Tracy Staedter

Jan 13th 2020

Populations Are Threatened as the Percentage of Water on Earth Shrinks


Water is life. But even as our warming planet’s sea levels and rainfall rise, the percentage of water on Earth is shrinking. Drought, water pollution, agricultural demand, exponential population growth and leaky infrastructure exacerbates the problem of water scarcity. At least 10 global cities, populated by tens of millions of people, face a future of limited water resources that will directly result in poor health, disease and death.

Researchers are working to address the problem, though. From technologies that purify polluted water to those that harvest it from thin air, solutions are coming online to quench the world’s thirst.

The Blue Marble

One of the most iconic images of planet Earth came in 1968, when the crew of the Apollo 8 spacecraft entered lunar orbit on Christmas Eve. NASA astronauts Frank Borman, Jim Lovell and William Anders produced a color photo that would later become known as Earthrise. It shows our planet as a fragile blue rock amid a vast, black cosmos. That blue is water. More than 70% of the planet is covered in it and the oceans alone hold 96.5% of all Earth’s water, according to the U.S. Geological Survey (USGS).

Although oceans support plenty of life, seawater is salty and undrinkable. Humans need fresh water and most of that is locked up in glaciers, ice caps or in deep underground reservoirs. Surface water, such as lakes and rivers, provide accessible water, but it’s comparably tiny. The USGS estimated that if all of the surface water in the world were collected into a sphere, the bubble would be only 35 miles tall and wide — a mere speck compared to the size of Earth.

Another way to think of it is that for every 100 raindrops that fall on land, only 36 drops are available for humans to drink, PhysOrg reported. In a recent study, scientists found that although global warming is causing more rainfall, it’s also drying out soils to drought-like conditions, reducing the chances the extra rain will flow into rivers and lakes.

“It’s a double whammy,” Professor Ashish Sharma of Australia’s University of New South Wales told PhysOrg. “Less water is ending up where we can store it for later use. At the same time, more rain is overwhelming drainage infrastructure in towns and cities, leading to more urban flooding.”

Will the Well Run Dry?

Assistant Professor Megan Konar studies hydrology and environmental science at the University of Illinois at Urbana-Champaign. She told Earther that although the percentage of water on earth a whole would not shrink to zero, certain locations would face water scarcity, which is already happening.

Back in January 2018, the government of Cape Town, Africa, announced that the city of 4 million people was three months away from running out of municipal water. Labeled “Day Zero,” the day would come, officials said, when dam levels would be so low, they would be forced to shut off the taps, according to The New York Times. An aggressive conservation plan swung into action, limiting each person to just 50 liters (13.2 gallons) a day.

Although Cape Town averted disaster, it’s still at risk, but other cities are close behind. CNN reported that Chennai, Mexico City, Cairo, Tokyo, Jakarta, São Paulo, Beijing, Bangalore, Melbourne and London are the top 10 cities most at risk for running out of water. Extended periods of drought, heavy agricultural demand, leaky infrastructure and pollution are some of the leading causes of water scarcity.

According to the World Health Organization, at least 1.8 billion people on the planet drink contaminated water. Unclean water and poor sanitation are leading causes of childhood mortality. Diarrhea alone results in 1.5 million child deaths annually. As climate change and population growth put increasing pressures on water access, improving the quality of the water we have left and dealing with water pollution is imperative.

Pure Solutions

Fresh, clean drinking water is within our grasp. Researchers around the world are working on technology to increase the percentage of clean water on earth. For instance, Innovative Water Technologies in Rocky Ford, Colorado, have invented the SunSpring Hybrid, a solar- or wind-powered filtration system that can purify more than 5,000 gallons of contaminated drinking water per day. Because it doesn’t need to be plugged into a reliable source of electricity, the device can be used in remote regions or be deployed urban areas that have been devastated after a natural disaster.

In southwestern Morocco, a nonprofit called Dar Si Hmad has been harvesting water from thin air. The region’s unique mountain setting, although quite arid, is frequently shrouded in a dense fog caused by a high-pressure system called the Azores High that sweeps in from the Canary Islands and becomes trapped against the High Atlas mountains. The fog doesn’t ever turn into rain, but folks at Dar Si Hmad have built tall net-like structures on which droplets of fog collect and accumulate. To date, this fog-harvesting system extends to seven reservoirs with pipelines that reach nine villages, reported the Weather Channel.

Although technology can address some of the world’s water problems, it cannot fix it all. Clean drinking water starts with the source, water resource educators Susan Boser and Diane Oleson of Pennsylvania State University wrote in an opinion piece for The Conversation. One of the most critical means for keeping water clean is regularly monitoring the lakes, rivers and wells that supply it. But countries also need to invest in infrastructure, public education, source water protection and regulation “to keep water flowing to a thirsty nation,” they said.