The point is there were no auto’s, no smoke stack industries, no airplanes, not even humans with fireplaces. So what cause the global warming to melt all that ice of last ice age?
Wrong answer: Cave man burned too many twigs.
Right answer: The million times bigger and hotter SUN which also has cycles.
Agreed, and of which we are in the bottom of the latest solar minimum, with remembrance of some time in the 1700’s. Today, with how the world is all “running on summer”, it is yet to be seen what this minimum will gather.