The UnAustralian

Tuesday, March 18, 2003
 
A New Low in Climate Pseudoscience: Conclusion

A well known global warming sceptic, John Daly, has tried to refute a 1999 paper by Michael Mann, Raymond Bradley, and Malcolm Hughes. This paper plays a important role in the IPCC's 2001 report into the scientific basis of global warming.

Daly's critique, has several major flaws which render it useless. I would guess that Daly has only read the abstract to the Mann paper (otherwise he is extremely dishonest), and based his attack on an incorrect assumption that the Mann paper denies the existence of a Medieval Warm Period and Little Ice Age. He also fails to correctly understand what the Mann paper researched, nor the efforts that went into validating the results.

This has lead him to try to refute it by proving the existence of a Medieval Warm Period and Little Ice Age. As the Mann paper supports the existence of these events, Daly's critique has had it core ripped out. Some of Daly's regional studies do support a warmer Medieval Warm Period than the current warming, however, these regional studies do not reflect larger scale trends.

Bibliography

NOAA Paleoclimatology Program

Crowley, T. J., and Lowery, T. S. How warm was the Medieval Warm Period?, Ambio, 29(1), 51-54, 2000

Mann, M. E., Bradley, R. S., and Hughes, M. K. Global-scale temperature patterns and climate forcing over the past six centuries, Nature, 392, 779-787, 1998

Mann, M. E., Bradley, R. S., and Hughes, M. K. Northern hemisphere temperatures during the past millennium: Inferences, uncertainties, and limitations, Geophys. Res. Lett, 26, 759-762, 1999

Yang, B., Braeuning, A., Johnson, K. R., Yafeng, S. General characteristics of temperature variation in China during the last two millennia, Geophys. Res. Lett, 29, 10.1029/2001GL014485, 2002
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