The competition for H2O
Dr. Robert M. Gresham, Contributing Editor | TLT Lubrication Fundamentals May 2018
Water is rationed in some cities. Why tribologists will play a role in finding a solution.
Cape Town officials are asking residents to consume 50 liters of water a day—less than a sixth of what the average American uses.
© Can Stock Photo / Sangoiri
One of the trends found in STLE’s 2017 Emerging Trends Report is the growing concern about the availability of potable water. This concern is based on the observation that, on a global level, the world population is steadily growing not so much in the developed countries but in the emerging economies. Many of these emerging countries are located in more geographically challenging environments. Thus, their ability to provide basic necessities for their growing populations is more of a challenge.
A good example is water. As it happens, while two-thirds of the Earth’s surface is water, only 2% of that water is reasonably accessible potable water. Further, we see cyclic weather extremes causing droughts that put considerable stress on those countries already somewhat limited in water supply. Indeed, as their populations grow, even slight droughts will lead to increases in privation, crime and wars.
Here is a recent example of this trend playing out.
Four million people in Cape Town, one of Africa’s most affluent metropolises, might have to stand in line surrounded by armed guards to collect rations of the region’s most precious commodity: drinking water. Population growth and record droughts appear to be the cause of the crisis. Last month the city was forced to limit available water due to perilous low levels in its reservoirs.
A recent article in National Geographic notes: “For years, a shutdown of this magnitude in such a cosmopolitan city had been almost inconceivable. But as overdevelopment, population growth and possibly climate change upset the balance between water use and supply, urban centers from North America to South America and from Australia to Asia increasingly face threats of severe drinking-water shortages.
Cape Town officials are storing emergency water at military installations and say using taps to fill pools, water gardens or wash cars is now illegal. The city requested even steeper cuts, asking residents to consume just 50 liters per day—less than a sixth of what the average American uses.
Much like our Southern California, South Africa is arid, but Cape Town’s most recognizable land mass, Table Mountain, traps onshore breezes coming off warm ocean waters, creating local rains that power rivers and fill underground aquifers. A decade ago, the city was told that population growth and shifts projected to come with climate change—drier, hotter weather with less winter rainfall and reduced stream flows—would require it to find additional water sources. In 2014 their six dams were full but, whether caused by climate change or just natural weather cycles, three straight years of drought followed—the worst in more than a century. Now reservoirs stand at 26% of capacity.
Droughts in recent years have helped spark famine and unrest in rural nations around the Arabian Sea from Iran to Somalia. Many of the 21 million residents of Mexico City only have running water part of the day. Several major cities in India don’t have enough. Water managers in Melbourne reported last summer that they could run out of water in little more than a decade. Jakarta is running so dry that the city is sinking faster than seas are rising, as residents suck up groundwater from below the surface. In 2015 Sao Paulo was down to less than 20 days of water supply. California’s bread basket agricultural area is now coming back from several years of drought.
As noted in STLE’s trends report, competition for water is increasing as population growth drives demand for water for drinking and agriculture and as countries become more affluent. Cape Town is building four new desalination plants. But desalination is an energy intense process that is not particularly cost-effective, even though Israel gets much of its water this way.
This is an opportunity for the technical community to develop a more cost-effective process. There certainly will be opportunities for tribologists to contribute to the development of these new technologies.
Bob Gresham is STLE’s director of professional development. You can reach him at email@example.com.