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An 800-Year History of Australian Tropical Cyclones
Nott, J. 2007. The importance of Quaternary records in reducing risk from tropical cyclones. Palaeogeography, Palaeoclimatoloogy, Palaeoecology 251: 137-149.

In introducing the subject of his review article, the author says that "in tropical Australia, palaeo-tropical cyclone records occur in the form of low-resolution millennial-scale sedimentary ridges and high-resolution centennial-scale stalagmite records of isotopically depleted tropical cyclone rainfall."

What was done
Nott describes the various records to which he refers, recounts their findings, and discusses their relevance to risk assessment and their role in "decoupling human induced changes in cyclone behavior from natural variability."

What was learned
The Australian researcher says the clear message of the several papers he reviewed is that "the historical/instrumental record substantially underestimates the frequency of the most extreme tropical cyclone events," citing the findings of Chappell et al. (1983), Chivas et al. (1986), Hayne and Chappell (2001), Nott and Hayne (2001) and Nott et al. (2007). More specifically, he notes that "tropical cyclone activity in north-east Queensland has been in a phase of quiescence since before European settlement of the region," and that "the period between AD 1600 and 1800 [during the Little Ice Age] had many more intense or hazardous cyclones impacting the site than the post AD 1800 period." In addition, he notes that the first 200 years of the tropical cyclone record -- from AD 1200 to 1400, which represents the latter part of the Medieval Warm Period (MWP), as one can see from the Interactive Map and Time Domain feature of our MWP Project) -- had the fewest intense cyclones of all. As per the criterion he used to define them, in fact, this period of significant global warmth had none, as did the latter decades of the 20th century, which according to climate alarmists were the warmest of the past one to two millennia. In fact, the entire 20th century had but one such intense cyclone (and that was in its early stages in 1911); while there were as many as seven intense tropical cyclones during the global chill that prevailed between AD 1600 and 1800.

What it means
Over the past eight centuries, it is clear that relative global warmth appears to translate into fewer intense tropical cyclones in the region of northeast Queensland, Australia.

Chappell, J., Chivas, A., Rhodes, E. and Wallensky, E. 1983. Holocene palaeo-environmental changes, central to north Great Barrier Reef inner zone. Journal of Australian Geology and Geophysics 8: 223-235.

Chivas, A., Chappell, J. and Wallensky, E. 1986. Radiocarbon evidence for the timing and rate of island development, beach rock formation and phosphatization at Lady Elliot Island, Queensland, Australia. Marine Geology 69: 273-287.

Hayne, M. and Chappell, J. 2001. Cyclone frequency during the last 5,000 yrs from Curacoa Island Queensland. Palaeogeography, Palaeoclimatology, Palaeoecology 168: 201-219.

Nott, J. and Hayne, M. 2001. High frequency of 'super-cyclones' along the Great Barrier Reef over the past 5,000 years. Nature 413: 508-512.

Nott, J.F., Haig, J., Neil, H. and Gillieson, D. 2007. Greater frequency variability of landfalling tropical cyclones at centennial compared to seasonal and decadal scales. Earth and Planetary Science Letters 255: 367-372.

Reviewed 17 September 2008