Last week, the US Geological Survey (USGS) released a report (PDF) concluding that fossil fuels extracted from public lands account for 23.7 percent of the nation's carbon dioxide emissions. Those numbers include carbon dioxide that's released during the drilling and coal mining process, as well as carbon dioxide that's released when the oil, gas, or coal that comes from public lands is processed and burned.
Drilling and mining in the US can occur on private land, or fossil fuel companies can seek leases from the federal government to drill and mine. Offshore oil drilling, a contentious topic among coastal states that are reluctant to see another Deepwater Horizon disaster ruin their beachfront property, counts as drilling on federal land.
The significance of the role that federal land leases play in contributing to climate change will likely be ignored by the Trump administration. Last week, the US federal government tried to bury a report on the dire effects that climate change will have on the nation's economy and health.
This newly released USGS report was requested by the Obama administration in January 2016. At the time, the federal government tried to limit fossil fuel extraction on federal lands in several ways. The Hill notes that the Obama administration created a number of new national monuments to preclude drilling operations. The former president also halted new coal leases on federal lands and instituted new rules to limit methane emissions on federal land.
The stats
Along with measuring carbon dioxide emissions, the USGS report says that fossil fuel extraction on federal lands contributes to 7.3 percent of the nation's methane emissions and 1.5 percent of the nation's nitrogen oxide emissions.
A weak silver lining is that between 2005 and 2014, all emissions from federal public land decreased slightly. For CO2, that meant decreases of 6.1 percent; methane saw a drop of 10.5 percent and nitrogen oxide 20.3 percent. The emissions that come from public land use are closely tied with fossil fuel production on those lands, the USGS writes, so when extraction decreases, emissions decrease too.
The USGS report also quantified how much carbon dioxide federal lands sequester. That is, plants and soil can store some CO2, and protecting federal lands means protecting the ecosystems that hold some amount of CO2 in storage.
The USGS report notes that federally owned ecosystems like forests, grasslands, and shrublands sequestered an average of 195 million tons of carbon dioxide equivalent per year 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."
The difference between what's being emitted due to federal land use and what federal lands sequester can help future federal government administrations make energy and leasing decisions. For now, the US' public lands are emitting much more CO2 than they can sequester, and the current administration's enthusiasm for leasing public lands is unlikely to change much.
Correction: A sentence in this article was changed to reflect that decreased production on federal lands causes a decrease in emissions, while a decrease in emissions isn't necessarily reflective of decreased fossil fuel production on federal and non-federal lands as a whole.