The world faces a growing tragedy of water. Without bold and concerted local, national and global actions, the problems of too little, too much and too dirty water – inextricably linked to climate change and the loss of biodiversity, with each reinforcing the other – will only get worse.

The crisis is fundamentally of a global and systemic nature, not merely local. For the first time in history, human activity and practices have put the global water cycle, on which all life depends, on an unsustainable course. The science also shows how communities and nations are hydrologically intertwined – not just by rivers and the surface water that we see, but through atmospheric moisture flows. Practices in any one region impact rainfall in others.

Unchecked, the global water crisis will endanger all the Sustainable Development Goals, making them virtually impossible to achieve. It will imperil food and health security, exacerbate poverty, and peace within and between nations. It will disproportionately affect women, vulnerable and marginalised groups among indigenous communities, youth, farmers, workers and small and medium-sized businesses.