Here's what I said Oct. 7, in response to a paper in Science by Hans von Storch raising questions about Michael Mann's hockey stick paleoclimate graph:
Those opposed to action to reduce greenhouse gas emissions have made the hockey stick a central focus, acting as though all they need to do is knock Dr. Mann's legs out from under him in order to doom the whole global climate change enterprise.
In global climate reports -- particularly the United Nations' Intergovernmental Panel on Climate Change (IPCC) Third Assessment Report (TAR) in 2001 -- it's used as proof that mankind's industrial revolution has over the last hundred years started dangerously pushing up global temperatures, thus justifying restrictions on emissions of human produced greenhouse gasses.