It Was the Best of Times, It Was the Worst of Times

Abstract

A slight warming trend has been observed in global temperature data over the last century, but is it caused by human activity? This important question is discussed in the Research Commentary by Jones, who looks at a recent reconstruction of the temperature trend since 1400 made with several high-resolution records by Mann et al . of the University of Massachusetts at Amherst. Such reconstructions are a start toward resolving the debate over human impact on climate.