Though much of the Trump administration’s policy agenda has been hobbled by chaos and scandal, Scott Pruitt’s Environmental Protection Agency has been remarkably productive. Under Pruitt’s leadership, the agency has limited communication between its staffers and the public—even shuttering its own climate-change website—and undertaken a regulatory rollback of historic proportions. According to a recent report in the New York Times, Pruitt has relied on the advice of industry lobbyists and political allies; several of his decisions have ignored previous agency findings on climate, water quality, and pesticide safety.

While these are dark times for federal environmental scientists, Pruitt is far from the first politician to discount science. When former Australian Prime Minister Tony Abbott, a climate-change skeptic, took office in 2013, he made brutal cuts in government research programs and eliminated the longstanding cabinet position of science minister. Canadian Prime Minister Stephen Harper, who served from 2006 to 2015, cut research funding, eliminated the nation’s science advisor, and prevented government scientists from speaking to the press. Under President George W. Bush, U.S. federal scientists were routinely discouraged from talking about climate change, and saw their work distorted in order to justify administration policies.

In a new paper in Conservation Biology, environmental scientists and policy experts look at past attacks on scientific integrity in the United States, Canada, and Australia, and consider how scientists and advocates can effectively respond—even in the most hostile of circumstances.

“People are outraged by the recent developments in the United States, but if you compare the experiences of scientists in different countries, you can see that there are some underlying issues that transcend administrations,” says Carlos Carroll, a conservation biologist at the Klamath Center for Conservation Research in California and the lead author of the paper.

Carroll and his co-authors point out that in previous cases, scientists within and without the government used setbacks to galvanize support for reform. “Policymakers have to make policy choices based on a whole mix of factors, but one of those factors has to be our best understanding of the world,” says Daniel Rohlf, a professor of environmental law at Lewis and Clark Law School and a co-author of the paper. “The distortions of that understanding have been so egregious, in some cases, that scientists have had no choice but to stand up and say these are the facts, and this is how science works.”

Thanks in part to these initiatives, the Harper government’s suppression of science became part of Justin Trudeau’s successful 2015 campaign. Katie Gibbs, the executive director of Evidence for Democracy and one of the organizers of the original Death of Evidence rally, says that while “there’s obviously still work to be done,” the Trudeau government has taken concrete steps toward protecting scientific integrity.

Gibbs, another co-author of the Conservation Biology paper, says that scientists laboring under unfriendly administrations should be sure to document firsthand evidence of scientific suppression. In Canada during the Harper administration, a single anonymous photograph of a pile of scientific books and papers in a dumpster stoked national outrage about the government’s destruction of seven historic fisheries libraries—and helped turn the political tide against Harper.

Gibbs and her co-authors add that when government scientists are silenced, scientists employed by universities and non-profit organizations can lead the fight for institutional reforms—both as individuals and through scientific societies. Independent scientists can also call out misrepresentations of science by the media and politicians. “There’s often a sense of ‘Oh well, maybe another scientist will take this on,’ but we all have to take responsibility,” Gibbs says. “Those of us who believe in truth and evidence and facts—we need to be pushing back on this constantly, day in and day out, rather than letting it go.”

So far, the most visible response to the Trump administration’s suppression of science has been the March for Science in late April, which was supported by some 300 scientific organizations and drew more than a million scientists and others to 600 events worldwide. While the march was criticized by some for its fuzzy goals, Gretchen Goldman of the Union of Concerned Scientists, another co-author of the new paper, says it helped embolden thousands of scientists to step up their activism. Her organization’s network of credentialed scientists has grown from 17,000 to 23,000 members in recent months, and its overall membership has grown by more than 20 percent. A UCS initiative launched earlier this summer, Science Champions, has recruited more than 500 scientists to engage in lobbying, media outreach, and other kinds of sustained activism on behalf of scientific integrity.

“Historically, scientists have been a cautious group, and there’s been a reticence to act,” says Goldman, “but what I used to know isn’t true anymore.” Experiences under past administrations, she says, have convinced many in the scientific community of the value of standing up to political interference. The actions of the Trump administration have only confirmed its urgency.