What a truly pile of junk that study was:
"
European settlers killed 56 million indigenous people over about 100 years in South, Central and North America, causing large swaths of farmland to be abandoned and reforested, researchers at University College London, or UCL, estimate. The increase in trees and vegetation across an area the size of France resulted in a massive decrease in carbon dioxide (CO2) in the atmosphere, according to the study."
They say that a tiny drop in CO2 levels over a 30-40 year period rapidly changed the temperature, yet ignore the fact that it cooled a lot over 100-200 years earlier WITHOUT a CO2 drop. Not only that land use impact changes was not large in those centuries either, which the paper failed to point out. The change from Forest to crops which was minor doesn't change the CO2 uptake much either, which they failed to quantify properly.
"
European settlers killed 56 million indigenous people over about 100 years in
South, Central and North America, causing large swaths of farmland to be abandoned and reforested, researchers at University College London, or UCL, estimate."
bolding mine
South, Central and North America is a
HUGE area of the continental land surface, around 65 million people at peak population level spread out in a 100 year period, the paper claims 90% of the people died out in that time frame. The impacts of change was spread out over 100 years time, which the planet barely noticed since the effects of land use change was actually in small areas of the Americas.
They used only hand labor for hunting and land use, no fossil fuels used, no tractors used, and used fires to clear land (a CO2 releasing activity, which they didn't mention in the paper).
A typically overblown paper.
Shall I go on...?
