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President Donald Trump's threats to back out of the Paris climate accord have revealed what is perhaps an unlikely foe: big businesses who may hate uncertainty more than regulation.

Twenty-five U.S. companies have signed a letter that will appear Thursday in full-page ads in the Washington, D.C. editions of the New York Times and the Wall Street Journal, exhorting the president not to exit the Paris Agreement, as he teased he might do in a tweet Wednesday and promised to do on the campaign trail.

I will be announcing my decision on the Paris Accord over the next few days. MAKE AMERICA GREAT AGAIN! — Donald J. Trump (@realDonaldTrump) May 31, 2017

The companies include Apple, Blue Cross Blue Shield of Massachusetts, Facebook, Google, Levi Strauss & Co, National Grid, PG&E, and Unilever.

"Climate change presents both business risks and business opportunities," the letter reads, saying that the Paris Agreement's "stable and practical framework" creates jobs and reduces "competitive imbalances" by requiring coordinated global action from developed and developing countries alike.

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In April, a group of 16 companies including Shell, mining company Rio Tinto, and Walmart signed a letter to Trump, expressing their support for the U.S. to participate in the agreement. And over 1,000 companies since November 2016 have reaffirmed addressing climate change through implementing the Paris Agreement by signing the Business Backs Low-Carbon USA statement.

CEOs — including those from major energy companies — have spoken out in favor of the Paris Agreement, despite estimates that the accord's pledge to keep global temperature increases below 2 degrees annually could cost as much as $4 trillion by the year 2050.

"We believe climate change is real," Shell CEO Ben van Beurden told NPR in mid-May. "One of the biggest concerns that I have around climate change is the unpredictability in which governments will go about it."

Related: Trump Leaning Toward Withdrawing U.S. From Landmark Paris Climate Deal

"If we have a very clear understanding that governments, successive governments, will continue to act consistently with a certain policy set that we believe in, I have no issue with it," he added.

Established energy companies that stand to profit from the continued shift towards natural gas and have a vested stake in seeing returns on the bets they've made aren't the only ones calling for Trump to stick with Paris.

Even some coal companies have been in favor, reflecting the capital expenditures they've made towards implementing "clean coal" technology and protecting their overseas power-plant products.

And early Wednesday afternoon, Tesla CEO Elon Musk threatened to leave Trump's business councils and advisory boards over the issue.

Will have no choice but to depart councils in that case — Elon Musk (@elonmusk) May 31, 2017

The call for clear guidance was also echoed in remarks by an executive at future-forward Apple, arguably one of the greenest and most progressive companies in terms of consumer perception.

Lisa Jackson, vice president of Environment, Policy and Social Initiatives at Apple noted to the Washington Post that the company had its facilities operating on 100 percent renewable energy in 24 countries and is working on transitioning its supply chain to using renewable sources — investments that could be undermined by competitors who choose to play by looser environmental standards.

Related: On Campaign Trail, Trump Pledges to Rip Up Paris Climate Agreement

"The time for debate on climate change has passed,” Jackson said. "Certainty is what business needs."

Coal and solar stocks fell 1.2 percent Wednesday on news that the U.S. was leaning towards withdrawing from the agreement.