This is about super long summers and super long winters. Previous ice age was triggered, according to one theory, by a bacteria infestation that abruptly consumed all CO2 from the atmosphere. Bacteria cannot compete with us in influence as we are about to prove to the universe. But there is also a giant clock ticking that dwarfs both us and bacteria.
There are significant geopolitical consequences of this global process in which humans chose to play a role that before was played by brainless bacteria.