Doing any small amount of research on the history of agriculture will show you that the time since the last Ice Age is the MOST stable climate compared to other parts of the history of the Homo genus existing. That said, there have been hundreds of collapses caused by short and medium term climate instability.

There have been many periods such as the Little Ice Age or the time period of the Sea People that there was outlier climate situations that threw things off balance. The Little Ice Age was the death nail for the Vikings in Greenland. But did major damage to crop production in Europe. Could have a crazy wet and cold year, then drought with hot temps the next year.

There was a massive drought in the time of the Sea Peoples that spanned the whole Mediterranean and into Westrn Asia. It was likely the cause of movement ir people.

This list goes on ad nauseum with small civilizations that fell apart due to some climate shift in their time.

I am maximally diversifying what I am growing do deal with all the different ways climate instability can play out.