Global Tropical Cyclone Activity of the Past Five Thousand Years
Reference Nott, J. and Forsyth, A. 2012. Punctuated global tropical cyclone activity over the past 5,000 years. Geophysical Research Letters 39: 10.1029/2012GL052236.
In the words of Nott and Forsyth (2012), "understanding the long-term natural variability of tropical cyclones (TCs) is important for forecasting their future behavior and for the detection and attribution of changes in their activity as a consequence of anthropogenically induced climate change." And they state, in this regard, that "critical to these endeavors is determining whether, over the long-term, TCs occur randomly or display identifiable patterns influenced by one or several factors." In an effort designed to shed some light on this important subject, Nott and Forsyth present what they describe as "new sedimentary data from the southwest (SW) Pacific and southeast (SE) Indian Ocean regions which allow us to make comparisons with existing sediment records from the Atlantic Ocean (Donnelly and Woodruff, 2007; Mann et al., 2009), northwest (NW) Pacific (Woodruff et al., 2009), Gulf of Mexico (Liu and Fearn, 1993, 2000; Lane et al., 2011) and the Gulf of Carpentaria, Australia (Rhodes et al., 1980)." And based upon such comparisons, the two Australian researchers report that "long-term global TC activity is not random." Rather, there is, as they demonstrate, "a substantial degree of synchroneity in global intense TC behavior over the past 3,000 to 5,000 years." Indeed, they say that "one of the most striking aspects of these records is they all display extended alternating periods (centuries to millennia) of relative quiescence and heightened intense TC activity irrespective of both the resolution and type of long-term TC record."
Based on such findings, it is clear that something has orchestrated the ebbing and flowing of global TC activity over the last 5,000 years, but that something has most certainly not been changes in the atmosphere's CO2 concentration, as it has remained quite stable over this entire period (with the exception of the past 100 years or so, when it has risen substantially, but without any demonstrable change in global TC activity). As a result, there is no compelling reason to believe that any further increase in the air's CO2 content will have any significant impact on these destructive storms.
Additional References Donnelly, J.P. and Woodruff, J.S. 2007. Intense hurricane activity over the past 5,000 years controlled by El Niño and the West African monsoon. Nature 447: 465-468.
Lane, P., Donnelly, J.P., Woodruffe, J.D. and Hawkes, A.D. 2011. A decadally-resolved paleohurricane record archived in the late Holocene sediments of a Florida sinkhole. Marine Geology 287: 14-30.
Liu, K. and Fearn, M. 1993. Lake sediment record of late Holocene hurricane activities from coastal Alabama. Geology 21: 793-796.
Liu, K. and Fearn, M. 2000. Reconstruction of prehistoric landfall frequencies of catastrophic hurricanes in northwestern Florida from lake sediment records. Quaternary Research 54: 238-245.
Mann, M.E., Woodruff, J.D., Donnelly, J.P. and Zhang, Z. 2009. Atlantic hurricanes and climate over the past 1,500 years. Nature 460: 880-883.
Rhodes, E.G., Polach, H.A., Thom, B.G. and Wilson, S.R. 1980. Age structure of Holocene coastal sediments, Gulf of Carpentaria, Australia. Radiocarbon 22: 718-727.
Woodruff, J.D., Donnelly, J.P. and Okusu, A. 2009. Exploring typhoon variability over the min-to-late Holocene: Evidence of extreme coastal flooding from Kamikoshiki, Japan. Quaternary Science Reviews 28: 1774-1785.
