climate change on UAE - Stockholm Environment Institute-US Center

3. Qualitative <strong>climate</strong>
impact assessment of
water resources
The hyper-arid <strong>climate</strong> of the UAE suggests
that the primary driver of water supply <strong>change</strong>s
will be demand and the subsequent rate of
groundwater abstraction. As the situation
stands today, precipitation and recharge are not
major contributors to the Emirate’s freshwater
resources. The water supply is dominated by
the abstraction of fossil groundwater or ground
water that has been in underground aquifers
for millennia. The intense rate of development
expansion, combined with additional pressures
from population growth and per capita
consumption in the Emirates has called upon
this non-renewable water resource.
An increase in municipal and industrial water
demand, due to <strong>climate</strong> <strong>change</strong>, is likely to be
rather small, e.g., less than 5% by the 2050s in
selected locations (Mote et al., 1999; Downing
et al., 2003). An indirect, but small, secondary
effect would be increased electricity demand
for the cooling of buildings, which would tend
to increase water withdrawals for the cooling
of thermal power plants. For example, all of
Al Ain city’s domestic water requirements
were once met from wellfields. More recently,
massive increases in domestic demands, from
an annual population growth rate of 8 %, has
meant that wellfields have been placed under
increasing stress, resulting in declining water
levels, increase in groundwater salinity with
a resultant decrease in total production.
Population growth and per capita increase
<strong>change</strong>s in water demand are likely to be the
primary drivers of water scarcity in the UAE;
however, the following sections will pull from
the international literature in order to raise
awareness to what can be understood as
potential <strong>climate</strong> <strong>change</strong> impacts on water
resources. These sections include:
3.1 Global Climate Change
3.2 Regional Climate Change
3.3 GCM Scenarios for the UAE
3.4 Temperature Increase and diminished
surface water reserves
3.5 Increased monthly precipitation
variability
3.6 - Rainfall variability and flash flooding
3.7 - “Greening the desert”: a vision at risk
3.8 - Vulnerability of Irrigated Agriculture
3.8.1 - Groundwater over pumping
3.8.2 - Salt buildup
We conclude with a discussion of the uncertainty
of <strong>climate</strong> <strong>change</strong>-related impacts, and a
challenge to water planners.
3.1. Global Climate Change
The scientific evidence for human-caused global
<strong>climate</strong> <strong>change</strong> has become quite compelling in
recent years. The Intergovernmental Panel on
Climatic Change (IPCC) recently released the
first of four parts of its Fourth Assessment Report
(AR4 IPCC 2007), describing the science and
physical evidence surrounding <strong>climate</strong> <strong>change</strong>.
The consensus among involved scientists and
policy makers is that “[… global atmospheric
concentrations of carbon dioxide, methane
and nitrous oxide have increased markedly as
a result of human activities since 1750 …] and
the understanding of anthropogenic warming
and cooling influences on <strong>climate</strong> leads to very
high confidence that the globally averaged net
effect of human activities since 1750 has been
one of warming“ (IPCC, 2007). Certainly, other
forcings act on the <strong>climate</strong> system beyond
human influences, most notably solar, volcanic,
oceanic, and cryogenic (ice), but when these
processes are included alongside human forcing,
an anthropogenic “fingerprint” emerges.
CO 2 is a major green house gas, contributing
somewhere between 10 and 25 percent of the
natural warming effect, second only to water
vapor. As the earth emits long wave radiation
toward space, atmospheric constituents like
water vapor, CO 2 , ozone, and methane absorb
this energy flow and radiate energy back to
earth. Climate models suggest that without
these greenhouse gases the average earth
temperature would be about -19ºC, and in the
absence of other <strong>change</strong>s and feedbacks in the
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Climate Change Impacts, Vulnerability & Adaptation