President Joe Biden’s climate change agenda has been front and center since entering the White House in January. But as he prepares to embark on a major climate change conference abroad in the coming weeks, new data released Monday showed that U.S. coal use may be on the rise.

The Department of Energy reported that the percentage of the U.S. power grid that relies on coal has gone up throughout 2021. It estimates that by the end of the year, coal will make up 22% of U.S. energy consumption, a 4% rise from 2020 and the first year-on-year increase since 2014.

The agency explained the rise of coal use as the result of an increase in natural gas prices. However, it predicted that coal use would fall in 2022 by up to 5% as more production plants retire and as natural gas prices begin to fall.

On Oct. 13, the Energy Department released its weekly update on natural gas production in the U.S. and showed that the supply of liquid natural gas (LNG) rose slightly, but cautioned that LNG exports were outpacing domestic production, leading to lower inventories for use at home.

Since entering office, President Biden has unveiled a number of initiatives to move the U.S. closer to renewable and clean energy technologies. In his Democratic Party’s multitrillion-dollar infrastructure plans, there are provisions that will address the climate resilience in physical infrastructure as well as new tax incentives for utility companies to move away from fossil fuels.

However, this bill has been held up by gridlock in Congress. Members of Biden’s own party, notably Sen. Joe Manchin, D-W.Va., and a cadre of House Democrats from fossil fuel-dependent states, have voiced their opposition to the climate change elements of the bills that could directly impact their states.

Recently, it has been reported that elements of their climate plans may be stripped from the larger $3.5 trillion social spending bill to win support from party moderates and bring down the price tag.

Abroad, the Biden administration has also reasserted a U.S. role as a global player in the fight against climate change by rejoining the Paris Climate Accords after former President Donald Trump left the agreement. Just last month, the president also announced at the United Nations General Assembly that the U.S. would be pledging $100 billion to countries hardest-hit by global warming.

Biden is due to attend the United Nations Climate Change Conference, or COP26, in Glasgow, Scotland, from Nov. 1 to Nov. 2.