Immerzeel et al.  have ranked all mountain-dependent water towers according to their water-supplying role and the downstream dependence of ecosystems, societies and economies. The resulting Global Water Tower index indicates that the upper Indus basin is both the most important and the most vulnerable water tower unit  in the world. A WTU is defined as 'the intersection between major river basins and a topographic mountain classification based on elevation and surface roughness'. Whereas all important transboundary WTUs in Asia remain highly vulnerable, it is the Indus WTU  where the average annual temperature is projected to increase by 1.9ºC between 2000 and 2050, with wide-ranging consequences and trans-sectoral spillovers. The Indus WTU faces a deep risk produced by a combination of factors including water stress, ineffective governance, hydropolitical tensions, population growth and density, urbanisation and social transformations, with a significant bearing on SDG 6 on water, SDG 2 on food and SDG 7 on energy.
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report