(Jenny Starrs/The Washington Post)

Jim Brainard is a Republican mayor in a Republican city in a Republican state. But that hasn’t stopped him from taking aggressive steps in recent years to combat climate change and become more energy efficient.

During his tenure, Carmel, Ind., has shifted its fleet to hybrid and biofuel vehicles, replaced streetlights with LED bulbs, installed hundreds of miles of bike paths and spent millions of dollars planting trees to absorb carbon dioxide and provide shade.

Carmel now has 102 roundabouts — more than any community in the country, he says proudly — that have reduced traffic accidents as well as helped to conserve gasoline, reduce air pollution and save electricity by negating the need for traffic lights. “For a long time, taking care of our environment was a nonpartisan issue,” Brainard said. “I have yet to meet a Republican or Democrat who wants to drink dirty water or breathe dirty air.”

But Tuesday afternoon, President Trump signed an executive order instructing the Environmental Protection Agency to roll back the Clean Power Plan, the Obama administration’s signature effort to combat climate change by limiting carbon emissions from power plants and requiring states to cut down on overall emissions.

Trump maintains that Obama-era regulations have unnecessarily hampered businesses and that freeing companies from such burdensome requirements will provide an economic boost.

Some mayors, governors and business leaders plan to press ahead with plans to clamp down on carbon emissions, saying it makes sense for the economy as well as the climate. “It doesn’t impact anything we’re doing,” Brainard said.

He’d rather not see the Clean Power Plan scrapped, but its absence won’t alter the trajectory of Carmel, which sits just north of Indianapolis, or many other places around the country. “Cities aren’t going to stop. They were working on things that save money and provide a better environment long before the federal government got involved with the Clean Power Plan, and they’ll continue to do so.”

[Trump moves decisively to wipe out Obama’s climate-change record]

It’s not only cities. About 30 states have established standards that require utilities and power companies to sharply increase their reliance on renewable energy over the next decade or more.

Falling prices for wind and solar and low prices for natural gas have further undercut coal’s share of the electricity market. According to the Sierra Club, 175 coal plants in the United States have shut down since 2010, and 73 others are scheduled to retire by 2030.

The Energy Information Administration is more sanguine about coal’s prognosis, but it still says that coal will be eased out of the electricity mix even without the Clean Power Plan. In a 2015 report, the EIA said that 90,000 megawatts of coal-fired capacity would be retired by 2040 with the plan in place. Without the plan, coal capacity would still fall by 40,000 megawatts.

“We’re not building any new coal plants in this country, and the existing ones are having a harder and harder time competing with ever-cheaper renewables,” said Mary Anne Hitt, the head of the Sierra Club’s “Beyond Coal” campaign. “There’s a . . . structural disadvantage for coal in the marketplace. That’s not something Donald Trump can wave away with the stroke of a pen.”

State-level programs to boost renewable sources of electricity have support, in some cases, across party lines. In the weeks after Trump’s election, Republican governors in three Midwestern states — Illinois, Ohio and Michigan — committed to adding more renewable power and boosting energy efficiency.

“If President Trump doesn’t recognize it, we’ve seen that Republican governors do see an investment opportunity with efficiency and renewable energy,” said Dick Munson, who works on clean energy programs in the Midwest for the Environmental Defense Fund.

(Peter Stevenson/The Washington Post)

In Illinois, Gov. Bruce Rauner (R) signed the Future Energy Jobs Bill, which was negotiated with the state’s Democratic-controlled legislature. The measure would channel more than $200 million a year into renewable energy investment. It also sets tougher standards for utilities, requiring them to reduce greenhouse gas emissions 56 percent by 2030. The Clean Power Plan would have required a comparatively modest cut of 34 percent.

In Ohio, Gov. John Kasich (R) vetoed a bill that would have weakened that state’s renewable standards. Major corporations such as Amazon and Whirlpool, as well as wind and solar developers, had urged him to stick to ambitious renewable goals. (Amazon chief executive Jeffrey P. Bezos owns The Washington Post.)

“I believe it’s real,” Kasich said of climate change in a speech last fall at the University of Texas at Austin. “You can’t read these stories about these things happening all over the world, on our coasts and the rising sea levels, without being concerned about it.”

Out west, California Gov. Jerry Brown (D) has made clear that he will eagerly push forward with his state’s efforts to combat climate change and shift to cleaner energy sources.

“Whatever they do in Washington, they can’t change the facts,” Brown said during a state of the state address days after Trump’s inauguration. “And these are the facts: The climate is changing, the temperatures are rising, and so are the oceans. Natural habitats everywhere are under increasing stress. The world knows this.”

Months earlier, Brown had signed legislation requiring the state to cut greenhouse gas emissions 40 percent below 1990 levels by 2030 — an ambitious goal compared with past targets. Weeks earlier, the state had hired an outside legal team that includes former U.S. attorney general Eric H. Holder Jr. to help defend its environmental and other policies in the age of Trump.

[Trump’s climate rollback could undermine our promises to the rest of the world]

Some of the nation’s biggest utilities also say that shelving the Clean Power Plan will have little effect on their long-term actions, which aren’t aimed at four-year presidential cycles but involve looking decades ahead.

“[Our] long-term strategy is focused on generating and delivering electricity in ways that meet the needs and expectations of our customers,” Nick Akins, chief executive of American Electric Power, one of the nation’s largest utilities, said in an email. “That includes diversifying our fuel mix and investing in renewable generation and other innovations that increase efficiency and reduce emissions. That won’t change.”

AEP’s 2016 carbon dioxide emissions were already 44 percent below 2000 levels, and Akins said the company expects further declines as it adds more natural gas and renewable power generation. It plans to invest about $1.5 billion in renewable energy over the next three years.

Marijke Shugrue, a spokeswoman for another major utility, NRG, said the company “set our sustainability goals back in 2014 unconnected to the Clean Power Plan. Whatever happens to that, our goals still stand. It made sense before, and it still makes sense.” The plan set a goal of reducing NRG’s carbon emissions by 50 percent by 2030.

Investors also understand that operating coal plants these days can be bad for the bottom line. After the owners of the 40-year-old Navajo Generating Station in Arizona announced Feb. 13 that they would close the station’s coal-fired power plant, Moody’s Investors Service called the decision “credit positive” for the owners.

Closing the enormous 2,250-megawatt facility — the largest coal plant west of the Mississippi River — “reduces risks associated with the coal-fired units meeting environmental standards,” Moody’s said. In addition, the shutdown “brings economic benefits to ratepayers.”

At the Environmental Defense Fund, Munson expects renewable energy will continue to surge even in states that lack renewable portfolio standards. “Look at Texas,” he said. “Not exactly a font of progressive policies.” Even so, Texas is home to one-fourth of the nation’s wind capacity, with more on the way.

On Nov. 27, wind energy set a record there, providing 45 percent of the state’s total electricity demand that day. Overall, wind provides 12.7 percent of the state’s electricity, and projects underway will bring that to about 16 percent when finished.

Yet it would still be a setback if Trump manages to stymie the Clean Power Plan, Munson said. “It was a symbol, and an important one, that suggests this is the path that our nation is going to take to tackle this challenge and do it in an investment-focused way,” he said. “Backing away from that sends the wrong message.”