Most basic of all their findings, the seven scientists report that China's surface air temperature (SAT) rose by only 0.3 to 1.2°C over the past century. And tempering even this modest finding was the fact, as they put it, that "climate warming was more evident in winter and spring than in other seasons," and that "the warming trend in summer was found the weakest almost everywhere." In fact, they indicate that "in the Yangtze River and Huaihe River basins, the summer mean temperature even dropped slightly." And they state that in the country's annual mean SAT series from 1960 to 2004 - based on the commonly used dataset of national stations - "at least 27% of the warming could be attributed to the urbanization effect," which leaves very little warming to get very excited about, which is probably why they say very little about the likelihood that annual mean SAT in the past few decades "may not have exceeded the highest level of the Medieval Warm Period," which is pretty much of an understatement, to say the least.

Next on the Chinese researchers' list of concerns, they state that "in the past 100 years and/or 50 years, no significant trends were detected in annual mean precipitation in the country overall." And in two related matters, they indicate that "the frequency of extreme drought and/or flood events in eastern China in the 20th century did not surpass the highest level in the past 2000 years, but approached the level of 'normal years'." They additionally note that "a decreasing trend was found in frequency of tropical cyclones or typhoons landing on and affecting the southeastern coastal areas," and they report that "the frequency and intensity of dust storms in northern China and thunderstorms over a few areas investigated in eastern China decreased."

It is not surprising, therefore, that "thus far," as Ren et al. write in concluding their report, "global and regional climate models have not performed well in capturing basic changes in precipitation and extreme climate events." And they consequently end their paper with the comment that confidence in the models' projections "is low," as well it should be, to add our own two cents' worth.

Sherwood, Keith and Craig Idso

Reference
Ren, G., Ding, Y., Zhao, Z., Zheng, J., Wu, T., Tang, G. and Xu, Y. 2012. Recent progress in studies of climate change in China. Advances in Atmospheric Sciences 29: 958-977.