Maryland and eight other states plan to further tighten air pollution limits aimed at reducing global climate change.
The states are part of the Regional Greenhouse Gas Initiative, which caps carbon dioxide pollution in the Northeast. The states announced Thursday that they plan to reduce the carbon pollution cap by 30 percent between 2020 and 2030.
Gov. Larry Hogan said the move is an important step in fighting climate change.
"Maryland is committed to finding real bipartisan, common-sense solutions to protect our environment, combat climate change, and improve our air quality," the Republican governor said in a statement Wednesday.
Hogan's environment secretary, Ben Grumbles, said the move will be "a win for both our environment and our economy."
The other states in the greenhouse gas initiative are Connecticut, Delaware, Maine, Massachusetts, New Hampshire, New York, Rhode Island and Vermont.
Through the program, states auction off greenhouse gas emission allowances and use the money to pay for energy efficiency and renewable energy programs. Power plants that use fossil fuels such as coal that can generate at least 25 megawatts of power are required to purchase allowances.
The total emissions cap has been decreasing by 2.5 percent each year, which was scheduled to continue until 2020. The new action sets the reductions for the decade after that.
Environmentalists praised the new caps, and singled out Hogan for supporting the RGGI program at a time when President Donald J. Trump has dismissed climate science and moved to withdraw the United States from an international climate treaty known as the Paris climate accord
"In this current national political environment, it's more important than ever for Governor Hogan to take the lead and stand strong with the other states in RGGI," Karla Raettig, executive director of the state's League of Conservation Voters, said in a statement. "Which is why we are pleased that the Hogan administration joined with other RGGI state governors to make additional reductions."
The Maryland Climate Coalition, which includes several environmental and civic groups, said RGGI has been "an unquestioned success." RGGI has reduced carbon dioxide emissions in the state while simultaneously funding clean energy and energy efficiency programs, according to the climate coalition.
While Hogan did not join other political leaders in urging support for the Paris climate accord — which drew criticism from environmentalists — he has taken other steps to combat climate change and support energy efficiency.
Last year, Hogan signed an extension of the Greenhouse Gas Reduction Act, which requires the state to keep working to reduce emissions that lead to climate change. And this year he signed a statewide ban on hydraulic fracturing for natural gas and passed a bill giving incentives to owners of plug-in electric cars.
The new RGGI emissions limits are not yet in place. The states will hold a public hearing in Baltimore on Sept. 25. After that, each state is expected to adopt the emissions limits by enacting its own regulations.