“caused” is the wrong word. “accelerated” might be the proper word. We do not know anything about it that is really in the long term, more than 150 years. What we know from the observation of the deliveries of farm communities to abbeys for example is that during the whole Middle Ages there were cycles of warm and cold climate of between 60 and 80 years each. We are far from being able to really explain the cyclical life of the universe, of the earth.