The Trump Administration’s revocation of California’s Clean Air Act waiver is devastating for our climate, and for our air quality. But it is equally, if not even more, pernicious in another way: It is the next in a long line of racially discriminatory policy moves. That is because while the California Waiver has delivered clean air benefits to all Americans, its most concentrated benefits—and, as a result, its elimination’s most concentrated consequences—accrue to the places and people that bear the brunt of our environmental burdens. Those places, we now know, are predominantly low-income places, and disproportionately communities of color.

For more than half a century, the U.S. Congress has protected California’s authority to enact its own motor vehicle standards in federal law. This core tenet of the Clean Air Act is familiarly known as the California Waiver. Recognizing California’s historic leadership on clean car regulations—which predated the federal Clean Air Act when California enacted the first tailpipe standards in the nation in 1966—Congress allowed California to continue its groundbreaking work by seeking waivers from EPA to enact standards that, if it were any other state, would be preempted.

While the Trump Administration’s revocation takes aim at California’s recent work on climate change, the most significant historic benefit of the California Waiver to date has been to reduce deadly so-called “criteria pollutants,” like ozone, particulate matter, lead, nitrogen dioxide, and sulfur dioxide. Through that work, over decades, the waiver has delivered on its promise to be a laboratory for innovation in clean air and automobile technology: It has borne out such fundamental vehicle emissions technologies as the catalytic converter, and also led to the elimination of lead in gasoline. In 2011, EPA granted California its first waiver to address motor vehicle greenhouse gas regulations—and the waiver again served as the tip of the Clean Air Act’s spear to begin carving solutions to our most vexing air pollution problem: climate change.

The California Waiver has saved millions of lives. It is responsible for reducing deadly smog and other motor vehicle pollutants that send people to the hospital with heart attacks, respiratory failure, asthma, and cardio-pulmonary disease. And it has been used for nearly a decade toward mitigating climate change.

Importantly, pioneering studies have recently shed light on the inequities of this type of pollution and its public health outcomes. We now know, for example, that the communities to bear the brunt of environmental burden are those that also typically bear the brunt of economic burden. But this problem goes much deeper: Those same communities are also those that have historically borne the burden of a set of racist housing, policing, and criminal justice policies. Communities previously subject to racist redlining policies (commonplace discriminatory lending and mortgage practices decades ago), and more recent discriminatory workplace practices, for example, now have higher rates of pollution-linked asthma, and other air quality-linked disease, missed school days, hospital visits, and premature deaths. (See, e.g., recent research from the University of California, Berkeley.) The same communities also experience higher rates of homelessness and housing burden, which leaves more people of color living on the streets, directly exposed to pollution from motor vehicles.

While President Trump likes to boast of the “cleanest air and water,” federal data shows that the United States has actually experienced more polluted air days during the last two years than the previous few before that. (Air quality in the United States had been improving prior to that.) Extrapolating from these emerging studies at the intersection of race and environment, it follows that Mr. Trump’s deregulatory work will not have uniform impact; to the contrary, Trump’s action will have disparate impacts that more severely impact communities of color, low-income communities, and already disadvantaged communities contending with a confluence of economic and environmental burden.

Take Southern California, for example, which consistently rates among the most polluted regions in the country, and where researchers have recently found a 10 percent increase in deaths attributable to ozone pollution from 2010-2017. That 10 percent increase will not be equitably distributed. Inland areas—where non-white populations exceed the state averages—will collect the exhaust blown in from the coastal sea breeze, where it will stagnate, and bake. The effect of climate change makes things worse: Heat exacerbates ozone pollution and makes it more deadly. As a result, as climate change accelerates, more people will suffer from the health impacts of polluted air, and a disproportionate percentage of those victims will be people of color.

California has historically relished the opportunity to lead in this area. Recognizing the potential for national benefit from California’s work, Congress, in 1977, allowed other states in nonattainment of their national air quality standards—in other words, states suffering from extraordinary air pollution and in need of additional air quality improvement tools—to adopt California’s motor vehicle standards. And the waiver has known little partisanship: President Nixon and governors Reagan and Schwarzenegger worked to protect and celebrate California’s authority because they understood the importance of public health for economic growth.

Now, as California also works to lead in the area of climate justice (the State’s attorney general recently established the first-ever Bureau of Environmental Justice), we must see Trump’s move to withdraw California’s Clean Air Act waiver as an affront on equity as much as the environment.

It may be true, unlike a host of his immigration and foreign policies, that Trump’s intent in revoking California’s waiver is not borne directly out of a racial animus. But that matters not: As the law sees it, for example, a violation of civil rights merely requires a disparate impact, not a naked discriminatory intent, to be unlawful. Southern California has already exceeded its federal ozone limits on over 100 days this year. On each of those days, people die. To be sure, we all suffer; but it’s the working class, and the communities of color further inland, who will hurt the most. And it’s the communities who can least afford to bear this cost who will, in one form or another, have to pay. That’s discriminatory policymaking, intent or not.