Background
The authors begin by noting that "tropical cyclones (TCs) are among the most destructive of all natural disasters," and that "some recent studies have claimed that the number of intense TCs is on the increase as a result of global warming," citing the papers of Emanuel (2005) and Webster et al. (2005), while indicating that other researchers have challenged this claim. Hence, they too probe the issue with a study of landfalling tropical cyclones of East Asia.

What was done
Based on TC data obtained from the Joint Typhoon Warning Center for the period 1945-2004 and the Annual Tropical Cyclone Data Book (edited by the Shanghai Typhoon Institute) for the period 1951-2000, Chan and Xu conducted a comprehensive study of variations in the annual number of landfalling TCs in three sub-regions of East Asia: South (south China, Vietnam and the Philippines), Middle (east China), and North (Korean Peninsula and Japan).

What was learned
As might have been expected, the two researchers report that "wavelet analyses of each time series show that the landfalling frequencies go through large inter-annual (2-8 years), inter-decadal (8-16 years) and even multi-decadal (16-32 years) variations, with the inter-annual being the most dominant, and the multi-decadal explaining most of the rest of the variance." And in what they call "an important finding," they state that "none of the time series shows a significant linear temporal trend, which suggests ...

What it means
... that global warming has not led to more landfalls in any of the regions in Asia."

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

Webster, P.J., Holland, G.J., Curry, J.A. and Chang, H.-R. 2005. Changes in tropical cyclone number, duration, and intensity in a warming environment. Science 309: 1844-1846.