The southern African climate under 1.5 °C and 2 °C of global warming as simulated by CORDEX regional climate models
The southern African climate under 1.5 °C and 2 °C of global warming as simulated by CORDEX regional climate models
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DOI：
10.1088/1748-9326/aab190
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发表时间：
2018-02
影响因子：
6.7
通讯作者：
G. Maúre;Izidine Pinto;Mzime R. Ndebele-Murisa;M. Muthige;C. Lennard;G. Nikulin;A. Dosio;A. Meque
中科院分区：
文献类型：
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作者：
G. Maúre;Izidine Pinto;Mzime R. Ndebele-Murisa;M. Muthige;C. Lennard;G. Nikulin;A. Dosio;A. Meque
利用非洲协调区域降尺度实验倡议的25个区域气候模式模拟的结果，评估了代表性浓度路径8.5下，相对于工业化前值，在两个全球变暖水平（即1.5°C和2.0°C）下，非洲南部温度和降水的预估变化。结果显示，与对照期（1971-2000）相比，1.5°C GWL的温度上升幅度为0.5°C - 1.5°C， 2.0°C GWL的温度上升幅度为1.5°C - 2.5°C。预计包括南非、纳米比亚和博茨瓦纳部分地区在内的南亚次大陆西南部地区的气温上升幅度最大，高于全球平均升温幅度，特别是在9月至10月至11月期间。另一方面，在1.5°C GWL下，模式显示林波波盆地和赞比亚赞比西盆地的较小地区以及南非西开普省的部分地区的降水量大幅减少，最多可达0.4 mm day - 1（约占气候值的20%）。模式预测南非中部和西部以及纳米比亚南部的降水将增加0.1毫米/天。在全球升温2.0°C下，预计在中部次大陆的大部分地区以及南非西部和莫桑比克北部的部分地区，更大比例的土地将面临0.2至0.4毫米天−1（约占气候值的10%-20%）的强劲下降。降水减少伴随着该地区连续干旱日数的增加和连续潮湿日数的减少。实现《巴黎协定》的重要性对南部非洲至关重要，因为在1.5°C和2.0°C GWL下的预测变化意味着对农业和经济生产力、人类和生态系统健康以及水资源的重大潜在风险，并意味着区域水资源压力的增加。
Results from an 25 regional climate model simulations from the Coordinated Regional Downscaling Experiment Africa initiative are used to assess the projected changes in temperature and precipitation over southern Africa at two global warming levels (GWLs), namely 1.5 °C and 2.0 °C, relative to pre-industrial values, under the Representative Concentration Pathway 8.5. The results show a robust increase in temperature compared to the control period (1971–2000) ranging from 0.5 °C–1.5 °C for the 1.5 °C GWL and from 1.5 °C–2.5 °C, for the 2.0 °C GWL. Areas in the south-western region of the subcontinent, covering South Africa and parts of Namibia and Botswana are projected to experience the largest increase in temperature, which are greater than the global mean warming, particularly during the September–October–November season. On the other hand, under 1.5 °C GWL, models exhibit a robust reduction in precipitation of up to 0.4 mm day−1 (roughly 20% of the climatological values) over the Limpopo Basin and smaller areas of the Zambezi Basin in Zambia, and also parts of Western Cape, South Africa. Models project precipitation increase of up to 0.1 mm day−1 over central and western South Africa and in southern Namibia. Under 2.0 °C GWL, a larger fraction of land is projected to face robust decreases between 0.2 and 0.4 mm day−1 (around 10%–20% of the climatological values) over most of the central subcontinent and parts of western South Africa and northern Mozambique. Decreases in precipitation are accompanied by increases in the number of consecutive dry days and decreases in consecutive wet days over the region. The importance of achieving the Paris Agreement is imperative for southern Africa as the projected changes under both the 1.5 °C, and more so, 2.0 °C GWL imply significant potential risks to agricultural and economic productivity, human and ecological systems health and water resources with implied increase in regional water stresses.