Background
The authors write that "typhoons are among the most damaging natural disasters in the world," and that "China is one of the countries that suffers tremendous typhoon damage." Thus, it should come as no surprise that tropical cyclones impacting China have been well studied -- see several examples under the heading Tropical Cyclones (Pacific Ocean) in our Subject Index -- and that they continue to be scrutinized. And this scrutiny should be even less of a surprise in light of the climate-alarmist claim that such storms should become both more frequent and more furious as global temperatures rise.

What was done
In further exploring this issue, Sun et al. analyzed data pertaining to tropical cyclones (TCs) over the northwestern Pacific and the South China Sea, which they obtained from China's Shanghai Typhoon Institute and the National Climate Center of the China Meteorological Administration, pertaining to the period 1951 to 2005.

What was learned
The four Chinese researchers determined that the frequency of all TCs impacting China "tended to decrease from 1951 to 2005, with the lowest frequency [occurring] in the past ten years."

Number of typhoons affecting China (1951-2005). Adapted from Sun et al. (2011)

In addition, they say that the average yearly number of super typhoons was "three in the 1950s and 1960s" but "less than one in the past ten years." Similarly, they write that "the decrease in the frequency of super typhoons, at a rate of 0.4 every ten years, is particularly significant (surpassing the significance test at the 0.01 level)," and they additionally report that "there is a decreasing trend with the extreme intensity of these TCs during the period of influence in the past 55 years."

Frequency of super typhoons impacting China (1951-2005). Adapted from Sun et al. (2011).

What it means
Over the period of time (1951-2005) when climate alarmists claim the world warmed at a rate and to a degree that they characterize as unprecedented over the past millennium or more, tropical cyclones and super typhoons impacting China have become both less frequent and less ferocious, which is just the opposite of what they typically contend should happen under such "extreme" warming conditions.