US greenhouse gas emissions fell 2.1 percent last year almost entirely because of a sharp drop in coal consumption, according to the Rhodium Group, a private data research firm.
Coal-fired electric power generation, which had rebounded slightly in 2018, fell by a record 18 percent to the lowest level since 1975, the Rhodium study said. Coal burning produces carbon dioxide, fueling climate change.
But much of that reduction was offset by rising emissions from the use of inexpensive natural gas. And transportation emissions remained relatively flat while emissions from buildings, industry, and other parts of the economy grew.
The modest overall drop in emissions left the United States in danger of failing to meet its commitments under international agreements.
‘‘Last year was definitely a good news, bad news story,’’ said Trevor Houser, a partner with the Rhodium Group and head of its energy and climate team. ‘‘There was the biggest drop ever in electric power emissions but little progress in other sectors of the economy.’’
Moreover, Houser said, ‘‘emissions are not falling fast enough to meet Copenhagen or Paris agreement targets without a significant change in public policy.’’
In 2019, US greenhouse gas emissions were roughly 12 percent below 2005 levels. That puts the United States at risk of missing the 17 percent target it agreed to reach by 2020 under the 2009 Copenhagen Accord, the Rhodium study said. In addition, US emissions last year were still ‘‘a long way off’’ from the 26 percent to 28 percent reduction that the United States pledged to carry out by 2025 under the 2015 Paris climate agreement, the study said. The Trump administration has said it will withdraw from the Paris accord next fall.
The United States accounts for 11 percent of global greenhouse gas emissions, Houser said.