Freshwater Use (HL) (DP IB Environmental Systems & Societies (ESS))

Freshwater use is considered a planetary boundary

• This means there is a limit to how much water can be used sustainably

Freshwater is essential for ecosystems, agriculture, and human consumption

• However, increasing demand is putting significant stress on these resources

If we exceed the freshwater planetary boundary, it could lead to abrupt changes in the hydrological cycle, such as:

• Dried-up rivers and lakes

• Depletion of groundwater reserves

• Loss of biodiversity and freshwater ecosystems

Measuring the boundary:

• Scientists monitor freshwater use by comparing the amount withdrawn for human activities to the natural replenishment rate (e.g., rainfall and groundwater recharge)

Mitigation strategies include:

• Reducing water waste through more efficient irrigation and industrial processes

• Recycling water in urban areas

• Protecting natural water storage systems like wetlands and forests

• Raising awareness and creating policies to manage water use sustainably

Local and global governance are critical to managing water resources and ensuring sustainable freshwater use

Local governance:

• In areas experiencing drought, local authorities can restrict water use to preserve supplies

  • For example, during droughts in the UK, local governments often ban garden watering and limit non-essential water use

• Local water management also includes building reservoirs and encouraging water conservation efforts at the household level

Global governance:

• International cooperation is often necessary for water sources that cross national boundaries

• Countries sharing rivers, lakes, or groundwater must collaborate to avoid overuse and conflict

• For instance, six countries share the Mekong River, including China and Vietnam

  • Cooperation is essential to balance energy production, agriculture, and ecosystem protection along the river

• Another example is the Indus Water Treaty between India and Pakistan

• The treaty regulates the use of water from the Indus River system, a key resource for both countries

A water footprint measures the total amount of water used to produce goods and services

• This can provide important information about the sustainability of water use by different societies

Individual water footprints measure how much water a person uses daily

This includes:

• Direct use (water for drinking and washing)

• Indirect use (water needed to grow the food and manufacture the goods that the person consumes)

National water footprints reflect the overall water consumption of a country

• This includes domestic use and the water used for the manufacturing of all imported goods

Water footprints can also apply to industries or products

For example:

• Growing crops like rice and cotton requires large amounts of water, leading to high water footprints

• Over 15 000 litres of water is needed to produce 1 kilogram of beef, making meat production extremely water-intensive

Water footprint analysis can inform sustainable decision-making

• Governments can use this data to create water-saving policies

• Consumers can reduce their water footprint by choosing products with lower water demands

Citizen science involves ordinary (non-specialist) people participating in scientific research to gather data

• This contributes to monitoring and managing water resources

Citizen science projects often use standard protocols to ensure high-quality data

Participants collect data on water quality, quantity, and other factors

• For example, the FreshWater Watch project encourages citizen scientists around the world to monitor freshwater bodies for pollution and ecosystem health

• Participants collect water samples and submit data

• This helps scientists and governments manage water resources

Benefits of citizen science:

• Increases public awareness of water issues and encourages local stewardship

• Provides large-scale data collection that scientists or governments may not have the resources to gather

• Allows communities to monitor local water conditions and identify problems, such as pollution

Limitations of citizen science:

• Data accuracy can vary depending on training and experience of volunteers

• Data collection is often limited to specific times and places, meaning it may not capture a complete picture of water issues