THE EFFECT OF GLOBAL WARMING TO OUR WATER RESOURCES

1.1 Introduction

Many water supply sources (rivers, lakes, groundwater basins, etc.) are already over

allocated, suffer degraded water quality, and are often not in sufficient condition to

support endangered species. Climate change will exacerbate these water challenges,

leading to insufficient water for people and the environment and making it increasingly

difficult to meet the needs of both.

Implementing actions now to improve water quality and supplies, protect aquatic

ecosystems, and improve flood management not only makes sense, but early action will

also help reduce future impacts related to climate change. Even if greenhouse gas

emissions are reduced today, there is already warming “in the pipeline” that will create

additional impacts. Adaptation is not a solution to climate change, but given the

importance of our water resources, immediate action is needed to avert significant

societal impacts.

Global warming occurs because of climate change, also known as climate disruption.

Climate is a fundamental driver of the water cycle. It determines how much water is

available (supply) and how much water we need (demand) in the short and long term.

The United Nations Framework Convention on Climate Change (UNFCCC) defines

climate change as, “a change of climate which is attributed directly or indirectly to

human activity that alters the composition of the global atmosphere and which is in

addition to natural climate variability observed over comparable time periods”.

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Climate change has an impact on weather and changes in weather patterns determine

variability in water supply and demand on a day-to-day and season-to-season basis –

the weather one year may be drier or wetter than the last. Changes in temperature and

precipitation patterns have affected the water cycle by changing its availability,

quantity and its quality. With raising atmospheric temperature and increase rate of

evapotranspiration the demand for water from human beings and the agriculture sector

will also increase. Without adaptation and mitigation measures, climate change may

threaten the sustainability of water systems, irrigation systems and farming systems.

Climate change is primarily caused by the growing concentration of heat-trapping gases

in the atmosphere, often referred as greenhouse gases. The increase of carbon dioxide,

methane, and other greenhouse gases has may many causes, but most of the increase

result from human activities, such as deforestation, pollution and burning fossil fuels.

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1.2 The Effects of Global Warming to Water Resources

Global Warming will have changes in the availability, quantity and quality of our water

resources, which will have impacts on the whole cycle of water supply, i.e. from water

demand, water resources and the water infrastructures.

The effects of global warming are vast and cover every sphere of one’s life. Both the

nature and the living beings are suffering from the effects of global warming. If we do

not take note of the alarming rate of growing global warming then our earth might

cease to exist someday. The water resources have been heavily affected by the global

warming phenomenon. Sea levels have risen, glaciers retreats are taking place often

and the most harmful affect is the shrinking of the Arctic Circle. This phenomenon has

caused concerns among all the sectors and geo-engineering is considered to be a way of

mitigation.

If we put it simply then the water bodies would be affected during the long and

scorching summers since the rate of evaporation would increases with hotter summers.

Water cycle is important for any kind of human activity and global warming would

adversely affect this cycle causing a topsy turvy in the human activities as well as the

climactic changes. Global warming might also lead to floods. The water levels in many

regions would lower due to excessive evaporation and this would cause in torrential

downpours increasing the chance of deluge.

The acceleration in the phenomenon of global warming has caused the ice sheets in the

West Antarctic Circle and Greenland to shrink. Carbon sediments have been released in

the air and due to the increase of carbon emission the reduction in the ice sheets has

taken place. This reduction might cause a huge flood around the world. By the end of

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twenty first century the water in the sea is expected to rise by 7.1- 23.2 inches. Due to

the augmentation of global warming effects the Thermohaline circulation might as well

get disrupted. The fresh water from the Polar Regions would interrupt the Gulf Stream

causing this distress. The implication of a change of course of the gulf stream would

have worldwide effect that would drastically accelerate climate change and extremes.

The imbalance created in the water cycle by global warming has far reaching effects.

Some places on the earth would face extreme temperatures along with torrential rainfall

while others would face scarcity of water and drought. In fact, according to the

scientists this phenomenon of global warming might even cause desertification in the

extreme Tropical areas like Africa.

The glacier rich areas like Western North America, Asia, Alps, Indonesia and Africa

are suffering badly due to global warming. The melting of glaciers in these regions has

raised concerns regarding the increase in water levels. Ocean circulation also suffers

due to global warming. The oceans act as the absorber of carbon dioxide and when it

reaches the saturation point it fails to absorb any more carbon dioxide. As a result the

ocean surface becomes warm.

Acidification of oceans is caused due to the concentration of carbon dioxide in the

atmosphere. This is an indirect effect of global warming causing distress to people

worldwide. The rise in sea level would cause infiltration of the saline water into the

groundwater. This will pose as a potential danger for the health of the living organisms.

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1.3 Change in Water Demand Pattern

During dry spells, the consumers will tend to consume more water either by watering

the garden or bathing more frequently. To ensure the existing water infrastructures

could cope with the water demand, contingency measures such as banning of car

washing and watering the garden has to be implemented during extreme drought, if

needed.

1.4 Impact on Water Resources

The climate change will affect water yield from the reservoirs, surface water and

ground water. With the change of rainfall patterns whereby a reservoir catchment area

may receive higher rainfall within a shorter duration but the reservoir storage capacity

was not designed to contain such high rainfall and the excess water could not be

harvested and will be ended up in the ocean. At the same time, the reservoir catchment

area may also experience a dry season with lower rainfall, higher evaporation rate and

extended dry period. This phenomenon will reduce the capacity of the reservoir to

supply reliable yield to water treatment plant.

Likewise, for raw water intakes rely on rivers extractions will see less runoff during

longer dry season, which may cause the raw water intakes to operate at with under

capacity condition more frequently.

As for water supply system, extracting ground water, the ground water dynamics are

expected to change due to climate change. During the extended droughts, recharge of

the ground water will be slower and the water extraction rate may have to be reduced in

tandem with lower recharge to avoid detrimental effects on the ecosystem.

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The effects of climate change are already being felt, for example:

1) Water

Rising global temperatures will lead to an intensification of the hydrology

cycle, resulting in dryer dry seasons and wetter rainy seasons, and subsequently

heightened risks of more extreme and frequent floods and drought. Changing

climate will also have significant impacts on the availability of water, as well as

the quality and quantity of water that is available and accessible; and

2) Coastlines

Melting ice and thermal expansion of the oceans are the key factors driving sea

level rise. In addition to exposing coastlines, where the majority of the human

population lives, to greater erosion and flooding pressures, rising sea levels will

also lead to salt water contamination of groundwater supplies, threatening the

quality and quantity of water resources access to large percentages of the

population.

Figure 0.1: Temperature change affects many natural processes that in turn affect the quality and quantity of our water resources.

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1.4.1 Availability & Quantity – Drought and Flood

Malaysian Climate Projection from NAHRIM Study in Peninsular Malaysia for future

annual rainfalls there will be a 10% increase for Kelantan, Terengganu and Pahang, and

5% decrease for Selangor and Johor. There will be more droughts i.e. dry years

anticipated (2028, 2029, 2034, 2042 and 2044) and higher maximum and lower

minimum rainfall will be observed in the future in many sub regions. Climate change

could play havoc with our water resources by changing our weather pattern, expected

dry months has changed to a wet months while expected dry months has changed to

wet month. Prolong drought was experienced in Kluang, Johor from Feb-March 2010

when the production of Sembrong Timur Water Treatment Plant almost fell to almost

zero due to decrease in river yield. In the 2009 & 2010 droughts in the Federal

Territory Labuan, extensive water rationing exercise was implemented and some

company such as Petronas Methanol had to close some of their operations - losing

millions of economic returns. As for the long term planning, the government launched a

project to extend the water treatment plant in Beaufort (Phase 2) which will increase

the supply of treated water to Labuan with an additional of 38.8 MLD. The total cost of

the project is RM 383 million and it involves huge CAPEX.

One of the well remembered, but localised incidence was the 1991 drought in Malacca

that caused the drying up of Durian Tunggal Dam and resulted in prolonged water

rationing in most parts of the state. The extreme droughts disrupted supply services,

especially in urban areas and frequent drought problems will further decrease the river

flow. Emergency measures were then followed to transfer raw water from the adjacent

Muar River as well as hundreds of water tankers were ferried around with drinking

water to relieve the distressed water shortage problem.

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The beneficial impacts of increased annual runoff in other areas are likely to be

tempered in some areas by the negative effects of increased precipitation variability and

seasonal runoff shifts on water supply, water quality and flood risks. Extreme flood

events had occurred in Kedah, Malacca and Johor. The state of Johor experience

extreme flood event early this year whereby road communications and water supply to

several districts were cut-off. Food, water, medical, and other humanitarian aids were

dispatched from neighboring states. At the end of 2010, the state of Kedah was hit by

flood – Bukit Pinang Treatment Plant in township of Alor Setar was submerged with

flood water leaving thousands of consumers without water supply. Flooding at river

intake will cause plant shut down because raw water pumps were submerged by flood

water and intake clogged with debris and sand. Water supply operator has to endure

high cost of cleaning, rebuilding damaged plants and equipments while consumers may

have to endure long duration of water supply disruption due to ongoing

maintenance/repair works.

1.4.2 Change in River Yield

Due to changing weather pattern, the safe yield of rivers may decrease and due to

decreasing yield, treatment plants could not produce to their design production. As an

adaptation and mitigation measures, river intake has to be relocated further downstream

where yield is higher or a barrage/weir has to be constructed across river to increase

water depth. To ensure there are enough raw water for plants to operate, dams and off-

river-storages have to be constructed to supplement this reduction. In the recently

reviewed Malaysia National Water Resources Study, RM 1.7 billion worth of source

works will be expected to be developed in the next 4 decades.

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1.5 Impact on Raw Water Quality

With higher water temperature, algae blooms in the storage reservoir could be expected

to increase and additional cost will have to be spent to remove it from the system.

Lower river runoffs during extended droughts are normally associated with a decreased

dilution capacity of the river on the pollutants, resulting in higher concentrations of

contaminants in the raw water. Higher rainfall intensity will cause water to overflow

the bank more extensively and erosion of the river bank will occur in the process, this

situation has led to an increase in water turbidity. It is often to find that the existing

water treatment plant may not be equipped with the facilities to deal with these

deteriorated raw water quality.

Raw water intakes or wells located near the coastal area will face the threat of saline

intrusion due to rising sea level compounded by lower surface runoff or lower ground

water recharge rate, limiting the use of these facilities for water supply. More capital

may have to be invested for building engineering structure such as barrage to prevent

saline intrusion into river intake.

The Initial National Communication (INC) prepared Peramu T/Plant intake (due to

saline intrusion). In the Ninth Malaysia Development Plan, the state of Terengganu

constructed Kemaman Barrage to raise river level and stop intrusion of saline water

into intake of Bukit Sah Water Treatment Plant.

Climate change causes prolong drought and with the reduced riverflow, deterioration of

river water quality due to pollution enhances. In the past this had lead to closing down

of treatment plants such as Cheras and Labu treatment plants. As the consequences, the

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affected river sources is either be abandoned or the water treatment plant be upgraded

by adding the advanced treatment such as membrane technology which requires high

capital outlay and would definitely increase the financial burden of the water operators.

In addition, the water operators also found that operating cost of the water treatment

plant is higher in tandem with the higher chemical dosage to treat the highly polluted

water sources. The situation is further compounded by higher residual produced and

cost of disposal the residual as the consequences of higher chemical dosage.

1.6 Development of Water Resources

The following recommendations are intended to guide the development of water

resources response measures:

a. Implement water use efficiency first.

Maximizing water use efficiency is one of the most cost-effective measures

communities can quickly implement to protect water supplies while also

reducing energy use and global warming pollution.

b. Use climate-smart water management tools.

Tools such as groundwater banking and water recycling may perform better in

a warmer future, while those that rely on historical hydrology (e.g., river

diversions and surface storage) are likely to perform less effectively in the

future.

c. Prioritize multi-beneficial approaches.

Adaptation measures that address multiple impacts, such as source water

protection, smart growth, and low impact development can benefit not only

water supply, but also interrelated issues including water quality, fish and

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wildlife habitat, flood management, reduced energy consumption, and reduced

global warming pollution.

d. Integrated regional water management.

Employing a regional planning approach can capitalize on solutions that benefit

a broad range of issues, stakeholders, and agencies and therefore will probably

have wide support and the ability to broadly distribute implementation costs.

e. Factor in energy use.

Each component of water use, from transport and treatment through

distribution, can require energy. Energy consumption and efficiency need to be

considered in response planning to ensure solutions are not exacerbating the

basic problem of carbon emissions.

f. Water system reoperation.

Regional water supply systems are often interconnected by tributary rivers and

canals. Reoperating water supply systems for improved flood control and

stormwater management can buffer climate-related impacts by distributing the

effect of changes in hydrology over a wider area.

g. Factor climate change into feasibility analyses and project design.

Evaluations of potential surface storage and other facilities should take into

account the effects of climate change on likely future hydrology, demand,

economic analyses of alternatives, and potential environmental impacts.

h. Incorporate the need for flood management.

Because most dams serve both water supply and flood management roles,

increasing downstream flood protection can enable existing dams to be operated

for increased water supply. Improved flood management should be incorporated

as a multi-beneficial tool for water supply management.

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Figure 0.2: Performance of Water Management Strategies After ConsideringGlobal Warming Effects

1.7 Conclusion

The impact of climate change will increase over the years, it will gain momentum and

if unattended, will cause havoc to our life. For millions of years human beings have

been able to survive in this planet because they are able to adapt and mitigate changes

that surround them. With the change in climate, we have to respond to it by changing

our lifestyle, not to stress the environment, be more protective and not to pollute it,

going for technologies, industries and crops that are water efficient.

There is a need to improve our understanding of long-term climate variability and

change. Where and which part of the water supply infrastructure are affected by climate

change. Are the effects localized or across state boundaries, a better understanding will

facilitate in policy response, going for appropriate water resource options, planning,

designing robust water supply systems or in short what are the adaptation and

mitigation measures to be implemented.

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To achieve efficient water demand management may take years and need resources but

it is an option we have to take. Sustainable water management with realistic pricing is

one way to curb wastage. A Tariff Policy, which discourages excessive and inefficient

use of water, should be in-place. Consumers can be the source and also solution to

unsustainable consumption of natural resources. Consumer education cannot be

sidelined if we want to achieve sustainable urban development in an ever-changing

environment. The expected changes in the hyrdologic regime of Malaysia due to the

impact of climate changes may require significant planning of the Malaysia‟s water

resources to accomodate aforesaid changes into the future water balances over the

Malaysia.

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