New paper finds tree-ring studies underestimate climate extremes of the past

A new paper published in Nature Climate Change finds tree-ring reconstructions of temperature, such as Mann's infamous hockey stick, "underestimate climate fluctuations of, for example, air temperature," due to data complicated by "the climate of past years and other factors like tree age" and precipitation. "Our results point to uncertainties in the global climate system that were previously not recognized," says David Frank, co-author of the study. 

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