The only assertion I made is that the earth has been much warmer pre-historically, which is a well-known fact and can easily be verified. https://en.wikipedia.org/wiki/Geologic_temperature_record
Second, the problem here is not only the total temperature variation but the speed at which the temperature is changing.
Think of the difference between a car going from 130 km/h to 0 km/h in 8 seconds, and a car going from 130 km/h to 0 km/h in 0.3 seconds. Not really endearing.
Just for the sake of argument, let's say you find yourself in a car in the second scenario, with no known way to stop it. What would you do? I say this as a pragmatist - if we take the headlines at face value, and we only have ~10 years to avert a catastrophe, then the only realistic way to avert it is if 90% of the world's population spends that 10 years planting trees before killing themselves.