Living within safe and just Earth System Boundaries for blue water

In a new paper, Earth Commission experts investigate how to ensure the basic water needs of the world’s population can be met in a safe and just manner.

About one third of the global population live in river basins where, in order to stay within safe and just boundaries for water, their basic water needs cannot be met from surface flows alone.

Earth Commission experts build on previous safe and just boundaries research for surface and groundwater, and tackle water scarcity questions by integrating blue water volumes required to provide minimum access to water for basic human needs. Blue water is defined as water sources found in rivers, lakes, groundwater or frozen in glaciers and polar ice caps.

We have been using our water in ways that negatively affect aquatic ecosystems and other people who rely on renewable freshwater supplies. This also affects the ecosystem services provided by aquatic ecosystems such as reliable clean water supply and fisheries production.” said lead author, Ben Stewart-Koster, Earth Commission expert and Senior Research Fellow, Australian Rivers Institute, Griffith University.

The paper identifies that in some regions, the deficit could be met from a relatively low proportion of available groundwater. However, they also discover that in many drier and more populous regions, 50% or more of the average annual groundwater recharge would be required to close the gap.

“Groundwater is an important source of water around the world, however, in many regions climatic driven declines in annual groundwater recharge increase the challenge of meeting the needs of people in a sustainable manner.” said Earth Commissioner Prof. Stuart Bunn, Australian Rivers Institute, Griffith University and co-author of the paper.

In dire need of transformation

The authors conclude that radical transformations are required to meet the basic water needs of all people (just access) while respecting the safe and just Earth System Boundaries for blue water. They outline that changing the way we use water is a critical step to prevent the ongoing loss of freshwater biodiversity and meeting the needs of people within safe and just Earth System Boundaries.

Transformations identified include;

  • Demand side – more efficient use of water in food production and reducing urban water demand.
  • Supply side – re-balancing the use of surface and groundwater, increased reliance on green water for food production and the use of safely treated recycled water.

There have been substantial improvements in producing more food with less water and our research has highlighted where demand side transformations such as this are needed to ensure the basic water needs of the world’s population can be met in a safe and just manner” continued Bunn.

About the paper

Read the full article in Nature here.
The Earth Commission is the scientific cornerstone of the Global Commons Alliance.

Photo credits

Man collecting water

City: Mutsamudu River

Country: Comoros



The Value of Clean Water: Community support for the protection and management of the Mutsamudu River Basin is critical for the success of the demonstration project. A water management plan has been developed following comprehensive consultations with stakeholders. Bolstering these interventions is an inclusive public awareness campaign that is engaging the people of Mutsamudu in an effort to keep the river clean.