Abstract

This technical note provides the underlying logic and calculations for the calculation that the world has already exceeded its blue water limit. In the absence of transformational change this blue water exceedance will grow much worse by 2050 imposing huge costs at the local to global level.

This technical note provides details of the calculations and data sources in relation to Figure 2.2, ‘The Water Cycle and the Economy’, within ‘The What, Why and How of the World Water Crisis’ Review and Findings of the Global Commission on the Economics of Water Review prepared for the UN 2023 Water Conference, March 2023.