Peabody Energy, America’s biggest coalmining company, has funded at least two dozen groups that cast doubt on manmade climate change and oppose environment regulations, analysis by the Guardian reveals.

The funding spanned trade associations, corporate lobby groups, and industry front groups as well as conservative thinktanks and was exposed in court filings last month.

The coal company also gave to political organisations, funding twice as many Republican groups as Democratic ones.

Peabody, the world’s biggest private sector publicly traded coal company, was long known as an outlier even among fossil fuel companies for its public rejection of climate science and action. But its funding of climate denial groups was only exposed in disclosures after the coal titan was forced to seek bankruptcy protection in April, under competition from cheap natural gas.

Environmental campaigners said they had not known for certain that the company was funding an array of climate denial groups – and that the breadth of that funding took them by surprise.

The company’s filings reveal funding for a range of organisations which have fought Barack Obama’s plans to cut greenhouse gas emissions, and denied the very existence of climate change.

“These groups collectively are the heart and soul of climate denial,” said Kert Davies, founder of the Climate Investigation Center, who has spent 20 years tracking funding for climate denial. “It’s the broadest list I have seen of one company funding so many nodes in the denial machine.”

Among Peabody’s beneficiaries, the Center for the Study of Carbon Dioxide and Global Change has insisted – wrongly – that carbon emissions are not a threat but “the elixir of life” while the American Legislative Exchange Council is trying to overturn Environmental Protection Agency rules cutting emissions from power plants. Meanwhile, Americans for Prosperity campaigns against carbon pricing. The Oklahoma chapter was on the list.

Contrarian scientists such as Richard Lindzen and Willie Soon also feature on the bankruptcy list.

So does the Washington lobbyist and industry strategist Richard Berman, whose firm has launched a welter of front groups attacking the EPA rules.

The filings do not list amounts or dates. But the documents suggest Peabody supported dozens of groups engaged in blocking environmental regulations in addition to a number of contrarian scientists who together have obstructed US and global action on climate change.

The support squares up with Peabody’s public position on climate change. The company went further than the fossil fuel companies and conservative groups that merely promoted doubt about the risks of climate change, asserting that rising carbon emissions were beneficial.

Just last year, Peabody wrote to the White House Council on Environmental Quality describing carbon dioxide as “a benign gas that is essential for all life” and denying the dangers of global warming.

“While the benefits of carbon dioxide are proven, the alleged risks of climate change are contrary to observed data, are based on admitted speculation, and lack adequate scientific basis,” the company wrote in the 24 March 2015 letter.

The company agreed in November to make fuller disclosures about global warming risks under a settlement deal reached with the New York attorney general. Peabody had been under investigation for misleading investors and the public about the potential impact of climate change on its business.

Even so, the full extent of Peabody’s financial support for climate denial is unlikely to be revealed until the completion of bankruptcy proceedings.

“The breadth of the groups with financial ties to Peabody is extraordinary. Thinktanks, litigation groups, climate scientists, political organisations, dozens of organisations blocking action on climate all receiving funding from the coal industry,” said Nick Surgey, director of research for the Center for Media and Democracy.

“We expected to see some denial money, but it looks like Peabody is the treasury for a very substantial part of the climate denial movement.”

Peabody’s filings revealed funding for the American Legislative Exchange Council, the corporate lobby group which opposes clean energy standards and tried to impose financial penalties on homeowners with solar panels, as well as a constellation of conservative thinktanks and organisations.

These included the State Policy Network and the Franklin Center for Government and Public Integrity, which worked to defeat climate bills in Congress and are seeking to overturn Environmental Protection Agency rules to reduce carbon pollution from power plants, as well as the Congress for Racial Equality, which was a major civil rights organisation in the 1960s.

The filings also revealed funding for the George C Marshall Institute, the Institute for Energy Research, and the Center for the Study of Carbon Dioxide and Global Change, which are seen as industry front groups.

The names of a number of well-known contrarian academics also feature in the Peabody filings, including Willie Soon, a researcher at the Harvard-Smithsonian Center for Astrophysics. Soon has been funded almost entirely by the fossil fuel industry, receiving more than $1.2m from oil companies and utilities, but this was the first indication of Peabody funding.

Soon and the Smithsonian did not respond to requests for comment.

Richard Lindzen and Roy Spencer, two contrarian scientists who appeared for Peabody at hearings in Minnesota last month on the social cost of carbon, were also included in the bankruptcy filings.

Peabody refused to comment on its funding for climate denial groups, as revealed by the bankruptcy filings.

“While we wouldn’t comment on alliances with particular organizations, Peabody has a track record of advancing responsible energy and environmental policies, and we support organizations that advocate sustainable mining, energy access and clean coal solutions, in line with our company’s leadership in these areas,” Vic Svec, Peabody’s senior vice-president for global investor and corporate relations, wrote in an email.

Over the last decade, fossil fuel companies distanced themselves from open climate denial. Much of the funding for climate denial went underground, with corporations and conservative billionaires routing the funds through secretive networks such as Donors’ Trust.

But the sharp drop in coal prices, under competition from cheap natural gas, and a string of bankruptcies among leading US coal companies has inadvertently revealed the coal industry’s continued support for climate denial - even as oil companies moved away from open rejection of the science.

Earlier this year, bankruptcy filings from the country’s second-biggest coal company, Arch Coal Inc, revealed funding to a group known mainly for its unsuccessful lawsuit against the climate scientist Michael Mann.

The $10,000 donation to the Energy and Environment Legal Institute (E&E) was made in 2014, according to court documents filed in Arch’s chapter 11 bankruptcy protection case.

Last October, court filings from another coal company seeking bankruptcy protection, Alpha Natural Resources, revealed an $18,600 payment to Chris Horner, a fellow at E&E.