The Medieval Warm Period saw the Glaciers in Greenland, Scandinavia, and Europe melt rapidly, along with Arctic ice. There were no reported floods, nor rise in sea level. The Medieval Warm Period was hotter than it is now, or even will be a hundred years from, based on Climate Changer's predictions.
Yet, a few hundred years later, there was what is called the Little Ice Age. The glaciers and Arctic ice, grew back rapidly. The Vikings who had settled Greenland, and it was very much a green land back then, were pushed into the sea, by the rapidly advancing glaciers.
This is very recent history. The Earth's climate can and has continually changed throughout its existence. It will continue to do so.
Saying that the tiny increase in CO2 levels during the last 120 years, is caused by the industrial revolution, only works if you ignore the existence of other variables that could've caused it, as has happened in the past.
Picking and Choosing what "evidence" will be considered, for what is considered as causative, is exactly why Climate Change is pseudo-science.