Morgan Folger is campaign director for Environment America's Clean Cars Communities . The opinions expressed in this commentary are those of the author. View more opinion articles on CNN.

(CNN) States across America are ready to hit the accelerator toward limiting carbon emissions from cars and trucks — so why is the federal government putting up a giant roadblock?

In effect, this regressive proposal will immediately affect 13 other states (plus the District of Columbia) that have adopted California's emissions standards. At the same time, the plan would put every state at risk of more pollution by weakening national standards that would have gone into effect over the next few years.

In defense of their right to cleaner cars, 24 states announced a lawsuit Friday challenging the Trump administration's reckless decision, which not only defies science, but also defies public opinion and even market forces. Two in three Americans say the United States needs to do more on climate change, and several leading automakers recently agreed to do their part by following the tough emissions standards set by California.

Avlon: Don't listen to what he says, look at what he does

Avlon: Don't listen to what he says, look at what he does 02:49

Avlon: Don't listen to what he says, look at what he does

The aims behind these higher standards are simple: to cut pollution and advance cleaner technology. By implementing higher standards, these states benefit from cleaner air — and from the peace of mind that comes from knowing they're helping America fight global warming.

That states have rallied for this cause shouldn't be a surprise. For more than 50 years, certain states have set stronger limits on tailpipe pollution as federal standards have failed to protect their citizens. This is not to say there hasn't been significant progress at the national level. Once fully implemented, the existing federal standards were set to reduce climate pollution by as much as 6 billion metric tons from vehicles sold between 2012 and 2025. That's equivalent to the amount of carbon pollution that 1,500 or so coal-fired power plants would produce over an entire year, per the Environmental Protection Agency's Greenhouse Gases Equivalencies calculator.

Now the EPA is slamming the brakes on this progress at the worst possible moment. It's self-evident that global warming is no longer a theoretical problem that exists somewhere in the future. July 2019 was the hottest month ever recorded globally.

Our planet has a fever, and Americans are suffering from it now.

In the Midwest, farmers have lost an entire planting season thanks to extreme weather and subsequent flooding. The wildfire season is just revving up, with the deadly 2018 fires a recent, tragic reminder of the toll of these events. Lyme disease, among other terrifying health dangers, is on the rise throughout the United States, as ticks move into new territory and thrive in warmer conditions.

Once-permanent ice on sea and on land is melting, changing life for many Americans, from large swaths of Alaska to Glacier National Park in Montana. Communities along the coasts are facing the choice of retreating or building $42 billion worth of sea walls.

Our nation's top scientists have warned that all these conditions are expected to get much worse unless we stop emitting greenhouse gases. To that end, we need to do everything we can to cut the carbon pollution that fuels global warming. And cars are the problem: Transportation is now the number-one source of global warming pollution in America.

And while climate impacts pose an ongoing threat, we also face daily dangers thanks to tailpipe emissions. From Los Angeles and Denver to Philadelphia to New York City, our communities are suffering from an increasing annual number of bad-air days, as our cars and trucks continue belching out pollution.

Follow CNN Opinion Join us on Twitter and Facebook

Over the years, countless state officials throughout the country have done their jobs of protecting their constituents — and their air — by adopting California's clean-car standards.

The federal government shouldn't be driving in reverse. The EPA should get back to its mission of protecting the environment and public health. Rather than stifling innovation at the state level, our federal government should give states an open road to continue taking bold action to reduce global warming pollution.