Twenty-eight curators at New York’s American Museum of Natural History are voicing “profound concern” about museum trustee Rebekah Mercer’s role in funding groups that challenge climate change science. A trustee on the board since 2013, Mercer has given $4 million to the museum over the last six years, according to records.

In an internal letter dated January 19 and addressed solely to Michael J. Novacek, the museum’s senior vice president and provost of science, the curators said the groups supported by Mercer “directly contradict the museum’s mission and impede our ongoing efforts to educate the public about the science of past and future climate change,” as reported by the New York Times.

Among the letter’s signatories are Susan Perkins, a curator in molecular systematics; Peter Whiteley, a curator of North American ethnology; and John G. Maisey, the curator-in-charge of the division of paleontology. The letter follows the publication of an open letter signed by over 250 scientists last week and published by Brooklyn, New York’s Natural History Museum. The organization has also launched a petition calling for Mercer’s removal.

“We are concerned that the vital role of science education institutions will be eroded by a loss of public trust if museums are associated with individuals and organizations known for rejecting climate science, opposing environmental regulation and clean energy initiatives, and blocking efforts to reduce pollutants and greenhouse gases,” reads the Natural History Museum’s letter.

Mercer’s position at the museum first came under scrutiny following the 2016 presidential election, when the Times investigated ties between cultural organizations and the Donald Trump campaign’s major donors. Mercer was responsible for bringing Kellyanne Conway, counselor to the president, and Steve Bannon, former chief strategist, to the Trump campaign, and was part of the president’s transition team.

The Mercer Family Foundation, which she runs with her father, Robert Mercer, has reportedly given $8 million to organizations that question climate change, such as the Heartland Institute in Illinois; the Cato Institute, in Washington, DC; and the Oregon Institute of Science and Medicine. Since 2014, Mercer has sat on the board of conservative think tank the Heritage Foundation, known for its skepticism about climate change.

“Since Trump’s election, the Mercer family has been flushed out of the shadows and revealed to be major supporters of the climate denial machine,” added Kert Davies, founder of a climate-focused transparency group, speaking to the Guardian. “Their support for climate deniers appears to be growing over time.”

Mercer isn’t the first board member to become the subject of controversy. A 2015 open letter from scientists, also organized by the Natural History Museum, called for the museum to cut ties with David H. Koch, a philanthropist, energy magnate, and powerful Republican donor, because he denied the existence of climate change. After 23 years on the museum board, Koch stepped down from his post at the end of 2015 but insisted that the decision was voluntary and not influenced by the over 550,000 signatories on a petition calling for his removal.

The museum did not respond to artnet News’s request for comment, but told Hyperallergic that human-driven climate change is “well supported by scientific evidence and one of the most serious issues currently facing our planet.” The museum insisted that it is not influenced by the political views of trustees.