Across the whole of the Americas, the introduction of infectious diseases from Europe resulted in a 90 percent fall in the population, from about 60.5 million in 1500 to 6 million a century later. The global population fell by 10 percent. The decline in slash-and-burn agriculture and the reforestation of tens of millions of hectares of cultivated land resulted in a reduction in carbon dioxide in the atmosphere that is visible in the ice cores drilled by scientists in the Antarctic. The demographic collapse cooled the global surface air temperature by 0.15 degrees Celsius, contributing to the
...more