These websites were referenced for figures and information about energy, conservation, as well as any additional figures.

World POPClock Projection
U.S. Census Bureau
BP
International Geothermal Association
Solar Energy Industries Association
Photovoltaic Power Systems Programme
European Wind Energy Association
European Wind Energy Association
Organization of the Petroleum Exporting Countries
Cambridge Energy Research Associates
Energy Information Administration
NaturalGas.org
World Energy
Crest.org
Nuclear Energy Institute
Uranium Information Centre