Conservative groups may have spent up to $1bn a year on the effort to deny science and oppose action on climate change, according to the first extensive study into the anatomy of the anti-climate effort.

The anti-climate effort has been largely underwritten by conservative billionaires, often working through secretive funding networks. They have displaced corporations as the prime supporters of 91 think tanks, advocacy groups and industry associations which have worked to block action on climate change. Such financial support has hardened conservative opposition to climate policy, ultimately dooming any chances of action from Congress to cut greenhouse gas emissions that are warming the planet, the study found.

“I call it the climate-change counter movement,” said the author of the study, Drexel University sociologist Robert Brulle. “It is not just a couple of rogue individuals doing this. This is a large-scale political effort.”

Brulle's study, published on Friday in the journal Climatic Change, offers the most definitive exposure to date of the political and financial forces blocking American action on climate change. Still, there are big gaps.

It was not always possible to separate funds designated strictly for climate-change work from overall budgets, Brulle said. “Since the majority of the organizations are multiple focus organizations, not all of this income was devoted to climate change activities.”

Some of the think tanks on Brulle's list – such as the American Enterprise Institute (AEI) – said they had no institutional position on climate change and did not control the output of their scholars. In addition, Brulle acknowledged that he was unable to uncover the full extent of funding sources to the effort to oppose action on climate change. About three-quarters of the funds were routed through trusts or other mechanisms that assure anonymity to donors – a trend Brulle described as disturbing and a threat to democracy.

“This is how wealthy individuals or corporations translate their economic power into political and cultural power,” he said. “They have their profits and they hire people to write books that say climate change is not real. They hire people to go on TV and say climate change is not real. It ends up that people without economic power don't have the same size voice as the people who have economic power, and so it ends up distorting democracy.

“That is the bottom line here. These are unaccountable organisations deciding what our politics should be. They put their thumbs on the scale … It is more one dollar one vote than one person one vote.”

Top-tier conservative think tanks

The vast majority of the 91 groups on Brulle's list – 79% – were registered as charitable organisations and enjoyed considerable tax breaks. Those 91 groups included trade organisations, think tanks and campaign groups. The groups collectively received more than $7bn over the eight years of Brulle's study – or about $900m a year from 2003 to 2010. Conservative think tanks and advocacy groups occupied the core of that effort.

The funding was dispersed to top-tier conservative think tanks in Washington, such as the AEI and Heritage Foundation, which focus on a range of issues, as well as more obscure organisations such as the Atlas Economic Research Foundation and the John Locke Foundation.

Funding also went to groups that took on climate change denial as a core mission – such as the Heartland Institute, which held regular conclaves dedicated to undermining the United Nations climate panel's reports, and the Competitive Enterprise Institute, which tried and failed to prosecute a climate scientist, Michael Mann, for academic fraud.

AEI was by far the top recipient of such funds, receiving 16% of total funding over the eight years, or $86.7m. Heartland Institute, in contrast, received just 3% of the total, $16.7m. There was also generous support to Americans for Prosperity, the advocacy group affiliated with the conservative Koch billionaires, which received $22.7m.

'It won't be going to liberals'

Brulle admits, however, that he was far less successful in uncovering the sources of funding for the counter-climate movement. About 75% of such funding sources remain shrouded in secrecy, with wealthy conservatives routing their donations through a system of trusts which guarantee anonymity.

The leading venue for those underground donations was the Donors Trust and Donors Capital Fund, which alone accounted for 25% of funding of the groups opposed to climate action. An investigation by the Guardian last February found that the Donors Trust and Donors Capital Fund had distributed nearly $120m to more than 100 anti-climate groups from 2002-2010. The Donors group has now displaced such previous prominent supporters of the climate denial movement as the Koch-affiliated foundations and corporations like Exxon Mobil, Brulle said.

Other conservative foundations funding climate denial efforts include: the Searle Freedom Trust, the John William Pope Foundation, the Howard Charitable Foundation and the Sarah Scaife Foundation, which also promote a free-market approach on other issues.

A number of the groups on Brulle's list – both as funders and recipients – refused to comment on his findings or disputed his contention that they were part of a movement to block action on climate change.

Whitney Ball, the president of the Donors Trust and Donors Capital Fund, said the organisation had no say in deciding which projects would receive funding. However, Ball told the Guardian last February that Donors offered funders the assurance their money would never go to Greenpeace. “It won't be going to liberals,” she said at that time.

“We do not otherwise drive the selection of grantees, nor do we conduct in-depth analyses of projects or grantees unless an account holder specifically requests that service,” Ball said in an email. “Neither Donors Trust nor Donors Capital Fund as institutions take positions with respect to any issue advocated by its grantees.”

Recipients of the funds also disputed the assertion they were part of a larger effort to undermine climate science or block action on climate change.

“Each of the scholars that work on any particular issue speaks for his or hers own work,” said Judy Mayka Stecker, director of media relations at AEI, in an email. She went on to write, however, that most of the AEI scholars who have worked on energy and climate change have moved on and would be unavailable to comment.

David Kreutzer, an energy and climate change fellow at the Heritage Foundation, said Brulle was unfairly conflating climate denial with opposition to policies that would require industry reduce greenhouse gas emissions.

“We do believe that CO2 is a greenhouse gas and that man-made emissions will lead to some warming,” said David Kreutzer, an energy and climate-change fellow at the Heritage Foundation. “We are opposed to mandatory greenhouse gas emissions cuts.”

He said many conservatives saw a carbon tax, cap-and-trade and other climate policies as a government takeover by stealth.

“What we are not interested in doing is a huge shift of power to the government under the guise of preventing some climate problem,” he said.

The Hoover Institution, which received about $45m, claimed to produce no work on climate change – while displaying on its website an article by a Hoover research fellow on an August 2013 Hoover poll on economic, energy and environmental issues.

"Hoover has no institutional initiatives on climate change,” a spokeswoman, Eryn Witcher, wrote in an email. “Individual Hoover fellows research and write on a wide variety of topics of their own choosing, but we're not aware of any who are working in that field at this time, nor are we aware of any gifts or grants that have been received for that purpose.”

In the article, the Hoover fellow, Jeremy Carl, who works extensively on energy and climate issues, discussed climate change and fracking, concluding: “Many Democrats and liberals are in denial when it comes to reality on energy and climate policy, endorsing both science and political fiction.”

• This headline on this article was amended on 21 December 2013 to reflect that not all the $1bn referred to will have funded climate change work.