1 "11 Facts About Droughts." Do Something. 2016. Accessed: August 31, 2016.
2 Botham, Noel. Book of Useless Information. New York, New York: Penguin Random House LLC, 2006.
3 Carrington, Damian. "Earth Has Lost Half of Its Wildlife in the Past 40 years, Says WWF." The Guardian. September 30, 2014. Accessed: April 22, 2017.
4 Coss, Lauren. Weird-But-True-Facts about Earth. Mankato, MN: The Child’s World, 2013.
5 “Earth.” 2009. Encyclopaedia Britannica Online. Accessed: July 14, 2009.
6 "‘Evolution Of Life On Earth’ VIDEO: 4.5-Billion-Year History Compressed Into Two Minutes." The Huffington Post. November 12, 2012. Updated Feb 25, 2013. Accessed: August 31, 2016.
7 Gosden, Emily. "More Plastic Than Fish in the Ocean by 2050, Report Warns." The Telegraph. January 19, 2016. Accessed: May 22, 2017.
8 Hazen, Robert M. 2012. The Story of Earth: The First 4.5 Billion Years, From Stardust to Living Planet. New York, NY: Penguin Group.
9 "Henry David Thoreau: Walden." The Literature Page. Accessed: July 12, 2017.
10 Krulwich, Robert. "Which is Greater? The Number of Sand Grains on Earth or Stars in the Sky?" NPR. September 17, 2012. Accessed: August 31. 2016.
11 Oskin, Becky. "What If Every Volcano on Earth Erupted at Once?" Live Science. January 2, 2015. Updated: August 31, 2016.
12 Palmer, Douglas. 2011. A History of Earth in 100 Groundbreaking Discoveries. Buffalo, NY: Firefly Books, Inc.
13 Stewart, Iain and John Lynch. Earth: The Biography. Washington, DC: National Geographic, 2007.
14 "The Driest Place on Earth." National Geographic. 2016. Accessed: August 31, 2016.
15 "The 'Highest' Spot on Earth?" NPR. April 7, 2007. Accessed: August 31, 2016.
16 "There Are 3 Trillion Trees on the Planet." Seeker. Sep 3, 2015. Accessed: August 31, 2016.
17 Ward, Peter D and Donald Brownlee. The Life and Death of Planet Earth: How the New Science of Astrobiology Charts the Ultimate Fate of Our World. New York, NY: Henry Holt, 2002.
18 "Would you Fall All the Way Through a Theoretical Hole in the Earth?" Scientific America. 2016. Accessed: August 31, 2016.