Asynchronous exposure to global warming: freshwater resources and terrestrial ecosystems
Asynchronous exposure to global warming: freshwater resources and terrestrial ecosystems
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DOI：
10.1088/1748-9326/8/3/034032
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发表时间：
2013-07-01
影响因子：
6.7
通讯作者：
Schellnhuber, Hans Joachim
中科院分区：
文献类型：
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作者：
Gerten, Dieter;Lucht, Wolfgang;Schellnhuber, Hans Joachim
该模型研究表明，全球平均气温上升 (Delta T-g) 达到什么水平时，区域将面临淡水供应量显着减少和陆地生态系统变化的影响。预测基于一组新的、一致的 152 个气候情景（到 2100 年，八个三角洲 T-g 轨迹将比工业化前水平高出 1.5-5 摄氏度，每个轨迹都根据 19 个大气环流模型的空间模式进行缩放）。结果表明，在 Delta T-g 为 2 摄氏度且主要在亚热带地区的情况下，19 种气候情景中超过 50% 的地区将出现更高程度的缺水。 2摄氏度时也会发生显着的生物地球化学和植被结构变化，但主要发生在亚极地和半干旱生态系统中。其他地区会受到较高 Delta T-g 水平的影响，但强度较低或置信度较低。总体而言，模拟的全球平均变暖水平为 2 摄氏度、3.5 摄氏度和 5 摄氏度，将分别使世界人口分别增加 8%、11% 和 13% 面临新的或加剧的水资源短缺，置信度 >50%（与已经生活在缺水地区的 13 亿人类似）。与此同时，在分别含有 1%（在 2 摄氏度受影响的区域）、10%（3.5 摄氏度）和 74%（5 摄氏度）现有特有维管植物物种的生物地理区域中，将发生实质性的栖息地转变。结果表明影响随 Delta T-g 的非线性增长，并突出了影响强度和临界 Delta T-g 水平的区域差异。
This modelling study demonstrates at what level of global mean temperature rise (Delta T-g) regions will be exposed to significant decreases of freshwater availability and changes to terrestrial ecosystems. Projections are based on a new, consistent set of 152 climate scenarios (eight Delta T-g trajectories reaching 1.5-5 degrees C above pre-industrial levels by 2100, each scaled with spatial patterns from 19 general circulation models). The results suggest that already at a Delta T-g of 2 degrees C and mainly in the subtropics, higher water scarcity would occur in >50% out of the 19 climate scenarios. Substantial biogeochemical and vegetation structural changes would also occur at 2 degrees C, but mainly in subpolar and semiarid ecosystems. Other regions would be affected at higher Delta T-g levels, with lower intensity or with lower confidence. In total, mean global warming levels of 2 degrees C, 3.5 degrees C and 5 degrees C are simulated to expose an additional 8%, 11% and 13% of the world population to new or aggravated water scarcity, respectively, with >50% confidence (while similar to 1.3 billion people already live in water-scarce regions). Concurrently, substantial habitat transformations would occur in biogeographic regions that contain 1% (in zones affected at 2 degrees C), 10% (3.5 degrees C) and 74% (5 degrees C) of present endemism-weighted vascular plant species, respectively. The results suggest nonlinear growth of impacts along with Delta T-g and highlight regional disparities in impact magnitudes and critical Delta T-g levels.