I came across this graph of the historical temperature. In the distant past, during the Eocene, which is when mammals first began to evolve, the earth was actually as much as 25 degrees Fahrenheit (14 Celsius) warmer than it was today. Even if the temperature models are correct, this is 17 degrees Fahrenheit (9 Celcius) warmer than the temperature they predict in 2100.
This makes the claim that we are crossing a tipping point to catastrophic warming that will make the earth uninhabitable seem pretty questionable. If the models are correct and we shift the earth’s temperature by 8 degrees Fahrenheit in only 100 years, it will be the relatively short time (a mere moment, in geological time) that causes grief, not the resulting temperature. In the past, changes of this magnitude have occurred over tens of thousands of years, giving the biome time to adapt gradually.