Storm clouds gather over the White House in August 2018. (LEAH MILLIS/Reuters)

The District would adopt one of the nation’s most aggressive plans to cut carbon emissions, aiming to use entirely renewable sources of energy for the city’s power grid just 14 years from now, under new legislation proposed by five D.C. Council members.

The bill — which would also enhance the city’s green building standards and authorize the mayor to enter regional agreements with Virginia and Maryland to cut greenhouse gas emissions — comes at a moment of international reckoning with the problem of climate change.

A report released this week by the world’s top scientific panel studying global warming warned that time has almost run out for governments to prevent catastrophic changes to the environment. The report by the U.N. Intergovernmental Panel on Climate Change stated that “there is no documented historic precedent” for government action of the kind needed to avert those changes.

Those findings arrive at a time when enthusiasm in the federal government for aggressive policies to combat climate change is at a low ebb. President Trump said last year that he would withdraw the United States from the landmark Paris climate accord, and he has consistently allied himself with the coal industry, whose activities are a major source of carbon emissions.

But if the outlook for an effective international response to climate change is dim, D.C. officials should still do what they can to reduce emissions at the local level, said council member Mary M. Cheh (D-Ward 3), who drafted the bill and heads the council’s committee on transportation and the environment.

“What’s the alternative — to do nothing?” Cheh said in an interview. “We either do our best and encourage others to do their best and the national government to change their position on this, or we give in and accept catastrophe.”

More than 80 witnesses were scheduled to testify on the bill Tuesday at an initial public hearing by the transportation and environment committee. The bill must also pass through the committee on business and economic development before going before the full council, which supporters hope could happen this year.

Along with Cheh, the bill’s introducers were Council Chairman Phil Mendelson (D) and members Brianne K. Nadeau (D-Ward 1), Charles Allen (D-Ward 6) and Trayon White Sr. (D-Ward 8).

Many of the witnesses expressed support for the bill’s core tenets at the hearing, the result of what Cheh said was a long process of discussion and debate with activists and businesses. Some supporters noted that the District could be directly harmed by climate change, experiencing dangerously hot summers and floods from the Potomac and Anacostia, both tidal rivers that would be affected by sea-level rise.

Others sounded a cautious note about the cost to ratepayers for an aggressive push toward entirely renewable power sources by 2032. (Under its existing policy, the city is on track to get 50 percent of its energy from renewable sources by that year.)

Sandra Mattavous-Frye, who heads the D.C. Office of the People’s Counsel — which represents the interests of utility customers in the District — said that while her office “supports the bill’s clean-energy goals,” those targets should be balanced with the “equally important public policy goal of affordability” for consumers.

The bill includes an increase in across-the-board fees on electricity and natural gas consumption that Cheh’s office estimates would add $2.10 to D.C. residents’ average monthly gas bills and less than $1 to their average monthly electricity bills. About 20 percent of the money generated from those fees would be used to provide financial assistance to low-income ratepayers, while the rest would fund other local sustainability initiatives.

Other states and cities have adopted ambitious goals for using cleaner power, though many are not as aggressive as those in Cheh’s bill.

California is working to supply 50 percent of residents’ electricity from renewable sources by 2030. Beginning in 2019, San Francisco will offer consumers the option of receiving electricity from renewable sources but does not require it.

Virginia’s renewable energy goal, adopted in 2007, aims for 15 percent renewable sources by 2025. It’s a voluntary goal, intended to encourage utilities to switch to renewables.

In 2016, the Maryland General Assembly passed legislation requiring the state to obtain 25 percent of its energy from wind, solar and other renewable sources by 2020.

Gov. Larry Hogan (R) vetoed the bill, saying it would lead to rate increases, but the Democratic-controlled legislature overrode his veto last year.

Gregory S. Schneider and Ovetta Wiggins contributed to this report.