Climate change science is not as unsettled as skeptics imply and doubts about global warming stem more from fear of regulation than from scientific uncertainty, professor and author Naomi Oreskes told an audience last week.

Oreskes made her comments to about 150 people, gathered Friday at the Greater Yellowstone Coalition’s 27th annual meeting in Jackson. The Bozeman, Mont., -based conservation group claims 8,000 dues-paying members.

Oreskes, a professor of history and science studies at the University of California, San Diego, started her presentation with science in the 1850s, when a physicist investigated heat-absorbing gases. She provided a brisk tour of science history to show how climate science is more established and certain than many people realize.

By the early 1900s, the Nobel Prize-winning scientist Svante Arrhenius suggested burning fossil fuels could warm the earth.

“Arrhenius was Swedish, so he thought global warming would be a good thing,” Oreskes said.

The conservation group chose this year to focus on how climate change will impact the Greater Yellowstone Ecosystem, one of the largest, nearly intact temperate ecosystems left on earth. The ecosystem covers 20 million acres, including two national parks, parts of six national forests, three national wildlife refuges, and state and private lands.

While Oreskes gave a history of climate science and campaigns designed to seed doubt about it, other presenters detailed what the latest and best climate data shows about how climate change could impact wildlife and watersheds in this region.

According to Oreskes, concerns about climate change more than four decades ago prompted the President’s Science Advisory Committee to request a report on the potential impacts of carbon dioxide-induced warming. President Lyndon Johnson saw the report and mentioned its findings to Congress that same year.

Said Johnson: “This generation has altered the composition of the atmosphere on a global scale through ... a steady increase in carbon dioxide from the burning of fossil fuels.”

Forecasts in that paper have proven true, she said, adding that the scientific surprise has been that climate change has been discernible earlier than expected.

“We knew,” she said. “We’ve known since 1965.”

With Erik Conway, Oreskes is co-author of the book, “Merchants of Doubt: How a Handful of Scientists Obscured the Truth on Issues from Tobacco Smoke to Global Warming.” Both during her talk and in her book, she details how a few scientists have led a campaign she calls “doubt mongering.”

“Why would scientists participate in this?” she asked.

The art of doubting science

According to Oreskes, a small group of physicists — Robert Jastrow, Frederick Seitz and William Nierenberg — formed the George C. Marshall Institute in 1984 to defend President Ronald Reagan’s Strategic Defense Initiative, also called Star Wars, from attacks from other scientists, especially the Union of Concerned Scientists. A 1987 article by Jastrow argued that in five years, the Soviet Union would overtake the United States, Oreskes said.

But as America’s Cold War enemy retreated instead, the institute turned its focus to environmental issues. Oreskes said the institute’s backers saw environmentalism — with its call for regulation to control pollution and other impacts to land, air and water — as a slippery slope tilting toward socialism.

The men viewed environmental regulation, including regulation of cigarette smoke, as interfering with free markets and putting the country on a path to more government control of people’s lives, she said. To preempt regulation, Oreskes said this loose-knit group of high-level scientists issued reports casting doubt on the science of everything from second-hand smoke to climate change, she said.

Fears of market regulation aside, she said, “It doesn’t mean the science is wrong and these aren’t real problems in need of real solutions.”

One of the best buffers to climate change could be protecting natural areas, from mangrove forests to wildlife migration paths, said Healy Hamilton, a scientist at the California Academy of Sciences, where she directs the Center for Applied Biodiversity Informatics.

Just as barrier islands, coral reef and mangrove forests are a good defense against storm surges, the Greater Yellowstone Ecosystem could serve as a refuge — or “ark” as another speaker put it — for plants and animals adapting to climate change, Hamilton said.

“Nature is actually part of our solution,” Hamilton said.

Hamilton presented two scenarios of warming. One showed a “worst case scenario” if humans do nothing to curb their carbon footprint. The other projected what might happen if humans globally reduce emissions of greenhouse gases, which contribute to global warming.

By understanding what conditions plants and animals require today, her research predicted where those species will likely be found in the future, through 2099.

“This is looking as rigorously as we can today at where they live today and where those climates might exist in the future,” she said.

Under both scenarios, the Greater Yellowstone stands out as a high-elevation “climate refuge” for animals, such as Canada lynx, mule deer, elk, moose and bighorn sheep, even as models project the region becoming drier and hotter in summer and fall.

Hamilton selected species that she said are important ecologically as food for predators, for example, and animals that contribute to local economies through hunting, wildlife watching, photography and other activities.

Places with the right ingredients — terrain, temperature and precipitation — for those species to thrive, shrink under both scenarios, but to a much greater degree under the worst-case scenario.

Keeping protected areas connected so animals can move between those places as the climate changes is one way to build landscapes to support wildlife adapting to shifts in temperature and precipitation, she said. She lauded efforts to plan oil and gas drilling and renewable energy projects in ways that aim to protect wildlife movements. Corridors for wildlife to roam freely from Yellowstone to Yukon may be one of the most important to preserve in North America, she said.

The Greater Yellowstone Coalition’s Scott Christensen presented more examples of how climate change might impact wildlife locally. Declining snowpack, for example, could affect how wolverines, Canada lynx and pikas build their homes, chase prey or regulate body temperature, respectively.

Already, peak run-off from snowpack is occurring 10 to 20 days earlier, setting the stage for lower late-season flows, he said. Moreover, stream flows in the Upper Yellowstone River are projected to decline 15 percent to 24 percent during drought periods between 2025 and 2100, he said. Such changes could lead to warmer water, eventually converting upstream portions of river from a cold-water trout fishery to warm-water habitat more suited for smallmouth bass, perch and paddlefish, he said.

The Greater Yellowstone Coalition will be putting a greater emphasis on climate modeling and projections, Christensen said, because “we want to know where to go, where we can get the biggest bang for our buck, doing this work.”

Hamilton, meanwhile, said citizens could take simple steps on their own to make a difference. For example, she asked how many in the room bought a carbon credit to offset greenhouse gases generated during their flight, if they flew, to the conference. Only one participant raised a hand.

That person paid $16.95 for a carbon offset credit for a $600 airline ticket. That money goes directly to “innovative things to suck carbon out of the atmosphere,” Oreskes said.

“I believe going carbon-neutral is one of the most important things we can do in our daily lives,” Oreskes said. “Mitigation is what is going to determine which of these two futures comes to pass.”