U. S. coal-fired power generation grew last year as President Biden’s Build Back Better plan, which would have devoted $555 billion to renewable and clean energy initiatives, was stalled by Joe Manchin, the West Virginia senator who owns a $1 million to $5 million stake in a family coal business.

Coal generation surged 17% in 2021, according to Rhodium Group, an independent research firm. It marks the first annual increase in U.S. coal power since 2014, and signals a shift back to coal from cleaner energy sources for generating electricity.

The rise in coal contributed significantly to the 6.2% rise in U.S. greenhouse gas emissions from all sources in 2021, the Rhodium Group said.

The increased coal generation, caused by higher oil and natural gas prices, highlights the difficulties the Biden administration faces in achieving its goal of slashing greenhouse emissions to 50% of 2005 levels by 2030. After last year’s jump, U.S. emissions will be just 17.4% below 2005 levels, according to the Rhodium Group.

Substantially reducing greenhouse gases, say leading climate scientists, is necessary to stop the earth’s average temperature from warming 1.5 degrees Celsius above preindustrial levels. Such warming—average temperatures are already up 1.1 degrees—could unleash catastrophic and irreversible changes to the planet’s environment.

Studies find that without energy policy changes, like those outlined in Biden’s Build Back Better plan, the country will fall short of achieving its climate objectives. The bill, however, has been blocked by Manchin, who says he “cannot vote” for the sweeping $2 trillion climate and social spending package.

Democrats, with a 50-50 split in the Senate against Republicans and the vice president as the tiebreaker, need Manchin’s vote to pass the groundbreaking act. They have spent months negotiating over the package to meet his demands, but they have been unsuccessful.

“I cannot vote to continue with this piece of legislation,” Manchin told Fox News Sunday host Bret Baier last month. “This is a no on this legislation.”

The senator cited rising inflation as the reason he wouldn’t support a large spending plan. Seventeen Nobel Prize–winning economists, however, have published a letter disputing that the bill would impact inflation.

Manchin, who has long-standing ties to the industry, has made millions of dollars from coal. He holds a stake worth $1 million to $5 million in Enersystems, the coal brokerage firm he founded, according to his most recent financial disclosure filings. Enersystems paid Manchin $492,000 in interest, dividends, and other income in 2020, more than his Senate income.

Manchin has a long history of resisting climate legislation.

When asked about his connections to the coal industry, Manchin has said that his investments in his family’s coal business have been held in a blind trust for 20 years. Reporting by the Washington Post, however, revealed that his blind trust is too small to account for all his reported earnings from the coal company.

Still, the surge in coal use was likely an anomaly caused by rising energy prices worldwide that caused a switch to coal. “Emissions from our power sector were pretty much at the whim of energy markets,” said Kate Larsen, who leads Rhodium’s international energy and climate research.

Over the long term, U.S. coal use has declined significantly, and overall, greenhouse gas emissions from all sources are still below pre-pandemic levels.