The current issue [August 2018]of Physics Today gives a circumstantial, although summary, account of “megadroughts” in the American West in the eleventh through fifteenth centuries of the Common Era. The data from tree rings indicates that long-term [more than 30 years in duration] shortfalls in precipitation and periods of heightened tempratures were much more severe than anything during that time than anything we have seen in postConquest centuries.
Although the account focusses on the destructive impact of these periods of prolonged climate change, the fact is that the Native American population did cope with and adapt to the disruption to their cultures, of a scale comparable to the expected global warming in coming decades. The Aztecs, for one example, migrated south during those centuries and built a substantial empire in the central plain of Mexico.
I have nothing substantial to buttress an impressionistic statement, but the fact that previous episodes of severe climate change have taken place in human history seems to me a ground for hope that this latest one will generate similar survival adaptations.