The report also presents a framework that people can use to think about a type of risk that we’ve never experienced before: For more than 10,000 years, and the entire history of human civilization, the climate has been relatively stable. Now it is not.
This, however, is a bit of a stretch. Humanity actually has survived radical climate change before: at the end of the last Ice Age. That change ultimately proved to be good, making life a lot easier. But at the time, it was the end of everything that anyone had ever known. They wouldn't have refrigeration again for thousands of years! The climate also got a lot less stable and predictable, which was terrifying.
A key difference, however, is that post-Ice Age climate change moved global temperatures toward the envelope in which humans could survive without extreme measures. The current climate change is moving temperatures away from that range, out the other side.