If you’re looking for an example of the way political debate warps reality, you couldn’t do much better than the recent treatment of the Environmental Protection Agency. Some politicians have made a hobby of attacking the agency—not for its work in keeping our air and water clean, but as a symbol for the government rules and regulations that, they say, strangle businesses and hinder the economy.

That these arguments have had any political success—even though environmental regulations cost less and have greater benefits than opponents claim—demonstrates the effectiveness of the EPA’s ongoing work: Many parts of the country have far cleaner air and water than when the agency was founded in 1970 to enforce new environmental laws passed by Congress to protect people and wildlife from pollution. So much so, that it’s hard to recall what life was like before the EPA was founded, when factories dumped waste directly into waterways and black smoke streamed from industrial stacks.

But those successes don’t matter to politicians devoted to anti-government posturing no matter the cost. The billion-dollar industries that donate to their campaigns (thanks, Citizens United) want to be free of what they see as burdensome rules and regulations—like cleaning up their hazardous waste or installing technologies to capture carbon pollution. In an ideal world, the EPA wouldn’t be necessary and companies would take responsibility for their own waste. But history has shown that, as long as there’s a buck to be made, polluters will quietly poison our shared resources.

Now, those polluters could have their way: Oklahoma Attorney General Scott Pruitt has been nominated to lead the EPA, an agency he has sued repeatedly, often with the cooperation of companies that funded his campaigns. In addition, he doesn’t believe the basic scientific facts of climate change or that it could be manmade.

Modern opponents of the EPA fail to remember—or, worse, choose to ignore—the good that the EPA has done. As a refresher, here are just some of the ways the EPA has kept our drinking water clean, our breathing air clear, and the environment safe for birds and wildlife.

Environmental Poisons

These two eagles, found dead in 1963, were sent to a lab to test for harmful pesticides like DDT. Photo: Seney Natural History Association

In the 1960s, birds became potent symbols of the way human industry infiltrated the environment and threatened human health. After World War II, the use of the pesticide DDT became widespread in U.S. agriculture. Rainfall washed the pesticide from fields into streams, where it was absorbed by plants and fish, and then consumed by raptors and other birds. Bald Eagles that ingested DDT laid eggs with shells so weak that parents crushed them just by sitting on the nest. By 1963, less than 500 nesting pairs of Bald Eagles survived.

After environmental scientist Rachel Carson publicized the effects of DDT in her 1962 book Silent Spring, it wasn’t hard for Americans to imagine the myriad health problems caused by blindly consuming the offerings of industry. Soon, research proved that DDT causes cancer in people and persists in ecosystems for decades. In 1972, the EPA banned the pesticide. And within a few decades, Bald Eagle populations (and those of other affected species, such as pelicans and falcons) recovered.

The EPA has worked to reduce levels of other environmental toxins, too. Some of these—such as lead and mercury—occur naturally, but are dangerous in high doses. Lead was used as an additive in paint, gasoline, pipes, and other materials, and causes brain damage, developmental delays, and even death in high doses in both people and birds. Meanwhile, the neurotoxin mercury, which is released to the air when fossil fuels are burned, accumulates in muscle tissue—allowing it to be passed up the food chain—and can kill birds and wildlife (and people, too).

After the EPA phased out leaded gasoline, the number of American children with elevated lead levels in their blood dropped from 88 percent in the late 1970s to less than 1 percent today. And, in 2011, the EPA published new standards to reduce mercury emissions from coal plants—an effort that Scott Pruitt tried, and failed, to overturn. The standards are expected to prevent 11,000 premature deaths, 4,700 heart attacks, and 130,000 childhood asthma attacks each year.

Smog and Air Pollution

If you want a vision of what the United States might look like without the EPA, you can look to China. This month, smog—a haze of pollution and fog so thick that it blocks sunlight—has settled on Beijing and 24 other cities. The government has declared a national red alert: schools are closed, driving is restricted, and factories are shut down. This happens year after year as Chinese leaders fail to enforce the environmental laws that would allow people to safely venture outdoors.

Their situation doesn’t look far off from the U.S. in the middle of the last century. Before companies that burned fossil fuels were required to install technologies to control soot and gas emissions from their smokestacks, smog choked American cities, causing a raft of chronic diseases and shortening the lives of many urban citizens. Birds and other wildlife suffer from similar respiratory problems when immersed in air pollution. It hurts their habitats, too. Ground-level ozone damages trees and plant communities, while nitrogen oxides and sulfur oxides mix with water in the air—better known as acid rain—and in rivers to poison environments and kill plants and animals.

Major amendments to the Clean Air Act, passed by Congress in 1970, called on the newly formed EPA to set national standards for healthy levels of common air pollutants, including those mentioned above. The agency helped states put together plans to reduce pollution from sources like cars, power plants, and other polluting industries by installing new technologies to capture particle pollution and dangerous gases and reduce emissions. As a result, today’s vehicles are 99 percent cleaner for common pollutants, and new power plants are 90 percent cleaner for dangerous gases, according to the EPA. Studies have also shown that the Clean Air Act saves hundreds of thousands of lives every year, while saving Americans trillions of dollars in healthcare costs.

Clean Waterways and Wetlands

In 1969, Cleveland caught the attention of the nation when an oil slick on the Cuyahoga River caught fire and became a symbol of the country’s abundant water pollution. At the time, factories regularly discharged pollution and sewage directly into rivers—around 70 percent of which was completely untreated—killing aquatic life and turning waterways into cesspools. Many lakes and rivers were ecologically dead, and if you fell off a boat into most urban rivers, you’d need to go to the hospital to treat skin rashes and the pathogens you had surely just contracted.

Outcry about water pollution led to the passage of the Clean Water Act in 1972, and the EPA was charged with enforcing it. The act made it unlawful to dump pollution into navigable waters without a permit and sought to make all U.S. waters “fishable and swimmable” by 1985. The EPA set standards for how clean water should be, and worked with local authorities and companies to design programs to clean wastewater, redesign sewer systems, and restore degraded rivers and lakes.

The act didn’t achieve its goal by 1985. Indeed, there is still work to be done, but it did improve water quality in one-third of the country’s waterways, which speaks to the challenges of addressing water pollution. Part of the problem is that there aren’t clear laws for pollution that comes from many sources, such as oil spilled in the streets or pesticides washed from lawns.

Another challenge is that, for decades, courts and politicians have argued over the definition of “navigable waters” and whether wetlands and streams near rivers and lakes should be protected under the Clean Water Act. Last year, the EPA and U.S. Army Corps of Engineers issued a rule that wetlands and streams are integral parts of waterways, and so also fall under the purview of the Clean Water Act. This is one of the EPA policies that Scott Pruitt and the new administration has vowed to overturn, a promise that threatens wetland habitat that birds and wildlife rely upon as feeding grounds during lengthy migrations and throughout the year.

Carbon Pollution and Climate Change

While black smoke is a rarer sight today than it was in 1970, not all pollution is visible to the human eye. Fossil fuel-powered industries continue to emit colorless greenhouse gases—such as carbon dioxide and methane—into the atmosphere. These pollutants prevent heat in our atmosphere from escaping to space, and as a result the planet is warming and its climate is changing, with dire consequences. Rising temperatures threaten the habitats birds need by redistributing their food and shelter, while rising seas encroach inland and put wetlands and beaches at risk. In North America, climate change threatens the survival of over 300 bird species, according to Audubon scientists.

In 2012, the Supreme Court upheld an EPA finding that greenhouse gases threaten public health, and that the U.S. government is required to regulate them under the Clean Air Act. In that case, the National Association of Manufacturers, the U.S. Chamber of Commerce, and 14 plaintiff states—including Oklahoma, led by Scott Pruitt—sued the EPA and argued that the environmental impacts of greenhouse gases haven’t been proven. "EPA is not required to re-prove the existence of the atom every time it approaches a scientific question," the Supreme Court wrote in their ruling. (15 states also went to court to support the agency.)

Since then, the agency has set standards for limiting carbon emissions from cars and new factories, and in 2015 it announced the Clean Power Plan to work with states to reduce emissions from existing power plants. The Clean Power Plan aims reduce U.S. carbon emissions by 32 percent below 2005 levels by 2030. Then in 2016, the EPA passed a rule to reduce methane pollution, which is hundreds of times more potent than carbon dioxide in terms of warming ability.

Both rules have been challenged in the courts. The Clean Power Plan is currently on hold after electrical utilities, 28 states (including Oklahoma led by Scott Pruitt), and others challenged it last year; the D.C. Circuit appeals court will rule on it any day now, and the case will likely be appealed to the Supreme Court regardless of the outcome. And more than a dozen states have sued the EPA over the methane rule, too, including—you guessed it—Oklahoma and Pruitt. Both of these rules are needed to uphold the U.S.’s pledges to the international community to reduce carbon emissions, as agreed to when the Paris Treaty was ratified in November.

The EPA’s progress on cleaning the country’s air and waterways in the past 40 years has been remarkable. But carbon pollution is a different beast; the impacts of climate change cannot be undone once they’re set into motion. If we want to see similar progress with carbon pollution and avoid the worst impacts—including forced migration, habitat loss, and rising seas—we need to keep our focus on the long-term gains for everyone instead of short-term profit for the few. And to do that, we need a strong EPA.