There IS considerable evidence linking cold spells that lasted for years to the land becoming more marginal, food production thus dropping, the population not being as well nourished and the death rates from communicable diseases exploding.
Warmer weather is associated with human flourishing. Colder weather is associated with the opposite. This is a pattern that repeated multiple times.
The evidence would indicate global warming is good for humanity.
Which is why they switched to “Climate Change”.