So will a million other factors, most of which can't be foreseen or predicted. Would your Grandparents have foreseen the day that you could access the entirety of human knowledge on a device that fits into the palm of your hand?
The Earth and humanity have never been and never will be static entities. The climate has changed a great deal during the geologically insignificant amount of time that humans have been around. Most of those changes occurred before we started digging carbon out of the ground. Changes will continue long after we've moved past carbon based energy supplies. The notion that the climate was "ideal" during some specific period would be laughable if there wasn't a serious movement trying to use it to make public policy.