The geography of future water challenges

A good example of how these extreme events are changing is the shift in the frequency and level of daily maximum temperatures. The curve shows the projected occurrence of daily maximum temperatures and is shaped like a bell.

Over time, the bell curve shows a shift towards higher temperatures and it changes in shape. We see this already in the data between 1950 and 2020.

This curve will continue to change in the future. The annual mean temperature is rising and, more importantly, the likelihood of extremely hot temperatures is increasing rapidly.

We all live in a river basin. River systems connect all landscapes through water and sediment flows, from their sources in the mountains down to the deltas and the sea.

Drylands — the global regions where fresh water is scarce — make up 40% of the earth's surface.

Deltas and coastal zones are at the interface where river dynamics — water and sediment flows, and their nutrients — meet the dynamics of the sea.

Cities — all these landscapes are home to large parts of the global population living in urbanised areas.

There are 17 Sustainable Development Goals (SDGs) and water is linked to all of them. For many of them this link is strong, for some it is indirect.

Under the business-as-usual scenario, a deterioration is projected for most of these Sustainable Development Goals.

A high ambition approach to tackle the water- and climate-related challenges can contribute in many ways to achieving the SDGs and thus to sustainable development; our high ambition pathway shows substantially more co-benefits for the SDGs than the business-as-usual scenario.

A wicked problem rises with respect to the construction of large hydropower dams. On the one hand, dams contribute to the production of renewable energy (SDG 7), but lead to displacement of local communities and disruption water and sediment flows, fish migration and sediment supply to downstream deltas and coasts, on the other.

1. We need to increase the level of urgency:

• Acknowledge the importance of water;
• Appreciate the value of water for both society and ecosystems;
• Start changing gear and direction today, while also planning beyond 2030.

Secretary General Antonio Guterres: ‘Water needs to be at the centre of the global political agenda.’

2. We need to innovate our approaches to water-related challenges:

• Let water be leading in the decisions and measures we take;
• Develop and implement high ambition pathways;
• Collaborate on policies across various scales and sectors.

Global Commission on the Economics of Water: ‘We must take actions that are bolder, more integrated, across sectors, and more networked at national, regional and global levels.’

3. We need to improve governance at the global scale:

• Increase the political awareness of what is at stake and improve the capabilities to act across the globe;
• Scale up funding for water and climate adaptation;
• Build a shared water agenda and process for concerted decisions on strategies, actions and financing on all levels, from global to local.

World Resources Institute: ‘We need a Paris Agreement-like treaty for water to address water resource management, sanitation, adaptation and mitigation, and transboundary cooperation, globally and regionally.’