Many of the world’s biggest financial firms spent the past several years burnishing their environmental images by pledging to use their financial muscle to fight climate change.

Now, Wall Street has flip-flopped.

In recent days, giants of the financial world including JPMorgan, State Street and Pimco all pulled out of a group called Climate Action 100+, an international coalition of money managers that was pushing big companies to address climate issues.

Wall Street’s retreat from earlier environmental pledges has been on a slow, steady glide path for months, particularly as Republicans began withering political attacks, saying the investment firms were engaging in “woke capitalism.”

But in the past few weeks, things accelerated significantly. BlackRock, the world’s largest asset manager, scaled back its involvement in the group. Bank of America reneged on a commitment to stop financing new coal mines, coal-burning power plants and Arctic drilling projects. And Republican politicians, sensing momentum, called on other firms to follow suit.

The reasons behind the burst of activity reveal how difficult it is proving to be for the business world to make good on its promises to become more environmentally responsible. While many companies say they are committed to combating climate change, the devil is in the details.

“This was always cosmetic,” said Shivaram Rajgopal, a professor at Columbia Business School. “If signing a piece of paper was getting these companies into trouble, it’s no surprise they’re getting the hell out.”

American asset managers have a fiduciary duty to act in the best interest of their clients, and the financial firms were worried that a new strategy by Climate Action 100+ could expose them to legal risks.

Since its founding in 2017, the group focused on getting publicly traded companies to increase how much information they shared about their emissions and identify climate-related risks to their businesses.

But last year, Climate Action 100+ said it would shift its focus toward getting companies to reduce emissions with what it called phase two of its strategy. The new plan called on asset-management firms to begin pressuring companies like Exxon Mobil and Walmart to adopt policies that could entail, for example, using fewer fossil fuels.

In addition to the risk that some clients might disapprove, and potentially sue, there were other concerns. Among them: that acting in concert to shape the behaviors of other companies could fall afoul of antitrust regulations.

“In our judgment, making this new commitment across our assets under management would raise legal considerations, particularly in the U.S.,” a BlackRock spokesman said in a statement.

BlackRock also said that one of its subsidiaries, BlackRock International, would continue to participate in the group — a tacit acknowledgment of the different regulatory environment in Europe. BlackRock also said it was initiating new features that would let clients choose if they wanted to pressure companies to reduce their emissions.

A State Street spokesman said that the company also saw potential legal risks, and that the firm determined the new approach “will not be consistent with our independent approach to proxy voting” and to engaging with the companies it invests in.

JPMorgan said it was pulling out of the group in recognition of the fact that, over the past few years, the firm had developed its own framework for engaging on climate risk.

On Friday, the day after JPMorgan, BlackRock and State Street pulled out, Pimco, another big asset manager, followed suit. “We have concluded that our Climate Action 100+ participation is no longer aligned with PIMCO’s approach to sustainability,” a firm spokesman said in a statement.

A spokesman for Goldman Sachs Asset Management, another member, declined to comment on Saturday when asked if it planned to remain in the group.

The fracturing of Climate Action 100+ was a victory for Representative Jim Jordan, Republican of Ohio, who has led a campaign against companies pursuing E.S.G. goals, shorthand for environmental, social and governance factors.

Embracing E.S.G. principles and speaking up on climate issues has become commonplace across corporate America in recent years. Chief executives warned about the dangers of climate change. Banks and asset managers formed alliances to phase out fossil fuels. Trillions of dollars were allocated for sustainable investing.

At the same time, a backlash grew, with Republicans claiming that banks and asset mangers were supporting progressive politics with their climate commitments.

Some states, including Texas and West Virginia, banned banks from doing business with the state if the firms were distancing themselves from fossil fuel companies. And late in 2022, Mr. Jordan began an antitrust investigation into the group, calling it a “climate-obsessed corporate ‘cartel.’”

On Thursday, he said in on a post on X that the news represented “big wins for freedom and the American economy, and we hope more financial institutions follow suit in abandoning collusive ESG actions.”

Mindy Lubber, the chief executive of Ceres and a member of the steering committee of Climate Action 100+, disputed the notion that the new strategy represented a change from the focus on enhanced disclosure.

“Phase two is not that different,” she said. “It’s basically investors working with companies and saying: ‘OK, you’ve disclosed the risk. We just want to know how you’re going to address it.’ Because that’s what the investors want. How are you dealing with risk?”

Ms. Lubber said she was disappointed that the big asset managers had pulled out of Climate Action 100+, but hoped that they would continue to pursue efforts to reduce the risks posed by the heat waves, floods, fires and storms being made worse by man-made global warming. “You cannot make a new theory that climate risk is no longer a material financial risk,” she said.

Several of the firms that backed out of Climate Action 100+ said they remained committed to the issue. JPMorgan said that it had a team of 40 people working on sustainable investing and that it believed “climate change continues to present material economic risks and opportunities to our clients.”

Aron Cramer, chief executive for BSR, a sustainable-business consultancy, said the Wall Street firms were responding to political pressure, but not abandoning their climate commitments altogether.

“The political cost has heightened, the legal risk has heightened,” he said. “That said, these corporations are not doing U-turns,” he added. “They continue to consider climate. That’s not going away. It’s adapting to the current environment.”