Editing IPCC:AR6/WGII/Chapter-10 (section)

===== 10.4.6.3.3 Precipitation extremes: excess rainfall, drought and water scarcity =====

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Warming from 1.5°C to 2°C will increase extreme precipitation events across Asia especially over East and South Asia ( ''medium evidence, high agreement'' ) (Zhang et al. 2018; [[#Supari--2020|Supari et al., 2020]] ; [[#Zhang--2020b|Zhang et al., 2020b]] ). In East and Central Asia, under 1.5°C warming, extreme 1- and 5-d precipitation will increase by 28 and 15% relative to 1971–2000 ( [[#Zhang--2020b|Zhang et al., 2020b]] ). In China’s urban agglomerations, an increase in global warming from 1.5°C to 2°C is ''likely'' to increase the intensity of total precipitation of very wet days 1.8 times and double maximum 5-d precipitation ( [[#Yu--2018d|Yu et al., 2018d]] ). Extreme rainfall has direct and increasing consequences on urban flooding risk ( [[#Dasgupta--2013b|Dasgupta et al., 2013b]] ), which is further exacerbated by urbanisation trends that reduce permeability, divert water flow and disrupt watersheds ( [[#Chen--2015b|Chen et al., 2015b]] ; [[#Duan--2016|Duan et al., 2016]] ).

Urban extent in drylands in expected to increase from 2000 to 2030 with large expansions in West Asia, Central Asia, South Asia and China and antecedent impacts on exposure to drought and water scarcity ( [[#Güneralp--2015|Güneralp et al., 2015]] ). Urban dryland extent in West Asia will increase from 19,400 to 67,400 km 2 ( [[#Güneralp--2015|Güneralp et al., 2015]] ). In the Haihe River basin in China, the proportion of people exposed to droughts at 1.5°C (without accounting for population growth) is projected to decrease by 30.4% but increase by 74.8% at 2°C relative to people exposed in 1986–2005 (339.65 million) ( [[#Sun--2017|Sun et al., 2017]] ). About 411 million people living in 330 cities above 300,000 population are exposed to drought risk, which include three Asian megacities Delhi (India), Karachi (Pakistan) and Kolkata (India). Drought-related economic losses are also high in Dhaka (Bangladesh) ( [[#Pervin--2020|Pervin et al., 2020]] ), Istanbul (Turkey), Manila (the Philippines) and Shenzhen (China), and Manila is also highly vulnerable to drought-related mortality ( [[#Gu--2015|Gu et al., 2015]] ).

Increasing urban drought risk will also have cascading impacts on regions from where water is imported, exacerbating drought exposure beyond urban settlements and limiting water availability in certain regions (Chuah et al., 2018; [[#Garrick--2019|Garrick et al., 2019]] ; [[#Zhang--2020c|Zhang et al., 2020c]] ; [[#Zhao--2020|Zhao et al., 2020]] ). There is ''medium evidence'' ( ''high agreement'' ) that urban water insecurity is experienced differentially based on income, risk exposure, and assets, and that urban drought and water scarcity is causing material and non-material losses and damage ( [[#Singh--2021a|Singh et al., 2021a]] ). Importantly, in several Asian cities, flood and drought risk is expected to occur concurrently, especially in South Asia which is projected to see the largest increase in urban land exposed to both floods and droughts (25–32% increase in flood and drought risk between 2000 and 2030).

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