All gone by the year 2020: some background

All glaciers in Glacier National Park (US) will be gone by 2020. That is the bold prediction that was communicated by the Glacier National Park officials. I learned about this claim viewing the story of Roger Roots who visited the St. Mary Visitor Center and noticed a diorama representing melting glaciers with following sign (my emphasis):

GOODBYE TO THE GLACIERS
The small alpine glaciers present today started forming about 7,000 years ago and reached their maximum in size and number around 1850, at the end of the Little Ice Age. They are now rapidly shrinking due to human-caused climate change. Computer models indicate the glaciers will all be gone by the year 2020.

He found this end date highly unlikely and prophesied that the park officials would have to remove that sign at some point. When he came back two years later, he saw that the diorama sign had been changed. One word in the second last sentence was changed and the last sentence (that computer models indicated that the glaciers will be gone by 2020) was replaced (my emphasis):

They are now rapidly shrinking due to human-accelerated climate change. When they will completely disappear, however, depends on how and when we act.

To me, that raised the question what exactly that claim was based on. Park officials don’t just put up such signs without a reason. They had to be really, really certain that claim was true, otherwise they wouldn’t communicate a date that was so close in the future. So what is the solid science behind this “gone by the year 2020” prediction?

While researching the post, I quickly came to the conclusion that I had too much material with different themes, so I will split it into smaller posts. In this post, I will give some more background about the claim that is needed to understand later posts on the subject.

There was no shortage of articles that reported on the claim that glaciers would be gone by 2020. I found the Thinkprogress post Another climate impact coming faster than predicted: Glacier National Park to go glacier-free a decade early the most concise (emphasis by Thinkprogress):

[I welcome your ideas for a new name for the park. The pictures below are Grinnell Glacier circa 1940, top, and 2004, bottom.]

National Geographic News reports (dead link] the oft-repeated statistic that the glaciers at Montana’s Glacier National Park will disappear by the year 2030 is being revised:

But Daniel Fagre, a U.S. Geological Survey ecologist who works at Glacier, says the park’s namesakes will be gone about ten years ahead of schedule, endangering the region’s plants and animals.

The 2030 date, he said, was based on a 2003 USGS study, along with 1992 temperature predictions by the UN’s Intergovernmental Panel on Climate Change (IPCC).

“Temperature rise in our area was twice as great as what we put into the [1992] model,” Fagre said. “What we’ve been saying now is 2020.”

Yet another climate impact occurring faster than the models had projected.

That post already gave me a lot of information: there was not one prediction, there were two. The first one was a model outcome that puts the end date of glaciers in the park around 2030. Then there was a revision, based on new observations that the temperature was twice as high as their previous input into the model, therefor the melting process would likely go faster than the earlier predicted with lower temperature input. Leading to putting the end date ten years earlier. Now I also had a name (Daniel Fagre) and an affiliation (U.S. Geological Survey). He also seems not to be a geologist, but an ecologist.

With that information it was pretty easy to find the 2003 paper. It is titled Modeled Climate-Induced Glacier Change in Glacier National Park, 1850–2100 and, as expected, it was a lot more nuanced than what I read in the news articles (more on that in a later post). There were two authors: Myrna Hall and of course Daniel Fagre. He is indeed a research Ecologist with degrees in animal ecology and a BA environmental science. He doesn’t seem to be a desk guy, unless you of course consider the Glacier National Park a desk.

Coming back to that prediction, how many glaciers did disappear between 2009 and 2020? It was rather hard to find and the data seems contradictory, so I will just give it as I found it. The articles around 2009 – 2010 mentioned 25 glaciers. Current sources mention 26 glaciers. Initially, I assumed that it was a naming issue. The number was associated with “active glaciers” or “named glaciers” or “glaciers larger than 25 acres”. Luckily, I found a page of the US Geological Survey (the organization that Fagre is affiliated with) on glacial retreat that used the same naming over time, so I was able to compare correctly. The first snapshot of that page stated this (my emphasis):

In 2010, we consider there to be only 25 glaciers larger than 25 acres remaining in GNP.

2010 is one year after Fagre revised his prediction. The current online version of that same page however states this (my emphasis):

In 2015, measurements of glacier area indicate that there were 26 remaining glaciers larger than 25 acres.

That seems odd. They are the ones who are surveying the glacier in the Glacier National Park and the “larger than 25 acres” is sharply delineated. Was one glacier wrongly measured in 2010? Did one glacier grew in size and became larger than 25 acres? Apparently none melted in the meanwhile and, if these figures are correct, then the number of glaciers even increased…
Update: the reason for this discrepancy is that the Grinnell glacier retreated in two different masses that were named separately: the Grinnell and the Salamander glaciers. If these are counted separately, then one arrives at 26, otherwise at 25.

The last sentence from the Thinkprogress quote (“Yet another climate impact occurring faster than the models had projected”) is not aging very well. This new result, based on the new observation, was seen as yet another confirmation that it is worse than the scientists thought. In hindsight that is found to be false. We just entered the year 2020 and it appears that not one glacier was lost. What back then was brought as another confirmation that reality is worse than what the models projected, turned out not to be a confirmation of that at all. Unfortunately, not many will hear about it. The media is silent about the fact that reality is better than what was projected, contrary to the emotional “gone by the year 2020” message, which was broadcast far and wide.

Go to Part 1 | Part 2 | Part 3 | part 4 | part 5 | part 6 | part 7

Advertisement