Chu and Clark (1999) analyzed the frequency and intensity of tropical cyclones that either originated in or entered the central North Pacific (0-70°N, 140-180°W) over the 32-year period 1966-1997. After doing so, they determined that "tropical cyclone activity (tropical depressions, tropical storms, and hurricanes combined) in the central North Pacific [was] on the rise." This increase, however, appears to have been due to a step-change that led to the creation of "fewer cyclones during the first half of the record (1966-81) and more during the second half of the record (1982-1997)," and accompanying the abrupt rise in tropical cyclone numbers was a similar abrupt increase in maximum hurricane intensity.

Although climate alarmists may claim these findings support their model-based contentions, i.e., that CO2-induced global warming leads to more frequent and stronger hurricanes, Chu and Clark say that the observed increase in tropical cyclone activity cannot be due to CO2-induced global warming, because, in their words, "global warming is a gradual processes" and "it cannot explain why there is a steplike change in the tropical cyclone incidences in the early 1980s."

Clearly, a much longer record of tropical cyclone activity is needed to better understand the nature of the variations documented by Chu and Clark, as well as their relationship to mean global air temperature; and the beginnings of such a history were presented by Liu et al. (2001), who meticulously waded through a wealth of weather records from Guangdong Province in southern China, extracting data pertaining to the landfall of typhoons there since AD 975. Calibrating the historical data against instrumental observations over the period 1884-1909, they found the trends of the two data sets to be significantly correlated (r = 0.71). This observation led them to conclude that "the time series reconstructed from historical documentary evidence contains a reliable record of variability in typhoon landfalls." Hence, they proceeded to conduct a spectral analysis of the Guangdong time series and discovered an approximate 50-year cycle in the frequency of typhoon landfall that "suggests an external forcing mechanism, which remains to be identified." Also, and very importantly, they found that "the two periods of most frequent typhoon strikes in Guangdong (AD 1660-1680, 1850-1880) coincide with two of the coldest and driest periods in northern and central China during the Little Ice Age."

Looking even further back in time into the Southern Hemisphere, Hayne and Chappell (2001) studied a series of storm ridges at Curacoa Island, which were deposited over the past 5,000 years on the central Queensland shelf (18°40'S; 146°33'E), in an attempt to create a long-term history of major cyclonic events that have impacted that area, with one of their stated reasons for doing so being to test the climate-model-based hypothesis that "global warming leads to an increase of cyclone frequency or intensity." The primary finding of this endeavor, as they describe it, was that "cyclone frequency was statistically constant over the last 5,000 years." In addition, they could find "no indication that cyclones have changed in intensity," leaving one little to conclude but that the climate-model-based hypothesis is inconsistent with their findings.

In a similar study, Nott and Hayne (2001) produced a 5000-year record of tropical cyclone frequency and intensity along a 1500-km stretch of coastline in northeast Australia located between latitudes 13 and 24°S by geologically dating and tropographically surveying landform features left by historic hurricanes, and running numerical models to estimate storm surge and wave heights necessary to reach the landform locations. These efforts revealed that several "super-cyclones" with central pressures less than 920 hPa and wind speeds in excess of 182 kilometers per hour had occurred over the past 5000 years at intervals of roughly 200 to 300 years in all parts of the region of their study. They also report that the Great Barrier Reef "experienced at least five such storms over the past 200 years, with the area now occupied by Cairns experiencing two super-cyclones between 1800 and 1870." The 20th century, however, which is claimed by climate alarmists to have experienced temperatures that were unprecedented over the past two millennia, was totally devoid of such storms, "with only one such event (1899) since European settlement in the mid-nineteenth century."

Also noting that "many researchers have suggested that the buildup of greenhouse gases (Watson et al., 2001) will likely result in a rise in sea surface temperature (SST), subsequently increasing both the number and maximum intensity of tropical cyclones (TCs)," Chan and Liu (2004) explored the validity of this assertion via an examination of pertinent real-world data because, as they put it, "if the frequency of TC occurrence were to increase with increasing global air temperature, one would expect to see an increase in the number of TCs during the past few decades." Their efforts, which focused on the last four decades of the 20th century, resulted in their finding that a number of parameters related to SST and TC activity in the Western North Pacific (WNP) "have gone through large interannual as well as interdecadal variations," and that "they also show a slight decreasing [our italics] trend." In addition, they say that "no significant correlation was found between the typhoon activity parameters and local SST," or "in other words," as they say to drive home their point, "an increase in local SST does not lead to a significant change of the number of intense TCs in the WNP, which is contrary to the results produced by many of the numerical climate models." Instead, they found that "the interannual variation of annual typhoon activity is mainly constrained by the ENSO phenomenon through the alteration of the large-scale circulation induced by the ENSO event."

In discussing their results, Chan and Liu write that the reason for the discrepancies between their real-world results and those of many of the numerical climate models likely lies in the fact that the models assume TCs are generated primarily from energy from the oceans and that a higher SST therefore would lead to more energy being transferred from the ocean to the atmosphere, or "in other words," as they once again say in striving to make their point as clear as possible, "the typhoon activity predicted in these models is almost solely determined by thermodynamic processes, as advocated by Emanuel (1999)," whereas "in the real atmosphere, dynamic factors, such as the vertical variation of the atmospheric flow (vertical wind shear) and the juxtaposition of various flow patterns that lead to different angular momentum transports, often outweigh the thermodynamic control in limiting the intensification process." Their final conclusion, therefore, is that "at least for the western North Pacific, observational evidence does not support the notion that increased typhoon activity will occur with higher local SSTs."

Much the same thing was found by Free et al. (2004), who looked, not for increases in actual hurricane intensity, but for increases in potential hurricane intensity, because, as they put it, "changes in potential intensity (PI) can be estimated from thermodynamic principles as shown in Emanuel (1986, 1995) given a record of SSTs and profiles of atmospheric temperature and humidity." This they did using radiosonde and SST data from 14 island radiosonde stations in both the tropical Pacific and Atlantic Oceans, after which they compared their results with those of Bister and Emanuel (2002) at grid points near the selected stations. In doing so, they report that their results showed "no significant trend in potential intensity from 1980 to 1995 and no consistent trend from 1975 to 1995." What is more, they report that between 1975 and 1980, "while SSTs rose, PI decreased, illustrating the hazards of predicting changes in hurricane intensity from projected SST changes alone."

Hall (2004) reviewed the characteristics of cyclones occurring south of the equator and eastward from longitude 90°E to 120°W in the South Pacific and southeast Indian Oceans, concentrating on the 2001-2002 cyclone season and comparing the results with those of the preceding four years and the 36 years before that. This analysis indicated that "the 2001-2002 tropical cyclone season in the South Pacific and southeast Indian Ocean was one of the quietest on record, in terms of both the number of cyclones that formed, and the impact of those systems on human affairs." In the southeast Indian Ocean, for example, he writes that "the overall number of depressions and tropical cyclones was below the long-term mean," while further east he found that broad-scale convection was near or slightly above normal, but that "the proportion of tropical depressions and weak cyclones developing into severe cyclones was well below average," which result represented "a continuation of the trend of the previous few seasons." More specifically, Hall writes that "in the eastern Australian region, the four-year period up to 2001-2002 was by far [our italics] the quietest recorded in the past 41 years." Consequently, and in stark contrast to the climate-alarmist claim that tropical cyclone numbers and strength tend to increase with global warming, these real-world observations suggest that, if anything, just the opposite appears to be occurring.

Noting that "according to Walsh and Ryan (2000), future global climate trends may result in an increased incidence of cyclones," and realizing that "understanding the behavior and frequency of severe storms in the past is crucial for the prediction of future events," Yu et al. (2004) devised a way to decipher the history of severe storms in the southern South China Sea. Working at Youngshu Reef (9°32'-9°42'N, 112°52 -113°04'E), they used standard radiocarbon dating together with TIMS U-series dating to determine the times of occurrence of storms that were strong enough to actually "relocate" large Porites coral blocks that are widespread on the reef flats there. This program revealed that "during the past 1000 years, at least six exceptionally strong storms occurred," which they dated to approximately AD 1064 ± 30, 1218 ± 5, 1336 ± 9, 1443 ± 9, 1682 ± 7 and 1872 ± 15, yielding an average recurrence time of 160 years. Interestingly, none of these six severe storms occurred during the past millennium's last century, which climate alarmists claim was the warmest such period of that thousand-year interval.

Noting that Emanuel (2005) and Webster et al. (2005) have claimed that "tropical cyclone intensity has increased markedly in recent decades," and saying that because they specifically argued that "topical cyclone activity over the western North Pacific has been changed in response to the ongoing global warming," Ren et al. (2006) decided to see if any increases in tropical cyclone activity had occurred over China between 1957 and 2004. This they did by analyzing tropical cyclone (TC) precipitation (P) data from 677 Chinese weather stations for the period 1957 to 2004, searching for evidence of long-term changes in TCP and TC-induced torrential precipitation events. Interestingly, this search indicated, in their words, that "significant downward [our italics] trends are found in the TCP volume, the annual frequency of torrential TCP events, and the contribution of TCP to the annual precipitation over the past 48 years." Also, they say that the downward trends were accompanied by "decreases in the numbers of TCs and typhoons that affected China during the period 1957-2004." In a conclusion that consequently differs dramatically from the claims of Emanuel (2005) and Webster et al. (2005) relative to inferred increases in topical cyclone activity over the western North Pacific in recent decades, Ren et al. say their findings "strongly [our italics] suggest that China has experienced decreasing [our italics] TC influence over the past 48 years, especially in terms of the TCP."

Nott et al. (2007) developed a 777-year-long annually-resolved record of landfalling tropical cyclones in northeast Australia based on analyses of isotope records of tropical cyclone rainfall in an annually-layered carbonate stalagmite from Chillagoe (17.2°S, 144.6°E) in northeast Queensland. Perhaps their most important discovery in doing so was their finding that "the period between AD 1600 to 1800" -- when the Little Ice Age held sway throughout the world -- "had many more intense or hazardous cyclones impacting the site than the post AD 1800 period," when the planet gradually began to warm at a rate that rose to ultimately become what climate alarmists characterize as unprecedented over the past millennium or more, and when temperatures rose to a level they claim was equally unprecedented. In harmony with the four researchers' feeling that "the only way to determine the likely future behavior of tropical cyclones is to first understand their history from high resolution records of multi-century length or greater," which is only common sense, it would thus appear that claims such as those of Emanuel (2005) and Webster et al. (2005) are lacking in real-world support from this region as well as many areas throughout the Pacific Ocean.

Last of all, Li et al. (2007) analyzed real-world tropical cyclone data pertaining to the western North Pacific basin archived in the Yearbook of Typhoon published by the China Meteorological Administration for the period 1949-2003, together with contemporaneous atmospheric information obtained from the National Center for Environmental Protection reanalysis dataset for the period 1951-2003. Following this endeavor, they used their empirical findings to infer future tropical cyclone activity in the region based upon climate-model simulations of the state of the general circulation of the atmosphere over the next half-century. This protocol revealed, first of all, that there were "more tropical cyclones generated over the western North Pacific from the early 1950s to the early 1970s in the 20th century and less tropical cyclones from the mid-1970s to the present." They further found that "the decadal changes of tropical cyclone activities are closely related to the decadal changes of atmospheric general circulation in the troposphere, which provide favorable or unfavorable conditions for the formation of tropical cyclones." Based on simulations of future occurrences of these favorable and unfavorable conditions derived from "a coupled climate model under the [A2 and B2] schemes of the Intergovernmental Panel on Climate Change special report on emission scenarios," they then determined that "the general circulation of the atmosphere would become unfavorable for the formation of tropical cyclones as a whole and the frequency of tropical cyclone formation would likely decrease by 5% within the next half century, although more tropical cyclones would appear during a short period of it."

In light of these several sets of hard evidence from the real world of nature, as opposed to the theoretical constructs from the virtual world of climate models, it would appear that the climatic implications of the two worlds are worlds apart from each other.

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