U.S. carbon dioxide and other emissions have fallen over the past 14 years while the economy expanded and then recovered from the Great Recession, according to the latest data released by the Environmental Protection Agency this week.
Nationwide greenhouse gas (GHG) emissions in the power sector have fallen 27 percent since 2005 while the economy expanded by 25 percent, according to the newest edition of U.S. Environmental Protection Agency’s (EPA) annual emissions report.
For nearly three decades EPA has filed its “Inventory of U.S. Greenhouse Gas Emissions and Sinks,” providing an annual account of “total greenhouse gas emissions for all man-made sources in the United States.
The gases covered by the Inventory include carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, sulfur hexafluoride, and nitrogen trifluoride.
The Inventory also calculates carbon dioxide removal from the atmosphere by ‘sinks,’ e.g., through the uptake of carbon and storage in forests, vegetation, and soils.”
The 2020 update released Monday runs from 1990 through 2018. Between 2005 and 2018, net emissions of carbon dioxide equivalent decreased 10 percent, “reflecting long-term trends in many factors including population, economic growth, energy markets, technological changes including energy efficiency, and energy fuel choices.”Much of the decline is attributable to switching from coal to natural gas as sources of fuel for generating electricity, along with renewable energy use, according to EPA.
“This report highlights declining emissions trends since 2005, showing that the U.S. is reducing GHG emissions while still being able to grow a robust economy,” said EPA Administrator Andrew Wheeler. “While there was a small rise in emissions due to weather and increased energy demand from the prior year in this report, based on preliminary data, we expect next year’s report to show that the long-term downward trend will continue.”
The recent COVID-19 health crisis and economic downturn due to enforced reductions in business activities including transportation and other fuel usage is likely to cause other emissions reductions, similar to the 2008-2009 Great Recession, but the magnitude of such an effect is unclear at this time.
CO2 emissions have tumbled 12 percent in the United States while skyrocketing 24 percent globally in the same 2005 to 2018 timeframe.
Preliminary data from the Energy Information Administration indicates that 2019’s emissions decreased 3 percent from 2018, following a one-year uptick of 3 percent from 2017 to 2018, the last full year with complete data.
Emissions had been decreasing for three straight year-to-year measures from 2014 to 2017.
According to EPA, CO2 emissions is the primary source of all GHG emissions in the U.S., totaling 81 percent of the overall emission sources in 2018.
Of that total, 93 percent of CO2 emissions derived from fossil fuel use in electric power generation and other generative activities.
Other uses with CO2 emissions include iron and steel production, cement production, industrial processes, and other chemical and systems productions.
Methane production has seen reduced emissions as well, with a 7 percent drop since 2005, with reductions driven by natural gas emissions in distribution, transmission, and storage.
Decreases from landfills via gas collection and decomposable waste has contributed to reductions there, while increasing cattle populations have increased livestock emissions from enteric fermentation, the largest source of methane in 2018.
Transportation emissions increased between 1990 and 2018 largely from increased travel activity, but fuel economy has pared increases in the rate of CO2 emissions.
Ninety-five percent of energy used for transportation is derived from petroleum-based products, according to EPA.
In contrast, electric power generation has seen a 13 percent decline in carbon intensity, with natural gas generation replacing coal in most areas.
From 2017 to 2018, generation increased three percent, but emissions only went up one percent, as a result of fuel switching and decreased carbon intensity.
A downturn in carbon dioxide emissions via coal generated electric power of 42 percent has driven the overall decrease in the electricity sector down 27 percent overall.
For other sectors, a small increase in commercial and residential emissions was contrasted with a small decrease in the industry sector, which has fallen 10 percent since 1990, led by changes in industrial intensity and production from “energy-intensive manufacturing products to less energy-intensive products” like computers.
For 2019, projections from EIA used by EPA include further carbon dioxide emissions reductions in the electric power sector and will account for the largest portion of the decline as natural gas and renewables displace coalMilder weather in 2019 will also lead to decreases, compared to an uptick in 2018 due to more extreme weather.
