The earth has been far warmer and far colder than today, and not millions of years ago either. In the time of the Vikings, vineyards flourished in areas of Europe where they have not been able to in the past few hundred years. In 1500 CE the Thames River froze for months at a time in winter, and the ice was so sturdy that "Frost Fairs" were held on the river, carnival type rides and various exhibitions and even a printing press putting out a special edition of the London Times! That's how thick the ice was! The last Frost Fair was held in 1810.
Getting back to the post-Viking era, around 1200 CE the great civilizations of what is now the Desert Southwest USA started getting squeezed by drought to the extent that death rates were so high in what is now Arizona that there are/were giant mass graves under what is today Phoenix, containing people with alarming malnutrition-related disorders. The drought they faced was far worse than the one there today, and eventually the Salt River Valley was abandoned, but the tribes did not go extinct, they just migrated. The Tohono and Akimel peoples are the likely descendants of those tribes.
One tribe that lived in the Salt River Valley in 1200-1400 CE is known as "Hohokam", which in the Pima language means "completely used up". Pima bards tell of how the peoples of the SRV used up all the resources available to them, and then most died and the rest fled.
Humanity will survive, but our civilization is likely doomed. Mankind will rediscover what it is like to work growing/raising your own food, or die. Whether that is good or bad is a matter of philosophy. The 1% are terrified that they will lose their cushy lifestyles, and they will.