The 800lb Gorrilla in the Hockey Stick’s Locker Room

Divergence is a serious problem in tree ring climatology reconstructions. Basically divergence means data which years ago vaguely correlated to temperature, diverged from temperature in recent years. So trees which used to be thought of as good thermometers — aren’t. This doesn’t stop scientists from using them however but some creativity in handling this inconvenient data is required. For instance, Mann 08 chopped off the divergent parts and pasted on his own non-divergent data.

In September 2007 Dr. Craig Loehle published a paper on the non-linear nature of tree growth. He holds a PhD in Mathematical Ecology and has published more than 100 papers in applied mathematics and ecology. In short he is the closest thing to an expert we could hope for on tree growth response to temperature. This paper is available on line at the link below.