19 Central America and the temporary colonization of southern Greenland

Scott Mandia, Suffolk University, "Vikings During the Medieval Warm Period," http://www2.sunysuffolk.edu/mandias/lia/vikings_during_mwp.html; Brian f.a.gan, The Long Summer: How Climate Changed Civilization (New York: Basic Books, 2004), p. 236.

20 paddled their kayaks to Scotland; farther south, millions died

Scott Mandia, Suffolk University, "The Little Ice Age in Europe," http://www2.sunysuffolk.edu/mandias/lia/little_ice_age.html.

21 a chain of events leading to the Black Death

Lei Xu et al., "Nonlinear Effect of Climate on Plague During the Third Pandemic in China," Proceedings of the National Academy of Sciences, May 4, 2011.

22 unusually large eruption of the Tambora volcano

"Volcanic Eruption, Tambora," Encyclopedia of Global Environmental Change (Chichester, UK: Wiley, 2002), pp. 73738.

23 An estimated 25 percent of the CO2

David Archer and Victor Brovkin, "The Millennial Atmospheric Lifetime of Anthropogenic CO2," Climatic Change 90 (2008): 28397; personal correspondence with Daniel Schrag, January 19, 2011.

24 have occurred in the last ten years

NASA, "NASA Finds 2011 Ninth-Warmest Year on Record," January 19, 2012, http://www.nasa.gov/topics/earth/features/2011-temps.html.

25 flooding in Pakistan that displaced 20 million people

"Pakistan Floods Leave 20 Million Homeless," CBC News, August 14, 2010, http://www.cbc.ca/news/world/story/2010/08/14/pakistan-floods-homeless.html.

26 unprecedented heat waves in Europe in 2003

J. Robine et al., "Death Toll Exceeded 70,000 in Europe During Summer of 2003," Comptes Rendus Biologies, February 2008.

27 Russia in 2010 that led to 55,000 deaths

"World Disasters Report: 2010 Death Toll Highest in Decade," Red Cross, September 22, 2011, http://www.redcross.org.au/world-disasters-report-2010-death-toll-highest-in-decade.aspx.

28 ma.s.sive fires, and crop damage that pushed global food prices

"World Food Prices at Fresh High, Says UN," BBC, January 5, 2011, http://www.bbc.co.uk/news/business-12119539.

29 the flooding of northeastern Australia in 2011

J. David Goodman, "Australia Flooding Displaces Thousands," New York Times, December 31, 2010.

30 the huge droughts in southern China

Edward Wong, "Drought Leaves 14 Million Chinese and Farmland Parched," New York Times, September 9, 2010.

31 southwestern North America in 2011

Kim Severson and Kirk Johnson, "14 States Suffering Under Drought," New York Times, July 12, 2011.

32 Superstorm Sandy

James Barron, "After the Devastation, a Daunting Recovery," New York Times, October 30, 2012.

33 warmer air holds more water vapor

Kevin Trenberth, "Changes in Precipitation with Climate Change," Climate Research 47 (2010): 12338.

34 has a large effect on the hydrological cycle

Ibid.

35 funnel it inward into the regions where storm conditions trigger a downpour