How did the genocide of indigenous Americans impact the health of planet Earth?

What was the impact of colonial violence, disease and genocide on the population of indigenous Americans when the lost Genoese predator, Christopher Columbus, stumbled into the islands of Taino peoples in 1492? How many indigenous people died? How did they die? What were the long-term effects of population destruction? What were the impacts on land use and CO2 emissions centuries before the Industrial Revolution?

In "Earth system impacts of the European arrival and Great Dying in the Americas after 1492," written by Alexander Koch, Chris Brierley, Mark M. Maslin, and Simon L. Lewis, we get a broad sense of the impact on life chances, ecology, and plant and animal species.

"Human impacts prior to the Industrial Revolution are not well constrained. We investigate whether the decline in global atmospheric CO2 concentration by 7–10 ppm in the late 1500s and early 1600s which globally lowered surface air temperatures by 0.15C, were generated by natural forcing or were a result of the large-scale depopulation of the Americas after European arrival, subsequent land use change and secondary succession.

From 119 published regional population estimates we calculate a pre-1492 CE population of 60.5 million (interquartile range, IQR 44.8–78.2 million), utilizing 1.04 ha land per capita (IQR 0.98–1.11). European epidemics removed 90% (IQR 87–92%) of the indigenous population over the next century."

Ninety percent of indigenous populations were destroyed within the first 100 years of Christian colonization. Under to hierarchical Christian European logic of "exterminating all the brutes," the devastation wrought by colonization was very efficient in attempting to rid the world of the "less than human," non-Christian savage. In other words, progress for some is genocide for others, especially if survival is claimed to be divinely determined.

For King James, the death of indigenous peoples was a "wonderful plague."

"Within these late years, there hath, by God's visitation, reigned a wonderful plague, the utter destruction, devastation, and depopulation of that whole territory, so as there is not left any that do claim or challenge any kind of interest therein. We, in our judgment, are persuaded and satisfied, that the appointed time is come in which Almighty God, in his great goodness and bounty towards us, and our people, hath thought fit and determined, that those large and goodly territories, deserted as it were by their natural inhabitants, should be possessed and enjoyed by such of our subjects." King James I

The authors of the research report conclude the report, "We estimate that 55 million indigenous people died following the European conquest of the Americas beginning in 1492. This led to the abandonment and secondary succession of 56 million hectares of land…. These changes show that the Great Dying of the Indigenous Peoples of the Americas is necessary for a parsimonious explanation of the anomalous decrease in atmospheric CO2 at that time and the resulting decline in global surface air temperatures. These changes show that human actions had global impacts on the Earth system in the centuries prior to the Industrial Revolution."