The Romans should be blamed for that 80B.C. global warming!! Those imperialists and their SUV sized chariots.
At the very least the Romans should be held accountable for the eruption of Vesuvius in 79 AD. That must've bumped global temperatures up by at least a thousandth of a degree.
They have made up for it in modern times by mass-producing cars that don't run. FIAT = Fix It Again, Tony.