The document discusses criticisms of the "hockey stick graph" used by the UN to show global temperature trends over the past 1000 years. It claims the graph is misleading because it does not show that global temperatures were as warm or warmer during the Medieval Warm Period and the margins of error in the tree ring data are too large to draw strong conclusions. It cites several scientists who have argued the hockey stick theory has been "effectively dismantled" and does not give an accurate depiction of historical temperature variation and trends.