Senate Democrats on Tuesday announced that they may have a path to a deal on the climate provisions included in the trillion-dollar spending bill. The provisions will include a methane fee that they think will sway Sen. Joe Manchin, D-W.Va., in the bill’s favor.

Senate Democrats expressed optimism that they were nearing an agreement on climate action, according to The Hill. The proposed clause would instate a methane fee, with the chance of a carbon tax remaining unlikely.

Senate Majority Leader Chuck Schumer, D-N.Y., announced that he feels confident a “robust” package of climate proposals will come together in the spending bill.

“There’s going to be a very strong, robust climate package. And our goal is to meet the president’s goal, and there are different ways to get there,” he said.

Democrats involved in drafting the climate proposal say the provision will promote clean energy instead of punishing polluters.

“There’s an amount of money that the administration thinks will reduce emissions to a level they think is important for us to achieve and a level of investment in infrastructure and [research and development],” one unnamed senator involved in the provision’s construction said.

The senator added that the climate package would involve money for energy-efficient infrastructure, research and development, and tax credits for clean and renewable energy production, as well as a methane fee.

Senate Environment and Public Works Committee Chairman Tom Carper, D-Del, said that “we’ve had an ongoing conversation with a number of our colleagues, including with Sen. Manchin’s staff,” over the methane fee.

But Manchin said that he hasn’t yet seen the text of the proposed methane fee and would need to review it before making any decisions.

“I haven’t seen the text,” Manchin said. “I think everybody’s being considerate, and we’re all moving in a positive direction.”

But Manchin warned that the methane fee would need to be carefully worded.

“You can’t use things as a hammer,” Manchin advised. “You’ve got to give an incentive to do the right thing. … Methane pricing done wrong is very detrimental. It won’t happen.”

“Incentivize or penalize. Penalize doesn’t work. Incentivize does work,” the West Virginia senator added.