Some important data about the water-energy-food nexus
The water, energy and food security nexus means that the three sectors — water, energy and food — are inextricably linked and that actions in one area more often than not have impacts in one or both of the others.
Some data will help us better understand the inter-linkages between water, energy and food
Water is necessary for agriculture and food production. To grow one apple needs 70 liter water; to produce 150g of beef steak takes 2025 liters water, to harvest 100g of vegetables need 20 liters water and to make one slice of bread require 40 liters of water (UN). Water is the foundation of life and development.
By 2030 food demand is predicted to surge by 50%, and by 2050 it will increase to 70% (World Bank). The increasing need for food poses large pressures on water supply. We “eat” more water than we drink. The water required to grow the food is much greater than the water we need to drink, bathe and wash. Food production and irrigation are the largest water consumer, accounting for about 70% of global freshwater withdraw. (UN) In some countries that are experiencing rapid economy development and continuous population expansion, this fraction can be even higher.
Energy sector also relies heavily on water. Water is an effective medium for carrying away huge quantities of waste heat. A vast majority of water is used for cooling in thermal power plants. Water is also important for power generation in the hydropower and for the extraction, transport and processing of fuels. The operations of power plants are often water-intensive. For instance, coal and nuclear plants use 2 and 2.5 times more water respectively than natural gas (Grace Communication Foundation).
Some 580 billion cubic meters of freshwater are withdrawn for energy production every year. This amount account for 15% of the world’s total water withdrawal, coming right after agriculture. By 2035, energy consumption will increase by 35%, which will consequentially increase water consumption in energy sector by 85% (US Energy Information Administration-EIA)
While food and energy sectors become ever more thirsty for water, the water availability is likely to decrease in many countries and regions. By 2025, 1800 million people will be living in countries or regions with absolute water scarcity, and two-thirds of the world population could be under stress conditions (UN). This situation already starts to influence the global development.
In Africa, Kenya had an overall drop in GDP of 10% due to the drought in 2008. In sub-Saharan Africa, levels of access to electricity in rural areas are typically much lower than coverage of water supply and sanitation (Burkina Faso, 1%; Kenya: 8%; Uganda 5%; Tanzania 4%, (SE4All, 2013)). Of 1.3 billion people with no access to electricity, 95% are in Sub-Saharan Africa.
In 2014 Liaoning province in northeast China experienced its most severe drought in 63 years, affecting more than two million hectares of crops and leaving 136,000 people without water.(Xinhua News) Yellow River, China’s iconic “mother river,” is severely over-exploited. Parts of the river have run dry, while the water is polluted and underground aquifers are severely stressed out. (Greenpeace)
In the US, due to reduced snowpack and low precipitation in the summer of 2012, California’s hydroelectric power generation was 38% lower than the prior summer. Companies that extract natural gas and oil via hydraulic fracturing face less access to water and higher water costs during the drought. Many power plants shut down or reduced power generation because of water scarcity (US Department of Energy).