Availability & Consumption of Water
Earth's water
- Freshwater makes up just 2.5% of all Earth's water
- Approximately 1.6% of the freshwater is locked away:
- The cryosphere holds 68.6% of freshwater as ice
- The remaining 30.1% is groundwater
- In total, just 0.9% of the Earth's total freshwater is accessible to humans
Availability of freshwater
Global availability of freshwater
- Water is unevenly distributed around the globe because of physical and human factors
Physical and Human Factors Affecting Global Water Distribution
Physical Factors | Human Factors |
The uneven spread of land to sea Geology, which enable aquifers to form Climatic differences: temperature and rate of precipitation Altitude and latitude—ice and glaciers Wetlands, lakes and river size Soil type: groundwater store |
Level of economic development Rate of abstraction Use of water Embedded water Population numbers Affordability Contaminated water |
- This means that people's access to water is uneven and dependent on where they live
Global availability of freshwater
Global availability of freshwater
- Global climate differences create varying amounts of groundwater, surface water, and precipitation levels
- Availability may also be affected by population levels and wealth
- The distribution of the human population does not match the distribution of water
- This creates areas that do not have adequate local water supplies
Patterns and trends
- Since 2000, 1.8 billion people have gained access to basic drinking water services
- Inequalities in access remain
Trends in global access to water
- According to the World Bank, inequality in access to water is the greatest threat to:
- Economic progress
- The eradication of poverty
- Sustainable development
- It is the poorest and most vulnerable that suffer the most
Increasing demand for water
- Demand for safe water is increasing due to:
- Economic development
- Population growth
- Increased use of renewable energy
- At present, HICs have some of the highest levels of consumption due to:
- Modern appliances
- Swimming pools
- Internal bathrooms
- Production of food and manufactured goods
- MICs are increasing their consumption and demand for water; much of this increase is due to industrialisation
- LICs have the smallest water footprint
Agriculture
- Agricultural production of food, fibres, livestock and industrial crops accounts for 70% of global groundwater withdrawals
- This figure is even higher in arid and semi-arid regions
- By 2050, there will be an estimated 50% increase in demand for food, adding extra stress on groundwater abstraction
- Much of this growth will be in LICs, which already experience water stress
Industry
- Approximately 17% of total water withdrawals are used for industrial purposes
- Freshwater use in industry includes:
- Dilution
- Steam generation
- Washing and cooling of manufacturing equipment and goods
- Industrial water is also used as a cooling agent for energy generation in fossil fuel and nuclear power plants (hydropower generation is not included in this category), or as wastewater from certain industrial processes
- At over 300 billion m³, the U.S. is the largest consumer of industrial water
- China is the second largest consumer at 140 billion m³
- Other regions use approximately one billion m³ of industrial water per year, with Sub-Saharan Africa and some parts of South Asia using less than 500 million m³ of industrial water per year
Domestic
- The remaining 13% is used for domestic, household or public services (cooking, cleaning, washing and drinking)
- The three countries with the highest domestic use of water are China, USA and India
Domestic use of water in China, USA and India
- Future demands for freshwater include:
- Population growth
- Growth of middle class - affluence leads to increased water consumption
- Growth in tourism and leisure
- Growth in urbanisation requires investment in water and sanitation infrastructure
- Climate change and increased climatic variability of precipitation rates
Embedded, hidden or virtual water
- This refers to water transported from one place to another through the export of foods, flowers, manufactured products, drinks, etc.
- It allows countries to reduce their water consumption by importing goods
- However, it can also lead to further water stress through exporting goods
- The Ica Valley is in the dry, coastal region of Peru and is one of the few places in the world, where high-quality asparagus can grow all year round
- Over 317 million cubic metres of water is needed from the aquifer to grow the exported asparagus
- This has reduced available water in the aquifer by over 60% and at its current rate, the aquifer will run dry within the next 20 years