IPCC AR6报告解读：水循环变化

doi:10.12006/j.issn.1673-1719.2021.160

摘要/Abstract

摘要：

水循环在全球和区域气候变化中扮演重要角色,与全球变暖背景下水循环变化密切相关的淡水资源短缺、副热带干旱区扩张、极端旱涝灾害频发等问题日益突出,严重制约生态系统和人类社会的可持续发展。在IPCC第六次评估报告中,第一工作组首次单独设立一章,即第八章,用于系统性评估全球水循环变化。评估显示,自20世纪中叶以来,人类活动已经显著地改变了全球水循环,包括大气湿度和降水强度的整体性增加,全球干旱模态改变,南半球风暴轴向极地移动等。已经发生的水循环变化受到温室气体、气溶胶、土地利用在内的多种人类强迫的影响,而未来全球水循环变化将逐渐由温室气体主导。

关键词: IPCC, 水循环, 评估, 人类活动

Abstract:

The water cycle plays an important role in global and regional climate changes, and problems such as shortage of freshwater resources, expansion of subtropical drylands, and frequent occurrence of extreme droughts and floods, which are closely related to water cycle changes in the context of global warming, are becoming increasingly prominent and seriously constrain the sustainable development of ecosystems and human society. In the IPCC Sixth Assessment Report (AR6), Working Group I established a separate chapter, namely Chapter 8, for an integrated assessment of global water cycle changes. AR6 suggested that human activity has significantly altered the global water cycle since the mid-20th century, including an overall increase in atmospheric moisture and precipitation intensity, changes in the global drought patterns, and the poleward shift of storm tracks in the Southern Hemisphere. Changes in the water cycle that have occurred were influenced by a variety of anthropogenic forcing including greenhouse gases, aerosol and land use change, while future water cycle changes will gradually be dominated by greenhouse gases.

Key words: IPCC, Water cycle, Assessment, Human activity

姜大膀, 王娜. IPCC AR6报告解读：水循环变化[J]. 气候变化研究进展, 2021, 17(6): 699-704.

JIANG Da-Bang, WANG Na. Water cycle changes: interpretation of IPCC AR6[J]. Climate Change Research, 2021, 17(6): 699-704.

图/表 1

图1 水循环示意图注：大气层中的水只占地球上所有水的0.001%,并主要以气体（水蒸气）的形式出现,但它亦以冰和云中液态水的形式存在。海洋是地球上的主要水库,它在全球大部分地区主要由液态水组成,但也包括极地地区被冰覆盖的区域。陆地上液态淡水组成包括地表水（湖泊、河流)、土壤水分和地下水储存,共占全球水的1.8%。以冰盖、冰川、地表冰雪和多年冻土形式出现的固体陆地水约占全球水的2.2%。冬季融雪补充了土壤湿度和河川径流,对人类活动和生态系统运行至关重要。图中数据来源见参考文献[4,5,6,7,8,9,10,11,12,13,14]。

Fig. 1 Depiction of the water cycle. (In the atmosphere, which accounts for only 0.001% of all water on Earth, water primarily occurs as a gas (water vapor), but it is also present as ice and liquid water within clouds. The ocean is the primary water reservoir on Earth, which is comprised mostly of liquid water across much of the globe, but also includes areas covered by ice in polar regions. Liquid freshwater on land forms surface water (lakes, rivers), soil moisture and groundwater stores, together accounting for 1.8% of global water. Solid terrestrial water that occurs as ice sheets, glaciers, snow and ice on the surface and permafrost currently represents 2.2% of the planet's water. Water that falls as snow in winter provides soil moisture and streamflow after melting, which are essential for human activities and ecosystem functioning. Data derived from references [4,5,6,7,8,9,10,11,12,13,14])

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