(CNSNews.com) - Just weeks before Alaska Gov. Sarah Palin (R.) was tapped by Sen. John McCain (R.-Ariz.) to be his vice presidential running mate, her administration filed suit against the federal government challenging the Interior Department’s listing of the polar bear as “threatened."

According to literature published by the International Union for the Conservation of Nature (IUCN), scientists estimated in the late 1950s through mid-1960s that there were anywhere from 5,000 to 19,000 polar bears.  The latest survey from the IUCN, conducted in 2005, said: “The total number of polar bears worldwide is estimated to be 20,000-25,000.”

In May, when the Interior Department  listed the polar bear as “threatened,” the Interior secretary said the bear’s population had in fact been growing in recent decades, although the department believed it could become endangered in the future due to projected declines in polar ice.

The suit Palin’s administration filed against the Interior Department, which was sharply criticized by environmentalist groups, was the latest salvo in a running battle she has waged with the department over listing the polar bear under the federal Endangered Species Act (ESA).

When Palin was inaugurated Alaska’s governor in December 2006, Interior was preparing to announce that it intended to list the polar bear as “threatened” under the terms of the ESA, a move that could prevent economic development deemed as putting the bear’s habitat at risk.

Days after she took office, Palin wrote and telephoned Interior Secretary Dirk Kempthorne to register her opposition to listing the polar bear.

Protecting the polar bear population was a good thing, she argued, but she counseled that the state and federal government should work together to find a “realistic” approach that was based on sound science.

“He assured me of his abiding commitment to work with the state to take actions to conserve polar bears, protect their habitat, and manage sustainable uses," Palin later said in a statement describing her conversation with Kempthorne.  “Alaska is home to a healthy population of polar bears. We intend to keep it that way.”

Shortly after this conversation, Kempthorne did in fact announce that the U.S. Fish and Wildlife Service was proposing to list the polar bear as “threatened.”

In late March 2007, the Alaska state house and senate backed Palin’s position, voting for a resolution opposing the federal proposal to list the polar bear as threatened.

Palin then submitted to the Interior Department a set of reports making Alaska’s case for not listing the bear.  She wrote Kempthorne again.

"I am concerned that the determination made by the [U.S. Fish and Wildlife] Service is based on incomplete information," Palin said in a statement released at that time.  “I want Secretary Kempthorne to have all the facts at his disposal before he makes a final decision. The consequences of listing the polar bear will have widespread social and economic impacts without providing any more protection for the bears.”

In October 2007, Palin’s administration issued a response to a set of studies that had been released by the U.S. Geological Survey that attempted to predict future melting of the Arctic ice cap and its effect on polar bear population.

“The State recognizes that a recent warming trend in portions of the Arctic is occurring, but the causes and effects are more diverse, complex and scientifically debated than is recognized in the USGS reports,” her office said in a statement. “As a result, the link between projected warming and the polar bear population in 50 years is highly speculative and questionable. Polar bears survived prior warming periods greater than the current one. The State notes that numerous respected scientists around the world question the forecasting methodologies used to project impacts to polar bears.”

Palin now sent another letter to Kempthorne.  "The listing of a currently healthy species based entirely on highly speculative and uncertain climate and ice modeling and equally uncertain and speculative modeling of possible impacts on a species would be unprecedented," she wrote.

On January 5 of this year, Palin brought the issue to the op-ed page of The New York Times, where she took on the Center for Biological Diversity, the principal environmentalist group advocating that the polar bear to be listed under the Endangered Species Act.

“The Center for Biological Diversity, an environmental group, has argued that global warming and the reduction of polar ice severely threatens the bears' habitat and their existence. In fact, there is insufficient evidence that polar bears are in danger of becoming extinct within the foreseeable future--the trigger for protection under the Endangered Species Act,” wrote Palin. “And there is no evidence that polar bears are being mismanaged through existing international agreements and the federal Marine Mammal Protection Act.”

“As a result of these efforts,” she said, “polar bears are more numerous now than they were 40 years ago. The polar bear population in the southern Beaufort Sea off Alaska's North Slope has been relatively stable for 20 years, according to a federal analysis.”

In Palin’s view, the real aim of the environmentalist group was to increase regulation aimed at limiting “greenhouse gases.”

“The Center for Biological Diversity, which petitioned for the polar bear to be protected, wants the listing to force the government to either stop or severely limit any public or private action that produces, or even allows, the production of greenhouse gases,” Palin wrote. “But the Endangered Species Act is not the correct tool to address climate change--the act itself actually prohibits any consideration of broader issues.”

In her New York Time piece, Palin also did not completely discount the prospect of climate change.  “What is justified is worldwide concern over the proven effects of climate change,” she wrote.

“Americans should become involved in the issue of climate change by offering suggestions for constructive action to their state governments,” she concluded. “But listing the polar bear as threatened is the wrong way to get to the right answer.

On May 14, Kempthorne officially announced that the polar bear was being listed as threatened.  In making the announcement, he also stated that the polar bear population had increased since the 1960s.

“Although the population of bears has grown from a low of about 12,000 in the late 1960’s to approximately 25,000 today, our scientists advise me that computer modeling projects a significant population decline by the year 2050,” Kempthorne said.  “This, in my judgment, makes the polar bear a threatened species--one likely to become in danger of extinction in the foreseeable future.  I have accepted the science presented to me by the Fish and Wildlife Service and the U.S. Geological Survey.”

Two days later, Palin announced her intention to join litigation fighting the listing.

“I will do everything within my power as governor to protect the interests of the people of Alaska,” she said in a statement. “I also want to do my part to minimize the impact of the Secretary's decision on the economy of the nation.”

“I want to assure Alaskans that my administration, through the Department of Law, will join with those parties seeking to challenge significant elements of the Secretary's listing decision,” she said.

She vowed to go all the way to the Supreme Court if necessary.  “Without question, litigation challenging the Secretary's decision will be of immense significance to Alaska and the nation,” she said. “I would not be at all surprised if the case is ultimately decided by the U.S. Supreme Court. As governor, I believe that my responsibility requires full State participation beginning at the trial court and ending with the last appeal.”

On Fox News, in an interview with Neil Cavuto she explained her reasoning. “We don`t believe that this speculation, again unprecedented, on computer modeling could forecast the effects of climate change, to the degree that leaves us in a comfortable position,” she said. “It’s just too far out into the future, this speculative modeling.”

In the same Fox interview, she pointed to “extreme environmentalists” whom she believes could hurt the U.S. economy if they succeeded in shutting down oil and gas development on the North Slope of Alaska.

“And we remain committed to ensuring that our polar bears are conserved. And we`re going to continue to monitor the populations and their behaviors in relation to that changing sea ice condition,” she said.  “But, you know, I will tell you, Neil, as you know, if extreme environmentalists have their way--and we do believe that what they would like to see, some of them, is oil and gas development shut down on Alaska`s North Slope--then the economic impact to our nation would really be catastrophic there,” she said.

On August 4, Alaska filed suit to overturn Secretary Kempthorne’s decision to list the polar bear as threatened.

“We believe that the Service’s decision to list the polar bear was not based on the best scientific and commercial data available,” Palin said in a press release.

Representatives of the Center for Biological Diversity, National Resources Defense Council (NRDC) and Greenpeace issued statements sharply criticizing Alaska’s lawsuit.

“Alaska is on the front line of global warming impacts, and the polar bear is our canary in the coal mine,” said Malenie Duchin of Greenpeace. “The state's lawsuit isn’t about the science of global warming and polar bears – it is merely doing the bidding of oil companies that want to drill for oil in sensitive polar bear habitat, without any concern for how that oil will impact the climate when it's burned.”

“The State of Alaska’s challenge to the protection of the polar bear is a lost cause based on discredited, industry-funded attacks on science,” said Kassie Siegal, the climate change program director of the Center for Biological Diversity.

“They have taken their cues from industry every step of the way.” said Andrew Wetzler of the NRDC’s Endangered Species Project.