Greenhouse Gas Emissions from Aviation and Marine Transportation: Mitigation Potentials and Policies

"This paper provides an overview of greenhouse gas (GHG) emissions from aviation and marine transportation and the various mitigation options to reduce these emissions. Reducing global emissions by 50 to 80 percent below 1990 levels by 2050—reductions scientific studies suggest are necessary to stabilize the climate and avoid the most destructive impacts of climate change (IPCC 2007)—will require lowering GHG emissions across all sectors of the economy. Aviation and marine transportation combined are responsible for approximately 5 percent of total GHG emissions in the United States and 3 percent globally and are among the fastest growing modes in the transportation sector. Controlling the growth in aviation and marine transportation GHG emissions will be an important part of reducing emissions from the transportation sector. The Intergovernmental Panel on Climate Change (IPCC) reports that global demand for aviation increased by 5.9 percent and demand for marine transportation by 5.1 percent, during 2005 alone (IPCC 2007). Business-as-usual (BAU) projections for CO2 emissions from global aviation are estimated at 3.1 percent per year over the next 40 years, resulting in a 300 percent increase in emissions by 2050 (IEA 2008b). The projected growth rate of global marine transportation emissions is more uncertain. BAU growth projections by the IEA (2008b) and IMO (2008) are between 1 and 2 percent per year. By 2050, international marine transportation emissions are estimated to increase by at least 50 percent over 2007 levels."