With respect to hurricane numbers, the five scientists report that "globally there has been no increase in tropical cyclone frequency over at least the past several decades," citing the studies of Lander and Guard (1998), Elsner and Kocher (2000) and Webster et al. (2005) in support of this statement. Furthermore, they note that research on possible future changes in hurricane frequency due to global warming has produced studies that "give such contradictory results as to suggest that the state of understanding of tropical cyclogenesis provides too poor a foundation to base any projections about the future."

With respect to hurricane intensity, Pielke et al. note that Emanual (2005) claims to have found "a very substantial upward trend in power dissipation (i.e., the sum over the life-time of the storm of the maximum wind speed cubed) in the North Atlantic and western North Pacific." However, they report that "other studies that have addressed tropical cyclone intensity variations (Landsea et al., 1999; Chan and Liu, 2004) show no significant secular trends during the decades of reliable records." In addition, they indicate that although early theoretical work by Emanuel (1987) "suggested an increase of about 10% in wind speed for a 2°C increase in tropical sea surface temperature," more recent work by Knutson and Tuleya (2004) points to only a 5% increase in hurricane windspeeds by 2080, and that Michaels et al. (2005) conclude that even this projection is likely twice as great as it should be.

Perhaps of greatest significance of all to the issue of future hurricanes and the destruction they will cause is the nature and degree of human occupation of exposed coastal locations. By 2050, for example, Pielke et al. report that "for every additional dollar in damage that the Intergovernmental Panel on Climate Change expects to result from the effects of global warming on tropical cyclones, we should expect between $22 and $60 of increase in damage due to population growth and wealth," citing the findings of Pielke et al. (2000) in this regard. Based on this evidence, they state without equivocation that "the primary factors that govern the magnitude and patterns of future damages and causalities are how society develops and prepares for storms rather than any presently conceivable future changes in the frequency and intensity of the storms."

In concluding their review, Pielke et al. note that many climate alarmists continue to claim a significant hurricane-global warming connection for the purpose of advocating massive anthropogenic CO2 emissions reductions that "simply will not be effective with respect to addressing future hurricane impacts," additionally noting that "there are much, much better ways to deal with the threat of hurricanes than with energy policies (e.g., Pielke and Pielke, 1997)."

We agree. We should be doing the right things for the right reasons. Anything less not only hurts us, it debases us.

Sherwood, Keith and Craig Idso

References
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Elsner, J.B. and Kocher, B. 2000. Global tropical cyclone activity: A link to the North Atlantic Oscillation. Geophysical Research Letters 27: 129-132.

Emanuel, K. 1987. The dependence of hurricane intensity on climate. Nature 326: 483-485.

Emanuel, K. 2005. Increasing destructiveness of tropical cyclones over the past 30 years. Nature 436: 686-688.

Knutson, T.R. and Tuleya, R.E. 2004. Impact of CO2-induced warming on simulated hurricane intensity and precipitation: Sensitivity to the choice of climate model and convective parameterization. Journal of Climate 17: 3477-3495.

Lander, M.A. and Guard, C.P. 1998. A look at global tropical cyclone activity during 1995: Contrasting high Atlantic activity with low activity in other basins. Monthly Weather Review 126: 1163-1173.

Llandsea, C.W., Pielke Jr., R.A., Mestas-Nunez, A.M. and Knaff, J.A. 1999. Atlantic basin hurricanes: Indices of climatic changes. Climatic Change 42: 89-129.

Michaels, P.J., Knappenberger, P.C. and Landsea, C.W. 2005. Comments on "Impacts of CO2-induced warming on simulated hurricane intensity and precipitation: Sensitivity to the choice of climate model and convective scheme. Journal of Climate, in press.

Pielke Jr., R.A., Landsea, C., Mayfield, M., Laver, J. and Pasch, R. 2005. Hurricanes and global warming. Bulletin of the American Meteorological Society 86: 1571-1575.

Pielke Jr., R.A. and Pielke Sr., R.A. 1997. Hurricanes: Their Nature and Impacts on Society. John Wiley and Sons.

Pielke Jr., R.A., Pielke, Sr., R.A., Klein, R. and Sarewitz, D. 2000. Turning the big knob: Energy policy as a means to reduce weather impacts. Energy and Environment 11: 255-276.

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