Author neglects to note that in the 13th and 14th centuries, there was minimal fossil-fuel use, so the carbon taken out of the atmosphere wouldn’t have been put there by humans.
“13th and 14th centuries” also corresponds roughly to the beginning of the Little Ice Age and the Bubonic Plague epidemic that hit Europe in the early 1300s, killing tens of millions of people.
I presume the author celebrates that also.
Clarifying, the article claims the Mongol invasion cooled the planet, which I am suggesting reinforced the cooling associated with the Maunder Minimum, the net total result of which was the Little Ice Age and Black Death.
Watermelons licking their chops trying to figure out how to replicate that today.
Rainbow Six - by Tom Clancy