According to the Intergovernmental Panel on Climate Change (IPCC), aviation currently accounts for about 2 percent of human-generated global carbon dioxide emissions, the most significant greenhouse gas and about 3 percent of the potential warming effect of global emissions that can affect the earth's climate, including carbon dioxide. This book discusses the IPCC's medium-range estimate forecasts that by 2050 the global aviation industry, including aircraft emissions, will emit about 3 percent of global carbon dioxide emissions and about 5 percent of the potential warming effect of all global human-generated emissions.