Last month, I packed my bags for Paris, joining nine of my fellow United States Senators to support the “high ambition coalition” for a strong international climate agreement. It was impressive to see so many nations represented in Paris, active, and trying to help. I brought home a really good feeling about that historic summit, particularly in three areas.

First, oceans were a part of the conference. I had the chance to speak at Oceans Day, where people were keenly aware that the effects of carbon pollution on our oceans are undeniable. You can measure the warming oceans with a thermometer. You measure sea level rise with a yardstick. You can measure the dramatic increase in acidification with a simple pH test, and you can replicate what excess CO2 does to seawater in a basic high school science lab

It’s pretty hard to dispute. That’s why the polluter-funded climate-denial industry steers away from oceans — it’s too plain and obvious a problem for denialism— but that makes it all the more important that we pay attention. The worst blows to humanity from carbon pollution may come at us from the oceans.

My second takeaway was how well America was represented there. I had the chance to cheer on our bright, young, negotiating team staff, who were working late hours in their windowless common workspace, and also to meet students and faculty visiting from Brown University. We also met with Todd Stern, long-time leader of the U.S. negotiating team, and Vice President Gore, our long-time champion. NOAA scientists ran the United States pavilion. It was great.

The only sad part was that our Senate delegation was all Democrats. No Republican was able to come with us. The fossil fuel industry would never let them. The American Republican Party is the last political bastion of the fossil fuel industry — now so in tow to the fossil fuel industry that it cannot face up to the realities of carbon pollution and climate change.

We were able to send the world the clear message that we had the President’s back. We will protect the Clean Power Plan. We will protect the Clean Air Act. And we will protect the American-led agreement that has now come out of Paris.

The third big take-away was the robust American corporate presence. Leading businesses and executives from America and around the world were there in Paris to support a strong international climate agreement. Companies like PG&E of California, VF Corporation of North Carolina, Citigroup of New York, Kellogg of Michigan, Ben and Jerry’s of Vermont, and Facebook of basically everywhere, all were there to cheer on a good climate deal. So was the American Sustainable Business Council. Unilever CEO Paul Polman met with our delegation to express the growing support in the corporate community for climate action, and to describe Unilever’s work to catalyze that support.

More than 150 companies had signed onto the White House’s American Business Act on Climate Pledge, joining the call for a strong outcome in the Paris climate negotiations. These companies have operations in all 50 states, employ nearly 11 million people, represent more than $4.2 trillion in annual revenue, and have a combined market capitalization of over $7 trillion: companies like AT&T of Texas, Coca-Cola and UPS of Georgia, Proctor & Gamble of Ohio, and Wal-Mart of Arkansas.

With Paris a success, now it’s time for them to turn their attention to Congress. America’s leading corporate voices were calling for a strong Paris agreement, yet many of their home-state Republican Senators are trying to undercut their work. This is the fault of the fossil fuel industry, primarily, and the climate denial apparatus it supports. The power the fossil fuel industry exerts over Congress is polluting American democracy; the propaganda it emits through its front groups is polluting our public discourse; and of course its carbon emissions are polluting our atmosphere and oceans — it’s a triple whammy and a disgrace.

Until now, the rest of corporate America has ceded the political field in Congress to the fossil fuel industry. But with a little effort on their part, the grip of the fossil fuel companies can slip.

It’s time now for corporate leaders to push Congress to take strong climate action.

I spoke recently on the Senate Floor about climate stars Coca-Cola and PepsiCo, who have terrific climate policies, and who supported a strong climate agreement in Paris. But their lobbying in Congress is done by the American Beverage Association, which is silent on climate, and by the U.S. Chamber of Commerce, one of our most implacable opponents. That can’t last.

Mark my words: as the rest of corporate America stands up, the fossil fuel industry’s fortress of denial and deceit will come tumbling down.

We’re back home now from Paris and a strong agreement was reached. The entire world has awakened to face the reality of climate change and take concrete steps to combat it. Congress now needs to wake up. And if America’s great corporations will line up their advocacy in Congress with their policy, that can happen.