Benjamin M. Sleeter Philip A. Freeman Jinxun Liu Peter D. Warwick Bradley C. Reed Matthew D. Merrill 2018 <p>In January 2016, the Secretary of the U.S. Department of the Interior tasked the U.S. Geological Survey (USGS) with producing a publicly available and annually updated database of estimated greenhouse gas emissions associated with the extraction and use (predominantly some form of combustion) of fossil fuels from Federal lands. In response, the USGS has produced estimates of the greenhouse gas emissions resulting from the extraction and end-use combustion of fossil fuels produced on Federal lands in the United States, as well as estimates of ecosystem carbon emissions and sequestration on those lands. American Indian and Tribal lands were not included in this analysis. The emissions estimates span a 10-year period (2005–14) and are reported for 28 States and two offshore areas. Nationwide emissions from fossil fuels produced on Federal lands in 2014 were 1,279.0 million metric tons of carbon dioxide equivalent (MMT CO₂ Eq.) for carbon dioxide (CO₂), 47.6 MMT CO₂ Eq. for methane (CH₄), and 5.5 MMT CO₂ Eq. for nitrous oxide (N₂O). Compared to 2005, the 2014 totals represent decreases in emissions for all three greenhouse gases (decreases of 6.1 percent for CO₂, 10.5 percent for CH₄, and 20.3 percent for N₂O). Emissions from fossil fuels produced on Federal lands represent, on average, 23.7 percent of national emissions for CO₂, 7.3 percent for CH₄, and 1.5 percent for N₂O over the 10 years included in this estimate.</p><p>In 2005, Federal lands of the conterminous United States stored 82,289 MMT CO₂ Eq. in terrestrial ecosystems. By 2014, carbon storage, or sequestration, was estimated at 83,600 MMT CO₂ Eq., representing an increase of 1.6 percent, or 1,311 MMT CO₂ Eq. Soils stored most of the ecosystem carbon (63 percent), followed by live vegetation (26 percent) and dead organic matter (11 percent). The rate of net carbon uptake in ecosystems ranged from a sink (sequestration) of 475 million metric tons of carbon dioxide per year (MMT CO₂ Eq./yr) to a source (emission) of 51 MMT CO₂ Eq./yr because of annual variability in climate and weather, rates of land-use and land-cover change, and wildfire frequency, among other factors. At the national level, the USGS estimates that terrestrial ecosystems (forests, grasslands, and shrublands) on Federal lands sequestered an average of 195 MMT CO₂ Eq./yr between 2005 and 2014, offsetting approximately 15 percent of the CO₂ emissions resulting from the extraction of fossil fuels on Federal lands and their end-use combustion.</p><p>The USGS estimates presented in this report represent a first-of-its-kind accounting for the emissions resulting from fossil fuel extraction on Federal lands and the end-use combustion of those fuels, as well as for the sequestration of carbon in terrestrial ecosystems on Federal lands. The net CO₂ emissions estimate, which is the difference between the emitted and sequestered CO₂, provides an informative combined result describing the emissions (fossil fuel extraction and end-use combustion) associated with a State’s Federal lands and sequestration on those same lands. The estimates included in this report can provide context for future energy decisions, as well as a basis to track change in the future.</p> application/pdf 10.3133/sir20185131 en U.S. Geological Survey Federal lands greenhouse emissions and sequestration in the United States—Estimates for 2005–14 reports