AMNA NAWAZ: Yesterday, the Environmental Protection Agency announced what it called the biggest deregulatory action in U.S. history.

The proposed rollbacks would impact dozens of rules, from emissions limits for power plants and vehicles to wastewater regulations and air quality standards.

Stephanie Sy has more.

STEPHANIE SY: Amna, the EPA was created by President Nixon in 1970 in essence to protect the air we breathe and the water we drink.

Under later presidents, that mission expanded to addressing greenhouse gases, which contribute to global warming.

Now EPA Administrator Lee Zeldin says his agency wants to drive a dagger straight into the heart of what he calls climate change religion.

With the stated goal of unleashing energy, Zeldin's proposals include a call to upend the basis for all the EPA's climate change actions.

To help us unpack some of this, we're joined by Zack Colman, who covers the topic for Politico.

Zack, just describe the scope and scale of these proposed changes.

ZACK COLMAN, Politico: This is the most sweeping rollback of environmental rules in the nation's history.

We're talking about going back to the 1970s era, where these rules didn't even exist yet.

So this is erasing decades of -- potentially erasing decades of climate and air pollution rules.

But, again, this is also going to be something that's litigated in the courts.

So we don't quite yet know exactly where this will end up.

STEPHANIE SY: So among the dozens of rules proposed that would roll back environmental protections, Zeldin also made it clear that he wants to revise the conclusion that greenhouse gases endanger public health.

That was a scientific finding reached by Obama's EPA in 2009.

Here's what Zeldin said yesterday.

LEE ZELDIN, Environmental Protection Agency Administrator: I have been told the endangerment finding is considered the Holy Grail of the climate change religion.

For me, the U.S. Constitution and the laws of this nation will be strictly interpreted and followed, no exceptions.

Today, the green new scam ends.

STEPHANIE SY: And indeed, this finding, as I understand is, Zack, is foundational to all the EPA's climate change regulations.

What would it take for the Trump administration to overturn that?

ZACK COLMAN: It would take a lot.

I mean, you have to come up with science that says the thing that we know is not true, that global warming isn't happening and that humans are not contributing to it and that climate change isn't a problem for public health and the environment.

It doesn't seem clear how exactly they would be able to accomplish that.

The other potential avenue is a legal avenue, and it's not yet clear exactly how the Trump administration would pursue that.

Again, the Trump administration tried to roll back a lot of environmental laws in its first term and it lost a lot.

It did not succeed in many of those cases.

So a lot of this is up in the air, but it's very clear that these are enormous strikes against foundational climate law and science.

STEPHANIE SY: I just want to follow up on that.

If the end goal is for the Trump administration to get this back to the Supreme Court, is there a world in which you envision a conservative-leaning court actually relitigating the case that brought us to the endangerment finding?

ZACK COLMAN: I think that's one of the big questions and it's certainly something that the Trump administration is willing to try.

This is a 6-3 conservative Supreme Court, and there has been a lot of disdain in the Republican circles about the decision that led to the endangerment finding.

There's a lot of people who think that that decision never should have been made.

So I think there is very much an interest in testing whether this court would pick that up.

And I think a lot of conservatives feel like they would be on pretty decent footing, at least compared to that 2007 decision that led to the endangerment finding.

STEPHANIE SY: Environmentalists and Democrats are slamming this announcement, saying it's about -- quote -- "lining the pockets of billionaire corporate polluters."

The Trump administration argues this deregulation will kick-start the economy and lower costs for everyday Americans.

How are relevant industries responding, Zack?

ZACK COLMAN: Well, industries are responding positively to the idea of rolling back climate and air pollution regulations.

A lot of them thought that the Biden administration policies were taking the markets to an unrealistic place.

You look at auto sector in particular, where there are a lot of companies that said, look, we agree that we need to transition to electric vehicles, but the marks that you're putting down are a little too aggressive and they're not based on consumer preference.

They're not -- people aren't buying these cars at the rate that we would need to actually produce them to meet these rules.

So there is a lot of applause from industry.

However, there is some concern from industry circles and even some Republicans about going after the endangerment finding, which they think could be a distraction and actually could be politically demotivating to getting some of these regulations done.

STEPHANIE SY: I want to ask you one quick question.

The EPA also announced it is shuttering its environmental justice offices.

What could the immediate impact be there?

ZACK COLMAN: When you think about environmental justice, this is about helping communities that have been disproportionately burdened with pollution.

They're often located near heavy-emitting facilities because of political disenfranchisement, where people didn't get a chance to push back against things that they didn't want in their backyard.

And if you get rid of those offices while at the same time lowering the floor of environmental standards for the entire country, it's really a double hit to those communities that have always taken a brunt of our nation's pollution and have the least ability to resist that being thrust upon them again.

STEPHANIE SY: Zack Colman, climate change reporter at Politico.

Thank you, Zack.

ZACK COLMAN: Thank you.