Water stress: a situation reinforced by global warming
Water stress is one of the most serious threats to sustainable development. Due to uneven rainfall, a warmer climate and more CO2 in the atmosphere – more than 2 billion people do not have adequate access to one of the essentials of life: clean water. And this number is expected to increase by 35% by 2025.
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Summary
What is water stress?
What are the causes of water stress?
Which countries are most affected by water stress?
Does water stress have an impact on the environment and health?
How to mitigate water stress?
Definition of water stress
Also known as “water scarcity”, water stress occurs when the demand for safe, usable water exceeds the available water resources required to meet human and environmental needs in a given geographic area or when its quality limits its use.
On the demand side, the vast majority (about 70%) of the world’s freshwater is used for agriculture, while the remainder is divided between industrial (19%) and domestic (11%) uses. On the supply side, water sources include surface water (rivers, lakes, reservoirs) as well as groundwater, accessible through aquifers.
Causes of water stress
💧 Pressure on the water
In several regions of the world, the pressure on water is increasing, due to human withdrawals from surface or groundwater, which are increasing, but also due to global warming which disrupts the water cycle and makes drinking water more difficult to access.
👨👩👧👦. The increase of the world population
Demographics are increasing exponentially and this has an impact on the planet’s reserves.
Indeed due to population growth, economic development, improved living standards, changing consumption patterns, as well as the expansion of intensive agriculture (crop irrigation), global water use over the past 100 years has increased sixfold and continues to increase fast at nearly 1% per year (AQUASTAT).
🌏 Climate disruption
Natural disasters or floods can interrupt the water supply and thus createrisks of epidemics (contamination of water supplies and outbreaks of dysentery or other waterborne diseases).
Rising temperatures accentuate soil drying due to increased evaporation.
🌳 Deforestation
Trees are central to the rainfall process of a region as well as to the production of oxygen in the air. Their roots hold water in the soil and their leaves, by transpiring, produce and maintain moisture in the air.
Because of deforestation, the water cycle is partially disrupted, causing some regions to dry out to the point of desertification.
Countries more affected than others by water stress
In several regions of the world, the demand for water is increasing, especially in arid areas.
The World Health Organization (WHO) declares a situation of water stress when water availability, per year and per capita, isless than 1,700 m³. Below the 1,000m³ threshold, there is a water shortage.
Good to know: In France, we have between 2500 and 6000 cubic meters of water available per day. However, France, like other European countries, is not always spared from water stress. As a proof, the last heat waves in France and elsewhere in Europe have caused water stress situations.
Good to know: In France, we have between 2500 and 6000 cubic meters of water available per day. However, France, like other European countries, is not always spared from water stress. As a proof, the last heat waves in France and elsewhere in Europe have caused water stress situations.
Water stress is particularly present in countries:
👉 of the Near and Middle East;
👉 of Africa;
👉 Asia such as India or Pakistan;
👉 belonging to the great plains of northern China.
Good to know: It should be noted that the risk of water stress does not only concern hot countries but can also concern cold countries where frost can block access to liquid water.
Good to know: It should be noted that the risk of water stress does not only concern hot countries but can also concern cold countries where frost can block access to liquid water.
Water stress will affect 52% of the world’s population by 2050. According to MIT researchers, some 52% of the world’s 9.7 billion people will live in water-stressed regions by 2050.
An impact on health and the environment
Impacts on vegetation
Water stress initially has an impact on the vegetation. When a lack of water is felt, plants implement defense mechanisms, notably by closing the stomata (small openings located under the leaves) which prevents transpiration and therefore water loss.
But this closure also reduces photosynthesis, which can impact their development and growth (like most cereals or vegetables) and thus lead to large agricultural losses.
Water stress also increases the risk of wildfire
Impacts on freshwater resources
In times of water shortage, rivers dry up and groundwater risks overexploitation with degradation on water quality related to:
👉 Pollution (by organic matter)
👉 Eutrophication (appearance of invasive plant and animal species that disrupt the aquatic ecosystem, particularly through the presence of algae)
👉 Saline intrusions.
Impact on public health
Water scarcity threatens the health and development of communities around the world.More than two billion people worldwide lack access to safe drinking water ; and nearly twice that number, more than half the world’s population, lack access to adequate sanitation. These deprivations can lead to the transmission of diseases such as cholera, typhoid, polio, hepatitis A and diarrhea.
In addition, as water scarcity makes agriculture much more difficult, it threatens communities’ access to food, which can lead to both acute and chronic hunger, exposing children to malnutrition-related illnesses such as stunting and wasting, and chronic illnesses due to poor nutrition such as diabetes.
Solutions to mitigate water stress
One study concluded that the world could face a 40% water deficit by 2030 if nothing is done to reverse the current situation (2030 WRG, 2009). To combat the limitation of water resources, and thus water stress, some solutions:
Desalination of sea water
It should be noted that 97% of the water on the planet is salty. Desalination of sea and ocean water is an effective way to fight against water stress in arid coastal regions to produce fresh water without overexploiting the groundwater.
According to the International Water Association, fresh water produced through seawater desalination currently meets about 1% of global needs.
This desalination can be done in two ways:
- By reverse osmosis,
- By a thermal technology leading to water evaporation.
Salt water treatment
Like seawater, wastewater exists in abundance. The reuse of wastewater is an essential lever to limit water stress.
Reusing wastewater is less expensive and less energy consuming than the desalination of sea and ocean water or to transport drinking water over a long distance.
It should be noted that the reuse of wastewater is strictly regulated by the legislator, at the global (WHO), European (European Union) and national levels.
The recycled wastewater can then be used for a multitude of purposes such as watering green areas, cleaning public spaces, agricultural irrigation, supplying air conditioning and cooling systems, etc.
The right things to do
Water is a precious good that must be preserved and everyone can act daily to limit its consumption of water (and energy!) through a few simple gestures:
- For domestic use 🏡
👉 Operating the washing machines at full capacity;
👉 Favour tap water over bottled water
👉 Take a 5-minute shower rather than a bath;
👉 Install water-saving sanitary equipment;
👉 Recover and reuse water.
- For agriculture 🌾
👉 Change of irrigation practices
👉 Choice of crops that consume less water
- For industry 🏭
👉 Improved and more water-efficient operating procedures
- For communities / cities 🏙️
👉 Maintenance of networks and repair of leaks
👉 Collection of rainwater for watering green spaces
👉 Citizen Awareness
In case of drought and in order to face an insufficiency of the water resource in period of low water level, the prefects can take exceptional measures of limitation or suspension of water uses in application of article L.211-3 II-1° of the environmental code such as: the ban on filling the swimming pool or washing the car, the ban on irrigation for agriculture or the obligation to recycle certain cleaning water for industry.
There has been some international mobilization around water security. Ensuring the availability and sustainable management of water and sanitation for all is one of the sustainable development objectives (SDG) of United Nations. Meersens works with territories and key players in the water sector to improve the quality of services and raise awareness of water quality by:
- Displaying the quality of drinking water;
- By engaging the populations in case of a water stress situation;
- Providing real-time information on the state of water stress and proposing good practices and recommendations.
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