What did you think about the point in the article suggesting millions of people dying on South America caused the earth to cool down due to reforestation absorbing more green house gas. I find this hard to believe.

What a strange question.

There was a noticable (and well recorded) change in the climate for awhile when Ghenghis Khan went on his rampage. And he was a lot less effective at killing people than novel old world diseases.

It doesn’t seem completely implausible.