President-elect Donald Trump speaks during an election night rally Nov. 9 in New York. (Evan Vucci/AP)

Call it the opening shot in a brewing war over scientific integrity in the future Trump administration.

More than 2,300 scientists, including 22 Nobel Prize winners, have issued an open letter to President-elect Donald Trump and the 115th Congress, urging them to “adhere to high standards of scientific integrity and independence in responding to current and emerging public health and environmental health threats.”

The letter underscores the extent to which many scientists, who have worked with the Obama administration to address climate change, pandemics and other major policy issues, are worried about whether Trump and his deputies will slash science funding and overhaul the way several federal agencies operate. While it does not directly refer to President George W. Bush’s eight years in office, many of the signatories spent years fighting the curbs imposed on federal scientists during that time.

Andrew Rosenberg, who directs the Union of Concerned Scientists’ Center for Science and Democracy and whose group organized the letter, said he and other scientists have become concerned both by comments Trump made over the course of the campaign and some of the people who have been advising him on energy, the environment and public health.

“We need to make sure there’s not political manipulation of the science,” Rosenberg said, adding that part of the challenge he and others face is there is not an obvious point person on the transition team who is communicating with outside constituency groups. “It’s hard to figure out even who to have a conversation with. There doesn’t seem to be much of an opening.”

The list of distinguished signatories, who hail from all 50 states, includes medical scientists, physicists and many climate researchers. The Nobel laureates include Harold Varmus, who headed the National Cancer Institute under President Obama; David Baltimore, the former president of Caltech; and Mario Molina, who helped discover the role of chlorofluorocarbons in depleting the ozone layer. James Hansen, the longtime NASA researcher who had previously denounced George W. Bush’s administration for interfering with his ability to communicate publicly the science of climate change, also signed the letter.

The scientists represent a broad range of disciplines: At least 440 in biology, 350 in ecology, 180 in environmental science, 171 in earth science, 108 in chemistry and 40 in agriculture signed the letter.

In the past, Trump has questioned the connection between human activity and climate change, suggesting that he would seek to withdraw from the accord forged last year in Paris that aims to cut the world’s carbon output over the next decade. In a New York Times interview this month, however, the president-elect said, “I have an open mind to it” and said protecting air quality and “crystal clear” water was crucial.

Several of the men and women who are either advising Trump or are being considered for administration posts have questioned the current trajectory of federal scientific research. In an interview last week with the Guardian, former congressman Robert Walker (R-Pa.) said NASA’s Earth Science division should be defunded because it engages in “politically correct environmental monitoring” and the agency should focus on space instead.

“We see NASA in an exploration role, in deep space research,” Walker said. “Earth-centric science is better placed at other agencies where it is their prime mission.”

Kathleen Hartnett-White, who used to chair the Texas Commission on Environmental Quality and met this week with Trump at his transition headquarters in New York City, said in an interview with The Washington Post in October that she did not consider carbon dioxide a pollutant under the Clean Air Act because it does not pose a threat to public health.

“Carbon dioxide has none of the characteristics of a pollutant that could harm human health,” she said, adding at another point that when it comes to scientific predictions that the world could be on the brink of disastrous climate change, “We’re not standing on a cliff from which we are about to fall off.”

“I think all scientists are extremely concerned about what Trump might do to our scientific infrastructure,” said climate scientist Ken Caldeira, a researcher at the Carnegie Institution for Science who signed the letter. “It takes decades to build up leadership in a scientific area, because you have to train people for many years. It would be very easy in just a couple of years to destroy what has taken many decades to build up.”

Obama — who has repeatedly emphasized the need to adhere to fact-based decision making in recent months, often as he was campaigning against Trump during the election — made a point of highlighting that idea during an Oval Office meeting Wednesday with the American winners of this year’s Nobel Prizes.

Sitting with four of this year’s laureates — two in physics, one in economics and one in chemistry, the president said, “We are incredibly proud of them.”

“And I think it’s just a reminder that one of the things that makes America unique is our ability to attract talent from all around the world, to study at some of our greatest universities, and for us to have very practical, reasoned, fact-based empirical ways to figure out how we can make the world a slightly better place,” Obama added.

The letter released Wednesday echoes a previous one released by the Union of Concerned Scientists that was directed at Bush in 2004. The only difference is that at that time, the Bush administration had governed for some four years and had come under fire for multiple science-related scandals. Here, by contrast, scientists are seeking to prevent them by articulating the principle that government researchers should be able to follow the evidence where it leads, and should be free to communicate their results to the public.

“Twelve years ago, the Republican president was . . . very crude in the way they dealt with science,” said Lewis Branscomb, a physicist at the University of California at San Diego and another of the statement signatories. “They very often had political people in the government rewriting reports that scientists in the government had written. That sort of thing happened.”

“And now we’re looking at the kinds of people that Trump is appointing, and we have no good reason to be optimistic about what they’re going to do,” Branscomb said. “We don’t know of course, and we’re not saying they’re going to do anything wrong. We’re simply telling them what we think is going to be important, and hope that they pay attention when they select the senior people in the various agencies that are dealing in science.”

If not, the science community will be watching, the letter cautions.

“We will continue to champion efforts that strengthen the role of science in policymaking and stand ready to hold accountable any who might seek to undermine it,” it concludes.

Read more at Energy & Environment:

Pope Francis: ‘Never been such a clear need for science’ to protect the planet

Over 2,000 scientists urge Trump to respect ‘scientific integrity and independence’

He created a beloved blog about the melting Arctic. But it got harder and harder to write

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