President Donald Trumps assault on policies to combat climate change have drawn fierce condemnation over the past few months from states across the Northeast.

On Wednesday, nine of those states translated words into tangible policy, passing the first major test of how serious they were about taking on the mantle of slashing planet-warming emissions.

The Regional Greenhouse Gas Initiative , the countrys only interstate cap-and-trade market, announced new, stricter targets for reducing climate-altering emissions from power plants. The states in the nonprofit program Connecticut, Delaware, Maine, Maryland, Massachusetts, New Hampshire, New York, Rhode Island and Vermont agreed to cap emissions at about 75 million tons in 2021, a number which would decline by 2.25 million tons every year until 2030, resulting in a total decline of 30 percent.

Factoring the impact that RGGI pronounced Reggie has already had since it began eight years ago, that would mean a reduction of 65 percent in overall emissions by 2030.

Its a major victory for the region, given the fact that it has all nine states on board, five of which are Republican governors, said Jackson Morris, the Natural Resources Defense Councils director of Eastern energy. You couch all that in the lens of the Trump federal situation, and its a major victory today for acting on climate.

The move comes a month after California voted to renew its own statewide cap-and-trade market.

Cap-and-trade programs a conservative policy idea devised by Reagan-era economists set a limit on total emissions and then allow companies to buy and sell pollution permits. If the cost per permit exceeds certain levels, RGGI automatically creates more, to prevent the program from rapidly driving up the cost of electricity. New allowances are issued if the price hits $10 per permit in 2017, and that figure rises at a rate of 2.5 percent each year. (That price, for instance, was $4 in 2014.)