Thirsty Planet

 In News

Summary – Thirsty Planet (The Economist 02.03.19)

How close are the reality to the dystopian world that is often portrayed in fiction literature and film-making where our freshwater resources are nothing but a few drops left? Climate change and population growth are two contributing factors to the water related problems we are facing today. Another reason, and maybe the more important one is how we use, or misuse our water resources.

The surface of the earth is covered by 70% water, but the amount of freshwater is only 0,75% which is divided into surface water (0,3%) which includes 59% of our water usage, and the rest is groundwater. 97,5% is our salty oceans, and 1,75% is frozen water. If we fail to use our surface water effectively, there is a possibility that we will face a severe catastrophe. The main problem is not technological, as this is under constant development, but rather deficient management. Another problem is the general idea that water is a fundamental human right, which leads not only to overconsumption, but people are also not willing to pay for it.

There is a natural cycle on Earth that recycles nearly 60% of the surface water, but it got its limitations, and in some cases, we have crossed that line. The Aral Sea is one example, the lake used to be the 4th biggest lake in the world, and now it is basically a salty desert. Water levels in Cape Town have gone below 20%, and in Sao Paulo, the water reservoirs sank to 5% of its capacity. A fourth of the world’s population live in areas where the water levels are dangerously low. About a century ago this number was down on 14%, and during those 100 years, we have multiplied our water usage by six. It is expected that our water usage will increase with another 20-50% by the year 2050, and the number of people living in areas with scarce water supplies is expected to grow from 1,9bn to 3,2bn the same year. The yearly usage of water is about 4600km³, which near the maximum that we can use.

By 2050 the population is expected to increase with 2bn people. How much water will be needed to feed these people is uncertain. Some think that this will demand a vast supply of water while the OECD expect only a minor decline due to technological advancements. Climate change is even harder to predict, but scientists agree that wet places will become wetter, and drier areas will dry out even more. Global warming has affected 300m people in the last decade by dramatic changes in weather. Rising temperature plus higher sea levels equals a forecast with intense and longer lasting storms. In the long run, the problem will not be rising sea levels though; it will be the very opposite. Decreasing streamflow is partly from declining rainfall, but another factor is the damming and diversion of rivers.

Rivers and lakes

The sacred flood Yamuna leads into the river Ganges, and they are highly polluted. The water contains about 3m more bacterias per 100ml than is considered safe. The water flow has decreased by 50% since 1970, and this is mostly because of hydroelectric dams but since the glacier of Himalaya is melting the flow is slightly and temporary increased. Despite two attempts to clean up the river Ganges, it remains dangerously contaminated. The government installed 92m toilets and planned to build treatment plants, but this has been delayed due to disagreements over the design. More than 400m people live on the plains of Ganges.

Three rivers have become test-cases in how to save the surface water problem, approaches used are; large scale infrastructure to transport water, manage water flow through digital monitoring and the use of economic levers. The Sea of Galilee has supplied Israel with freshwater in most of its history but was hit by the worst drought in a century, and after five years the crisis ended with a heavy rain flow that went on for two months. However, it did not secure their water supply. More than half of Israel’s water usage is from desalinated water. During the drought they decreased the amount of water pumped from the Sea from 400km³ to 70m in 2018. The Sea is now filled with desalinated water and used as a reserve. The second one is the Yellow River in China, that has been through extreme flooding and have been close to a drought. 1997 the water usage was so high that the flood only reached the sea 139 days per year. Today China has the most advanced water-rationing system in the world, and it keeps the flow steady. The third river is Murray-Darling in Australia. Even during the worst drought in over a decade farmers still used excessive amounts of water. The Australian government tried to save the situation by buying entitlements farmers could buy and sell in accordance with their water needs. They also financed more efficient irrigation systems. Unfortunately, these actions have been less effective.

Groundwater

India is one of few countries that use more of its groundwater. Exploitation of the groundwater has led to high levels of chemicals such as fluoride, and this exposes the poor people of India to great dangers. The chemicals come from industrial effluent and overuse of pesticides amongst other things. Water is entirely free in India and landowners are by law entitled to all the water that is on their land. Politicians often lavish cheap, or free electricity two attract voters which contributes to the exploitation.

Desalination

Desalination plants are in many ways effective to fetch water, and the sea is a great resource of water. However, there are three problems with desalination plants; it’s expensive to transport water inland, it’s even costly for coastal regions, and that is why these plants are found in high-income countries. Another problem is the high use of energy, though Israel has invented membranes that are energy efficient. The third problem is the salty sludge that are the leftovers from desalination; if this reaches the sea, it will reduce the levels of oxygen.

Saving water

Significant quantities of water are wasted every year. 30% of the water that is used for agriculture is lost in food waste; other reasons are inefficient irrigation system, leak, theft and people’s lack of knowledge about their water consumption. By using drip irrigation, 97% of the water will be used, compared to 50% in flood-irrigation. Putting out sensors that can locate leakage will fasten the process of fixing the leaks, and it is expected that people in high-income countries will eventually be more aware of their consumption. Many big companies are taking their responsibilities, Nestlé to give an example, have soon reached their goal to decrease the water usage in all of their product categories.

Conclusion

There are two ways of approaching the problem. One is by finding new water sources and find more effective ways of fetching, treating and delivering water. Another is to find more effective ways of catching and the usage of water from freshwater sources. That is something that could be done by educating locals and install storage systems, harvesting rainwater and ensure that the water is free from dangerous bacteria and chemicals.