Part 143 (1/2)

Tom Philpott, ”New Research: Synthetic Nitrogen Destroys Soil Carbon, Undermines Soil Health,” Grist, February 24, 2010, grist.org/article/2010-02-23-new-research-synthetic-nitrogen-destroys-soil-carbon-undermines/.

286 by pus.h.i.+ng subsistence farmers to clear more forests

David Lapola et al., ”Indirect Land-Use Changes Can Overcome Carbon Savings from Biofuels in Brazil,” Proceedings of the National Academy of Sciences, January 2010.

287 have proven that a.s.sumption to be wrong

Claude Mandil and Adnan s.h.i.+hab-Eldin, International Energy Forum, ”a.s.sessment of Biofuels: Potential and Limitations,” February 2010, /news/news-details.aspx?nid=311.

288 20 to 50 percent of all living species on Earth within this century

Nicholas Stern, The Economics of Climate Change.

289 Approximately one third of all amphibian species

Camila Ruz, ”Amphibians Facing 'Terrifying' Rate of Extinction,” Guardian, November 2011.

290 hit by a spreading fungal disease

Mich.e.l.le Nijhuis, ”A Rise in Fungal Diseases Is Taking Growing Toll on Wildlife,” Yale Environment 360, October 24, 2011.

291 the encroachment of human activities

Owen Clyke, ”The Militarization of Africa's Animal Poachers,” Atlantic, July 31, 2012; David Braun, ”Human Encroachment Threatens Thousands of Gorillas in African Swamp,” National Geographic, November 24, 2009; Yaa Ntiamoa-Baidu, United Nations Food and Agriculture Organization, ”West African Wildlife: A Resource in Jeopardy,” 1998, /docrep/s2850e/s2850e05.htm.

292 caused by a large asteroid cras.h.i.+ng into the Earth

Anthony Barnosky et al., ”Has the Earth's Sixth Ma.s.s Extinction Already Arrived?,” Nature, March 2011.

293 ”precipitated entirely by man”

Richard Leakey and Roger Lewin, The Sixth Extinction: Patterns of Life and the Future of Humankind (New York: Anchor Books, 1995), p. 235.