When European colonizers headed for the Americas, they not only killed many Native Americans, but also caused what is known as the “Great Extinction. Recent research has shown that this process had an indirect effect on the carbon cycle, resulting in a cooling of the planet and the beginning of the Little Ice Age.
In A.D. 1492, a team from University College London estimated the number of Native Americans at 60.5 million based on historical records, including the size of armies, census data and archaeological evidence. The team estimates that over the next century, newly introduced pathogens killed about 90 percent of the population.
Impact on the carbon cycle
There has been an indirect impact on the carbon cycle, as previously cultivated land has turned into forests and savannahs, which absorb more carbon than farmland. According to a paper published in Quaternary Science Reviews in 2019, this was enough to cool the planet.
“The carbon sequestration thought to have occurred after the arrival of the epidemics in the Americas may have lowered atmospheric CO 2 levels and led to a reduction in radiative forcing, which may then have contributed to the coldest part of the Little Ice Age,” the study says.
“The great Native American extinction led to a global human impact on the Earth system two centuries before the Industrial Revolution.”
The team estimates that 56 million hectares (138 million acres) of farmland went out of use during this time. The drop in CO2 can be seen in ice core records around the time of the Little Ice Age. The team believes that abandoned land may explain the drop in CO2 levels of about 7-10 parts per million (ppm).
Little Ice Age.
“To put it in a modern context, we’re basically burning (fossil fuels) and producing about 3 parts per million per year. So we’re talking about a lot of carbon being sucked out of the atmosphere,” Professor Mark Maslin, a co-author, told the BBC, the author of the study.
“Around this time (1500-1600s) there is a noticeable cooling, which is called the Little Ice Age, and what’s interesting is that we can observe natural processes that give a slight cooling, but actually a total cooling – double natural. processes – you have to have this genocide-induced drop in CO2.”
Thus, the colonization of the Americas led to global climate change and the beginning of the Little Ice Age. This underscores the importance of taking into account the impact of human activity on the environment and the need to be careful with natural resources.