from your post... this is what is different...
"Models predict that Earth will warm between 2 and 6 degrees Celsius in the next century. When global warming has happened at various times in the past two million years, it has taken the planet about 5,000 years to warm 5 degrees. The predicted rate of warming for the next century is at least 20 times faster. This rate of change is extremely unusual."
--
Models don't actually "predict" they model scenarios base don the input. The input is the scientists pick is that increased co2 causes warming. That is an input... not a scientific finding.