Just another moronic prediction by the MMGW Cult that blew up in their faces.
https://nypost.com/2020/01/10/the-telling-tale-of-glacier-national-parks-gone-by-2020-signs/
You might want to like, read your own link. Had you done so you would have seen a sign that says, and I quote:
"Computer models indicate the glaciers will be gone by the year 2020."
--- which is a different statement from saying "The glaciers will be gone by the year 2020".
Literacy is a lost art.