The millions who died of cold and starvation during the Little Ice Age might beg to differ there.
It's currently a lot warmer than then. If the Sun decides to cool off a bit for the next century or so, then thank you Mr. Sun and I think human civilization has better sources of heat and more enlightened agricultural practices than in the 1600s and 1700s. We can always increase our CO2 emissions if it looks like it's getting too cold!