Climate History: Written In Ice, Wood, And Stone |  Global Warming Basics | Allianz Knowledge

[Q] Some people say that temperatures back then were higher than today. Is that right?

[Climate scientist Stefan Rahmstorf] According to these proxy data, the Middle Ages were the warmest era of the past 1,500 years. Only in the last few decades have global temperatures soared above those found in the Middle Ages.

[Q] Man-made CO2 can’t have caused warming in the Middle Ages. How do you explain it?

[A] The two main drivers of climate variations in the past one or two millennia were changes in solar activity and volcanic activity. If we drive climate models by these two factors we find similar climate variations in the models as are shown by the proxy data.