Prof. Ian Plimer: 'We've Been Cooling for 4000 Years—It's All About When You Start Measuring'

"As soon as someone tells you it's warming, the reply you give is: Since when?"

Australian geologist, Prof. Ian Plimer: "We have been cooling down for the last 4000 years. It's all about when you start the measurements."

"If you take measurements from the Medieval Warming... we've cooled about five degrees since then. If you take measurements from the Roman Warming, we've cooled about five degrees."