The Dictionary of the Climate Debate (DCD)

Hughes, Malcolm

His bark is worse than his bite.
His bark is worse
than his bite.

A climatologist who is a professor of dendrochronology at the University of Arizona's Laboratory for Tree-Ring Research. He uses proxies - such as tree rings and ice cores - to study historical climate variability.

In 1998, he was a co-author with Michael Mann and Raymond Bradley on the paper that spurred the hockey stick controversy. This resulted in mass-media attacks and senate hearings — a real tree-ring circus. To read the paper, click here

Hughes and his tree rings

1. He was challenging the existence of the Medieval Warm Period way back in 1994. Click here to read his 1994 paper Was There a "Medieval Warm Period', and, if so, Where and When.

Here's the abstract:

"It has frequently been suggested that the period encompassing the ninth to the fourteenth centuries A.D. experienced a climate warmer than that prevailing around the turn of the twentieth century. This epoch has become known as the Medieval Warm Period, since it coincides with the Middle Ages in Europe.

In this review a number of lines of evidence are considered, (including climate-sensitive tree rings, documentary sources, and montane glaciers) in order to evaluate whether it is reasonable to conclude that climate in medieval times was, indeed, warmer than the climate of more recent times.

Our review indicates that for some areas of the globe (for example, Scandinavia, China, the Sierra Nevada in California, the Canadian Rockies and Tasmania), temperatures, particularly in summer, appear to have been higher during some parts of this period than those that were to prevail until the most recent decades of the twentieth century.

These warmer regional episodes were not strongly synchronous. Evidence from other regions (for example, the Southeast United States, southern Europe along the Mediterranean, and parts of South America) indicates that the climate during that time was little different to that of later times, or that warming, if it occurred, was recorded at a later time than has been assumed.

Taken together, the available evidence does not support a global Medieval Warm Period, although more support for such a phenomenon could be drawn from high-elevation records than from low-elevation records. The available data exhibit significant decadal to century scale variability through-out the last millennium. A comparison of 30-year averages for various climate indices places recent decades in a longer term perspective."

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