AsianScientist (Mar. 28, 2011) – New research reveals that more than one billion urban residents will face serious water shortages by 2050, with China’s two cities – Beijing and Shenyang, and India’s six biggest cities – Mumbai, Delhi, Kolkata, Bangalore, Chennai and Hyderabad – among those most affected.
The authors of the Proceedings of the National Academy of Sciences article found that under current urbanization trends and climate change effects, by 2050 some 993 million city dwellers will live with less than 100 liters each day of water each – 2/3 of the volume of a bathtub.
This 100-liter daily threshold is defined by the World Health Organization as the minimum a person needs for “optimum” long-term health and sanitation. Currently, around 150 million people fall below that threshold. The average American has 376 liters delivered a day, although that number varies widely.
As climate change worsens effects of urbanization, an additional 100 million people will lack what they need for drinking, cooking, cleaning, bathing and toilet use. Water shortages will subsequently cause issues with sanitation and pose risks to wildlife and the ecosystem if cities pump in water from outside.
According to the paper, the 20 biggest cities who in 2050 will suffer from perennial water shortage, defined as a lack of sustainable flow of surface or groundwater within 100 km, are:
- Delhi, India
- Mumbai (Bombay), India
- Mexico City, Mexico
- Lagos, Nigeria
- Tehran, Iran
- Calcutta, India
- Manila, Philippines
- Cotonou, Benin
- Johannesburg, South Africa
- Beijing, China
- Abidjan, Ivory Coast
- Caracas, Venezuela
- Chennai (Madras), India
- Bangalore, India
- Dubai/Abu Dhabi, United Arab Emirates
- Lahore, Pakistan
- Hyderabad, India
- Riyadh, Saudi Arabia
- Tel-Aviv/Jerusalem/Haifa, Israel
- Shenyang, China
“Don’t take the numbers as destiny. They’re a sign of a challenge,” said lead author Rob McDonald of The Nature Conservancy, a private environmental group based near Washington.
McDonald believes that there are solutions to providing water to a billion people, but this will require more investment in either infrastructure or water use efficiency.
For example, cities will need to get “smarter” about how they use their water in agriculture and industry – two of the biggest users of water worldwide. Cities will also need to adopt strategies such as desalination, and find natural ways to supply clean water from uplands to cities in the lowlands.
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The report in PNAS can be found here: McDonald RI et al. (2011) Urban growth, climate change, and freshwater availability.
The interview with Robert McDonald on The Nature Conservancy Blog can be found here: Q&A with Robert McDonald on The Nature Conservancy Blog.
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Source: Brisbane Times, The Nature Conservancy.
Disclaimer: This article does not necessarily reflect the views of AsianScientist or its staff.
