December 07, 2017

New study challenges methane emission estimates

UNIVERSITY PARK, Pa. — A new study of methane emissions from livestock in the United States — led by a researcher in Penn State's College of Agricultural Sciences — has challenged previous top-down estimates that suggest the U.S. Environmental Protection Agency is underestimating agricultural methane emissions by up to 90 percent, and bottom-up estimates accepted by the federal government showing lower emissions.

Top-down emissions estimates involve monitoring atmospheric methane concentrations by satellites or from air samples collected at high altitude by planes, and using models to estimate the sources of emissions. Bottom-up estimates take into account livestock populations and animal emission factors.

Read more in Uncertainty surrounds U.S. livestock methane emissions from Penn State via EurekAlert!