Regional variations in freshwater overconsumption

Date:
September 2, 2020
Source:
American Chemical Society
Summary:
Freshwater -- which falls to the earth as precipitation or exists
beneath the surface as groundwater -- is desperately needed to
sustain people, plants and animals. With an ever-increasing human
population, water shortages are already occurring in many areas are
only expected to get worse. Now, researchers have estimated the
freshwater supply and demand of about 11,000 water basins across
the globe, determining that one- fourth of freshwater consumption
exceeds regional capacities.



FULL STORY ========================================================================== Freshwater -- which falls to the earth as precipitation or exists
beneath the surface as groundwater -- is desperately needed to sustain
people, plants and animals. With an ever-increasing human population,
water shortages are already occurring in many areas are only expected
to get worse. Now, researchers reporting in ACS' Environmental Science
& Technology have estimated the freshwater supply and demand of about
11,000 water basins across the globe, determining that one-fourth of
freshwater consumption exceeds regional capacities.


========================================================================== People use freshwater for many essential purposes, including drinking,
hygiene and irrigating crops. Studies have estimated that the current
global level of freshwater consumption does not exceed the global
supply. However, regional variations exist, and the need to grow more
food for larger populations will increase freshwater demand. In addition, international trade -- for example, water-scare countries importing
food from water-rich countries -- can influence regional freshwater
supply and demand. Masaharu Motoshita and colleagues wanted to conduct
a comprehensive analysis of how much freshwater is available for human consumption in many different regions. They also wanted to determine how
much of this water is essential to sustain human life, and how much is
surplus or "luxury" consumption.

To find out, the researchers calculated the freshwater available for
humans in about 11,000 watersheds around the world and compared that
amount with the water consumed in that region for basic human needs
(drinking water, food production and hygiene), as well as luxury
use. They found that about 24% of total freshwater used by humans in
these watersheds exceeded regional capacities, often at the expense of ecosystems. About 59% of this overconsumption was to satisfy basic human
needs, while the rest was luxury use. In many areas, overconsumption
occurred only at certain times of the year.

International trade alleviated about 4.8% of global
overconsumption. Although options to reduce water overconsumption vary
by region, some possibilities include improving irrigation efficiency,
shifting to less water-intensive crops or different production sites, increasing water storage in reservoirs, reducing food waste and changing
food consumption patterns, the researchers say.


========================================================================== Story Source: Materials provided by American_Chemical_Society. Note:
Content may be edited for style and length.


========================================================================== Journal Reference:
1. Masaharu Motoshita, Stephan Pfister, Matthias Finkbeiner. Regional
Carrying Capacities of Freshwater Consumption--Current Pressure
and Its Sources. Environmental Science & Technology, 2020; 54
(14): 9083 DOI: 10.1021/acs.est.0c01544 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/09/200902101816.htm

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