President Joe Biden’s climate change agenda is facing a difficult path forward with his two signature infrastructure bills caught up in a divided Congress.

The president has made fighting global climate change a central facet of his domestic and foreign policies. His administration has unveiled ambitious policies to increase the use of renewable energy over fossil fuels, cut emissions, and work together with other nations to fund climate change initiatives worldwide.

However, these ambitions are at risk of unraveling as his legislative agenda risks going off the rails in Congress.

The House of Representatives is set to vote on the $1.2 trillion bipartisan infrastructure bill on Thursday after it passed in the Senate last month. Under this bill, money would be allocated towards building climate-resilient infrastructure, updating the national energy grid, and investment in infrastructure for electric vehicles in the U.S.

However, the bill is being held up over internal disagreements within Biden’s Democrats over a second larger “human infrastructure” bill. This $3.5 trillion package includes more climate policies that would make up for the removal of other climate provisions in the physical infrastructure bill during negotiations with Republican senators.

Under a proposal submitted in July, the bill would introduce a new Clean Energy Standard for the utilities sector, tax incentives for clean energy and electric vehicle use, and investing more in clean energy technologies.

Since the start of negotiations on the $3.5 trillion bill, it has been met with opposition from centrist Democrats. Sen. Joe Manchin, D-W.Va., has been a persistent opponent of the proposal because of what he considers its unacceptable price tag. He has insisted that the bill is "not urgent" to pass at this time, earning him the ire of progressive Democrats.

Manchin, whose home state remains reliant on the fossil fuel sector, has particular gripes with climate change provisions in the legislation as well.

One measure, the Clean Electricity Performance Program (CEPP) that looks to incentivize utilities to shift over to zero emissions power sources, is a sore point for Manchin. From his perch atop the Senate's Committee on Energy and Natural Resources, the centrist Democrat holds significant power over the bill's progress through the upper chamber if it ever reaches there.

Republicans are universally opposed to the multitrillion-dollar package and Democrats’ plans to seek its passage through the budget reconciliation process that requires only a simple majority. This gives Manchin outsized importance since the party cannot afford a single defection if it wants the legislation enacted.

President Biden met with Manchin on Tuesday in an attempt to persuade him to drop his objections but to seemingly no avail.

The smaller bipartisan bill also faces a different set of challenges in the House.

While Speaker of the House Nancy Pelosi wants to bring it to a vote this week, she has been fighting resistance from progressive Democrats who have made any ‘Yes’ vote contingent on the $3.5 trillion bill getting a vote in the Senate. Without it, they pledge to withhold their vote on the physical infrastructure bill, a worrying prospect for the party as it heads into the 2022 election season and a serious setback to Biden’s climate agenda.

There are also moderate Democrats in the House who, like Manchin in the Senate, are opposed to the larger bill and represent states that depend on the fossil fuel industry.

Seven House Democrats from Texas sent a letter to Speaker Pelosi this week outlining specific objections to the clean energy portions of the bill. They argue that the "taxes and fees, as well as exclusion of natural gas production clean energy initiatives, constitute punitive practices."