LEOPOLD, Ind. — On the ceiling of Abbie Brockman’s middle school English classroom in Perry County, the fluorescent lights are covered with images of a bright blue sky, a few clouds floating by.

Outside, the real sky isn’t always blue. Sometimes it’s hazy, with pollution drifting from coal-fired power plants in this part of southwest Indiana. Knowing exactly how much, and what it may be doing to the people who live there, is why Brockman got involved with a local environmental organization that’s installing air and water quality monitors in her community.

“Industry and government is very, very, very powerful. It’s more powerful than me. I’m just an English teacher,” Brockman said. But she wants to feel she can make a difference.

In a way, Brockman’s monitoring echoes the reporting that the Environmental Protection Agency began requiring from large polluters more than a decade ago. Emissions from four coal-fired plants in southwest Indiana have dropped 60% since 2010, when the rule took effect.

That rule is now on the chopping block, one of many that President Trump’s EPA argues is costly and burdensome for industry.

But experts say dropping the requirement risks a big increase in emissions if companies are no longer publicly accountable for what they put in the air. And they say losing the data — at the same time the EPA is cutting air quality monitoring elsewhere — would make it tougher to fight climate change.

Rule required big polluters to say how much they are emitting

At stake is the Greenhouse Gas Reporting program, a 2009 rule from President Obama’s administration that affects large carbon polluters like refineries, power plants, wells and landfills. In the years since, they’ve collectively reported a 20% drop in emissions, mostly driven by the closure of coal plants.

And what happens at these big emitters makes a difference. Their declining emissions account for more than three-quarters of the overall, if modest, decline in all U.S. greenhouse gas emissions since 2010.

The registry includes places not usually thought of as big polluters but that have notable greenhouse gas emissions, such as college campuses, breweries and cereal factories. Even Walt Disney World in Florida, where pollution dropped 62% since 2010, has to report along with nearly 10,600 other places.

“We can’t solve climate change without knowing how much pollution major facilities are emitting and how that’s changing over time,” said Jeremy Symons, a former EPA senior climate advisor now at Environmental Protection Network, an organization of ex-EPA officials that monitors environmental policies. The group provided calculations as a part of the Associated Press’ analysis of impacts from proposed rule rollbacks.

Symons said some companies would welcome the end of the registry because it would make it easier to pollute.

Experts see a role for registry in cutting emissions

It’s not clear how much the registry itself has contributed to declining emissions. More targeted regulations on smokestack emissions, as well as coal being crowded out by cheaper and less polluting natural gas, are bigger factors.

But the registry “does put pressure on companies to … document what they’ve done or at least to provide a baseline for what they’ve done,” said Stanford University climate scientist Rob Jackson, who heads Global Carbon Project, a group of scientists that tally national carbon emissions yearly.

Gina McCarthy, a former EPA administrator under Obama, said the registry makes clear how power plants are doing against each other, and that’s an inducement to lower emissions.

“It is money for those companies. It’s costs. It’s reputation. It’s been, I think, a wonderful success story and I hope it continues.”

The potential end of the reporting requirement comes as experts say much of the country’s air goes unmonitored. Nelson Arley Roque, a Penn State professor who co-authored a study in April on these “monitoring deserts,” said about 40% of U.S. lands are unmonitored. That often includes poor and rural neighborhoods.

“The air matters to all of us, but apparently 50 million people can’t know or will never know’’ how bad the air is, Roque said.

EPA seeks to cancel money to fund some air monitoring

The EPA is also trying to claw back money that had been earmarked for air monitoring, part of the termination of grants that it has labeled as targeting diversity, equity and inclusion. That includes $500,000 that would have funded 40 air monitors in a low-income and minority community in the Charlotte, N.C., area.

CleaneAIRE NC, a nonprofit that works to improve air quality across the state that was awarded the grant, is suing.

“It’s not diversity, equity and inclusion. It’s human rights,” said Daisha Wall, the group’s community science program manager. “We all deserve a right to clean air.”

Research strongly links poor air quality to diseases like asthma and heart disease, with a slightly less established link to cancer. Near polluting industries, experts say what’s often lacking is either enough data in specific locations or the will to investigate the health toll.

Indiana says it “maintains a robust statewide monitoring and assessment program for air, land and water,” but Brockman and others in this part of the state, including members of Southwestern Indiana Citizens for Quality of Life, aren’t satisfied. They’re installing their own air and water quality monitors. It’s a full-time job to keep the network of monitors up and running, fighting spotty Wi-Fi and connectivity issues.

Fighting industry is a sensitive subject, Brockman added. Many families depend on jobs at coal-fired power plants, and poverty is real. She keeps snacks in her desk for the kids who haven’t eaten breakfast.

“But you also don’t want to hear of another student that has a rare cancer,” she said.

Walling, Borenstein, Bickel and Wildeman write for the Associated Press. AP writer Matthew Daly contributed to this report from Washington.