evidence: The claim: Earth has not warmed in the last 38 years, warmed by only 1.08 degrees in 150 years and has cooled for the last 4,000 years [...] "We have been cooling down for the last 4,000 years," Plimer says. "If we look at the last 38 years, there has been no change in temperature. If we look at the last 150 years, we've had three warming periods and three cooling periods with a total warmth of about 0.6 degrees Celsius (1.08 degrees Fahrenheit)." [...] In the video, Plimer unequivocally asserts that global temperatures have cooled over the last 4,000 years. But there is not a clear scientific consensus on this point.