The interesting part of this article is the description of a study that shows a correlation between skull size and higher latitudes. The author of the Wired article misinterprets the study to claim that thus global warming might shrink brain size. One hopes he's kidding.
The study might indicate that surviving in colder climates requires more brain power, thus smarter people lived longer than dumber people in more challenging environs. This is not the same as suggesting that cold climate caused bigger brains (killed smaller brains would be more accurate). Hence warmer climate would not cause smaller brains.
The author of this article demonstrates he might not have been one of the survivors in an icier era.
Worse, he demonstrates that the only way to promote his global warming theory is to attempt to ridicule its critics into silence rather than to present convincing evidence to the contrary. This is not science, but scaring people into believing pseudo-science is not about science. It's about controlling other people.