Climate change denialists love to bring up the Little Ice Age (and the Medieval Warm Period before it) as examples of natural variation in climate that wasn’t human-caused, and therefore cast doubt on all the arguments about anthropogenic climate change. Except…what if the cooling recorded for the 17th-19th centuries was actually caused by human activity? A new analysis suggests that that might be our fault, too.
It’s the UCL group’s estimate that 60 million people were living across the Americas at the end of the 15th Century (about 10% of the world’s total population), and that this was reduced to just five or six million within a hundred years.
The scientists calculated how much land previously cultivated by indigenous civilisations would have fallen into disuse, and what the impact would be if this ground was then repossessed by forest and savannah.
The area is in the order of 56 million hectares, close in size to a modern country like France.
This scale of regrowth is figured to have drawn down sufficient CO₂ that the concentration of the gas in the atmosphere eventually fell by 7-10ppm (that is 7-10 molecules of CO₂ in every one million molecules in the air).
“To put that in the modern context – we basically burn (fossil fuels) and produce about 3ppm per year. So, we’re talking a large amount of carbon that’s being sucked out of the atmosphere,” explained co-author Prof Mark Maslin.
It’s horrifying enough that the American genocide killed about 50 million people, but that it was so immense that it affected the climate is stunning. I also have to wonder how much the earlier Black Death in Europe contributed to a decline in CO2.
This does suggest an obvious solution to our current climate change concerns. Annihilate a few billion people, and the problem goes away.
It looks like the American and Russian leaders are working on a plan to do just that.