Surely everyone interested in the climate change debate is well aware of the "hockey stick controversy". There is a new twist to the story: Michael Mann and colleagues just published a new temperature reconstruction in PNAS, confirming that the recent warmth is anomalous for the past 1300 years in the northern hemisphere.
The important point: This holds even if tree rings are not used as climate proxies. One of the more serious concerns about the old hockey stick was that tree rings may not correctly reflect long-term trends but dominated the combined record. The new reconstruction indeed more clearly shows the medieval warm period, but it does not come out as warm as today.
I look forward to a storm in the climate skeptics scene!