able to prolong interglacial Holocene conditions, justifying the term “Homo sapiens”.

Instead, since the mid 18^th century, uncontrolled release of fossil carbon from hundreds of million years-old fossil biospheres at <2 ppm/year, a rate unprecedented in geologic history (barring major volcanism and asteroid impacts), is pushing mean global temperatures toward climate conditions of millions of years ago when tropical conditions dominated much of the Earth and large parts of the continents were covered by seas.

[1] http://www.columbia.edu/~jeh1/2008/TargetCO2_20080407.pdf

[2] http://www.columbia.edu/~jeh1/mailings/2011/20110118_MilankovicPaper.pdf; http://climateprogress.org/2011/01/20/hansen-sato-climate-tipping-point-multi-meter-sea-level-rise/

[3] Lenton et al. 2008.

http://researchpages.net/esmg/people/tim-lenton/tipping-points/

[4] Dakos et al.,2008. http://www.pnas.org/content/105/38/14308

[5] http://eis.bris.ac.uk/~glyms/Siddalletalbook2005.pdf

[6] http://www.agu.org/journals/ABS/2009/2009GL040222.shtml

[7]http://www.ingentaconnect.com/content/klu/clim/2003/00000061/00000003/05145667 , http://www.springerlink.com/content/p80k8m717qm01710/

[8] http://www.ipcc.ch/publications_and_data/publications_and_data_reports.shtml

[9] http://www.sciencemag.org/content/326/5958/1394.abstract