A non-scientist whose funders have included ExxonMobil, the American Petroleum Institute, and coal giant Murray Energy Corporation, Ebell has been a consistent taunter of both scientists and environmentalists. As a talking head on TV news, he has for years offered false balance on climate change in the form of views so far outside of the mainstream as to be downright bizarre. For Ebell, Al Gore is “an extremist” who “lives in a fantasy world,” the Pope’s encyclical on climate change is “ diatribe against modern industrial civilization ,” and current climate patterns indicate an imminent ice age rather than a warming planet.

Environmentalists who were hoping that somehow a Donald Trump presidency wouldn’t be as catastrophic as they feared had those hopes dashed on Friday, when the president-elect announced Myron Ebell as his choice to oversee the transition at the Environmental Protection Agency. Ebell, head of both the right-wing think tank the Competitive Enterprise Institute and the Cooler Heads Coalition , has spent most of his career tossing out industry-funded nonsense bombs about climate change.

Since we were already falling short of our climate goals before the election, and since the potential consequences of inaction may be irreversible , Ebell’s leadership in this realm seems to pose the gravest danger. He has already given much thought to how to get out of the Paris Agreement , the global treaty the U.S. signed in September, which is aimed at holding the increase in global temperature rise below 2 degrees.

There are several ways a Trump administration could do so. While Secretary of State John Kerry is scrambling to get the treaty implemented before President Obama leaves office, Trump is already signaling that he may try to withdraw from the global agreement in his first year, a move that is within his power and could increase the likelihood that other countries would also shirk their obligations.

Also caught in Trump’s crosshairs is the Clean Power Plan, the rules limiting carbon emissions from coal-burning power plants, which his administration could simply fail to enforce. The administration could also resurrect the Keystone XL pipeline and expand drilling on public land.

But there is much more to the EPA than the protection of the climate. And Ebell also runs a pro-chemical industry front group from the website saferchemicalpolicy.org, where you can read about the “life-enhancing value of chemicals” and the absurd idea that man-made toxic chemicals couldn’t possibly cause cancer because the average human lifespan has increased since 1950.

Indeed, Ebell’s hostility seems to extend to all scientific fact and the entire cause of environmentalism, and he will have a range of opportunities to inflict harm on human health and the environment. Still, certain protections of the earth, water, and land will be harder for him to reverse than others.

Here is a brief overview of some of the damage Trump and Ebell can — and can’t — inflict while they control the EPA.

Surrendering to Industry on Rules

Among the most vulnerable of the EPA’s efforts are rules that industry has already attacked through the legal system and are now wending their way through the courts. In any of these suits, the EPA could simply stop defending their rules. Or, worse still, they could reissue them so that they are friendlier to industry and less protective of people and the environment. Some of the most consequential of these rules tied up in ongoing suits are:

Mercury and Air Toxics Standards: In 2013 the EPA issued a rule to limit the emissions of mercury, nickel, arsenic, and other toxins in air pollution around power plants. But several states and at least one coal company sued the EPA challenging the rule, which is in place while the parties fight in court. The new administration could pull the rule back, which would allow power plants not to comply with it moving forward. If it remains in place, the limit on emissions is expected to reduce developmental problems among children living near power plants as well as cancer, heart attacks, and respiratory illnesses in adults.

In 2013 the EPA issued a rule to limit the emissions of mercury, nickel, arsenic, and other toxins in air pollution around power plants. But several states and at least one coal company sued the EPA challenging the rule, which is in place while the parties fight in court. The new administration could pull the rule back, which would allow power plants not to comply with it moving forward. If it remains in place, the limit on emissions is expected to reduce developmental problems among children living near power plants as well as cancer, heart attacks, and respiratory illnesses in adults. Waterways: The EPA is in the midst of litigation over the protection of thousands of waterways. The Waters of the United States Rule clarified that certain streams and wetlands are under federal jurisdiction, which would allow the EPA to prosecute people who pollute them using laws such as the Clean Water Act. But after the EPA issued the rule in May 2015, the pesticide, timber, and dairy industry joined forces with the Chambers of Commerce, real estate developers, mining companies and others to challenge it.

The EPA is in the midst of litigation over the protection of thousands of waterways. The Waters of the United States Rule clarified that certain streams and wetlands are under federal jurisdiction, which would allow the EPA to prosecute people who pollute them using laws such as the Clean Water Act. But after the EPA issued the rule in May 2015, the pesticide, timber, and dairy industry joined forces with the Chambers of Commerce, real estate developers, mining companies and others to challenge it. Ozone: When it issued a more protective standard for ozone in October 2015, the EPA noted that the noxious gas can cause chest pain, coughing, wheezing and shortness of breath even in healthy people. Weeks later, the coal company Murray Energy Corporation sued the EPA over the rule, calling it “job killing.” Coal production — along with industrial facilities and electric utilities —increases ground level ozone, which is particularly dangerous for people with asthma, children, and the elderly. If the proposed standard takes effect, it is expected to prevent an estimated 11,000 premature deaths.

When it issued a more protective standard for ozone in October 2015, the EPA noted that the noxious gas can cause chest pain, coughing, wheezing and shortness of breath even in healthy people. Weeks later, the coal company Murray Energy Corporation sued the EPA over the rule, calling it “job killing.” Coal production — along with industrial facilities and electric utilities —increases ground level ozone, which is particularly dangerous for people with asthma, children, and the elderly. If the proposed standard takes effect, it is expected to prevent an estimated 11,000 premature deaths. Oil Refineries: In September 2015, the EPA issued a new rule to tighten up the regulation of oil refineries. Scheduled to take effect next year, it will require refineries to monitor their emission of airborne chemicals such as the carcinogen benzene. More than 6 million residents of fenceline communities around these plants, who are disproportionately low-income and people of color, will benefit.

Slashing Budgets

While it’s illegal to fire civil servants for political reasons, a Trump administration could slash budgets for entire programs affecting the environment both within and outside the EPA. Though much of this would require congressional action, a Republican-dominated Congress working with Ebell could put the funding of certain efforts on the chopping block. Here are a few that have already come under attack:

The Integrated Risk Information System: The chemical industry often rails against this program, which pulls together the toxicity information on chemicals and reports on the health hazards they pose. These findings not only help shape EPA’s policy but are often referenced in state and international laws.

The chemical industry often rails against this program, which pulls together the toxicity information on chemicals and reports on the health hazards they pose. These findings not only help shape EPA’s policy but are often referenced in state and international laws. International Agency for Research on Cancer: This branch of the World Health Organization, which receives funding from the National Institutes of Health, has become a target for industry groups and conservative lawmakers. IARC has also, not coincidentally, pointed to the carcinogenicity of several blockbuster products, including glyphosate, the active ingredient in Monsanto’s Roundup.

This branch of the World Health Organization, which receives funding from the National Institutes of Health, has become a target for industry groups and conservative lawmakers. IARC has also, not coincidentally, pointed to the carcinogenicity of several blockbuster products, including glyphosate, the active ingredient in Monsanto’s Roundup. Safer Choice: This EPA program provides a label certifying that companies have invested in testing their products to make sure they meet rigorous safety standards and searches for alternatives to toxic chemicals. While some retailers have embraced the program, the American Chemistry Council has waged a fierce campaign that has tried to weaken it.

Shelving Long-term Efforts

Particularly frustrating may be the demise of several of the EPA’s long-term efforts, some of which stretch back more than a decade, which could be squelched just as they near completion.

Perfluorinated chemicals : In recent months, the EPA has been working on developing analytical methods to measure the amount of perfluorinated chemicals such as PFOA and PFOS in groundwater, soil, and sludge. The cleanup of these toxins, some of which have seeped from firefighting foam used on military bases into nearby ground and drinking water, has become a recent focus of EPA, according to a source within the agency. “It’s very apparent that EPA had to do something,” he told me, adding: “Or at least it was last week.”

: In recent months, the EPA has been working on developing analytical methods to measure the amount of perfluorinated chemicals such as PFOA and PFOS in groundwater, soil, and sludge. The cleanup of these toxins, some of which have seeped from firefighting foam used on military bases into nearby ground and drinking water, has become a recent focus of EPA, according to a source within the agency. “It’s very apparent that EPA had to do something,” he told me, adding: “Or at least it was last week.” Lead: The danger lead poses to children has been well known for decades. And in the wake of the Flint, Michigan, disaster, the EPA has made lead a priority. The agency is in the process of eliminating the leaded fuel used by piston jet planes, which is the biggest source of lead in the air. And it recently announced over 100 enforcement actions aimed at protecting the public from lead exposure. “I feel like we were finally on the cusp of making some headway on lead,” said Eve Gartner, a staff attorney at Earthjustice.

The danger lead poses to children has been well known for decades. And in the wake of the Flint, Michigan, disaster, the EPA has made lead a priority. The agency is in the process of eliminating the leaded fuel used by piston jet planes, which is the biggest source of lead in the air. And it recently announced over 100 enforcement actions aimed at protecting the public from lead exposure. “I feel like we were finally on the cusp of making some headway on lead,” said Eve Gartner, a staff attorney at Earthjustice. Organophosphate pesticides: The EPA is very close to essentially banning the use of chlorpyrifos, a widely used organophosphate pesticide that is linked to a range of neurodevelopmental problems in children. And because the EPA recently decided to evaluate entire classes of pesticides together, it seemed likely that other organophosphates that cause neurological harm would also be restricted. But that progress may grind to a halt. Dow Chemical, which makes chlorpyrifos, has friends in the new administration, including Dow lobbyist Mike McKenna and Ebell himself, whose think tank received funding from the company.

Beyond Trump’s Reach, At Least for Now

Although candidate Trump threatened to do away with the EPA altogether, he has since walked back that promise, saying that he’s interested in protecting clean air and water. It seems likely that the EPA will continue to exist, at least in name. But even if the Republicans abolished the EPA, it would be more difficult to repeal all the environmental statutes the agency exists to enforce.

Federal Statutes: These laws, which include the Clean Water Act, the Endangered Species Act, and the Superfund law, are designed to stand up to rogue leaders. The Clean Air Act, for instance, clearly lists carbon pollution as a danger and requires EPA to take action, and may thus be an important tool in forcing the administration to limit carbon emissions. And while a gutted EPA will likely neglect the day-to-day work of enforcing the laws, the agency can’t disregard them altogether. “It’s not up to the president or EPA whether to take action,” said David Goldston, director of government affairs at NRDC . “They have to address it. If they don’t, they get sued, and the court imposes restrictions.”

These laws, which include the Clean Water Act, the Endangered Species Act, and the Superfund law, are designed to stand up to rogue leaders. The Clean Air Act, for instance, clearly lists carbon pollution as a danger and requires EPA to take action, and may thus be an important tool in forcing the administration to limit carbon emissions. And while a gutted EPA will likely neglect the day-to-day work of enforcing the laws, the agency can’t disregard them altogether. “It’s not up to the president or EPA whether to take action,” said David Goldston, director of government affairs at NRDC “They have to address it. If they don’t, they get sued, and the court imposes restrictions.” Toxic Substances Control Act: Similarly, the agency will be obligated to take some actions set by the recently passed Toxic Substances Control Act. It has no choice, for instance, but to evaluate a certain number of chemicals, though several provisions in the law could be easily abused. One would allow the agency to shield some chemicals from testing by designating them “low priority.” And once chemicals are declared safe by the federal agency, states won’t be allowed to independently regulate them.

Similarly, the agency will be obligated to take some actions set by the recently passed Toxic Substances Control Act. It has no choice, for instance, but to evaluate a certain number of chemicals, though several provisions in the law could be easily abused. One would allow the agency to shield some chemicals from testing by designating them “low priority.” And once chemicals are declared safe by the federal agency, states won’t be allowed to independently regulate them. Emergency response: The administration will also have to respond to emergencies. “Let’s say we have another BP spill, Trump isn’t going to be able to wake up and ignore it,” said Lisa Garcia, vice president for litigation at Earthjustice. “There will be a legal obligation for someone to go in and try to shut it down and clean it up.”

Although agency rules and guidelines and advisories are easier to reverse than federal law, even those would be difficult and time-consuming to undo. “Everyone hates the bureaucracy but it could be our friend in the next few years,” said Garcia. “There are laws and processes and procedures and you need scientific data and backup in order to do these things. To roll it back takes time.”

Some environmentalists seem to be taking comfort in the fact that the EPA has already survived an internal attack. In 1981, Reagan tasked Anne Gorsuch Burford with essentially dismantling the agency from within. But Burford went too far with her budget cutting and downsizing and less than two years after she took the post, was forced to resign.

Ironically, the chemical industry may help force the incoming administration to do its job, according to Mike Belliveau, executive director of the Environmental Health Strategy Center. “Unless EPA delivers meaningful and timely reductions in public exposure to toxic chemicals, then public confidence in the chemical industry will never be restored as they desire. That will mean continued unchecked consumer campaigns and state policy initiatives that require retailers and consumer product manufacturers to end their use of dangerous chemicals,” said Belliveau. “Myron Ebell could be the chemical industry’s worst nightmare in disguise.”

Environmentalists I spoke with agree that public pressure will play a critical role in forcing the EPA to do its job. “If an assault is met with apathy, we’re not going to be as able to stop it,” said Goldston, who predicts that Trump will face a backlash if he goes after environmental safeguards, much as Reagan and George W. Bush did before him.

David Rosner, a historian of public health at Columbia University, reaches even further back for hope that an Ebell-led EPA might not be as destructive as it could be. “Until 1970, we had no federal involvement in environmental protection. This is all very new the idea that the EPA can effect and have any kind of change on the county and world,” said Rosner. “I take solace in the idea that we survived until then.”