Abstract/Summary

Cold winters in China are expected to become rarer in a warming climate. By employing high quality station observations and model simulations, we estimate that anthropogenic influences have reduced the occurrence probability of an extreme cold event with the intensity equal to or stronger than the record in 2016 by approximately two-thirds. Conversely, if there were no anthropogenic influences, the probability of an extreme cold pentad in 2016 would be more than double. The return period of such a record cold event is estimated to have been extended by about 28 years due to human influences. Our results are in line with McCusker et al. (2016) and Sun et al. (2016) and agree with Trenary et al. (2016) that despite severe cold surges and recordbreaking extreme cold-day occurrences during 2016, winters have become warmer. Our results also imply that even under human-induced warming, extreme cold events can still occur as a result of natural variability, such as Arctic Oscillation, which was believed to be responsible for the reporting event (Cheung et al. 2016)