Background
The authors write that the Intergovernmental Panel on Climate Change (IPCC, 2001, 2007) has twice suggested that "precipitation and extreme winds associated with tropical cyclones may have become more intense." However, they note that this dual claim is "mainly based on numerical models," and they have had the good sense to demand something more substantial, such as real-world observations, before accepting such contentions.

What was done
Working with tropical cyclone (TC) best track and related observational severe wind and precipitation datasets created by the Shanghai Typhoon Institute of the China Meteorological Administration, the four researchers determined trends in various TC characteristics over the period 1955 to 2006 for the whole of China and four sub-regions: South China (SC) comprising Guangdong, Guangxi and Hainan Provinces, East China (EC) comprising Fujian, Hiangxi, Zhejiang, Anhui, Jiangsu and Shandong Provinces plus Shangahi, and Northeast China (NEC) comprising Liaoning, Jilin and Heilongjiang Provinces, and China's inland area (CI) including all remaining provinces.

What was learned
First of all, Ying et al. report that over the past half-century there have been no changes in the frequency of TC occurrence, except within NEC, where they determined that "years with a high frequency of TC influence have significantly become less common." Second, they say that "during the past 50 years, there have been no significant trends in the days of TC influence on China," and they add that "the seasonal rhythm of the TC influence on China also has not changed." Third, they found that "the maximum sustained winds of TCs affecting the whole of China and all sub-regions have decreasing trends." And, fourth, they state that "the trends of extreme storm precipitation and 1-hour precipitation were all insignificant."

What it means
For the whole of China and essentially all of its component parts, major measures of TC impact have either remained constant or slightly decreased, which is quite different from what the IPCC has been predicting for the world as a whole over the past decade or more.

References
IPCC. 2001. Climate Change 2001: The Scientific Basis. Contribution of Working Group I to the Third Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, United Kingdom.

IPCC. 2007. Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, United Kingdom.