In
its 2018 World Water Development Report, the UN calculated that an estimated
3.6 billion people live in areas where water can be scarce at least one month
per year
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Governments should focus
on "greener" policies to improve the supply and quality of water as
climate change and a growing global population threaten the water security of
billions, the United Nations said on Monday.
Countries
that are short of fresh water
|
In
its 2018 World Water Development Report, the UN calculated that an estimated
3.6 billion people — nearly half the global population — live in areas where water can be scarce
at least one month per year.
And
this number could rise to 5.7 billion by 2050, the report warned.
"If
we do nothing, some five billion people will be living in areas with poor
access to water by 2050," said UNESCO Director General, Audrey Azoulay, at
the presentation of the report in Brasilia.
"This
report proposes solutions that are based on nature to manage water better. This
is a major task all of us need to accomplish together responsibly so as to
avoid water-related conflicts," she said.
Global
water use has increased by a factor of six over the past century "and
continues to grow steadily at a rate of about one percent per year," the
report said.
And
use is expected to rise significantly due to population growth, economic
development and changing consumption patterns, among other factors.
"The
vast majority of the growing demand for water will occur in countries with
developing or emerging economies," the report said.
At
the same time, the global water cycle was intensifying due to climate change,
"with wetter regions generally becoming wetter and drier regions becoming
even drier."
- 'Ecosystem-friendly' -
So-called
"grey" or man-made water infrastructure — such as reservoirs, irrigation canals and
treatment plants — were
no longer sufficient to meet these challenges, said the report's
editor-in-chief, Richard Connor.
There
is increasingly limited room to build more reservoirs because of silting,
environmental concerns and restrictions, as well as the fact that in many
developed countries the most cost-effective and viable sites had already been
used, the UN argued.
"In
many cases, more ecosystem-friendly forms of water storage, such as natural
wetlands, improvements in soil moisture and more efficient recharge of
groundwater, could be more sustainable and cost-effective than traditional grey
infrastructure such as dams."
"Nature
plays a unique and fundamental role in regulating the different functions of
the water cycle," Connor said.
Nature-based
solutions "can act as regulator, cleaner and water supplier".
The
report said that green solutions were already showing great potential.
New
York, for example, has protected the three largest watersheds that supply water
to the city since the late 1990s through forest preservation programmes and
paying farmers to take on environmentally friendly practices.
"Disposing
of the largest unfiltered water supply in the US, the city now saves more than US$300
million (€245 million) yearly on water sea treatment and maintenance
costs," the UN said.
Another
example was China's "Sponge City" project to improve water
availability.
By
2020, China plans to build 16 pilot projects across the country with the aim of
recycling 70% of rainwater through greater soil permeation, retention and
storage, water purification and the restoration of adjacent wetlands.
- Feed more people -
"These
solutions are cost-effective" and not more expensive than traditional
systems, said Connor.
The
UN pointed to estimates that agricultural production could be increased by
about 20%worldwide if greener water management practices were used.
In
addition to improving water availability and quality, "it is possible to
increase agricultural production per hectare with better water management"
and thus feed more people, said Stefan Uhlenbrook, programme coordinator at the
UN World Water Assessment Forum.
"Green"
infrastructure also helps fight erosion, drought and flood risks while boosting
soil quality and vegetation.
And
indigenous peoples could be involved in implementation, something which was not
the case in "grey" infrastructure," the report said.
At
the moment, however, only "marginal" use was made of such
nature-based solutions.
"Accurate
figures are not available", but investments in these techniques
"appear to be less than one percent... of total investment in
infrastructure and water resource management," according to the report.
They "are often
perceived as less effective" because they are less visible, Connor said.
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