Lynx Global warns; a circular water economy is a must for greener, healthier and more prosperous cities
July 5th, 2021
The challenges that cities face could be mentioned as; urban areas around the globe are becoming less liveable due to water stress, exacerbated by climate change. This needs to change right now.
Over the next three decades, the world’s population living in urban areas is projected to swell to nearly 7 billion people, which will be more than two thirds of all humanity. Yet in this time cities will be less liveable due to climate change, unstable weather patterns and extreme meteorological events.
Cities face a real challenge with increasing water stress, as some are already running out of water. In 2018, Cape Town was poised to become the first major global city to hit “Day Zero”, the day when the taps would be turned off due to drought, high demand and inadequate supply. The metropolis came close. It isn’t alone – Istanbul, Mexico City and Chennai have all faced water crises recently.
One in four cities – representing over $4 trillion in economic activity – are already water stressed.This is also true of 70% of the world’s megacities. If the world continues with business as usual, 45 cities, each with over 3 million residents, will face extremely high-water stress by 2030; and by 2050, the number of urban dwellers facing acute water shortages could climb to over 1 billion.
Water problems are not limited to droughts; the number of extreme rainfall events is also growing due to more energy in the atmosphere. These produce intense precipitation, resulting in increased urban flooding. Extensive cityscapes consisting of concrete, tarmac and buildings create higher flood flows within metropolitan areas. In 2020, Jakarta saw the highest daily rainfall since records began in 1866: floods killed 19 people and 62,000 people were evacuated.
At the same time, cities are becoming hotter. Nine of the planet’s 10 warmest years have taken place since 2005, with the five warmest all occurring since 2015. By 2050, more than 970 cities will experience average summer temperature highs of 35?C. Right now, only 354 cities are this hot. By 2050, heat waves will affect more than 1.6 billion people in urban centres. Towards the end of the century, cities could warm by as much as 4.4?C on average. Builders predominantly construct cities using concrete, which traps this warmth and creates an urban heat island effect, increasing temperatures.
Climate change is exacerbating these impacts, making them more frequent and intense. Adding to this, rapid urbanization is escalating demand for and pressure on city resources. Every month, 5 million people migrate to urban centres around the globe, much of this in the developing world. This means increasing demand for water and energy, as well as more human waste and water pollution. This puts increasing strain on wastewater treatment plants and utilities, and the riverine systems into which water is often discharged.
Water pollution is making waterways sick and deteriorating the environment, potentially having adverse effects on human health. Over 80% of the world’s wastewater is still released into the environment without treatment; roughly 30% in high-income countries; 62% in upper middle-income countries; 72% in lower middle-income nations; and a staggering 92% in low-income countries.