It would be interesting to read an article that actually analyzed this research. This one is basically a digg/reddit comment macroexpanded into the form of a newspaper editorial.
When the "white man" came to North America, at least by all accounts I've read, it was nearly entirely virgin forest (the old "a squirrel could travel from the Mississippi to the Atlantic without touching ground" chestnut). So where was this mass deforestation?
More recent scholarship suggests the Americas, before the arrival of european plagues, were far more densely populated, and the environment more shaped by native agriculture, than you might expect. A good summary of the ideas is Charles C. Mann's article "1491":
One estimate is that in the first 130 years of contact, 95% of a prior American population of over 100 million died.
Those 130 years happen to be about the first half of the 'little ice age', and the natives often used large-scale burns to clear and prepare land. So while IBD mocks the idea that the depopulation of the Americas caused the little ice age, it's at least plausible.
Umm... temperatures dropped with no lead time? Most feedback systems (especially on a global scale) do not work nearly that quickly due to negative feedback. The idea that man caused the little ice age is ludicrous.
I thought I read someplace that sun spots had to do with the 1600's mini-ice age? Tying the fall of for example the Mayan civilization with the triggering of an ice age due to decrease in agricultural activity and associated re-forestation seems like a stretch.
