Turns out that much of the global warming science is based on data from Yamai in Siberia. The Yamai data has never been released, but it turns out that by looking at tree rings, people have been making assumptions about the temperature 2000 years ago. Apparently using tree rings is fraught with danger, as they aren’t very reliable. However, if you use enough trees you should be OK. It turns out that these people have been only using 12 hand picked trees that support the theses they wanted to prove!

Treemometers: A new scientific scandal • The Register.