Slightly enhanced drought in the Yellow River Basin under future warming scenarios

Abstract

Yellow River Basin (YRB) in China has been frequently featured as one of the most vulnerable areas to climate change and climatic extremes, mainly due to its fragile arid and semiarid ecosystems.While previous researches mainly focused on the evaluation of historical drought periods, it is also meaningful to understand future drought conditions in YRB, in particular, alleviated drought trends under carbon peak and carbon neutrality periods. Based on climate outputs from the Coupled Model Intercomparison Project Phase 6 (CMIP6), we projected future climate conditions and drought characteristics in YRB, especially under the three SSPs (the Shared Socioeconomic Pathways) (e.g., SSP1–2.6, SSP2–4.5, and SSP5–8.5). For this, the monthly climate variables from CMIP6 models are in better agreement with the observation from 1961 to 2014, after (Equidistant Cumulative Distribution Functions) EDCDF Bias Correction method (e.g., the RMSE is reduced by 50% and 25% - 67% for temperature and precipitation, respectively). From 2015 to 2100, an increasing trend in temperature and precipitation is anticipated in YRB. When comparing with the reference period (1995–2014), drought conditions after 2040s will markedly be alleviated under the listed three SSPs. There will be a slight drying trend in YRB for all the three SSPs under four warming scenarios (e.g., 1.5 °C and 2.0 °C global warming, carbon peak and carbon neutrality) compare with the reference period. Drought conditions under carbon neutrality will be mostly alleviated among all the four warming scenarios. By 2100, YRB areas will witness a drier tendency, mainly in upstream and northern region (e.g., Inner Mongolia). We argue that reaching the carbon neutrality goal by the end of this century is essential for mitigating the impacts of climate-induced disasters on society, as such goal would help people coping with challenges posed by climatic extremes and drought conditions in a sustainable way.