Regional Impacts - Climate Resilient Agriculture for Ensuring Food Security - page 95

There is growing evidence that adaptation is
occurring in response to observed and anticipated
climate change. For example, climate change
forms part of the design consideration in infra-
structure projects such as coastal defense in the
Maldives and prevention of glacial lake outburst
fl ooding in Nepal.
There are many adaptation measures that
could be applied in various parts of Asia to mini-
mize the impacts of climate change on water
resources, several of which address the existing
ineffi ciency in the use of water: modernization of
existing irrigation schemes and demand manage-
ment aimed at optimizing physical and economic
effi ciency in the use of water resources and recy-
cled water in water-stressed countries; public
investment policies that improve access to avail-
able water resources, encourage integrated water
management and respect for the environment,
and promote better practices for the sensible use
of water in agriculture; and the use of water to
meet non-potable water demands. After treat-
ment, recycled water can also be used to create or
enhance wetlands and riparian habitats.
Effective adaptation and adaptive capacity,
particularly in developing Asian countries, will
continue to be limited by various ecological, social
and economic, technical, institutional, and political
constraints. Water recycling is a sustainable
approach towards adaptation to climate change
and can be cost-effective in the long term.
However, the treatment of wastewater for reuse
that is now being practiced in Singapore, and the
installation of distribution systems, can initially be
expensive compared to water supply alternatives
such as the use of imported water or groundwater.

eastern New Zealand, due to increased drought
and fi re. In contrast, there could be moderate
yield increases in northeastern Australia and
main parts of New Zealand due to a longer
growing season, less frost, and increased
rainfall.
• Livestock productivity in Australia is projected
to suffer heat stress, lower pasture productivity,
lower forage quality, and expansion of animal
diseases such as cattle tick.
• Forests will benefi t from CO 2 fertilization,
higher rainfall, and longer growing season
along with negative impacts of increased
water stress, pests, fi res, and erosion.
• Marine fi sheries will have additional stress
due to increasing sea surface temperature, ris-
ing sea level, acidifi cation, and changes in the
Southern Ocean circulation which will cause
changes in species distribution, particularly
for species at the edges of suitable habitats.
Although Australia and New Zealand are very
different hydrologically and geologically, both
are already experiencing water supply impacts
from recent climate change, due to natural
variability and to human activity. The strongest
regional driver of natural climate variability is
the El Niño Southern Oscillation cycle. Since
2002, virtually all of the eastern states and the
southwest region of Australia have moved into
drought. This drought is at least comparable to
the so-called Federation droughts of 1895 and
1902 and has generated considerable debate
about climate change and its impact on water
resources and sustainable water management.
Large shifts in the geographical distribution of
agriculture and its services are very likely.
Farming of marginal land in drier regions is likely
to become unsustainable due to water shortages,
new biosecurity hazards, environmental degrada-
tion, and social disruption. Cropping and other
agricultural industries reliant on irrigation are
likely to be threatened where irrigation water
availability is reduced. For maize in New Zealand,
a reduction in growth duration reduces crop water
requirements, providing closer synchronization
of development with seasonal climatic conditions.
The distribution of viticulture in both countries
is likely to change depending upon suitability

5.3 Australia and New Zealand

• Water security problems to intensify by 2030 in

southern and eastern Australia, New Zealand's
Northland, and some eastern regions. Major
land degradation problems such as erosion and
salinization are likely to expand.

• Agricultural production is projected to decline

by 2030 throughout much of southern and
eastern Australia and throughout parts of