Topic: Tree Rings

Critics examine the "hockey stick" graph created by Michael Mann, alleging that he cherry-picked tree ring data to create a dramatic temperature spike at the end of the record. The graph became an iconic tool for the UN Intergovernmental Panel on Climate Change (IPCC) to argue that human industry caused unprecedented warming starting in the 1880s. Skeptics claim the data was manufactured to justify political goals rather than reflect accurate historical temperature variations.

In a featured audio clip, Dr. Tim Ball explains his defense against Michael Mann's lawsuit, alleging that Mann "rewrote climate history" by removing the Medieval Warm Period from his models. Ball claims Mann grafted modern instrumental temperature records onto cherry-picked tree ring data to create the illusion of unprecedented warming. The segment criticizes the UN IPCC for using the hockey stick graph as a primary tool for climate policy.