PROVIDENCE — The need for action on climate change is becoming more urgent, according to proponents of a bill that places a fee on all instate fossil fuels.

The call to action is bolstered by research showing an acceleration of global warming. A United Nations draft report suggests that reversing the trend will be difficult.

At the national level, prominent old-school Republicans endorse a fee on fossil fuels. Few, however, hold positions of power in Washington, D.C. The default position of Republican leadership is to cast doubt on the human role in climate change and spread conspiracy theories that discredit the scientific consensus.

The face of the carbon-tax effort in Rhode Island is J. Timmons Roberts, a professor at Brown University who has been studying climate change for 25 years. Roberts leads a team of students who assist with carbon-tax research and help the advocacy group Energize Rhode Island with pushing a carbon-tax bill.

“This a major piece of legislation because this is a major issue,” Roberts said at a March 28 Senate hearing. “We need boldness. And small tinkering on the edges is not going to be enough.”

The bill is running through the General Assembly for a fourth year. In 2017, the Senate made a concession by passing a bill (S108) that ordered a study of the impacts of a carbon tax on Rhode Island. Gov. Gina Raimondo signed the bill, but the study has languished because of a lack of funding.

Roberts said the cost of the study is about a quarter of the original estimate and urged the Senate to pull together money from the budget and private foundations. The report was supposed to be completed by Dec. 31, 2017.

A study commissioned by Energize Rhode Island in 2015 found that a carbon tax would create up to 5,000 new jobs and generate about $140 million annually. Forty million dollars would subsidize renewable-energy projects and energy-efficiency programs. The remainder would returned to the public as a dividend.

Raimondo favors a federal carbon tax or a regional one run by the Regional Greenhouse Gas Initiative (RGGI).

Carbon tax bills sponsored by Sen. Sheldon Whitehouse, D-R.I., have never had congressional hearings.

“We would all love this to be dealt with on the federal level but it’s just not moving in our current Washington situation. In fact, climate legislation is going backwards,” Roberts said.

The Senate bill is opposed by the Oil Heat Institute of Rhode Island, an advocacy group for the state’s home heating oil industry. The group notes that 40 percent of the heating oil shipped to the Port of Providence is used in Connecticut and Massachusetts.

“The carbon pricing program can be interpreted as penalizing energy consumers in R.I.,” according to Roberta Fagan, executive director of the Oil Heat Institute of Rhode Island. “Perhaps a tax should be considered on methane leaks rather than imposing a carbon pricing program based on CO2 emissions.”

The bill is also opposed by Guardian Fuel & Energy, a heating oil sales company in Westerly that sells biodiesel. Other opponents claim that a fee on fossil fuels will slow the economy. Those opponents include the Greater Providence Chamber of Commerce, New England Convenience Store & Energy Marketers Association, Northern Rhode Island Chamber of Commerce, Rhode Island Lumber and Building Materials Dealers Association, Rhode Island Public Expenditure Council and the Rhode Island Business Coalition.

The renewable-energy advocacy group Acadia Center noted that the fee on power-plant emissions under the RGGI program has been the single-biggest tool for reducing Rhode Island’s carbon emissions. RGGI states also have had stronger economic growth than non-RGGI states.

The bill is supported by the Audubon Society of Rhode Island, Citizens Climate Lobby, Sierra Club Rhode Island Chapter, Environment Council of Rhode Island, People’s Power & Light and Save The Bay. Washington, D.C., conservative think tank R Street Institute supports a carbon tax but wants all of the tax revenue returned to the public and not used for renewable-energy projects.

“Everyone is in agreement that something has to be done. … This bill gives us an outline of how to do that,” said Nicole DiPaolo of the Sierra Club Rhode Island Chapter.

The bill was held for further study. A House version (H7400) has yet to have a hearing scheduled.