DAYS ZERO

More than scarcity, water management became the debate point

While the world’s most dramatic urban crisis unfolds in Cape Town in South Africa, recent studies say at least 200 cities across the world are fast running out of water. An analysis by Down To Earth shows 10 of them are headed towards Day Zero—when the taps will run dry. This comes as a surprise because cities across the world have grown, thrived and expanded along rich, perennial sources of water, be it lakes, rivers, springs or even seas. So, where did all the water go? Robert McDonald, lead scientist at the US-based environmental group Nature Conservancy offers an explanation. “The main long-term driver of these shortages is the unprecedented urban growth occurring around the world,” he says. Rightly so.

The crisis at Cape Town has shown what unplanned urbanisation can do to water availability in the world’s urban centres. Not only are our metropolises headed to a dry future, the scarcity will increase as people are migrating to

urban areas at unprecedented rates.

About 54 per cent of the world, or 3.9 billion people, live in urban areas and they will grow between 60 and 92 per cent by the end of the century, says a study published in Nature this January. As a result, the urban water demand will increase by 80 per cent by 2050, it adds. It is worrying that “climate change will alter the timing and distribution of water,” it says. About 400 million urban dwellers currently face water shortage, states a 2014 study published in Global Environmental Change. This when the average global temperature has not even risen by 1.5°C above pre-industrialisation levels. What will happen when it rises by 2°C? A study, published in Earth System Dynamics in November 2017, has made projections for those scenarios. A 1.5°C rise in the average global temperature will expose 357 million urban dwellers to extreme droughts while the figure for a 2°C rise will be 696 million, it says. The number of city dwellers facing water shortage by 2050 could be much higher, about 1 billion, says the Nature study.