Talk:Controversies in Science/Are humans causing global warming/A Critique of Global-scale temperature patterns and climate forcing over the past six centuries

Tree rings are used to measure past temperatures specifically over the past 1000 years. This is not an effective indicator shedding light on the issue of global warming as trees sometimes grow at varying rates thereby making the age of the tree inconclusive. If a scientist is not able to the age of the tree, then it's impossible to predict a given temperature in a specific time period. (Shagor475 (talk) 16:32, 26 October 2012 (UTC) = Shagor475 10:31am, 26 October 2012 (UTC)