Strategies to Combat Water Scarcity In the Face of Climate Change

Experts project a global water crisis as demand surpasses fresh water supply by the end of this decade or by 2030. A landmark report from the Global Commission on the Economics of Waters, “Turning the Tide, A Call to Collective Actions”, calls for collective action from governments and communities globally to more sustainable water management by transforming the economics and restructuring water governance.

“Our collective actions have pushed the global water cycle out of balance for the first time in human history, wreaking increasing damage on communities everywhere. Further, countries are interconnected not only through transboundary rivers or streams of groundwater but also through atmospheric flows of water vapour. And dangerously, we face water’s deepening connection with climate change and biodiversity loss, with each reinforcing the other.”

For example, this will require actions such as stopping government subsidies for the extraction of groundwater for agricultural use, which tends to generate excessive water consumption, overhauling wasteful water practices in industries from mining to manufacturing, protecting natural assets like wetlands and groundwater from depletion, and investing in water recycling and reuse technology and infrastructure.

A study in Nature shows that the combined effects of urbanisation and climate change are exacerbating water scarcity. This indicates that water scarcity will increase from 933 million (a third of the global urban population in 2016) to 2.373 billion people or nearly half of the global urban population in 2050. Cities in India will be the most affected, impacting from 153 million to almost 500 million people by 2050.

Factors influencing urban water scarcity

Urban population growth will increase water demands, contributing to 87.5% worldwide water scarcity. In comparison, climate change’s effect of altering water availability will account for 4.6% of the total rise in water scarcity.

Cities at risk for water scarcity

Of the world’s 526 large cities or those with a population of more than 1 million, 193 (37%) are in water-scarce regions. Of the 30 megacities, or those with 10 million or more, 9 (30%) are in water-scarce areas. Six of these, including Los Angeles, Moscow, Lahore, Delhi, Bangalore, and Beijing, were located in regions with perennial water scarcity, and three (Mexico City, Istanbul, and Karachi) were seasonally water-scarce.

Cities that are facing water scarcity in 2050

According to the study, nearly half of the world’s large cities will be in water-scarce regions by 2050. In megacities, more than half, at 63%, will face water scarcity by 2050. These include ten new megacities, such as Cairo, Dhaka, Lima, Manila, Jakarta, Mumbai, Sao Paulo, Shanghai, Tianjin, and New York.

Solutions to combat water scarcity

The study presented location-specific solutions that cities could implement to address the problem. In Los Angeles, they can adopt desalination, groundwater exploitation, inter-basin water transfer, and/or virtual water trade. Unfortunately, in some large megacities, such as Delhi, India and Lahore, Pakistan, their geography and economic development will not allow them to apply these strategies, making them vulnerable to the problem. For some, domestic virtual water trade is the most effective solution, as well as other solutions like seawater desalination.

Virtual water is a relatively new concept, introduced in 1993 by Tony Allan. In 2008, he received the Stockholm Water Prize for his idea.

According to an IHE Delft report, virtual water comes from the fact that producing goods and services requires water, and when a country exports a water-intensive product to another country, it also exports water in a virtual form. This way, countries can support others in their water needs. For water-scarce countries, it can help them achieve water security when they import water-intensive products instead of growing or producing them domestically. 

A study in Nature, “Future changes in the trading of virtual water”, projects that virtual water trade (WVT) will increase this century due to water scarcity driven by socioeconomic factors and climate change. According to the study, the trading of goods and products that use renewable water sources will triple, while those from non-renewable sources or groundwater could double by 2100. These exports will come from the Basins in North America and the La Plata and Nile Rivers, while much of Africa, India, and the Middle East will rely heavily on virtual water imports by the end of the century.

Although reliance on virtual water trade can alleviate water stress in some regions, a study shows that it will affect regional economies, increase transport sector GHG emissions, and may exacerbate social inequality and affect the local environments producing the goods.

According to the study, not all cities can access water scarcity solutions. For example, improving water use efficiency entails large-scale infrastructure construction, rapid development of new technologies, and significant economic investment, which is not feasible in low- and middle-income countries. These cities also face several socioeconomic and environmental issues, such as poverty, rapid population growth, and over-extraction and pollution of groundwater.

However, by implementing relevant policies and regional planning, they could apply strategies such as promoting water conservation and reducing water demand, controlling population growth and urbanisation in water-scarce regions.