CEOs are cautious by nature, circumspect in their words and actions.

So maybe the most amazing thing that occurred Thursday wasn't that President Trump pulled out of the Paris climate deal. It was the response from the corner office: A string of CEOs loudly voiced strong opposition to his action.

"It's an absolutely bizarre and unprecedented moment in American history," presidential historian Douglas Brinkely told CNNMoney. He called the reaction a sign of just how damaged the Trump brand is in the eyes of corporate America.

"Donald Trump is such a pariah figure that companies want zero association with his brand," Brinkley said. "He's championing dirty air and polluted water. He's anti-science. Why would a Fortune 500 CEO want to be associated with that?"

Related: Top CEOs tell the CEO president - You're wrong on Paris

Critics of Trump's decision worry that U.S. companies will miss out on opportunities to profit from a global move to reduce carbon emissions. Countries, businesses and consumers will spend trillions in the coming decades on greener vehicles, equipment and sources of power.

More immediately, CEOs might be worried about selling their products abroad, where Trump's decision is overwhelmingly unpopular.

"There could be a stigma attached to every U.S. firm," said Greg Valliere, chief global strategist with Horizon Investments. "If you're marketing a movie or a product in Western Europe, you've got to be worried about how this is being perceived. They can now say, 'Don't blame us, we came out strongly against this.' It's in their own self-interest."

And it's not just people in the rest of the world who are upset with the president's actions. The decision plays well with his base. But a joint poll by the Harvard school of public health and Politico found 62% of Americans supported staying in the Paris agreement.

"You can not run a major American corporation appealing to Donald Trump's 38%," said Brinkley.

Opposition came from Silicon Valley environmentalists like Tesla (TSLA) CEO Elon Musk, who was the first to quit a presidential advisory committee in protest.

It also came from Wall Street bankers like Goldman Sachs (GS) chief executive Lloyd Blankfein, who happens to be the former boss of Trump's top economic adviser. Blankfein tweeted for the first time to criticize the deal.

Related: Paris climate deal - Trump thinks one thing. Business believes another

Jeffrey Immelt, who runs that quintessential industrial conglomerate General Electric (GE), also tweeted his disapproval. And he did so knowing that GE depends on the federal government for more than $3 billion in sales and $600 million of government-sponsored R&D spending.

Walt Disney (DIS) CEO Bob Iger also quit the president's advisory council in protest. And tech executives who head some of the most valuable companies on the planet also criticized Trump. Apple's Tim Cook, who said he had lobbied the White House not to pull out, denounced the move, as did Google (GOOGL) CEO Sundar Pichai, Microsoft (MSFT) president Brad Smith, and Facebook (FB) founder Mark Zuckerberg.

In stark contrast, few executives voiced support for Trump's move.

The U.S. Chamber of Commerce has raised questions about the Paris climate deal, but it did not endorse or oppose withdrawing from the agreement. It issued a somewhat neutral statement after Trump's announcement. The American Coal Council issued a statement supporting Trump's action but did not immediately post it on its website or tweet it.