Climate scientists are predicting rough weather for their profession in 2017. US president-elect Donald Trump’s statements on climate change, his appointments to head environmental agencies, and the threatening actions of his transition team all have the nation’s weather professionals on alert and preparing for the worst.

The Center for Science and Democracy at the Union of Concerned Scientists in Cambridge, Massachusetts, has established a hotline for National Oceanic and Atmospheric Administration (NOAA) employees to report political meddling. There’s currently concern among NOAA scientists about who Trump’s pick to head the agency will be. “I am hearing a lot of worry,” union director Andrew Rosenberg told Bloomberg. “The worry is that they will be putting another ideologue in place.”

Trump’s pick to lead the Department of Energy (DOE), former Texas governor Rick Perry, has denied climate change altogether, and the future head of the Environmental Protection Agency, Oklahoma attorney general Scott Pruitt says the science isn’t certain. These choices signal storms ahead generally and for NOAA specifically. Trump himself has tweeted that climate change is a fiction created by the Chinese to harm US manufacturing, and more recently said “nobody really knows” if it’s real.

Other ominous signs for scientists include the Trump transition team request to the DOE for the names of all employees and contractors who attended annual global climate talks hosted by the United Nations within the last five years, scientists who have worked on climate change, and the professional memberships of lab workers. On Dec. 13, DOE spokesman Eben Burnham-Snyder said the agency would not honor the request—after which the Trump team denied the questionnaire was authorized and withdrew the demand.

Fearful that a Trump administration might destroy or bury climate-science findings, scientists are also collaborating on ways to preserve existing government data on independent servers. At a “guerrilla archiving” event in Toronto on Dec. 17, volunteers copied irreplaceable public data in case of emergency deletion. Scientists and database experts at the University of Pennsylvania are collaborating on mass downloads of federal data, compiling them online to harbor scientific information. “Something that seemed a little paranoid to me before all of a sudden seems potentially realistic, or at least something you’d want to hedge against,” said Nick Santos, an environmental researcher at the University of California at Davis, told the Washington Post.

On Dec. 13, climate scientists gathering for the fall American Geophysical Union conference took to the streets of San Francisco in between sessions on nonlinear geophysics, seismology, and the study of the earth’s deep interior, to denounce the president-elect’s positions on climate change. “This is a frightening moment,” said Harvard history of science professor Naomi Oreskest at the protest. “We have to get out and explain to people why this science matters.”

But Gina McCarthy, the outgoing EPA head, says it will not be easy to undo all the work her agency has done during the Obama years. For example, the Trump administration will be required by the Clean Air Act to establish a scientific foundation for any new law or action that undoes regulations in existence that curb carbon dioxide emissions. As she told the Financial Times: