Methane Management

摘要

According to the U.S.Environmental Protection Agency's(EPA)”Inventory of U.S.Greenhouse Gas Emissions and Sinks,”methane accounts for about 10% of U.S.greenhouse-gas(GHG) emissions.Of this,one-quarter is from the natural gas industry.Expressed as a percent of natural gas production,this equates to 1.3% of production.While other studies have suggested much higher emissions levels,some as high as 7.9%,the most recent and most comprehensive non-EPA study-a multiyear study organized by the Environmental Defense Fund and involving various universities and research organizations-found emissions only slighdy higher at 1.7%.The paper tabulates emissions for both crude oil and natural gas systems at 2.3% of gas production.Consulting service ICF International estimates that the natural gas portion equates to 1.7% of emissions.ICF has been a leader in measurement and mitigation of methane emissions from the oil and gas industries for more than 20 years.This has included work for the industry,regulators and nongovernmental organizations ranging from policy analysis and development to direct support for industry operations.Over the last five to 10 years,the company has seen increasing focus on methane emissions from these industries for several reasons.Among those is that the climate-forcing effect of methane is greater than that of CO2.The global warming potential(GWP) describes the ratio of methane equivalent to 1 ton of CO2 and can range from 34 to 86,depending on the timescale being considered.