Future changes in coverage of 1.5 ℃ and 2 ℃ warming thresholds

• 来源期刊: 科学通报（英文版）
• 年，卷（期）: 2017,（21）
• 页码范围: 1455-1463
• 页数: 9页
• 语种: 英文

摘要

The areas covered by 1.5 ℃ and 2.0 ℃ warming thresholds under RCP2.6,RCP4.5,and RCP8.5 were analyzed based on 22 CMIP5 models.More than 90％ of the model runs are in agreement that by the end of the 21st century,near-surface air temperature changes over ～5％ (～2％),～40％ (～18％),and ～92％ (～86％) of the globe will cross the 1.5 ℃ (2.0 ℃) threshold under RCP2.6,RCP4.5,and RCP8.5,respectively.Under RCP8.5,nearly the whole of North America,Europe + Russia,Africa,and Asia-Russia will cross the 1.5 ℃ (2.0 ℃) threshold in ～2050 (～2060),while the coverage rates over South America and Oceania are ～80％ (～75％) and ～50％ (～30％),respectively.The threshold-onset time (TOT) for 2 ℃ warming is earliest over Europe + Russia and North America,followed by Africa,Asia-Russia,South America,and finally Oceania under the RCP4.5 and RCP8.5 scenarios.The TOT for 1.5 ℃ is ～10-30 years ahead of that for 2.0 ℃.