 
Yahoo News, TODAY
Fresh water shortages damage environment too
PARIS (AFP) - The problems caused by the world's dwindling supply
of fresh water go far beyond perpetual thirst, extending to severe
pollution, species loss, and even food insecurity, according to
a UN
study.
"Freshwater shortages are likely to trigger increased environmental
damage over the next 15 years," notes the UN Environmental
Program's (UNEP) Global International Waters Assessment (GIWA)
report, based on the input of 1,500 experts worldwide.
Inadequate potable water is an immediately critical problem for
billions of people, the study points out.
But freshwater shortages caused by massive damming and depleted
aquifers are provoking a chain reaction of environmental problems
as well, beginning with falls in river flows, rising saltiness
in biologically-rich estuaries, and the reduction in coastline
sediment.
The knock-on impact of these changes, the study predicts, will
be a serious loss of fish and aquatic plant life, shrinking farmland,
damage to fisheries and food insecurity by the year 2020.
At the end of the chain of consequences, it says, are increases
in malnutrition and disease.
The problem is aggravated by changes in the pattern of human
food consumption.
"Globally, there has been an increased demand for agricultural
products and a trend towards more water-intensive food such as
meat rather than vegetables and fruits rather than cereals,"
the study concludes as nations mark World Water Day on Wednesday.
Irrigated agriculture now accounts for 70 percent of freshwater
withdrawals, with only 30 percent returned to the environment,
studies have shown.
Industry and households, by comparison, return up to 90 percent
of the water used.
The fact that many developing countries do not have adequate
scientific or technical information about their water supplies
is also an aggravating factor.
Such nations are "operating in the dark on the size of their
water resource, and the precise patterns of supply and demand,"
the study says.
"Aquifers represent the largest information gap, which is
an increasingly significant hindrance for effective water management,"
it continues.
The study also points to "market failures" as contributing
the problem, noting that many of the factors contributing to environmental
degradation and pollution -- including use of pesticides and herbicide,
water for irrigation, dam construction -- are heavily subsidized
by governments.
Topping the list of medium-term concerns related to water is
pollution.
By 2020, the environmental impacts of pollution "are predicted
to increase in severity in over three quarters" of the areas
studied, "making this the most negative future outlook for
any of the GIWA concerns," the study says.
The report says that suspended solids, mainly resulting from
deforestation and agriculture, have already severely affected
coral reefs and river habitats in the Caribbean Sea, the Brazil
Current, the east African Rift Valley lakes and all the regions
of Southeast Asia.
It also cautioned against increasing the impact of eutrophication,
a process which triggers oxygen deficiencies as a result of excessive
richness in nutrients, frequently a result of fertilized agricultural
run-off, untreated sewage and air pollution. |
