Carbon Dioxide and Earth's Future Pursuing the ... - Magazooms

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data really suggest, and, of course, why. And even when these questions are answered, the
temporal length of the underlying database will still be far too short to differentiate between a
long-term trend that might possibly be tied to the warming that produced the Little Ice Age-to-
Current Warm Period transition and a shorter-term cyclical regime shift. However, it is worth
noting that in reporting results described at the International Summit on Hurricanes and
Climate Change that was held on the Greek island of Crete in May of 2007, Elsner (2008)
indicates that what he calls paleotempestology -- which he defines as the study of prehistoric
storms based on geological and biological evidence -- indicates that “sedimentary ridges in
Australia left behind by ancient tropical cyclones indicate that activity from the last century
under-represents the continent’s stormy past.”
With respect to hurricanes occurring over multiple ocean basins, Fan and Liu (2008), who also
focused on paleotempestology, conducted a brief review and synthesis of major research
advances and findings in this emerging field of work, which they describe as “a young science”
that “studies past typhoon activity spanning several centuries to millennia before the
instrumental era through the use of geological proxies and historical documentary records.”
And this analysis indicated, as they describe it, that “there does not exist a simple linear
relationship between typhoon frequency and Holocene climate (temperature) change,”
especially of the type suggested by climate alarmists. They report, for example, that “typhoon
frequency seemed to have increased at least regionally during the coldest phases of the Little
Ice Age,” and they also note that there are typically “more frequent typhoon landfalls during La
Niña years than during El Niño years.”
In the realm of theoretical modeling, Nolan and Rappin (2008) extended the methodology of
Nolan et al. (2007) to include a prescribed wind as a function of height that remains
approximately constant during the genesis of tropical cyclones in environments of radiativeconvective
equilibrium that are partially defined by sea surface temperature, which they then
employed to explore what happens when SSTs rise. And when subsequently running the
adjusted model, they report that “an unexpected result has been obtained, that increasing sea
surface temperature does not allow TC genesis to overcome greater shear.” In fact, they say
that “the opposite trend is found,” and that “the new and surprising result of this study is that
the effect of shear in suppressing TC genesis actually increases as the SST of the radiativeconvective
equilibrium environment is increased.”
This new model-based result is eerily analogous to the recent observation-based result of
Vecchi and Knutson (2008), who found that as the SST of the main development region of North
Atlantic TCs had increased over the past 125 years, certain aspects of climate changed in ways
that may have made the North Atlantic, in their words, “more favorable to cyclogenesis, while
at the same time making the overall environment less favorable to TC maintenance.” Hence, it
is doubly interesting that Nolan and Rappin conclude their paper with the intriguing question:
“Do these results explain recent general circulation modeling studies predicting fewer tropical
cyclones in a global warming world,” citing the work of Bengtsson et al. (2007).”
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