Preliminary data shows U.S. greenhouse gas emissions fell 2.1 percent in 2019 following a spike in 2018.

A report put together by the Rhodium Group, an independent research provider, estimates emissions actually increased in nearly every sector except for the energy industry.
"In buildings, transportation and industry, we've yet to see the development of low carbon technologies at sufficient scale to lead to large scale reduction in emissions," said Trevor Houser, Rhodium Group partner and co-author of the report with Hannah Pitt.

He said the reason for the emissions decline came down to the power sector. In 2019, the coal industry saw its largest year-over-year drop in generation, falling 18 percent nationally. Several major coal producers filed for bankruptcy last year. That includes Cloud Peak Energy and Blackjewel in Wyoming.

Houser said the biggest surprise was the speed of coal generation's decline.

"We ended the decade with coal generation at about half the level at which we started the decade. I think that speed is a bit surprising to most analysts," he said.

An increase in energy efficiency in transportation and buildings has also slowed the pace of emissions growth, Houser added.

U.S. greenhouse gas emissions have fallen more than 12 percent since 2005 levels. The Copenhagen Accord sought a 17 percent reduction by the end of 2020, which Houser said is still possible though unlikely with emissions not falling that much since the Great Recession.

Have a question about this story? Contact the reporter, Cooper McKim, at cmckim5@uwyo.edu.