[Illustrations, footnotes and references available in PDF version]
Climate models have long suggested that the intensity and frequency of hurricanes or tropical cyclones (TCs) may be significantly increased in response to global warming, as noted by Free et al. (2004), who have written that "increases in hurricane intensity are expected to result from increases in sea surface temperature and decreases in tropopause-level temperature accompanying greenhouse warming," citing in support of this statement the studies of Emanuel (1987), Henderson-Sellers et al. (1998) and Knutson et al. (1998). Before accepting this climate-model-based projection, however, it is important to see what the world of nature has to say about the issue.
Truly, something yet unknown has orchestrated the ebbing and flowing of global tropical cyclone activity over the last 5,000 years. hat we do know, however, is that it has not been changes in the atmosphere's CO2 concentration, which has remained quite stable over this entire period ... except for the past 100 years, when it has risen substantially, but without any demonstrable change in global tropical cyclone activity. Hence, 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.