Michael Gerrard

Good to be with you.

Well, he's weakened the regulations on clean cars.

There had been significant rules that required cars to be more energy efficient.

California had the ability to adopt stronger standards, which were driving a push toward electric vehicles in California and other states.

So all of that has been wiped out.

They've also taken away the standards for cleaning up power plants.

There were various programs to help low-income and minority communities to have rooftop solar, to have more energy efficiency, other areas which would reduce fossil fuel use.

A lot of those have been wiped out, although much of that is being challenged in court, and we don't yet know what the final outcome will be.

So Congress passed the Clean Air Act in 1970, the major federal law for cleaning up the air, which has been very successful for lots of different kinds of pollutants.

But EPA, under President George W. Bush, was refusing to regulate greenhouse gases under the Clean Air Act.

2007, the US Supreme Court issued a landmark decision called Massachusetts versus EPA that said that EPA did have the power to regulate greenhouse gases if they find that it poses an endangerment to public health and welfare.

So EPA, under President Obama,

did issue this finding, this endangerment finding that greenhouse gases do endanger public health and welfare.

That became the basis for lots of regulations issued under the Obama and Biden administrations.

And now EPA under President Trump has canceled that.

We used to think that they were going to argue that the science of climate change was too unsettled, but they seem to have dropped that argument wisely.

And instead, they're saying that the regulation of greenhouse gases is such a major thing with important political and economic significance that EPA can't do it without explicit congressional authorization, even if the words of the Clean Air Act would seem that EPA could do that.

Another major argument is that the emissions of greenhouse gases from motor vehicles in the U.S.

are such a small part of the global climate problem that it's not going to make any difference.

Although, in fact, if U.S.