THE climate science denial industry doesn't like Penn State University's Professor Michael Mann very much.
Mann is the scientist behind the famous “hockey stick” graph that first appeared in the journal Nature in 1998. Mann and two other scientists Professor Raymond Bradley and Professor Malcolm Hughes had reconstructed temperatures in the Northern Hemisphere from the year 1400 to present day using data mainly from tree rings, ice cores and modern temperature readings.
The following year, the same three scientists extended their study to reconstruct 1000 years of temperatures and published this in the journal Geophysical Research Letters. Each time the team plotted their data on graphs and each time the plots showed what is the now famous “hockey stick” shape with a sharp uptick in temperatures towards the end of the century.