Dr. Nevle is quoted, "“We have a massive reforestation event that’s sequestering carbon … coincident with the European arrival.”
I am not going to doubt the sincerity of this research. The world was changed by the European discovery of the new world. Lots of things happened. But Columbus sailing his boats across the Atlantic caused the Little Ice Age in Europe? I think it goes to show how we just don't understand everything about the global weather and how it acts over the long term yet.