Monday, March 21, 2016

Climate - P64 to 67 (causes, impact, solutions to climate change)

H) IMPACTS OF CLIMATE CHANGE
BOWEN SEC PRELIM  
     14
‘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.
[6]

Other factors [at least 1 more besides the given factor]:
-        Sea level rising
-        Lengthening of the crops period
-        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.


CAUSES OF CLIMATE CHANGES/ RESPONSE TO CLIMATE CHANGES
*
‘Deforestation is the main cause of global warming.’ How far do you agree with this statement? Support your answer using evidence.                                                                                                                                                          [6]

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.

SCGS PRELIM  

15
Using specific examples, explain two anthropogenic factors that have led to enhanced greenhouse effect and



Possible Introduction:
·        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
·        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
·        2nd largest contributor of greenhouse gases in the atmosphere
·        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
·        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
·        The largest carbon dioxide emissions from industrial processes are found in North and Central America, Europe and Asia
·        In recent years, countries such as China and India are also contributing more to global carbon dioxide emission due to their rapid industrialization

Urbanisation
·        Large amounts of fossil fuels are burnt to provide energy for household activities in urban areas
·        These activities include heating, cooling, cooking, lighting
·        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
·        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
·        An international convention set up with the goal of reducing the levels of greenhouse gases in the atmosphere
·        The protocol was first drawn up in Kyoto on 11 Dec 1997 and came into force on 16 Feb 2005
·        Many countries came together to sign the Protocol to come up with measures to address climate change and put them into practice
·        Under the protocol, various targets to reduce greenhouse gas emissions were set for participating countries
·        However greater responsibility to reduce greenhouse gas emissions was placed on 37 developed countries & European countries
·        From 2008 to 2012, these countries were obliged to reduce their combined greenhouse gas emissions by at least 5% below their 1990 levels

·        Success:
·        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
·        The Protocol was also successful in encouraging sustainable development
·        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
·        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

·        Limitations:
·        There were still some countries such as Austria, Spain and Denmark that did not achieve their targets
·        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
·        Hence countries with high greenhouse gas emissions may not be able to achieve their emission targets as easily
·        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
·        Since 1997, the global emissions have increased by 35%. A large portion of the increase came from China, India and USA

Copenhagen Conference
·        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
·        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:
·        It successfully brought together a group of important political figures to discuss the measures that will address the issue of climate change effectively
·        Targets for the reduction of greenhouse gas emissions were successfully set during the conference
·        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

·        Limitations:
·        The targets set are insufficient to reduce emissions to within 2 deg C of the temperatures before 1850
·        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







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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