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

==== 10.4.4.1 Key Drivers ====

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Across Asia and its various sub-regions, the key drivers behind an increasingly inadequate supply of freshwater resources, affecting the livelihood security of millions, are varied, complex and intersect with multiple social, cultural, economic and environmental stressors ( [[#Luo--2017|Luo et al., 2017]] ; [[#Tucker--2015|Tucker et al., 2015]] ; [[#Kongsager--2016|Kongsager et al., 2016]] ). Water stress has been defined as the situation ‘when the demand for water exceeds its supply, during a certain period of time, or when poor quality restricts its use’( [[#Felberg--1999|Felberg et al., 1999]] ; see also Figure 4.32 in Lee et al., 2021a).

Freshwater resources in Asia, which include both surface water and groundwater, are considerably strained, and changing climate is ''likely'' to act as a major stress multiplier ( [[#Dasgupta--2015|]] [[#Dasgupta--2015|Dasgupta et al., 2015]] ; [[#Fant--2016|Fant et al., 2016]] ; [[#Gao--2018c|Gao et al., 2018c]] ; [[#Mack--2018|Mack, 2018]] ). In Southern and Eastern Asia (SEA) nearly 200 million people are at risk of serious water-stressed conditions. Effective mitigation might reduce the additional population under threat by 30% (60 million people), but still there is a 50% chance that 100 million people across SEA might face a 50% increase in water stress and a 10% chance that water stress will almost double in the absence of wide-ranging, multi-scalar adaptive measures ( [[#Gao--2018c|Gao et al., 2018c]] ). With Millennium Development Goal 7c, which aimed to halve the population that had no sustainable access to water and basic sanitation before 2015, not having been fully realised, and Sustainable Development Goal 6 on water and sanitation not having been effectively operationalised, the water stress is ''likely'' to increase by the end of 2030 ( [[#Weststrate--2019|Weststrate et al., 2019]] ).

In Asia and elsewhere the interplay between the challenge of sustainability and climate change poses major policy challenges ( [[#von%20Stechow--2016|von Stechow et al., 2016]] ). The pursuit of SDG 6—protection and restoration of water-related ecosystems, universal and equitable access to safe and affordable drinking water for all, improvement in water quality by reducing pollution, elimination of dumping and significant reduction in release of hazardous chemicals and materials, and treatment of waste water through recycling and safe reuse globally—could be directly or indirectly challenged and undermined by climate change ( [[#Parkinson--2019|Parkinson et al., 2019]] ). Dissolved organic materials from sewage can enhance CO 2 emissions, especially in rapidly urbanising river systems which receive untreated waste water and/or sewage across developing countries ( [[#Kim--2019b|Kim et al., 2019b]] ). Conversely, policy interventions aimed at significant augmentation in water-use efficiency across all sectors, ensuring sustainable withdrawals and supply of freshwater to address water scarcity and a significant reduction in the number of victims of water scarcity, especially the poor and marginalised, could mitigate vulnerabilities caused by climate change. More interdisciplinary research is needed on highly precarious future pathways and the intersection between CIDs and non-climate drivers in order to anticipate and mitigate diverging and uncertain outcomes.

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