>> The EPA is set to start rolling back regulations on greenhouse gas emissions and what President Trump is calling quote to the single largest deregulatory action in American history.

This comes after the agency repealed the 2009 endanger meant finding in which the agency found greenhouse gases that contribute to climate change are a danger to public health and welfare.

Now a coalition of environmental and health groups are suing the EPA over this change.

Here's the announcement from earlier this month.

>> Effective immediately where repealing the ridiculous endangerment finding in terminating all additional green emission standards imposed unnecessarily one vehicle models and engines between 2012 2027 and beyond.

This action will save American consumers.

Trillions of dollars.

And will lower the average cost of a new vehicle by.

Close to $3,000.

>> Joining us to talk about this, our Liz Moyer, a professor of atmospheric science at the University of Chicago.

And Susan, much senior policy advocate at the Environmental Law and Policy Center.

Thanks to both for joining us.

So Susan, let's start with the endangerment finding.

explain briefly for us what it is and how it came about.

under the Clean Air Act, which has been law in this country for over 50 years.

If a pollutant, any pollutant is found to endanger public health.

The EPA is bound to regulate it.

Scientists such as Liz have been finding for decades that.

And greenhouse gas emissions are harming public health.

Therefore the EPA back in 2008 excuse me, 2009 came up with the endangerment, finding another words.

Yes, science is showing that these pollutants caused public health and therefore we're going to regulate them.

So since 2009, a number of regulations that limit air pollution such as on cars, trucks, buses have limited the amount some of the pollutants coming out of tailpipes, I'm Liz briefly remind us just think everybody knows.

how greenhouse gases of their impact on climate change, how they contribute to climate change.

So greenhouse gases are the primary dot the primary factor that controls Earth's climate of the temperature at the surface and Co 2 is really the most important greenhouse gas on the earth.

Adding was here to make harder for the surface.

The shed and so in order to send off the heat to the gets from the sun has to warm up 0.

3rd, a basic stuff.

>> And the basic theory was laid out in 18 96 by a Swedish scientists then spent every day S and I like to tell people we've refined the predictions, but nothing has really changed in that time.

So.

It's very standard.

Pretty basic size.

They were initially predictions and then obviously.

Now we have data technology proving out those predictions that it's happening to the one thing that's changed since 2009 is that we are now seeing the effects.

So I would say we need to refining, went into effect was made in 2009.

It was based on predictions about climate change with do but not realized.

And in the last 17 years since then, there's been pretty severe changes in climate that really are allowing us to test those predictions.

And the answer is basically we were pretty correct.

You know, there's nothing if anything, the case is stronger than it would have been in 2009, the Environmental Law and Policy Center.

Susan, you are suing the EPA over these changes.

What is at stake for the environment if this rollback?

>> endangerment finding.

So the opc along with 17 other health, such as the American nurses for healthy environment, the American Lung Association.

>> 17 other groups are with us on this and what we're doing is seeking a review in the DC Circuit Court of Appeals, which is the second-highest court in this country asking to review Pa's decision.

And the review various legal back and forth.

But the idea is to.

say that pa's flimsy legal argument is not a reason to roll back this finding up in the summer suggested the science wasn't any good.

We're wrong.

And they realized after it was shown by others that they couldn't, they couldn't try to roll back based on science.

Instead, they try legal argument, which we don't have the authority to do this.

So even though that was the Supreme Court upheld Pa's authority and obligation to do this almost 20 years ago.

The EPA is now we really don't have the power to do this.

So you the you when the EPA announced its intent to repeal the finding, it relied heavily on a report from a climate working group that the administration had convened.

>> What do we know about this working group and their findings?

It was a hand-picked cherry pick group of 5 known climates do not deny ERs.

>> And they put together this group and worked in secret without the obligatory public public meetings and came up with a report for the Department of Energy climate science there's really not a problem here.

But that's not true.

As winds and other experts attest, research data.

What what do we know about what the used to to make this argument upon which this rollback of the endangerment finding is based.

>> They said.

They said there's, you know, that this is not a problem.

He said it wasn't causing public health problems.

how do you have think regulatory agency is should be weighing the different cost and benefits winterset in climate policy?

Wilson, one of the interesting things about it in Dayton at finding repeal not based on a cost-benefit analysis.

So they didn't say that Co 2 dozen cars, climate change and they didn't say the cost of mitigating it is too high.

>> They just basically said it would be futile to mitigate it because the U.S.

is only a small part of the global system.

And that's really the only basis.

So there was no direct challenge to the endangerment finding from Mike economic perspective and 11, a challenge for the scientific perspective.

That's a very tentative and weak argument that they ultimately put together.

How much truth to that argument is there that the U.S.

is only a small player, small contributor to the problem.

We are a small player, especially as you know, other countries have become richer and use more energy.

So the United States is not the matter anymore.

China's the leading emitter in the world and this is only about our transportation sector, which is about a 3rd of our missions.

So, you know, it's it's true that it's a modest contribution to a global problem that we spent several decades building economic theories of how to assess the value of contributing extra admissions on top of a system where the people aren't doing anything that's called the social cost of carbon.

And there's, you know, there's arguments about about exactly how this computed, but the the entire methodology for computing.

That was assuming that no one else is doing anything and asking is it still cost effective for us to mitigate extra time?

And the conclusion has been that it is.

He said this finding and this repeal mostly impacts the transportation sector, which is about a 3rd of our contributions.

There's the other two-thirds.

Do you anticipate that the EPA will also take steps on on that?

>> And those other contributions, factories, et cetera.

>> Well, we already have rolled back most of regulations power plant emissions.

Most of plan and some of that as few court cases, can talk about more than where that I 2022.

So this is clearly part of a broader attack.

It is and attempt to undercut the entire legal basis for regulating emissions at all.

And so it's significant in that sense more so than for the immediate actual impact of what they're doing.

You know, the practical emissions of active, what they're doing is less of the key here than the fact that it's trying to set up a legal framework to prevent the EPA from regulating emissions.

>> Susan, the EPA is claiming that the role how rollback of greenhouse gas regulations, it's going to save taxpayers over a trillion dollars.

As we just heard the president say in that sound bite.

What is your response to that claim?

>> The pa's own analysis which came out the same night as their decision, which is called the regulatory impact.

Analysis completely undermines that statement.

In fact, while they say what they say they're going to save money on is reduced vehicle prices.

And slashed electric vehicle prices purchases and lowered spending on the infrastructure for electric vehicles.

That's what they claim is going to be.

1.0, 4 trillion in savings.

But in fact, their own analysis shows that there will be increased fuel purchases because cars that people will be offered to buy in the future will be less energy efficient.

The rolling back those standards vehicle repair and maintenance costs will go up.

Insurance costs will go up.

Traffic congestion will go up, increased refueling time in their own analysis shows that the costs of that or 1.5 trillion.

So the costs to American consumers are higher.

Then the savings that they're projecting and that's before you even count the social and climate costs that was referring to.

It's OK, so we've got about a minute left we just talked about a minute.

Elizabeth.

Susan, how does the rollback of the endangerment finding fit into this broader pattern changes that we've seen?

>> From the EPA last year.

>> Unfortunately, this is one of many things.

But one of key thing that the that the this administration is doing to undermine hate safe safety and health of American residents.

They are attacking one by one with this in danger finding other actions, the things that protect Americans, health.

The EPA has sole job and reason for existence is to protect public health and the environment that supports public health.

But they are seeing with their attacking the standards that regulate water, quality, air quality, all the things that protect us all every day.

We'll have to