Research advances in projections of regional climate change over China

Research on climate change projections aims to provide decision-makers with more reliable and less uncertain information about future climate change. This paper reviews the major progress made in China over the past decade regarding climate change projections, and discusses future perspectives in this field. Climate model projections indicate that both regional average temperatures and precipitation in China will increase, with the largest increases occurring under the scenarios of the highest emissions. In the future, extreme cold events in China are expected to decrease, while extreme heat events will become more frequent; extreme precipitation will continue to rise significantly in intensity and frequency; and compound extreme events will also see a notable increase, in particular the rarest extreme events, which will rise more significantly. Statistical bias-calibration, model weighting, constraint based on detection and attribution, and emergent constraint have been widely applied in regional climate change projections in China. Overall, constrained projections do not alter the qualitative conclusions of the raw model projections, but adjust the magnitude of the projected change. The observational constraint methods have demonstrated the ability to reduce uncertainty in projections across different regions and variables in China. To further advance the regional climate change projection research in China, it is essential to deepen understanding of the climate system and its feedback processes, improve the quality of observational data and the performance of climate model simulations, and enhance the application of emerging technologies such as machine learning.