Climate Change - Where Did It All Start?

We're now in what we call an interglacial. So the temperature is around about 15 degrees now and we can see that if we look in the past we should be going into another ice age airlock. This is a planet that hasn't been here at least for 800,000 years. And it's all about humans exploiting ancient carbon burning fossil fuels. The pace of change in the last century or so is 10 times faster than anything in the past.