States are stepping up efforts to regulate a group of potent greenhouse gases used in air conditioners, refrigerators and insulating foams.

The push to restrict use of hydrofluorocarbons, or HFCs, playing out in state capitals across the country represents one of the clearest examples of interstate coordination on climate policy.

It follows two years of inaction at the White House, where President Trump has not submitted a 2017 international treaty restricting HFCs to the Senate for ratification, and a federal court decision knocking down an Obama-era rule to phase out the chemicals nationally.

The state measures are modeled after the Obama EPA effort and come as the Trump administration has proposed scaling back a rule aimed at preventing HFC leaks (Greenwire, Sept. 20, 2018).

“This is in line with our work to look at the federal actions that are happening and to push back where anti-climate rollbacks are occuring,” said Reed Schuler, a climate adviser to Washington Gov. Jay Inslee (D). “The EPA under President Trump is not moving to confront the issue of HFCs. We know HFCs are growing in Washington and across the country and are increasing share of national emissions.”

California passed a law to limit HFCs last year. Washington lawmakers appear poised to follow suit. A bill calling for a reduction in HFCs has passed the state House and is now under consideration in the state Senate. Regulators in Connecticut, Maryland and New York are weighing similar rules.

More states may soon follow. The issue has emerged as a focal point for the U.S. Climate Alliance, a coalition of 22 states and Puerto Rico committed to the Paris climate accord.

“If you have widespread adoption across alliance states, which is not where we are, you’re talking about half the population using alternatives” to HFCs, said Julie Cerqueira, the alliance’s executive director. “It certainly is a significant opportunity.”

States have struggled to pass meaningful carbon reduction policies in the two years since Trump initiated America’s withdrawal from the Paris Agreement, despite pledges to redouble their climate efforts.

That has begun to change this year. New Mexico recently passed a law to green its electricity supply, and several other states may soon follow. Washington lawmakers are advancing a suite of bills aimed at slashing emissions from electricity, transportation and buildings. Oregon looks like it will join California’s cap-and-trade program. And a collection of Northeastern states are working on their own cap-and-trade program for transportation.

HFCs nonetheless represent a unique opportunity for states to make a meaningful contribution to climate policy. Unlike vehicle emission standards, federal law does not preempt states from regulating HFCs.

The pollutants, commonly used as a coolant in air conditioners and refrigerators, are also something of a rarity among greenhouse gases. Not only are they uncommonly powerful at trapping heat in the Earth’s atmosphere, but there is widespread agreement that their use should be limited.

In 2016, 197 countries agreed to amend the Montreal Protocol to reduce their use (Climatewire, Oct. 17, 2016). The deal reached in Kigali, Rwanda, calls for a 40% reduction in HFCs by 2024 and ultimately envisions use of the superpollutant falling to 15% of 2011-2013 levels by 2036.

Companies like Honeywell International Inc., Chemours Co., Carrier Corp. and the industry’s main trade group, the Air-Conditioning, Heating and Refrigeration Institute (AHRI), have argued the agreement could be a boon for American firms through the manufacture of HFC alternatives and next-generation air conditioners and refrigerants (Climatewire, Jan. 7). An industry-backed study estimated ratification of the Kigali Amendment would result in the creation of 1,400 jobs and $1 billion in capital investment.

“We’ve made it clear to the administration that the economic benefits of this transition, of an HFC phasedown, are significant domestically, and what it will let us do to capture a global market,” said Kevin Fay, who represents the Alliance for Responsible Atmospheric Policy, an industry group in favor of Kigali ratification.

A White House spokesman declined to comment.

Environmentalists support the restriction of HFCs on climate grounds. Some HFCs have a global warming potential several thousand times greater than carbon dioxide over their lifetime in the atmosphere. Full implementation of the Kigali Amendment is projected to limit nearly a half-degree Celsius of additional planetary warming. That would be a major boost to efforts to keep a global rise in temperatures below 2 C.

Greens say state action is important because not all companies are on board with the timetable for reducing HFC use. Two HFC manufacturers, Mexichem Fluor Inc. and Arkema SA, sued EPA over its 2015 plan to reduce the chemicals. The U.S. Court of Appeals for the District of Columbia Circuit ruled in favor of the companies, saying the agency had exceeded its authority under the Clean Air Act (Greenwire, Aug. 8, 2017).

“The goal of the state actions is to keep American industry on the transition pathway and to have the U.S. do its part in the reduction of HFCs,” said David Doniger, senior strategic adviser for the Natural Resources Defense Council’s climate and clean energy program. “You could get there by having 50 states adopting state rules, but you don’t have to if half a dozen or more large states send a signal that keeps the de facto national trend moving forward.”

Industry representatives have expressed unease at the state efforts, raising concerns about the creation of a regulatory patchwork and states’ ability to enforce the rules.

“Letting us devolve to a number of state programs will significantly scale down the economic benefits that are possible,” Fay said.

AHRI also strongly prefers a federal standard to state ones, said Francis Dietz, a spokesman for the trade group.

“But we’re sympathetic to states being concerned that the federal government isn’t moving as quickly as we’d like,” he said. “We’re working with them to make sure that at very least they harmonize their own phasedown plans.”

Environmentalists and state officials acknowledge those concerns. They, too, express a preference for a federal standard.

To address industry’s worries, state officials have routed their efforts through the Climate Alliance in an effort to standardize their rules.

Maryland Environmental Secretary Ben Grumbles said in a statement that alliance members are planning meetings later this year to “promote consistency among states on HFC regulations.” Maryland is working on a draft rule now and is aiming to finalize a standard by 2020.

New York officials said they are now accepting informal feedback and anticipate releasing a draft regulation later this year. They also noted they would consider changes to synchronize the rules to those in California and Washington.

Reprinted from Climatewire with permission from E&E News. E&E provides daily coverage of essential energy and environmental news at www.eenews.net.