What is bad is the variance. We know that the variance in weather is increasing, and the average temperature is also moving up.

Yes earth has been hot and cold, but the point is to avoid enormous fluctuations due to variance as they lead to extreme events. We saw huge droughts and floods in Europe, China, and the US, events that we hadn’t seen in a long time.

We also know that these cause a split of the polar vortex in Europe which creates heat domes and traps air from Northern Africa. The world we have built was not designed to withstand such heat, see infrastructure melting in England last summer, and much of the world is not prepared to deal with extreme heat, ask the Scandinavians how they handled last couple of summers, I know I suffered in CPH.

We also know that it is caused by our emissions, while we use “CO2” it’s only a few different gases and we scale their potency to equivalent CO2.

I can recommend “firmament” as an introduction to weather science. Dr Simon Clark is an excellent science communicator with a PhD in meteorology, and has a great YT channel.