Thirsty Cities: the Looming Water Crisis

Water levels within the aquifers in Kabul, the capital of Afghanistan, have declined by up to thirty meters in the past ten years, while almost half of the city's boreholes have dried out, with water extraction presently more than the natural recharge rate at 44m cubic meters a year, eighty percent of the city's groundwater unsafe.

In Cape Town, water levels within its aquifers almost dried out in 2018, when the city's reservoirs stood at 26 percent of capacity, with officials planning to cut the taps when the reservoirs hit 13.5 percent, a move that would have affected millions of people.

In Mexico City water levels within its aquifers verged on the brink of catastrophe last year, when the reservoirs of the Cutzamala water were running dry, denying supplies to millions of the city's residents, with most of them staring at a water crisis.

These three cities are not the only ones facing the prospect of running out of water, as they join others such as Bogota, Colombia, Johannesburg, South Africa, Las Vegas, U.S.A., Sao Paulo, Brazil, Harare, Zimbabwe, Chennai, India, Jakarta, Indonesia, Melbourne, Australia, Phoenix, U.S.A., New Delhi, India, and others.

An estimated 33 million people in Afghanistan face severe water shortage, with reduced precipitation and rising temperatures from climate change impacting water resources in large cities such as Kabul, worsened by population explosion and unsustainable water extraction practice.

An estimated five million people faced the severe water challenge in Cape Town during the 2015-2018 drought, when climate change made changes in rainfall patterns during the winter months three to six times more likely, dam levels dropping from 92.5 percent in 2014 to 23 percent by 2017.

An estimated 21 million people in Mexico City last year faced the prospect of running out of water, with excessive evaporation and drastic decline in rainfall causing 76 percent of the country to experience drought through the end of May 2024, a crisis exacerbated by a 30 percent increase in consumption.

While many factors account for water at risk of running out in cities, climate change is one of the leading reasons, through reduced precipitation and rising temperature, bringing about evaporation and the drying up of water bodies.

Global evapotranspiration has been increasing, coming at an accelerated rate since the 1980s, meaning the quantity of water evaporating from the earth's surface and transpired by plants is growing with time.

Water scarcity has been increasing electricity costs in many parts of the world, such as California's electricity costs from 2012 to 2016 increasing by $2.45 billion, the carbon emissions from accelerated electricity generation contributing to climate change.

Water scarcity has been found to increase the inability of the ecosystem to sequester carbon, through a study that found diminished carbon sequestration by 67 percent, despite an 11 percent increase in water use efficiency during drought.

Consequences of water scarcity such as evapotranspiration, rising electricity costs, and reduced carbon sequestration could become more severe in cities in the near future, especially when they run out of water, as global warming worsens.

Cities can reduce their vulnerability to water scarcity during this era of climate crisis by water conservation, sustainable use of water, rainfall harvesting, irrigation, and other measures.

What to Eat

Vegan food from Mexico, Credit, BBC Good Food