Anthropogenic influence has increased climate extreme occurrence over China

Abstract

The changes in occurring probability of exceeding historically observed climate extreme events under the future warming scenario of SSP5-8.5. The probability ratios are estimated relative to the current state of 1995–2014. Maps in the left column show the probability changes for the period 2046–2065 and the mid column displays the results for the period 2081–2100. The projected changes in regional frequencies of climate extreme events are also displayed in the right panels for the future years. The shaded areas show the interquartile model spread, i.e., the range between the 25th and 75th percentiles of model ensemble, representing the confidence level. Climate change has exerted substantial influence on climate extreme events. To what degree anthropogenic influence has increased the risks of climate extreme events is of high public concern and still heavily debated. We find that the observed trends have exerted substantial influences on the severity and probability of the unprecedented hot, cold, wet, and dry events during the past decades across China. Attribution analyses based on different forcing simulations of CMIP6 indicate that humans have increased probabilities of historical hot and wet extremes, including in more than 75% and 56% of the areas in China, respectively. Particularly for the hottest day, the probability has increased by more than two times in over 20% of the area, while the probability of historical clod events decreases over most of China. Increasing emissions in the future are likely to cause substantial and widespread additional increases, including more than tenfold for the hottest day and twofold for the extreme wet events by the end of this century. For example, the observed hottest day would occur for each year over 80% of China from 2080, while the observed coldest night would never occur, and the driest events would markedly decrease by the end of this century. Therefore, it is now urgent for governments and the public to properly adopt effective strategies to mitigate anthropogenic influence on climate change in the future.