The supreme court hit the pause button on Barack Obama’s plans to cut climate pollution from power plants, injecting new uncertainty into the viability of Obama’s climate plan once he leaves office in 2017. But that will not bring back coal from the brink, and it may not stop some states and power companies from moving ahead on their own to clean up the US electrical grid.

A day after the supreme court’s 5-4 ruling to halt the Environmental Protection Agency rules cutting carbon emissions from power plants, the White House dared to describe the decision as little more than “a bump in the road”.

Tuesday’s decision puts a temporary freeze on Obama’s signature climate policy: a plan to cut carbon emissions from power plants 32% on 2005 levels by 2030.

But the EPA will keep on working with states that decide to go ahead with their plans and “the administration will continue to take aggressive steps to make forward progress to reduce carbon emissions”, the White House said on Tuesday.

The White House said the rule, though aimed at the biggest single source of US emissions, was part of a suite of climate measures.

“We’re going to continue to take aggressive steps to reduce greenhouse gas emissions,” said White House deputy press secretary Eric Schultz, pointing to stricter emissions standards for cars, trucks and aircraft, as well as the long-term extension of renewable energy tax credits. Those credits, he said, will have a larger impact on emissions than the clean power plant law.

More than 30 states were actively working to comply with the EPA rules, including Michigan, Minnesota, Pennsylvania and Virginia, according to the Ceres sustainable business network. A number of major utilities, including American Electric Power in Ohio, Xcel in Minnesota and DTE in Michigan were also working to cut emissions, Ceres said.

The governors of California, Colorado and New York reaffirmed they would push ahead on their climate action plans. Jerry Brown, California’s governor, accused the justices of being “tone-deaf”.

“This arbitrary roadblock does incalculable damage and undermines America’s climate leadership,” Brown said. “But make no mistake, this won’t stop California from continuing to do its part under the Clean Power Plan.”

Andrew Cuomo, New York’s governor, also said his state would move forward on its climate plan. “New York State remains committed to moving forward with our own actions to protect the environment and the public health,” he said in a statement. “But this issue requires a global response – and the Clean Power Plan is crucial to ensuring a cleaner, greener, and safer future for all.”

Fitch, the major credit rating service, also said that some power companies and states had already started to move funds to clean energy, in anticipation of the rules.

“Fitch has assumed compliance by states in its longer-term sector outlook,” the ratings service said. “The clean power plan had already begun to influence the business strategies and capital expenditures across the US power sector, and it is unclear how the industry participants would react to the delay induced by the stay.”

Fitch said there were now doubts about whether the EPA could keep to a schedule that required states to put forward plans for power plants by September.

However, Vicki Arroyo, who heads the Georgetown Climate Center, noted that the judges had refrained from extending the timeline in their decision on Tuesday.

“Since the court declined to extend the actual (later) compliance deadlines, it is possible that states will still be held to a similar timeline for compliance,” she said.

But she acknowledged that any slippage in the timeline increased the risk that a Republican president could stall the regulations – if the party takes the White House in November. “Obviously that does get us close to the Presidential election and it’s possible that a future Administration might try to slow-walk any changes required or not continue to defend it – to your question on timing, though I sincerely hope that does not happen,” she said in an email.

As you know, the Supreme Court has been clear in three separate cases now that the EPA has the authority and responsibility to regulate greenhouse gases under the Clean Air Act – with the AEP v CT case pointing to the 111 approach with states in particular as an alternative to that nuisance suit. We’re optimistic that much if not all of the rule will be upheld on the merits.

Administration officials told reporters in a conference call they remained confident in the EPA’s strong track record of winning environmental lawsuits brought by industry. When the power plant rule gets a full review by the court later this year, the White House expects to win.

“We do remain confident that we’re going to prevail on the merits when the clean power plant rule gets its full day in court,” said Schultz.

Officials also noted that other air pollution rules – which have a knock-on effect on carbon emissions – remained in effect, and that states were moving ahead on policies promoting renewable energy.

California, which has the most aggressive plan, has committed to obtain 50% of its electricity from renewable sources by 2030. Such measures being rolled out in other states were bound to push more coal-fired power plants out of service, experts said.

Other states – and utility companies – were pushing ahead to clean up their fleets of power plants, clean energy industry groups said.

“This is not the end of the story,” Gregory Wetstone, chief executive officer of the American Council on Renewable Energy, said. “Public and private sector momentum behind the shift to lower carbon power generation will continue.”

Meanwhile, campaign groups said a historic transition away from coal-fired power plants was already occurring – with or without the EPA rules.

“The shift in the electricity from coal and natural gas towards clean power is ongoing, and it doesn’t depend on the clean power plan,” Joanne Spalding, the Sierra Club’s chief climate counsel. “It is actually following the trends in the electricity sector. It is not setting them. There is no reason for that to slow down even though the rule is stayed.”

Coal made up just over a third of US electricity generation last year – the lowest on record and in line with EPA forecasts. In November alone coal use fell further, making up only 29% of the power mix, according to government data.

That was well on its way to the EPA projections for 2030, the target date of the clean power plant rules. The agency has projected that coal would account for just 27% of US power generation by 2030.

Even so, some leading Democrats admitted the court decision had injected an element of doubt into the future of the power plant rules once Obama leaves the White House in 2017.

Some of the states and industry groups suing the EPA also said they saw the decision for a stay as an indication they would eventually succeed in overturning the rules.

Paul Ryan, the US House speaker, called the ruling “a victory for the American people and our economy”.

“This rule should be struck down permanently before coal country is destroyed completely, and American consumers are consigned to higher energy prices,” he said in a statement.

Harry Reid, the Democratic leader in the Senate, said the supreme court decision was “an unfortunate setback” and completely unexpected. “This was an especially stunning move by the supreme court given just weeks ago the DC circuit court of appeals categorically rejected a halt of the clean power plan.”