any significant degree (no pun intended) by mankind or is it simply the Earth's normal cycle of heating and cooling? Some so-called experts are going to be pretty shocked if we're on the verge of another ice age.
Also, all it would take is one major volcanic eruption (on the scale of Tambora in 1815) to lower global temps by several degrees almost immediately. And that eruption could happen in what is now Yellowstone Park. Hope y'all have a big stash of MREs somewhere.
https://www.youtube.com/watch?v=DgSZADL5svQ