Fresh water a precious resource
Logo PBL Netherlands Environmental Assessment Agency

ACT 1


Setting the Scene

As the climate changes, so do extreme weather events and the impact of natural hazards. The current and future availability of freshwater resources, and the frequency and intensity of extreme weather events are closely linked to climate change. Global warming not only leads to gradual changes in mean temperature, precipitation and sea level rise, it also increases the likelihood of extreme weather events, such as heatwaves and flash flooding. As a result, the risk of natural hazards causing casualties and economic losses is increasing.

The probability of occurrence of daily maximum temperatures

A good example of how these extreme events are changing is the shift in global daily maximum temperatures. The curves shown in this figure describes the global daily maximum temperatures measured in 1950 and 2020, and those projected for 2070. These curves are shaped like a bell.
Over time, the bell shape changes due to an increase in the frequency and level of the highest temperatures and a lower frequency of average temperatures. This shift can already be seen in the daily temperatures measured over the 1950 to 2020 period.
This curve is expected to continue to change in the future, with rising annual mean temperatures and, more importantly, the rapid increase in the likelihood of extremely hot temperatures.

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.

Annual impact from water-related disasters
and diseases, globally, 1980-2021

For five water-related disasters and diseases — wildfires, storms, flooding, drought and inadequate water and sanitation — this illustration compares the related global number of people annually affected, including fatalities, and the annual economic damage between 1980 and 2020.
Flooding and drought affect the highest annual number of people (i.e. 106 million).
The highest number of fatalities is due to lack of clean water and inadequate sanitation, with 2.1 million, while most annual economic damage is caused by flooding, with USD 39 billion.

Tens of millions of people are affected by water-related disasters, such as flooding, heavy rains, storms and drought.

Millions of people die every year because of polluted water and a lack of adequate sanitation.

The annual economic damage from extreme weather events runs in the tens of billions of US dollars.

Key Message

key message icon

The urgency to take action is high and, more than ever, water and climate adaptation should be at the top of all agendas, from local to global and from public to private levels.

ACT 2


Hotspot Landscapes

The water challenges we face depend on the landscape we live in. The study The Geography of Future Water Challenges identifies four hotspot landscapes with specific clusters of water- and climate-related challenges: River Basins, Deltas and Coasts, Drylands and Cities.

River basins in integrated landscapes

This world map shows that all global land areas are part of a river basin, and that the deltas of these rivers form an substantial part of global coastal zones.
The map also shows the drylands, covering large parts of all continents, and the large cities with over half a million inhabitants.
Most cities with over 2 million inhabitants are located in Asia and Africa.
World Map - Step 4

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.

Hotspot landscapes: change in pressures 2020-2070

Indicators that will relatively improve or deteriorate
between 2020 and 2070, under different pathways.

This figure shows that water withdrawal from surface and groundwater resources is projected to increase by 46% between 2020 and 2070, under a business-as-usual scenario.

Hotspot landscapes: change in pressures 2020-2070

Indicators that will relatively improve or deteriorate
between 2020 and 2070, under different pathways.

This is a deterioration of sustainable use of groundwater resources. Under a low ambition pathway, this withdrawal is projected to increase by 31% between 2020 and 2070.

Hotspot landscapes: change in pressures 2020-2070

Indicators that will relatively improve or deteriorate
between 2020 and 2070, under different pathways.

Under the moderate and high ambition pathways, however, it is projected to decrease by 22% and 52%, respectively. This is an improvement in the sustainable use of groundwater resources, compared with the situation in 2020.

Hotspot landscapes: change in pressures 2020-2070

Indicators that will relatively improve or deteriorate
between 2020 and 2070, under different pathways.

This figure shows the projected change, between 2020 and 2070, for several indicator variables that describe the conditions of having too little water in dryland regions worldwide, under a business-as-usual scenario and for low, moderate and high ambition pathways.

Hotspot landscapes: change in pressures 2020-2070

Indicators that will relatively improve or deteriorate
between 2020 and 2070, under different pathways.

All of these projections show that these conditions with respect to too little water will improve between 2020 and 2070. The strongest improvement is projected for the high ambition pathway.

Hotspot landscapes: change in pressures 2020-2070

Indicators that will relatively improve or deteriorate
between 2020 and 2070, under different pathways.

This figure shows the projected change, between 2020 and 2070, for several indicator variables that describe worldwide conditions of having too little, too much or too dirty water in river basins, as well as the projected changes in the state of biodiversity, under a business-as-usual scenario and low, moderate and high ambition pathways. Most of these projections show a deterioration under a business-as-usual scenario. From a low to moderate and high ambition pathway, ever more indicators show an improvement in these conditions between 2020 and 2070.

Hotspot landscapes: change in pressures 2020-2070

Indicators that will relatively improve or deteriorate
between 2020 and 2070, under different pathways.

This figure shows the projected change, between 2020 and 2070, for several indicator variables that describe the worldwide conditions of having too little, too much or too dirty water in deltas and coastal zones, as well as the projected changes in the state of biodiversity, under a business-as-usual scenario and low, moderate and high ambition pathways. Most of these projections show a deterioration of these conditions between 2020 and 2070 under a business-as-usual scenario. From a low to moderate and high ambition pathway, ever more indicators show an improvement in these conditions between 2020 and 2070.

Hotspot landscapes: change in pressures 2020-2070

Indicators that will relatively improve or deteriorate
between 2020 and 2070, under different pathways.

This figure shows the projected change, between 2020 and 2070, for several indicator variables that describe the worldwide conditions of having too little or too dirty water in cities, under a business-as-usual scenario and for low moderate and high ambition pathways. About half of these projections show a deterioration of these conditions between 2020 and 2070 under a business-as-usual scenario. From a low to moderate and high ambition pathway, ever more indicators show an improvement in these conditions between 2020 and 2070.

Water and climate-related challenges manifest in four types of issues: too little, too much and too dirty water, and impacts on biodiversity.

We can identify many factors that indicate whether these issues are worsening or improving over time. Assessment of the projected future changes in these indicators will reveal the fingerprint of these changes.

For instance: water withdrawal from surface and groundwater resources is an indicator related to too little water. Under a business-as-usual scenario, withdrawal will continue to increase in support of increased crop production.

Under a high ambition pathway, water use — and thus water withdrawal from surface and groundwater resources — can be reduced while crop yields are increased as a result of more efficient irrigation.

We assessed the projected changes between 2020 and 2070 for 28 indicators across the four hotspot landscapes.

Hotspot Landscape 1

Drylands

There is good news for the drylands: the indicators of too little water show improvement, illustrating that we are able to produce more food using less water, partly thanks to a higher efficiency of irrigation. Improved water management and crop production also reduces conflict risk related to water stress.

Hotspot Landscape 2

River Basins

Little improvement is projected for biodiversity. Already today, the ecological quality of our rivers is under great pressure. This is largely due to dams, constructed since the middle of the previous century, and the high loads of nutrients from agricultural fields and discharges from households and industries.

Hotspot Landscape 3

Deltas and Coasts

For deltas and coastal zones, the improvement regarding the indicator of too much water illustrates the strong reduction in the population exposed to flooding under a high ambition pathway, compared with a business-as-usual scenario. This reduction results especially from investments in dykes and levees, and zoning restrictions for urban development in flood-prone coastal zones.

Little change is projected for the indicator of too dirty water; high loads of nutrients to coastal seas remain high, even under a high ambition pathway.

Hotspot Landscape 4

Cities

These high loads of nutrients are partly related to the cities; bending the trend of nutrient emissions from households and industries continues to be a challenge. However, there is a lot of perspective to improve wastewater treatment, sanitation, and sewerage connections.

Compared with the projected changes in the other indicators, those in flooding-related economic risk are extremely high. This reflects the continuing growth in population and GDP, and the ongoing urbanisation along rivers and in deltas and coastal zones. Urban damage caused by flooding can however be reduced under various ambition pathways, compared with the business-as-usual scenario.

Improvement or deterioration

Number of the assessed indicators for the four hotspot landscapes
that will deteriorate or improve between 2020 and 2070

This illustration shows the number of these indicators that either deteriorate or improve by more than 5% for the business-as-usual scenario and the low to high ambition pathways.
The number of them that deteriorate decrease from 60% under the business-as-usual scenario to 20% for the high ambition pathway, while those that improve increase from 25% to 75%.

A stepwise increase in the ambition level for future pathways, from low to moderate and high, gradually decreases the number of indicators that show substantial deterioration, compared with the situation for 2020.

The percentage of assessed indicators that show more than 5% improvement increases from about 25% under the business-as-usual scenario to about 75% under the high ambition pathway.

Improvements are particularly strong for indicators related to issues of too little and too dirty water. Clearly, under the high ambition level, there is a lot of perspective to improve water use efficiency, food production and the conditions for water, sanitation and hygiene (WASH), and reduce water stress and related conflict risk.

Projected changes in water- and climate-related impact indicators, 2020-2070

This world map shows whether global water challenges in river basins, deltas and coasts, drylands, and cities are likely to improve or deteriorate between now and 2070, in 11 global regions, according to the 28 assessed indicators.
The figure shows two situations: the business-as-usual scenario and the high ambition pathway. Compared with the business-as-usual scenario, the high ambition pathway shows a strong improvement for all regions, with the smallest improvements in Sub-Saharan Africa, South Asia and Southeast Asia.

Projected future developments at the global scale are not the same for each region. The business-as-usual scenario shows a further deterioration for most indicators between 2020 and 2070, especially in Africa and Southeast Asia. The indicator scores are positive for China, illustrating the positive effect of population decline.

The strong improvement under the high ambition pathway for the global picture is reflected in all regions. Sub-Saharan Africa, however, is clearly lagging behind; ongoing strong population growth and low economic growth continue to put a lot of stress on freshwater supply and sanitation in Africa.

All Sustainable Development Goals are linked to water

This figure shows a circle with 17 segments representing the 17 Sustainable Development Goals. The segments are colour coded to indicate the extent to which the particular SDG is related to water.

Business-as-usual scenario

This figure also shows the same circle with 17 segments representing the 17 Sustainable Development Goals. The colour coding in this circle, however, indicates how the projected changes in water- and climate-related challenges between 2020 and 2070 will affect the conditions for achieving these goals, under a business-as-usual scenario. For almost all Sustainable Development Goals conditions are projected to deteriorate.

High ambition pathway

This figure also shows the same circle with 17 segments representing the 17 Sustainable Development Goals. The colour coding in this circle shows how the projected improvement in water- and climate-related challenges between 2020 and 2070 will create co-benefits for the 17 Sustainable Development Goals, under the high ambition pathway. For almost all Sustainable Development Goals conditions are projected to improve.

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.

Key Message

key message icon

The business-a-usual scenario shows that current value systems, practices and policies structurally overlook the essential role of water.

key message icon

Much can be achieved under a high ambition pathway, but regional differences are large.

ACT 3


The Way Forward

Fundamental changes for a water-robust and climate-resilient future. Bending the trend of future water challenges requires three types of fundamental changes in water-related approaches, politics and economics.
Gearbox This illustration is schematic of a gear box in which 3 gears must rotate together to create the change that is needed to bend the trend of global future water challenges towards a water-secure and climate-resilient world. These 3 gears illustrate the need for more urgency, innovative approaches, and improvement in global governance. Bending the trend towards a water-secure and climate-resilient world Increase urgency C H A N G I N G G E A R A N D D I R E C T I O N InnovateapproachesImproveglobalgovernance Bending the trend requires a package of coherent turnarounds to shift gear and change direction

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.’

Agreed total annually required climate financing

This illustration shows 4 circles in a row. The size of the circles illustrates the amount of climate financing in four situations. From left to right: developed countries are to make USD 100 billion available, annually, for climate mitigation and adaptation in developing countries. However, by 2020, only USD 83 billion USD had been made available, whereas the estimated amounts that are needed by 2030 and 2050 for such adaptation are far larger, with between USD 160 and 340 billion by 2030, and between USD 315 and 565 billion USD by 2050.

Agreed total annually required climate financing

Finance Graph - Step 2

Adaptation needs are 5 to 10 times greater

Finance Graph - Step 3.1
Finance Graph - Step 3.2
Finance Graph - Step 4
Finance Graph - Step 5

Developed countries have agreed to make USD 100 billion a year available to developing countries, so that they can take measures to mitigate global warming and adapt to the impacts of climate change.

In 2020, these countries had not fully honoured that agreement.

Moreover, the developed countries had only allocated a small part of their financial aid for adaptation to the changing climate ...

... while we already know that this will require much more money, up to hundreds of billions of US dollars per year, by 2050.

Key Message

key message icon

Rising to the challenges requires a transition towards radically different, water-based policies and practices, and strengthening of the governance on all levels, from local to global.

key message icon

The water sector cannot do it alone.

Final thought

‘Climate change is largely due to the greenhouse gas emissions of high-income countries, whereas low-income countries seem to be bearing most of the consequences, overstretching their adaptation capacities.’

This Shortread is part of the following series:

other The Geography of Future Water Challenges products

Part I: The Geography of Future Water Challenges

Book and Website

Part II: The Geography of Future Water Challenges - Bending the Trend

Book and Policy Summary

Navigating Rivers and Deltas towards a Sustainable Future

Website