CR 64:227-242 (2015)  -  DOI: https://doi.org/10.3354/cr01328

ABSTRACT: Based on the experiments of 26 global climate models (GCMs) participating in the Coupled Model Intercomparison Project Phase 5 (CMIP5), we projected climate change relative to the period of 1986-2005 over China associated with a 2°C increase in global temperature above pre-industrial levels, based on Representative Concentration Pathways 4.5 (RCP4.5) and 8.5 (RCP8.5). Results indicate that under RCP4.5 (RCP8.5), a global warming of 2°C will occur in the year 2059 (2045), accompanied by an atmospheric CO₂-equivalent concentration of 550 (585) ppm. Annual (seasonal) warming averages of 2.6°C (2.4-2.8°C) over the entire country as well as local warming are projected to be greater than the natural internal variability, with an average regional annual (seasonal) signal-to-noise ratio of 4 (2-3). Projections of annual (seasonal) precipitation over China vary from –2 to +20% (–13 to +39%), averaging 7% (5-13%). Precipitation will increase over most of China, except for the southwestern part in winter and northeastern part in summer, with an increase in heavy rainfall days. Meanwhile, almost all local precipitation changes are projected to be smaller than the natural internal variability. Using the 5-95% range among the 26 GCMs as a measure of uncertainty, regional averages of annual (seasonal) temperature and precipitation changes are projected to be 1.1-3.2°C (0.6-3.8°C) and –9 to 29% (–23 to 60%), respectively, with corresponding signal-to-noise ratios of 1.9-6.3 (0.4-5.7) and –0.5 to 1.6 (–0.5 to 1.4), respectively.

KEY WORDS: 2°C global warming · Regional climate change · Signal-to-noise ratio · China