A grizzly bear walks past Sperry Glacier in Glacier National Park/NPS file

Climate science is just that, science, which ebbs and flows through the refinement of technology and physical observation. But the Trump administration's refusal to recognize the science its land-management agencies conduct neither ebbs nor flows; you could say it's frozen in place. Sadly, that clamp down is preventing a thorough discussion of what's going on with the glaciers at Glacier National Park.

A few weeks ago, there was something of a furor from some media over the decision by staff at Glacier to remove interpretive displays that had said "computer models indicate the glaciers will all be gone by the year 2020." Fanning the uproar was that the Park Service had "quietly" removed the display.

Now, parks do from time to time change interpretive materials, and sometimes they announce the changes, sometimes they don't. Fine. But what's really disturbing about this episode is that the administration's gatekeepers at U.S. Geological Survey and the National Park Service evidently don't want to hear their experts provide detailed discussions of what's going on with Glacier's glaciers.

The short story, Glacier Superintendent Jeff Mow told me, was a change in the weather.

"Those signs were based on the observation prior to 2010 that glaciers were shrinking more quickly than a computer model predicted they would," he said. "Subsequently, larger-than-average snowfall over several winters slowed down that retreat rate and the 2020 date used in the NPS display does not apply anymore."

A new display at St. Mary Visitor Center in Glacier National Park holds to predictions that the park's rivers of ice will one day be gone, but doesn't project whenNPS

But what's the deeper, more detailed story? Are the glaciers growing, has their retreat merely slowed, are they stagnating? What is driving them?

Mow referred me to USGS researcher Dr. Dan Fagre, who has studied the park's glaciers, as well as those in surrounding national forests, since 1991.

"I will say that in the almost six years that I've been here, I've never used the 2020 date," added Mow. "In conversation, I've never heard Dan use the 2020 date for all glaciers parkwide. Glaciers are complex in how they are defined and how they behave; we all like simple answers, but Dan has that gift that can communicate that complexity in an understandable manner."

Unfortunately, Fagre wasn't allowed to talk to me.

"The USGS communications staff declined the request and felt it should go to Kathy Kupper at the NPS headquarters," he replied in an email when I asked what was going on with the glaciers.

But would a public affairs specialist at the Park Service headquarters be able to explain the park's glacial dynamics with the same authority as Fagre? Jeremy Barnum, the Park Service's chief of public affairs, fielded my questions to Kupper.

"The park works closely with the U.S. Geological Survey to understand glacial retreat and how it impacts the park ecosystem," he replied, adding that, "the park continually updates its interpretive material, including exhibits, based on the latest research available for multiple park resource topics."

OK, but what is the understanding of what's going on with the glaciers? What research is driving the interpretive materials for Glacier? What, frankly, is the latest research?

My request to discuss the matter with someone more knowledgeable about Glacier's glaciers, someone who could talk in specifics, went unanswered. And that's disturbing for the country's leading land-management agencies, that they would decline an opportunity to share what they know about climate and recent weather and their impacts on glaciers. 

Instead I was referred to webpages with studies that stated that "varied model projections suggest that certain studied GNP glaciers will disappear in the next few decades, between 2030 to 2080."

The new displays at Glacier National Park's St. Mary Visitor Center give a very brief history of the park's glaciers/NPS

Now, obviously something changed between the time those studies came out and when Glacier created the displays saying glaciers would vanish by next year and when those interpretive panels were removed.

But what?

How much snow has fallen on Glacier National Park in the past two or three years? Have the daily high temperatures decreased? Are the park's glaciers still retreating, are they advancing, or are doing neither? Why did the now-removed displays say the glaciers would be gone by 2020, when USGS studies said otherwise? What research went into the new interpretive displays? The park's specialists who designed the displays weren't available to tell me.

Suffice to say, the USGS and NPS are missing an opportunity to point out the vagaries of weather and how they differ from climate change, to discuss the details about what is known about the park's glacial behavior, and to show that they're not letting politics muzzle them.

Unfortunately, this isn't a new treatment of science surrounding Glacier's ice rivers, but just the latest episode under the Trump administration. Remember back during the summer of 2017 when Facebook CEO Mark Zuckerberg headed to Glacier to spend a day in the park, both to enjoy the vistas and learn a bit more about climate change? His staff set up a meeting with Fagre. Folks within USGS viewed the meeting as "an incredible opportunity."

But then top Interior officials in then-Secretary Ryan Zinke's office dashed that opportunity, supposedly in the name of spending tax dollars wisely. Heather Swift, then Zinke's press secretary, in Interior's official statement about the matter did, however, point out that "Gracie, the 'bark ranger,'" was able to meet Zuckerberg.

Good dog, bad climate scientist? (You can follow the email paper trail here.) 

In the aftermath, USGS officials realized the bad press that welled up around that event, and said the final decision was not up to them. Come forward two years, and the agency is still muzzled and the Park Service is an accomplice.

What information on the glaciers USGS will release is that the park's rivers of ice have shrunk by 68 percent through 2015, when they covered little more than 5 square miles. How much they cover today seems to be a secret both USGS and NPS don't want to share. Also apparently too sensitive to discuss is whether the current recalibration on glacial movement is momentary, in geologic time, or a wholesale reversal of concerns that Glacier soon would lose its calling cards.

Looking beyond a reporter's questions, what are rangers in the park allowed to tell inquisitive visitors who wonder about the glaciers' current lifespan? That "(T)he park works closely with the U.S. Geological Survey to understand glacial retreat and how it impacts the park ecosystem," now go take a hike?

In an age when there is such needed emphasis on STEM (Science, Technology, Engineering and Mathematics) education, silencing scientists is illogical. It's not a particularly good recruitment practice, either, for agencies that employ scientists or hope to retain them.

As for Glacier's interpretive materials, this past winter the park received funding to update those in the St. Mary Visitor Center. The new displays (shown above) do not contain an "end of life" date for the 26 glaciers that were counted in 2015, but leave it open-ended, based on "how and when we act" in response to "human-accelerated climate change."