[Celjabba]

Originally Posted by Mailanka

GURPS Dungeon Fantasy 16: Wilderness Adventures is your best bet, even if your game isn't a fantasy game.

Besides GURPS Dungeon Fantasy 16: Wilderness Adventures,
-Gurps Fantasy have a couple pages on natural disasters including blizzard, sandstorm,...
-Gurps After the end 2 have a section on survival in various climate.
-Gurps Underground adventures have everything about underground hazards and hostile environment.