Asian climate change under 1.5–4 °C warming targets

Based on simulations of 18 CMIP5 models under three RCP scenarios, this article investigates changes in mean temperature and precipitation and their extremes over Asia in the context of global warming targets of 1.5–4 °C, and further compares the differences between 1.5 °C and 2 °C targets. Results show that relative to the pre-industrial era, the mean temperature over Asia increases by 2.3 °C, 3.0 °C, 4.6 °C, and 6.0 °C at warming targets of 1.5 °C, 2 °C, 3 °C, and 4 °C, respectively, with stronger warming in high latitudes than in low latitudes. The corresponding enhancement in mean precipitation over the entire Asian region is 4.4%, 5.8%, 10.2%, and 13.0%, with significant regional differences. In addition, an increase in warm extremes, a decrease in cold extremes, and a strengthening in the variability of amounts of extreme precipitation are projected. Under the 1.5 °C target, compared with the climate under the 2 °C target, the mean temperature will be lower by 0.5–1 °C over Asia; the mean precipitation will be less by 5%–20% over most of Asia, but will be greater by about 10%–15% over West Asia and western South Asia; extreme high temperatures will be uniformly cooler throughout the Asian region, and the warming in extreme low temperatures will decrease significantly in high latitudes of Asia; extreme precipitation will be weaker over most of Asia but will be stronger over West Asia and western South Asia. Under the 1.5 °C and 2 °C warming targets, the probability of very hot weather (anomalies greater than 1σ, σ is standard deviation), extremely hot weather (anomalies greater than 3σ), and extremely heavy precipitation (anomalies greater than 3σ) occurring will increase by at least once, 10%, and 10%, respectively, compared to the reference period (1861–1900).