H) IMPACTS OF
CLIMATE CHANGE
BOWEN SEC PRELIM
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14
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‘The spread of insect-borne diseases
is the most significant impact of enhanced greenhouse effect.’
To what extent do you agree with this statement? Give reasons
for your answer.
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[6]
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Other
factors [at least 1 more besides the given factor]:
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Sea
level rising
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Lengthening
of the crops period
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Extreme
weather conditions
Impact of climate change
Sea level rise refers to the
increase in the mean height of the sea’s surface between high tide and low
tide relative to land. Low-lying areas and islands are threatened. 33% of the
coastal land and wetland habitats are likely to be lost in the next few
hundred years if sea levels continue to rise at the current rates. E.g.
Majuro Atoll in the Pacific Ocean will lose 80% of its land by half a metre.
More extreme weather events such as
heat waves, floods, drought and tropical cyclones have increased in the last
few decades. This is due to higher land and sea surface temperatures that
resulted in greater amount of water vapour and latent heat in a warmer
atmosphere which is a powerful driving force for extreme weather events.
Increased temperatures and rainfall
may cause the spread of infectious insect-borne diseases such as malaria and
dengue fever. E.g. Cool climate areas of Nepal and Bhutan for the first time
in 2004.
Higher temperatures may result in longer growing seasons for
crops in some regions. New crops such as blackberries and maize can be
cultivated in UK. However, in Yunan province of China, fruits such as apples
and cherries and nuts like almonds and walnuts that require cool weather
conditions are reduced.
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CAUSES OF CLIMATE CHANGES/ RESPONSE TO CLIMATE CHANGES
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‘Deforestation is the main cause of
global warming.’ How far do you agree with this statement? Support your
answer using evidence.
[6]
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Candidate may provide information on
the following points:
Deforestation is the loss of forests
due to the removal or clearance of trees in forested areas. Deforestation
takes place as wood is required to make products such as paper, building
materials and space is needed for mining and farming. Between 2000 to 2010,
52,000 square kilometres of forest were lost every year. The greatest loss
was in South America followed by Southeast Asia. With deforestation, there
are fewer trees and plants to take in carbon dioxide, leading to an increase
in carbon dioxide in the atmosphere. Carbon in the soil accumulates through
the decay of organic matter like dead leaves and animals. Deforestation
increases carbon oxidation in the soil to produce carbon dioxide that traps
heat.
Burning of fossil fuels like coal,
oil and natural gases which are formed from dead organic matter that has
decomposed over many millions of years will produce large amount of energy
for man’s daily use and release large amount of carbon dioxide which is a
greenhouse gas. Large consumers of fossil fuels include China, the United
States of America, Canada and the United Kingdom. In 2010, global carbon
dioxide emissions totalled 30.6 billion tonnes, which was 5.6 per cent
increase from 2009.
Agriculture which is the practice of
cultivating land, producing crops and raising livestock also contribute to
greenhouse gases. In rice producing countries such as China and India,
organic matter such as dead leaves and manure releases huge amount of methane
during rapid decomposition in the rice fields due to the high level of
moisture in the soil. The use of inorganic fertilisers increases the amount
nitrous oxide in soil and it is released when soil is ploughed or when rain
flows through the soil. Cattle raising such as cow produce a lot of methane
as a waste gas too.
Variation
in solar output is another factor causing global warming. The sun emits
varying amount of solar radiation due to changes in its magnetic field.
Occurrence of sunspots may cause an increase in the global temperature.
Sunspots are cooler regions on the sun’s surface that appear as dark spots.
The areas surrounding the sunspots will radiate more energy, which
compensates for the lower temperature of the sunspot areas. For example, a
peak in the number of sunspots in 2000 coincided with higher solar activity.
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SCGS PRELIM
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15
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Using
specific examples, explain two
anthropogenic factors that have led to enhanced greenhouse effect and
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Possible Introduction:
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The enhanced greenhouse effect refers to an increase in the
concentration of greenhouse gases in the atmosphere leading to a rise in
global temperatures
·
It occurs when human activity causes greenhouse gases to be
released at a far greater rate than that of natural emissions of greenhouse
gases
·
Anthropogenic factors are factors caused by human activities
such as the burning of fossil fuels, deforestation and changing land use
Anthropogenic factors:
Burning fossil fuels
·
the major fossil fuels are oil, coal and natural gas. The
burning of these fossil fuels produces large amount of energy that is
important for human activities
·
The energy produced is used for industries, transportation,
other commercial activities
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Fossil fuels are estimated to produce more than 80% of global
energy
·
Large consumers of fossil fuels include China, the US, Canada and
UK
·
Due to the high carbon content, fossil fuels contribute to the
increase in greenhouse gases by producing large amounts of carbon dioxide
when burnt
·
The world’s usage of fossil fuels has increased in recent years,
releasing billions of tonnes of carbon dioxide into the atmosphere each year.
For e.g., in 2010, global carbon dioxide emissions totalled 30.6 b tonnes
which was a 5.6% increase from 2009
Deforestation
·
Refers to the loss of forests due to the removal /clearance of
trees in forested areas
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2nd largest contributor of greenhouse gases in the atmosphere
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Trees are felled for wood to make products such as paper and
building materials.
·
Trees are also removed to clear the area for mining, grazing of
animals, plantations, construction of infrastructure
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With fewer trees to absorb carbon dioxide, which leads to an
increase in the carbon dioxide levels in the atmosphere
·
Deforestation also increases carbon oxidation as soil is exposed
to sunlight, thereby increasing the soil temperature
·
When soil temperature increases, the rate of carbon oxidation
also increases
·
Carbon oxidation is the process by which carbon in the soil
reacts with oxygen in the atmosphere to produce carbon dioxide
·
The greatest loss of forests occurs in South America, followed
by Southeast Asia
Changing landuse
i)
Agriculture:
·
Rice cultivation contributes to an increase in greenhouse gases
in the atmosphere
·
For e.g. tractors run on fossil fuels release carbon oxide; the
use of chemical fertilisers increases the amount of nitrous oxide in soil.
Nitrous oxide is released when soil is ploughed or when rain flows through
the soil
·
Cattle farming contributes to greenhouse gas emissions because
cattle release methane as a waste gas. Millions of tonnes of methane are
released each year from cattle farming
ii)
industries:
·
industrial activities involve the burning of fossil fuels that
result in greenhouse gas emissions
·
Greenhouse gases are also released as by-products when goods are
produced.
·
Some processes or products result in greater emissions than
others
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The largest carbon dioxide emissions from industrial processes
are found in North and Central America, Europe and Asia
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In recent years, countries such as China and India are also
contributing more to global carbon dioxide emission due to their rapid
industrialization
Urbanisation
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Large amounts of fossil fuels are burnt to provide energy for
household activities in urban areas
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These activities include heating, cooling, cooking, lighting
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The high concentration of cars, buses and other forms of
transportation in urban areas also contribute to the amount of greenhouse
gases emitted in these areas
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In addition, construction of infrastructure and producing
construction materials also release greenhouse gases into the atmosphere
Assess the international agreements that have been implemented
to address global warming [6]
International agreements
Kyoto protocol
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An international convention set up with the goal of reducing the
levels of greenhouse gases in the atmosphere
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The protocol was first drawn up in Kyoto on 11 Dec 1997 and came
into force on 16 Feb 2005
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Many countries came together to sign the Protocol to come up
with measures to address climate change and put them into practice
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Under the protocol, various targets to reduce greenhouse gas
emissions were set for participating countries
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However greater responsibility to reduce greenhouse gas
emissions was placed on 37 developed countries & European countries
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From 2008 to 2012, these countries were obliged to reduce their
combined greenhouse gas emissions by at least 5% below their 1990 levels
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Success:
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Many countries have met /exceeded their targets set by the Kyoto
Protocol, such as Finland, Greece, Iceland. Countries were required to
monitor and report their greenhouse gas emissions, helping to ensure that
they were on track in keeping to their emission targets
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The Protocol was also successful in encouraging sustainable
development
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Certified Emission Reduction (CER) credits were given to
countries which carried out emission –reduction projects (e.g. installing
energy-efficient infrastructure) in LDCs. Each credit is equivalent to one
tonne of carbon dioxide
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CDM not only encouraged sustainable development , but also
helped DCs to reduce their greenhouse gas emissions when they take on
emission- reduction projects in LDCs
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Limitations:
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There were still some countries such as Austria, Spain and
Denmark that did not achieve their targets
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The Protocol does not make it compulsory for the countries with
low greenhouse gas emissions to provide support to other countries with high
greenhouse gas emissions
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Hence countries with high greenhouse gas emissions may not be
able to achieve their emission targets as easily
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On the whole, the Protocol has limited impacts on global
greenhouse gas emissions. This is because countries which did not sign the
Protocol contribute significantly to the global emissions
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Since 1997, the global emissions have increased by 35%. A large
portion of the increase came from China, India and USA
Copenhagen Conference
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In 2009, Copenhagen hosted a UN Climate Change Conference. The
purpose of the conference was to improve on the measures developed for the
Kyoto Protocol to deal with the issue of climate change
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The Copenhagen Accord was drawn up during the conference. It is
an international agreement with the long term goal of keeping any increases
in the global mean maximum temperatures to within 2 deg C of the global
temperatures before 1850
Success:
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It successfully brought together a group of important political
figures to discuss the measures that will address the issue of climate change
effectively
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Targets for the reduction of greenhouse gas emissions were
successfully set during the conference
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DCs agreed to provide a total of US$30b to LDCs between 2010 and
2012 and provide long term financial aid of US$100b a year by 2020. The funds
will help LDCs to reduce their greenhouse gas emissions
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Limitations:
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The targets set are insufficient to reduce emissions to within 2
deg C of the temperatures before 1850
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Moreover, there was no agreement made on how the reduction of
greenhouse gases is to be carried out, making it difficult for countries to
carry out any action.
·
Many DCs have refused to sign the Accord, hence it is not
legally binding
·
The targets set by various countries to reduce the emission of
greenhouse gases were a guideline rather than a condition that must be
fulfilled. Thus, many countries did not keep to their targets
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Assess the national effects that have been implemented to address global
warming [6]
I agree to a small extent that the Singapore Green Plan is the
most effective response in Singapore in reducing greenhouse gas emissions.
Greenhouse gases, such as carbon dioxide, methane and halocarbons, are found in
the atmosphere. When greenhouse gases absorb long wave radiation, they
re-radiate it in all directions. In my essay, I am going to discuss the Singapore Green Plan and India's Energy Labelling Programme.
Possible points:
Singapore Green Plan is launched by the Ministry of the
Environment in 2002 and aims to generate 60% of Singapore’s energy needs using
natural gas by 2012. Natural gas is a cleaner form of energy in comparison to
coal because it does not produce smoke.
As early as 2010, about 79% of Singapore’s electricity was being
generated from natural gas. This exceeded the Ministry of Environment’s target
ahead of schedule.
However, the natural gas requires complex treatment plants to
process and pipelines to transport. These pipelines have high maintenance costs
because they need to be laid underground and have to be checked regularly for leakage.
There is other response at the national level such as Green Mark
Scheme by constructing ‘green’ buildings. It is launched by the Building
Construction Authority in 2005 and allows buildings to be evaluated and
certified according to how energy-efficient and environmentally friendly they
are. The scheme aims to encourage more new ‘green’ buildings, which are more
energy-efficient and use less energy to provide the same service.
For example, Plaza by the Park Standard Chartered @ Changi and the
National Library Building. They have reported energy savings of 15% to 35%
compared to conventional buildings. This cuts down greenhouse gas emissions by
reducing the use of fossil fuels to generate electricity.
However, the construction companies and developers in Singapore
tend to be conservative about adopting new ideas and materials to build ‘green’
buildings. They may cost more to build because ‘green’ materials may be more
expensive.
Plant-A-Tree Programme is started in 1971 by the Singapore City
Fund and Singapore Environment Council aims to maintain Singapore’s status as a
Garden City by planting trees. Residents are encouraged to donate money to buy
a tree or take part in tree planting events that take place monthly throughout
Singapore.
The programme has contributed to an estimated 60,000 trees planted
yearly throughout Singapore by the National Parks Board. Trees can remove the
carbon dioxide from the atmosphere.
However, trees take a long time to mature, so the positive effects
of tree planting will take time to materialise.
India’s Energy labeling Programme:
Reducing energy consumption
The Bureau of Energy Efficiency of
India enforced an energy labeling programme in 2007 informing consumers of the
amount of energy used by a product. Products that use little energy and emit
less carbon dioxide are sold at a cheaper price to encourage reduction in
greenhouse gas emissions. The label is compulsory for frost-free refrigerators,
fluorescent lamps and air conditioners and is voluntary for other appliances as
ceiling fans, television sets and washing machines and computers. Sales of
products with energy labels have increased steadily since 2007.
However, standards and labeling have
yet to be developed for many other appliances such as battery chargers,
computer monitors, heat pumps and freezers. Majority of the public is still
unaware of the labeling programme.
Limitation
E.g. The attempt to manage global
warming through Kyoto Protocol is more successful than Plant-A-Tree Programme
in Singapore as the former is able to get international countries together to
cut down emission of greenhouse gases. It is dealing with global warming at a
national level where Plant-A-Tree Programme is only at a national level and
trees will take many years to mature.
E.g. All the attempts to manage global warming as discussed above
have their merits and disadvantages but there is no one most successful/best
method. Countries attempting to manage global warming need to consider its
economy needs and available resources before implementing a one-best or a set
of best-executable measures that allow the country to develop but at the same
time keeping greenhouse gases that result global warming to a minimum.
In conclusion,
Singapore Green Plan has to work alongside with other projects to achieve its
maximum effectiveness in reducing gas emissions in Singapore.
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