I really wish XKCD would've gone back 400,000 years instead of only 20,000 for that strip. CO2 and temperature have been higher during the longer time frame, a

I really wish XKCD would've gone back 400,000 years instead of only 20,000 for that strip. CO2 and temperature have been higher during the longer time frame, and it would be valuable for someone to explain the bigger picture adequately.