Many of the world’s largest rivers draw a lot of water, often drying up before reaching the ocean. More than half of all great lakes are shrinking, and many of the world’s largest underground aquifers are irreparably depleted as agricultural pumping drains water that took hundreds or thousands of years to accumulate.
In a report this week, UN scientists warned that the world has entered a new era of “global water scarcity” – a term that clearly underlines the urgency of the efforts needed to protect what is left.
“We have been living beyond our hydrological capacity for too long,” said lead author Kaveh Madani, director of the UN University’s Institute for Water, Environment and Health.
Using extensive research, the report states that many regions of the world are overspending on all their water accounts, and their resources are declining. The term “water crisis” is often used locally and globally, but scientists say it describes a temporary emergency from which the region can recover, while many parts of the world use water beyond safe limits and are now dry or on the verge of bankruptcy.
Many rivers, lakes, underground wells and wetlands have been transferred from “tipping points” and cannot go back, the report said.
“Millions of farmers are trying to grow more food from dwindling, polluted or disappearing water sources,” Madani said.
About 70% of the world’s water is used for agriculture. When water resources are depleted, it can mean the collapse of economies, displacement and conflict. The report states that nearly three billion people, and half of the world’s food production, are concentrated in areas where water resources are diminishing.
Scientists say more than half of the world’s great lakes have shrunk since the 1990s. About 35 percent of the planet’s natural wetlands, almost the size of the entire European Union, have been cleared since the 1970s.
Excessive groundwater pumping has led to long-term declines in about 70% of the world’s largest aquifers, and in many places this decline is causing land to sink. Land subsidence linked to groundwater flooding, the report says, is occurring in more than 2.3 million square miles, about 5% of the world’s land area. This permanently reduces what aquifers can hold and increases the risk of flooding.
About four billion people endure severe water scarcity for at least one month each year.
Water scarcity is not just a problem in the dry areas of the world, said Madani. “Like bankruptcy, it’s not how rich or how poor you are. What matters is how you spend your money.”
And in many states, people who use water continuously go over water year after year, effectively breaking the budget.
The report points to the Colorado River and its depleted reservoirs, which California and other western states rely on, as signs of over-promised water. Other hot spots for chronic overuse include parts of South Asia, the Middle East and North Africa.
“We must make it a priority to avoid further damage to the remaining money,” said Madani. “By acknowledging the reality of water scarcity, we can finally make the tough decisions that will protect people, the economy and the environment. The longer we count, the greater the deficit.”
Water loss is also caused by deforestation, loss of wetlands and pollution, researchers say. These problems are compounded by climate change, which increases the water cycle and brings more severe droughts and floods.
I report he was released before a UN water conference in the United Arab Emirates in December.
Madani has also written a peer-reviewed book the subject this week introducing the definition of water scarcity, says the term is diagnostic “to speak of the severity of the problem and the urgency of a new and transformative beginning.”
The banking analogy used throughout the report, he said, points to the same solutions as managing bankruptcy – preserving surpluses while reducing spending.
Solutions to dealing with depleted water resources will vary by region, Madani said, and will need to account for the fact that “just taking water away from farmers can mean unemployment, increased emergency situations, poor conditions,” and that farmers and others need help to use less water and adapt.
Related learn published last year, scientists analyzed more than two decades of satellite data and found that large areas of the world are losing fresh water and becoming increasingly dry.
The latest World Bank reportthe researchers say that global water use “increased by 25 percent from 2000 to 2019, and nearly a third of this growth occurred in already arid regions.”
Jay Famiglietti, a hydrologist and professor at Arizona State University, said adopting the term water scarcity is “a good way to express that water resources are mismanaged, overused, and no longer available to current and future generations.”
He said water experts are struggling to find the right “hook” to express the severity and urgency of the problem, and calling it a water crisis promises to continue.
