I am a skeptic of “man caused” climate change. In the northern states we have a phenomenon called “lake turnover”, where the temperature of the water on the top layer of the lake becomes colder than the bottom due to low air temperature in late fall. This layer falls to the bottom of the lake and the warmer bottom water raises to the top. I would not like for the colder layer in the upper atmosphere to fall and instantly cool the earth’s surface. That may explain why the instant freezing of animals and the start of an ice age. Just a thought.
I recall reading such a theory many years ago involving volcanic activity and gases reaching the edge of space, being super-chilled and falling to Earth in huge "blobs" which instantly killed and froze plants and animals. It would certainly account for the state of preservation of Mammoths and other creatures in the far north.