The Trump administration’s unusual efforts to keep some federal agencies open during the government shutdown is creating widespread confusion for federal workers at the Environmental Protection Agency, the National Oceanic and Atmospheric Administration, and the National Park Service, among other agencies.

On Friday, EPA Administrator Scott Pruitt sent an email to his agency’s 14,000 employees telling them to report to work on Monday because the agency “has sufficient resources to remain open for a limited amount of time during this shutdown.”

.@EPA has sufficient resources to remain open for a limited amount of time during this shutdown. All employees should follow their normal work schedule for the week of January 22, 2018. Thanks to EPA staff for your hard work, dedication, and all you do for the American people. — Administrator Pruitt (@EPAScottPruitt) January 20, 2018

The announcement came after White House Budget Director Mick Mulvaney said some agencies would use “carry-forward funding” from the previous budget appropriation.

But keeping offices open is a departure from previous shutdowns, and employees are unsure of what to expect.

“It’s very confusing [for employees],” John O’Grady, a career employee who heads a national council of EPA unions, told the Washington Post.

The EPA has a government shutdown contingency plan posted on its website. Among other things, the plan calls for many of the agency’s employees to stay home and stops work at EPA’s 29 laboratories across the United States, except to respond to imminent threats to public health.

In a cryptic series of statements, the agency said last week that it wouldn’t stick to the script. “To take that plan and deduce what is actually going to happen is not accurate reporting,” spokesperson Jahan Wilcox told Bloomberg.

The NOAA is also sending mixed messages. The agency’s main Twitter account declared that it would not update during the shutdown.

The U.S. federal government is currently shutdown. This account will not be updated until appropriations are enacted. Only sites necessary to protect lives and property will be maintained. Go to https://t.co/83F2guq6DU for weather information and visit https://t.co/JGGeA2nKqb pic.twitter.com/0lXrEESZmm — NOAA (@NOAA) January 22, 2018

But the NOAA’s climate Twitter feed was still posting stories on Monday.

Ice cores are cut, packaged, and shipped to labs all over the world where scientists use them to study indicators of climate change (such as isotopic composition or trapped air bubbles) from the past. pic.twitter.com/92vncMOjHG — NOAA Climate.gov (@NOAAClimate) January 22, 2018

The NOAA operates 17 satellites and is the premier supporter of climate and weather research. Some staff will still be on hand to maintain these instruments, but much of the analysis work is stopped and new projects are on hold.

According to the Department of Commerce’s shutdown plan, “most research activities” at the National Institute of Standards and Technology and NOAA shut down except computer modeling for hurricanes and for flight planning.

As Scott Waldman at E&E News reported, this is a huge setback for climate science:

While the orbiters will be operating and continuously collecting a vital stream of climate data, much of the government’s science apparatus will grind to a halt. If the 2013 shutdown, which lasted for 16 days, is any guide, that has the potential to waste tens of millions of dollars in federal research. The shutdown puts research projects, science grants and data collection at risk, and it could set some scientific operations back months, while permanently crippling others, according to a federal report on the last shutdown.

Much of climate field research requires extensive careful planning, and research sites like the polar ice caps are only accessible at certain times of the year. Stopping work in these areas during the 2013 shutdown proved especially disruptive for data collection: It created gaps in the record and added unexpected shutdown and restart costs.

Climate researchers in Antarctica funded through the National Science Foundation and NOAA were forced to stop working and start packing. Researchers who didn’t work for the federal government but relied on data like satellite observations from federal agencies were affected too.

Other agencies that deal with the environment and implement energy policy are also trying to carry on as usual.

The US Department of Energy, which runs 17 national laboratories and funds research on clean energy, said it will remain open regardless of the shutdown.

“All DOE federal employees are expected to report to work on your next scheduled work day and subsequent work days unless you have previously approved leave or are given formal notice by your management not to report to work,” according to an email sent to agency employees.

The Department of the Interior said it will keep some national parks open, a reversal of its policy during the 2013 shutdown, but lawmakers said they’re concerned the parks could still close.

Nebraska is home to 5 National Parks with 307,319 visitors to these parks, which could potentially close if @SenateDems shut down the government. #SchumerShutdown — Natural Resources (@NatResources) January 19, 2018

The Washington Post reported that workers at national parks don’t know how this will play out, and Emily Atkin at the New Republic warned that keeping parks open during a government shutdown could prove dangerous, since facilities like bathrooms may not be opened and there may not be enough workers on hand to handle emergencies.

Some of the federal government’s energy development projects, like the proposal to open almost all US coastal waters to offshore drilling, will also stall.

If government shuts down, I'm told @BOEM_DOI meeting next week -- the 23rd -- in Anchorage to discuss draft offshore drilling proposal will be cancelled. — Elizabeth Harball (@ElizHarball) January 19, 2018

But other government groups, like the Federal Energy Regulatory Commission, an independent regulatory body, are still running.