The following correction was printed in the Guardian's Corrections and clarifications column, Friday November 28 2008

In the article below, we describe the geophysicist Professor Syun-Ichi Akasofu as a founding director of the Heartland Institute. In fact he has never held any formal position with the US thinktank.

The Republican Sarah Palin and her officials in the Alaskan state government drew on the work of at least six scientists known to be sceptical about the dangers and causes of global warming, to back efforts to stop polar bears being protected as an endangered species, the Guardian can disclose. Some of the scientists were funded by the oil industry.

In official submissions to the US government's consultation on the status of the polar bear, Palin and her team referred to at least six scientists who have questioned either the existence of warming as a largely man-made phenomenon or its severity. One paper was partly funded by the US oil company ExxonMobil.

The status of the polar bear has become a battleground in the debate on global warming. In May the US department of the interior rejected Palin's objections and listed the bear as a threatened species, saying that two-thirds of the world's polar bears were likely to be extinct by 2050 due to the rapid melting of the sea ice. Palin, governor of Alaska and the Republican nominee for US vice-president, responded last month by suing the federal government, to try to overturn the ruling. The case will be heard in January.

Though the state of Alaska has no polar bear specialists on its staff, the governor's stance has pitted it against the combined scientific fire-power of the US Fish and Wildlife Service, the US Geological Survey, and world experts on the mammal.

In its lawsuit, Alaska said it opposed the endangered label partly because the listing would "deter activities such as ... oil and gas exploration and development". Oil companies recently bid $2.7bn (£1.5bn) for rights to explore the Chuckchi sea, an established polar bear habitat.

The threatened species status might also impede the building of an Alaskan natural gas pipeline, which Palin has called the "will of God". In a letter last year to the US interior secretary, Dirk Kempthorne, she said she believed the polar bear population was "abundant, stable and unthreatened by direct human activity". She opposed the call for the listing because it "did not use the best available scientific and commercial information".

Her own Alaskan review of the science drew on a joint paper by seven authors, four of whom were well-known climate- change contrarians. Her paper argued that it was "certainly premature, if not impossible" to link temperature rise in Alaska with human CO2 emissions.

The paper, entitled Polar Bears of Western Hudson Bay and Climate Change, has been criticised for relying on old research and ignoring evidence that Arctic sea-ice is melting at a quickening pace. Walt Meier, a world authority on sea ice, based at the National Snow and Ice Data Centre, said: "The paper doesn't measure up scientifically."

One co-author of the paper, Willie Soon, completed the study with funding from ExxonMobil - which has oil operations in Alaska's North Slope - as well as from the American Petroleum Institute. Soon was a former senior scientist with the George C Marshall Institute, which acts as an incubator for climate-change scepticism. The institute has received $715,000 in funding from ExxonMobil since 1998.

In May, ExxonMobil announced that it was no longer funding Marshall and other groups linked with contrarian views. It said this was to avoid "distraction from the need to provide energy while reducing greenhouse gas emissions" and stressed that the company did not "control the research itself".

Another co-author of the document was Sallie Baliunas. In 2003 she and Soon were criticised when it was revealed that a joint paper had been partially funded by the American Petroleum Institute. Thirteen scientists whom they cited issued a rebuttal and several editors of the journal Climate Research resigned because of the "flawed peer review". A third co-author of the polar bear study, David Legates, a professor at Delaware University, is also associated with the Marshall Institute.

The citation by Palin and her officials prompted complaints from Congress. One member, Brad Miller, dubbed the polar bear study phony science.

Palin told Miller: "Attempts to discredit scientists ... simply because their analyses do not agree with your views, would be a disservice to this country." Miller now says that Palin's use of the paper shows she differs greatly from John McCain, the Republican presidential contender, who has pressed for scientific integrity. "Turning to the cottage industry of scientists who are funded because they spread doubt about global warming is not integrity," Miller said.

Palin's submission consulted J Scott Armstrong, a specialist in forecasting, who regards the global warming issue as "public hysteria".

Two other contrarian scholars were cited. One was Syun-Ichi Akasofu, formerly director of the International Arctic Research Centre, in Alaska, who argues that climate change could be a hangover from the little ice age. He is a founding director of the Heartland Institute, a thinktank that has received $676,500 from ExxonMobil since 1998.

Timothy Ball, a retired professor from Winnipeg, is cited for his climate and polar bear research. He has called human-made global warming "the greatest deception in the history of science". He has worked with both Friends of Science, and the Natural Resources Stewardship Project, which each had funding from energy firms.

Kert Davies, research director at Greenpeace US, said the state of Alaska under Palin's leadership had relied on scholars who argue the opposite view to that of the overwhelming consensus in the scientific community. "It shows that she is completely out of touch with the urgency of the climate crisis."

Last month Palin agreed that the Alaskan climate was changing but added: "I'm not one though who would attribute it to being man-made." She later tried to retract the statement.