PROJECTING ANTHROPOGENIC METHANE EMISSIONS AND POTENTIAL REDUCTION STRATEGIES OF SIX SOURCES IN SIX NATIONS

Methane concentrations in our atmosphere have more than doubled since pre-industrial times. Although the rate of change of global concentrations has recently slowed, studies predict that this stabilization will be short-lived. There is a growing need to better understand the emissions sources for this potent greenhouse gas and to assess possible reduction strategies. Global methane emissions pathways have been proposed by the IPCC but the relative contributions from different source types and individual countries is not well determined. I analyze six main anthropogenic sources including emissions from enteric fermentation, rice production, landfills, wastewater treatment, coal mining, and natural gas and oil production. Future changes in the main drivers of population, economic, and technological parameters can impact methane emissions from these six sources in Brazil, China, India, Mexico, Russia, and the United States through 2050. I develop a simple framework to characterize and project methane emissions enabling the building of a business as usual and multiple alternative scenarios. The methane concentration implications of these projections are analyzed using a simple climate model. Finally, a technological potential reduction scenario is proposed by maintaining baseline assumptions while improving methane capture technologies and options. Under business as usual assumptions, global anthropogenic methane emissions are projected to double by 2030 but there is potential to cause a global decrease by 40 % per year of projected baseline levels which would reduce global temperature changes by 0.5 degrees Celsius by 2100.