Read here. Climate alarmists have made careers of claiming that severe weather is more frequent and of increasing intensity as a result of global warming. Many scientists, including those in China, don't necessarily believe the climate science emanating from green/left/liberal sources so they end up doing their own research to determine facts. In the case of hail size, Chinese scientists examined climate records to determine if hail was growing larger because of global warming.
Xie et al. examined records from four regions of China covering the 25 year span of 1980-2005. They found no significant relationship overall with global warming and the size of hail.
"...produced by a trio of scientists from Peking University and the University of Hawaii who must not have received the memo on global warming and extreme precipitation events as they state “The question remains as to whether hail size has been changing in response to the warming climate” (go look up “Global Warming and Hail” and enjoy 50,000 sites on the subject). Xie et al. collected hail size information from stations throughout China and at the end of their analyses, they state “Here, we found no significant long-term trend in hail size based on the proportion of severe hail indirectly in the four regions in China, suggesting that hail size, as an important aspect of hail climatology, may not be sensitive to the intrinsic natural variability or climate change in the last 2–3 decades.” Oops, another failure to link extreme precipitation to global warming." [Baoguo Xie, Qinghong Zhang, Yuqing Wang 2010: Journal of Climate]
Additional severe-weather and peer-reviewed postings.