Relative impacts of mitigation, temperature, and precipitation on 21st-century megadrought risk in the American Southwest.
Relative impacts of mitigation, temperature, and precipitation on 21st-century megadrought risk in the American Southwest.
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DOI：
10.1126/sciadv.1600873
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发表时间：
2016-10
期刊：
影响因子：
13.6
通讯作者：
Smerdon JE
中科院分区：
文献类型：
--
作者：
Ault TR;Mankin JS;Cook BI;Smerdon JE
更高的气温将使美国西南部更有可能发生特大干旱，但减少排放可以降低风险。特大干旱的严重程度与20世纪最严重的干旱相当，但持续时间要长得多。美国西南部的特大干旱将对该地区有限的水资源造成前所未有的压力，因此，不仅要评估不同气候变化缓解情景下的未来风险，还要评估区域水文气候的不同方面。我们发现，决定美国西南部特大干旱风险的是平均水文气候状态的变化，而不是其变异性。仅基于降水的特大风暴概率估计往往低估了风险。此外，不管降水的不确定性有多大，一切照旧的温室气体排放将推动区域变暖和干燥。我们发现，即使降水分别适度增加、不变或减少，到本世纪末，仅区域温度升高就会使特大干旱的风险超过70%、90%或99%。尽管每种可能性都得到了一些气候模式模拟的支持，但在耦合模式比较第5代模式中，后者是美国西南部最常见的结果。积极减少全球温室气体排放可以将全球变暖的风险降低近一半。
Higher temperatures will make megadroughts more likely in the American Southwest, but cutting emissions reduces risk. Megadroughts are comparable in severity to the worst droughts of the 20th century but are of much longer duration. A megadrought in the American Southwest would impose unprecedented stress on the limited water resources of the area, making it critical to evaluate future risks not only under different climate change mitigation scenarios but also for different aspects of regional hydroclimate. We find that changes in the mean hydroclimate state, rather than its variability, determine megadrought risk in the American Southwest. Estimates of megadrought probabilities based on precipitation alone tend to underestimate risk. Furthermore, business-as-usual emissions of greenhouse gases will drive regional warming and drying, regardless of large precipitation uncertainties. We find that regional temperature increases alone push megadrought risk above 70, 90, or 99% by the end of the century, even if precipitation increases moderately, does not change, or decreases, respectively. Although each possibility is supported by some climate model simulations, the latter is the most common outcome for the American Southwest in Coupled Model Intercomparison 5 generation models. An aggressive reduction in global greenhouse gas emissions cuts megadrought risks nearly in half.
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影响因子：
4.6
作者：
Cook, Benjamin I.;Smerdon, Jason E.;Coats, Sloan
通讯作者：
Coats, Sloan
DOI：
10.1002/joc.1181
发表时间：
2005-05-01
期刊：
INTERNATIONAL JOURNAL OF CLIMATOLOGY
影响因子：
--
作者：
Mitchell, TD;Jones, PD
通讯作者：
Jones, PD
影响因子：
56.9
作者：
Hodell, DA;Brenner, M;Guilderson, T
通讯作者：
Guilderson, T
影响因子：
56.9
作者：
Seager, Richard;Ting, Mingfang;Naik, Naomi
通讯作者：
Naik, Naomi
影响因子：
4.9
作者：
Meehl, Gerald A.;Hu, Aixue
通讯作者：
Hu, Aixue