Carbon dioxide emissions from the U.S. power sector increased significantly in 2018 following three straight years of decreases, according to a new report, putting the nation further off track to reach global climate change goals.
Power sector emissions rose an estimated 1.9% as higher electricity demand and increased natural gas-fired generation outpaced a decline in coal power, the research firm Rhodium Group reported. Emissions from the transportation, industrial and buildings sectors also rose, leading to an estimated 3.4% overall increase.
The news comes as climate scientists warn global economies must rapidly decarbonize over the next decade to stave off the worst impacts of climate change. While a number of state governments are poised to enact clean energy and climate policies in 2019, the Trump administration plans to continue rolling back federal greenhouse gas regulations on multiple sectors of the economy.
The new Rhodium group report represents a worrying reversal for the electric utility industry, raising questions about whether its recent formula for emissions reductions has outlived its usefulness.
For the last decade, the sector's emissions have declined largely due to economic forces — a decrease in power demand during the recession and a shift from coal to cheaper natural gas brought on by the fracking boom.
Those trends, combined with increased renewable energy, allowed the power sector to reduce carbon emissions more than 12% from 2007 to 2015, Rhodium reported, and economywide carbon reductions continued at a slower pace until 2017.
In 2018, however, those economic factors changed. Power demand increased as the economy grew and utilities burned more natural gas to meet it, outpacing more than 14 GW of expected coal capacity closures in the year.
"Natural gas not only replaced most of the lost coal generation but also fed the vast majority of the load growth last year," Rhodium reported. "Natural gas-fired generation increased by 166 million kWh during the first ten months of the year. That's three times the decline in coal generation and four times the combined growth of wind and solar."
The emissions increase in the power sector is particularly significant because energy experts expect the utility system to be critical in decarbonizing other sectors — allowing a shift away from fossil fuels in vehicles and factories through increased electrification.
Like the utility sector, those industries also saw their emissions increase in 2018.
The report's release comes after the United Nations Intergovernmental Panel on Climate Change warned in October that humans have little more than a decade to virtually eliminate greenhouse gas emissions to stand a good chance of averting the worst impacts of global climate change.
That pace falls at the ambitious end of targets envisioned by the 2015 Paris Agreement, the world's largest international climate treaty. President Trump announced in 2017 that the U.S. would leave the agreement, and Rhodium reported the nation was already behind the pace to meet its targets — a 26% to 28% carbon emissions reduction by 2025 — before last year.
The Rhodium estimates do not take into account greenhouse gases other than carbon, such as methane, that contribute to warming. Figuring those in, the research firm said the U.S. would need to completely reverse its emissions trends in the power sector to meet the targets.
"Assuming proportional reductions in other gasses, the U.S. will need to reduce energy-related CO2 emissions by 3.3% per year, on average, in 2019 and 2020 to meet the … target," researchers wrote. "That is significantly faster than the 1.2% average annual reduction between 2005 and 2017. In reality, the pace of energy CO2 emission reductions will likely need to be even faster as the decline in non-CO2 gasses has underperformed that of energy-related CO2 in recent years."
Despite mounting urgency in the scientific community, the Trump administration plans to continue reducing regulations on a number of greenhouse gas-emitting sectors in 2019. The Environmental Protection Agency is currently working to finalize proposals that would roll back carbon emissions on automobiles and new and existing power plants, as well as reduce pollution rules for industrial facilities and oil and gas drilling.
Those actions are likely to increase calls in Congress and liberal states for more ambitious climate and clean energy policies. Already in 2019, House Speaker Nancy Pelosi, D-Calif., has resurrected a special committee on climate change and more than 30 federal lawmakers have signed on to a "Green New Deal" proposal calling for a complete phase-out of fossil fuels.
Republican control of the Senate and White House means federal climate initiatives are unlikely to be enacted in 2019, but a number of states could take action on clean energy following Democrat gains in the November elections last year.
That night included wins for a number of gubernatorial candidates who had endorsed a 50% renewable energy standard or higher and will come into office with one-party Democrat control in their legislatures — in Illinois, California, Colorado, Nevada, New Mexico and Maine.
Correction: An earlier version of this post misstated the expected percentage increase in power sector carbon emissions.