This is a hoax that's come around before, that snow burns instead of melting, now. It's an urban legend among the chemtrails people, and they keep making these videos, and they don't want to hear your science explanations. Now it's a Q thing too, apparently.

Flat Earth stuff I think is already part of some Q believers' worldview. Which you would think would make engineering a continent-wide system of tunnels tricky, like how would they know not to go too far and make a hole in the bottom of the world? But they manage to believe.