Canada and the United
States Facing Costly Water Shortages and
Loss of Biodiversity Unless Adaptation Mainstreamed
into Economic Life
10 April 2007 - Escalating tensions between
water users are among the key challenges
facing North America says the Intergovernmental
Panel on Climate Change (IPCC).
Many water resources across the region
are already heavily utilized by industry,
agriculture, for drinking water and hydropower.
Shifts in rainfall patterns, melting mountain
glaciers, rising temperatures, increased
demand and reduced supplies in some places
are likely to aggravate the situation unless
cuts are made in greenhouse gases to reduce
the scale and pace of climate change.
Ground-water flows from the Edwards Aquifer
in Texas for example could drop by up to
40 per cent leading to economic losses for
farmers.
Summer flows in some river systems such
as the Colorado and Columbia basin are likely
to decline sharply within four decades.
This is expected to increase competition
between industry, cities, hydropower operators,
farmers and fishermen for freshwater supplies.
Other climate-related impacts include increased
growth of Lodge pole pine-- a widespread
species in North America-- in its northern
range, decreased growth in its middle range
and devastation of its southern forests
under a three degree C temperature rise.
North American producers of wood and timber
could suffer losses of between $1 billion
and $2 billion a year during the 21st century
if climate change also sparks changes in
diseases, insect attacks and forest fires.
Between 15 per cent and close to 40 per
cent of plant and animal species will be
"committed to extinction" by 2050.
Over the coming decades, up to a fifth
of the remaining coastal wetlands in the
mid-Atlantic region of the United States
like those in Chesapeake Bay will be at
risk of inundation as a result of impacts
such as sea level rise and storm surges.
Cities could also be at risk from high
tides and storm surges. Towards the end
of the century-- under a strong warming
scenario--a current one in 100 year flood
in New York could have a return period of
three to four years.
A 25 per cent increase in heat waves is
projected for Chicago later this century
with the estimated increase in Los Angeles
rising from the current 12 days to between
44 and close to a 100.
The report notes that while North America
has "considerable adaptive capacity,
actual practices have not always protected
people and property from adverse impacts
of climate variability and extreme weather
events".
Some of the challenges facing North America
in terms of adaptation include a lack of
information on climate change and its likely
local impacts, financial barriers and the
slow turnover of existing infrastructure.
The report cites the case of Hurricane
Andrew in the early 11000s and the development
of property building codes. "If all
properties in southern Florida met this
updated code, the property damage would
have been lower by nearly 45 per cent".
"Some early steps toward planned adaptation
have been taken by the engineering community,
insurance companies, water managers, public
health officials, forest managers and hydroelectric
producers," says the report but adds
that there is a great deal still to be done.
"Mainstreaming climate change issues
into decision making is a key prerequisite
for sustainability," it says.
Achim Steiner, Executive Director of the
UN Environment Programme (UNEP) which co-founded
the IPCC, said: "Canada and the United
States are, despite being strong economies
with the financial power to cope, facing
many of the same impacts that are projected
for the rest of the world".
"Moreover in some areas, such as already
heavily utilized water resources, the impacts
could be acute and may require very careful,
strategic planning and investment if tensions
are to be avoided between humans and nature
and between a wide-range of economically
and socially important water users,"
he said.
"Overall the findings underline that
the best and probably most cost effective
form of adaptation is mitigation-in other
words deep and decisive cuts in greenhouse
gas emissions to avoid dangerous climate
change in the first place," said Mr
Steiner.
Water
"Heavily-utilized water systems of
the western US and Canada, such as the Columbia
River, that rely on capturing snowmelt runoff
will be especially vulnerable," says
the Fourth report of IPCC Working Group
II.
A two degree C warming by the 2040s is likely
to lead to sharply reduced summer flows
coinciding with sharply rising demand.
The report estimates that Portland, Oregon
will by then require over 26 million additional
cubic meters of water as a result of climate
change and population growth.
This will coincide with a fall in summer
supplies from the Columbia River by an estimated
five million cubic meters.
Meanwhile, just over 40 per cent of the
supply to southern California is likely
to be vulnerable by the 2020s due to warming
triggering losses of the Sierra Nevada and
Colorado River basin snow pack.
"Lower levels in the Great Lakes are
likely to influence many sectors. Adapting
infrastructure and dredging would entail
a range of costs," says the report.
This is likely to exacerbate controversies
linked with water diversions to cities such
as Chicago and the competing demands of
water quality, lake-based transport and
drought mitigation.
Summer temperatures in Midwestern and southern
lakes and reservoirs could exceed 30 degrees
C.
Levels of phosphorus, a nutrient from sources
like sewage and detergents which can trigger
algal blooms and oxygen scarce waters, are
likely to rise in some bays in the Great
Lakes by as much as 98 per cent.
Heavily-utilized ground waters are likely
to come under increasing stress as a result
of climate change.
"Simulations of the Edwards aquifer
in Texas project lower or ceased flows from
springs, water shortages and considerable
negative environmental impacts," says
the report.
Economic losses, for example to agriculture
could amount to just over $2 million to
nearly $7 million a year as water allocation
is shifted to industry and cities.
Other vulnerable supplies include Ogalla
Aquifer-a shallow formation which underlies
South Dakota, Nebraska, Wyoming, Colorado,
Kansas, Oklahoma, New Mexico and Texas.
Here a 2.5 degree C temperature rise or
more reduces natural re-charge of the aquifer
by over a fifth.
Cities and Towns
Some northern settlements are at "moderate
to high hazard" by the middle of the
21st century as a result of coastal erosion
and the thawing of permafrost, says the
report.
These include Shishmaref, Nome and Barrow
in Alaska and Tuktoyaktuk in the Northwestern
Territories. Infrastructure at risk includes
the Dalton Highway in Alaska, the Dempster
Highway in Yukon, airfields in the Hudson
Bay region and the Alaska railroad.
By the 2090s, a one in 500 year flood in
New York could be a one in 50 year event
"putting much of the region's infrastructure
at risk".
Boston's urban transportation network may
also be at risk from a sea level rise of
3 mm a year and an increased probability
of a 100 year storm surge.
Tourism and Recreation
Nature-based tourism is a major market sector
with over 900 million visitor-days in national,
provincial and state parks in 2001. Canada's
national parks may see an increase of up
to 40 per cent by the 2080s as a result
of a longer warm weather season.
However, this might be offset by other
climate change-induced factors such as loss
of glaciers, changes in biodiversity and
fire and pest-related impacts on forests.
The costs of replenishing Florida's beaches
with sand, in order to counter a sea level
rise of half a metre, could be between nearly
$2 billion and close to $9 billion.
The North American snowmobiling industry,
currently worth $27 billion, may be hardest
hit because it relies on natural snowfall
rather than artificially-made snow.
A reliable snowmobile season disappears
from most regions of eastern North America
by the 2050s.
Notes to Editors
The Working Group II report of the Fourth
Assessment of the Intergovernmental Panel
on Climate Change can be found at www.ipcc.ch
or www.unep.org
Nick Nuttall, UNEP Spokesperson / Michael
Williams, UNEP Information Unit for Conventions
