A group of international investors managing more than $15 trillion in assets has sent a letter urging the administration of Donald Trump to not to pull out of the Paris Accord to fight climate change, as he has threatened, and to implement US commitments to the landmark agreement.

“As long-term institutional investors, we believe that the mitigation of climate change is essential for the safeguarding of our investments,” according to the letter signed by 214 institutional investors and published on Monday.

The letter, which was broadly addressed to leaders of the Group of Seven Industrialized Nations, comes as the argument in the Trump White House is reportedly tilting toward withdrawing from the accord reached at the COP 21 talks in 2015. Under Paris, 197 countries agreed to hold world temperature increases to between 1.5 and 2 degrees Celsius, and to present national plans that would contribute to staying within that limit.

“We urge all nations to stand by their commitments to the Agreement,” the investors’ letter said. Signatories of the letter included the California Public Employees Retirement System, Nordea Wealth Management, HSBC Bank and other powerful pension funds from Sweden to Australia.

Trump campaigned on populist promises to “cancel” the Paris accord, painting it as an undue restraint on America’s coal and gas industry. Since coming to office, he has populated his administration with climate skeptics, and chiseled away at Obama-era environmental regulations with executive orders propping up oil exploration.

Climate marchers filing past Trump Tower Chicago in 2016. Credit: Flicker/Max Herman, Survival Media

Last week, an outraged public took to the streets in record numbers in Washington, New York and dozens of other cities to demand the US live up to its commitment to combat climate change.

Now concerns that Trump will hedge on the Paris Agreement have reached global levels.

The letter from the Investors Platform For Climate Change comes before the Group of Seven meets in Italy later this month, where international partners will inevitably ask questions about US participation in the Paris Climate Accord. The letter is also addressed to the wider G20, and is timed to coincide with the United Nations Climate talks in Bonn, Germany, which begin Monday.

Other business groups have jumped on board with pleas to Trump to leave the Paris Agreement alone. Last week Shell, BP, General Mills, and Walmart sent an appeal the White House. That was followed by a full-page ad in the New York Times urging Trump to stay in Paris from US-based companies including Apple, Facebook, Microsoft, Hewlett Packard, Intel and others.

“As some of the largest companies based or operating in the United States, we strongly urge you to keep the United States in the Paris Agreement,” the ad stated simply. They argued that adhering to climate goals strengthened US competitiveness and created job opportunities within clean technologies.

The European Union has likewise scrambled to persuade Trump to stick with the accord.

The letters and appeals may be falling on deaf ears. According to US media, the argument in the White House is between those who would stay in the Paris Accord only to weaken US commitments to it, and those who would abandon it all together.

According to the New York Times, the White House is circling around Article 4.11 of the agreement, which states that a nation “may at any time adjust its existing nationally determined contribution with a view to enhancing its level of ambition.”

The question is whether the ability to “adjust” implies only progress in national commitments, or permits backsliding without violating the terms of the deal. The administration’s nationalist right wing argues that the language of the provision does not allow nations to weaken their commitments, and urges Trump to walk away to avoid international legal problems.

More moderate voices, among them Secretary of State and former ExxonMobil CEO Rex Tillerson, believe that the agreement does allow downward adjustments to nations’ goals and targets, and that the administration should modify the commitment, not walk away.

One thing is clear: If the Trump does stay in the Paris accord, he is unlikely to stick with the United States’ current pledges to cut its emissions 26 to 28 percent below 2005 levels by 2025.

Yet backing out of Paris might be more harmful to the US that to the rest of the world. UN Environment chief Erik Solheim, told Reuters that a back out by Washington would mean the US would cede wind and solar jobs to India and China while Trump tries to resuscitate America’s dwindling coal industry.

And with green advances being led by international businesses, Solheim said the momentum no longer rises and falls with Washington’s bad choices.

“Even if the worst were to happen and the United States were to withdraw, the consequences would be much less than people think,” he said.