[aminok]

The Dorset culture was spread all across Northern Canada and parts of Greenland. It was found in widely divergent latitudes, with different climates.

It's simply not plausible that such a widely dispersed culture would disappear in such a short time due to climate change.

Disease transmitted from Norse settlers/traders being the cause is also not plausible, as the Dorset disappeared first in the Western stretch of Northern N. America, where the Thule were expanding from, rather than the East, where they would have first had contact with the Norse. Competition from an invasive culture, the Thule, is the likely cause.