Good catch. Of course they want us to believe it's man-made climate change. However, I believe there has been real climate change, at least as long as mankind has had written language and recorded things.
Some say the Medieval Warm Period topped out around AD 1300 (900 years ago) and began the Little Ice Age cooling period. Whenever exactly it began, with it began about 500 or 600 years of lower crop yields, less predictable rain patterns, and more deaths by plague. This is just like the other cooling periods (Dark Age from about AD 300 to AD 900, and Minoan Dark Age from about 11th century BC to maybe 3rd century BC -- corresponding to the Era of Kings in the Bible).
An argument can be made that many of the atrocities committed during these times are because the various people groups are struggling to survive. The warm periods have a few leaders like Hitler, Stalin, and Mao who push atrocities. But during the cooling periods, just about every people group is Hitleresque, taking over each other's land and killing or enslaving to get more crop yield out of tough growing seasons.
Yet during the warming periods the crop yields improve, the precipitation is more predictable, and there are less deaths by plague. Including in our Modern Warm Period.
