Some scientists even suggest that the effect was so great on the Native American population, with a death toll estimated at 56 million, that the climate moved into a cooling cycle due to a lack of crop rotation.

一些科学家甚至认为，这些疾病对美洲原住民的影响是如此之大，估计死亡人数达 5600 万，以至于由于缺乏作物轮作，气候进入了降温周期。