We truly live in the post-science era of scientism where bizarre pseudoscientific nonsense is used to build political mythologies.
Colonisation of the Americas at the end of the 15th Century killed so many people, it disturbed Earth's climate.
That's the conclusion of scientists from University College London, UK.
The team says the disruption that followed European settlement led to a huge swathe of abandoned agricultural land being reclaimed by fast-growing trees and other vegetation.
This pulled down enough carbon dioxide (CO₂) from the atmosphere to eventually chill the planet.
And their basis for this is...
The team reviewed all the population data it could find on how many people were living in the Americas prior to first contact with Europeans in 1492.
It then assessed how the numbers changed in following decades as the continents were ravaged by introduced disease (smallpox, measles, etc), warfare, slavery and societal collapse.
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.
We don't know how many people were living in America before European colonization. We don't know, for that matter, how many people were living there afterward.
All of these are estimates and guesstimates.
Population estimates range from 2 million to 100 million. None of them are based on hard, solid facts.
We don't know how much cultivated land was in use. And parts of the relevant populations were nomadic and didn't engage in large scale land cultivation.
"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.
"There is a marked cooling around that time (1500s/1600s) which is called the Little Ice Age, and what's interesting is that we can see natural processes giving a little bit of cooling, but actually to get the full cooling - double the natural processes - you have to have this genocide-generated drop in CO₂."
Genocide is still the favorite environmentalist solution to global warming. Or, as they call it, zero population growth.