With the amount of fresh water we use on a daily basis, the current amount of fresh water will not last very long. To combat this reality, researchers at McGill University have come up with measures that could reduce fresh water scarcity in 35 years.
The key to their plan is to reduce the amount of stress on water systems worldwide. This would mean reducing the amount of pollution that goes into the water so that more is available, using less water in our day to day activities and changing our infrastructure to make better use of water resources.
Water systems are stressed when there is a demand for water that the system cannot match. We use more than 40% of the world’s available water; this currently affects a third of the world: a segment which could increase to half of the world population by the end of the century.
Tom Gleeson, McGill Department of Civil Engineering, states: “There is no single silver bullet to deal with the problem [of water scarcity]… Significant reductions in water-stressed populations are possible by 2050, but a strong commitment and strategic efforts are required to make this happen.”
McGill University has released six different strategies to help reduce fresh water scarcity. They split these strategies into two categories: hard measures and soft measures. Hard measures involve building infrastructure to better process water, and soft measures focus on the social side of reducing fresh water used.
There are two hard measures: one is to increase the water storage in reservoirs and the second is to increase the desalination of sea water.
It is estimated that the capacity of reservoirs needs to increase to approximately 600 km3. This can be done by expanding existing reservoirs or building new ones. Unfortunately, these increases could have negative ecological and social impacts since reservoirs disrupt the natural flow of ecosystems. Furthermore, expanding existing reservoirs or building new ones is costly.
The desalination of seawater would mainly be used in coastal areas and would require building new desalination plants or expanding existing ones. An estimated increase of 50 times the amount of water processing would be required to help reduce water scarcity.
Desalination can be quite costly as it requires high amounts of energy and disposing of waste water. There is currently a 46% recovery rate of water through thermal desalination, which requires approximately 7-18 kWh per cubic metre of water processed.
The soft measures require an increase in agricultural irrigation productivity, increased irrigation efficiency, improvements in domestic and industrial water use, and limiting the rate of population growth.
Most of these issues can be solved by the addition of new cultivars and a switch in irrigation techniques. It would require a significant investment of capital and social change to implement these reforms.
Reducing domestic and industrial water use would be a challenge since people generally are not willing or unable to change their way of living to be more water conscious. But the biggest social challenge would be to limit population growth, specifically in water-stressed areas.
McGill University’s suggested goal is to limit the population to 8.5 billion by 2050. Giving the current rate of population growth, it is estimated that the population will be approximately 13.5 billion by 2050.
In order to keep the population to 8.5 billion by 2050, the rate of population growth would have to be around 0.005%. Since the current rate is 1.7%, this provides a significant challenge. But the goal is not unreachable; through family planning and education targeted in water-stressed areas, it is possible to keep population growth to a minimum and save Earth’s water.