A new analysis shows US greenhouse gas levels are increasing as the Trump administration unravels efforts to slow climate change.

Carbon emissions rose sharply last year, increasing 3.4%, according to new estimates from the economic firm Rhodium Group. That year’s jump in emissions is the biggest since the bounce back from the recession in 2010. It is the second largest gain in more than two decades.

Coal plants are shutting down, but electricity demand is growing. Natural-gas fired power emits about half as much carbon as coal but still contributes to climate change. The fossil fuel is replacing most of the coal plants that are closing and also fed most of the higher demand, increasing power-sector climate pollution. Outside of the power sector, transportation, industry and buildings all increased their emissions as well, according to the estimates.

The numbers undercut one of the Trump administration’s key defenses for dismissing federal science reports that show rising temperatures will wreak havoc on the economy, kill people and cause more extreme weather. Trump has said he doesn’t believe the findings and his officials have argued they are exaggerated.

The Environmental Protection Agency chief, Andrew Wheeler, often trumpets declines in greenhouse gases, citing data showing that they fell 2.7% from 2016 to 2017.

But the EPA is rescinding Obama-era climate work, including regulations meant to speed a shift from coal. The agency contends that Donald Trump’s agenda is driving energy innovation that could help cut emissions. Energy experts, however, say Trump is doing the opposite by rolling back the rules and policies that could have sped renewable growth and by forgoing new regulations beyond the electricity sector.

Rhodium Group tracks the most prevalent greenhouse gas, carbon dioxide. The firm found a modest decrease in carbon emissions between 2016 and 2017, in part because of a warmer-than-usual winter that didn’t require as much heating. Since then carbon output has surged.

“The tailwinds of Obama administration policy are dissipating,” said Trevor Houser, a partner at the firm. “This year makes it abundantly clear that energy market trends alone – the low cost of natural gas, the increasing competitiveness of renewables – are not enough to deliver sustained declines in US emissions.”

Houser said the numbers would have been worse without the state and local policies enacted during the past five to 10 years. But that the groundswell of climate commitments by governors and mayors since Trump said he would exit the international Paris climate agreement might not translate into policy for some time, he added. He said those efforts are likely to be significant but not sufficient to meet the levels the US pledged.