1. Impacts of climate change
1.1. Sea level rise
1.1.1. Causes
1.1.1.1. 1. Caused by melting of glaciers in Greenland and Antarctica.
1.1.1.2. 2. Caused by the expansion of water in seas and oceans.
1.1.2. Negative impact
1.1.2.1. Seawater reaches farther inland, it can destroy coastal communities such as destruction of properties and infrastructures which will have a negative impact on economy.
1.1.2.1.1. It threatens low-lying coastal regions such as Shanghai, London and NYC.
1.1.2.2. Seawater intrusion may hurt agriculture due to salt water contamination which will exert negative impact on economy.
1.1.2.2.1. Researchers have shown about 600 million people live in low-lying coastal regions hence their properties and livelihoods are threatened.
1.1.2.3. Coastal ecosystems such as wetland habitat and mangrove forests are at risk of being submerged, ecosystems such as Arctic and Antarctica are disappearing which affects wildlife and coastal ecosystems adversely.
1.1.2.3.1. According to IPCC (Intergovernmental Panel on Climate Change), 33% coastal land and wetland habitats are likely to disappear in 100 years time of sea level continues to rise at this rate.
1.1.2.4. According NASA, global sea level is rising approximately 3.3mm a year.
1.1.3. Benefits
1.1.3.1. More sea routes are likely to be opened and shortened hence reducing transport cost and traveling time.
1.1.3.1.1. Northwest Passage and Northern Sea routes would be opened and shortened.
1.1.3.1.2. Travel time between Yokohama and Rotterdam ( Netherlands) is likely to be cut by 40% and fuel expenditure reduced by 20%.
1.2. More frequent extreme weather events
1.2.1. Causes
1.2.1.1. Higher temperatures increase evaporation that abundant water vapors and latent heat in the atmosphere which trigger extreme weather events.
1.2.2. Negative impact
1.2.2.1. Destroys properties and infrastructure and loss of lives.
1.2.2.1.1. Floods have destroyed rice fields in Bangladesh in 1974 that caused the worst famine in recent decades which has killed 1.5 million people.
1.2.2.1.2. Extreme drought has caused crop failure in Sudan that 2.8 million people in Sudan are affected by droughts every year.
1.2.2.1.3. Tropical storms have destroyed farmland, properties, infrastructure and loss of lives and livelihood in Philippines that have killed 6300 people.
1.2.2.1.4. The 2003 heat wave in Europe killed more than 70000 people as body cannot cool itself down.
1.2.3. Benefits
1.2.3.1. Relieve over population. Lol
1.3. Spread of infectious insect-borne diseases
1.3.1. Causes
1.3.1.1. It is induced by increased temperatures, humidity and rainfall across the world which has boosted insect populations in aquatic habitats and favored transmission of insect-borne diseases.
1.3.2. Negative impacts
1.3.2.1. Spread of such diseases may cause higher health care bills and lost work productivity of infected people and loss of lives.
1.3.2.1.1. The mosquitoes have extended their geographical boundaries to cooler areas that have become warmer.
1.3.2.1.2. Malaria, dengue and Zika are transmitted by mosquitoes that nearly 700 million people contract mosquito-borne illnesses each year, causing more than 1 million deaths.
1.3.3. Benefits
1.3.3.1. Relieve over population. Lol
1.4. Lengthening the growing season in certain regions
1.4.1. Causes
1.4.1.1. It is caused by higher temperatures in cold temperate regions.
1.4.2. Negative impacts
1.4.2.1. Cool temperate regions are getting hotter which are less conducive for temperate crops.
1.4.2.1.1. The 2007 one-week extension of the growing season in central and eastern United States was estimated to have reduced the production of winter wheat by 19%, peaches by 75%, apples by 67%, and pecans by 66%, causing over 2 billion in economic loss. — https://www.nature.com/articles/s41467-017-02690-y
1.4.3. Benefits
1.4.3.1. Cold regions are now warmer and more conducive for crop growing that more types of crops can be grew.
1.4.3.1.1. It is beneficial for especially Northern Europe that it introduce new species and cultivars such as grapes, maize and blackberries. Greater harvests hence greater incomes for farmers.
2. Natural causes of recent climate change
2.1. Variations in solar output
2.1.1. During intense solar magnetic activity period, sun spots increase hence solar radiation increases in order to compensate the temperature for the lower temperatures of sunspots areas.
2.1.1.1. Researcher has shown that the number of sunspots rises and falls with an 11 years cycle which associated with the earth’s cycle of high and low global temperatures.
2.2. Volcanic eruption
2.2.1. Carbon dioxide, Sulfur dioxide, dust and ashes are released into the atmosphere during volcanic eruptions.
2.2.1.1. This reflect solar radiations and also block sunlight from penetrating below hence the temperature decreases.
2.2.1.1.1. The 1991 eruption of Mount Pinatubo in Philippines had lowered global temperature by 0.6C for 2 years.
2.3. Green house effect
2.3.1. The shortwave radiation(high frequency waves, in this case is visible light) from the sun reaches the surface and bounces back to the atmosphere in the form of longwave radiation(low frequency waves, in this case is infrared radiation) that is absorbed and trapped by green house gases. Thus keeping earth warm and creates green house effect.
3. Anthropogenic causes of recent climate change
3.1. Deforestation
3.1.1. There are less trees to absorb carbon dioxide and lead to an increase in carbon dioxide levels in the atmosphere that higher amount of heat is trapped in the atmosphere and thus increases the global temperatures.
3.1.2. Deforestation exposes soil to the sunlight that allows the carbon in the soil reacts with oxygen through carbon oxidation process which produces carbon dioxide.
3.1.3. Deforestation occurs greatly in South America ,Southeast Asia, Australia and Africa due to the need for development. Between 2000 and 2010, yearly frost loss was 52000 sq km.
3.2. Agriculture
3.2.1. Tractors run on fossil fuels which release carbon dioxide.
3.2.2. Chemical fertilizers increases the amount of nitrous oxides released when soils are ploughed and rain splashes on carbon rich soil.
3.2.2.1. This contributes to 68% of total output of N2O globally.
3.2.3. Rapidly-decaying (decomposition) of organic matter releases methane due to the high moisture in the soil.
3.2.3.1. This is because the wetlands are natural homes for methane-producing bacteria.
3.2.4. Cows releases methane through farting due to their poor digestive system.
3.2.4.1. Each cow emits 1000 to 8000 liters of gas daily that contributes to 40% of annual methane budget.
3.3. Industrialization
3.3.1. Manufacturing goods and providing services require combustion of fossil fuels.
3.3.1.1. Paper, petroleum, chemicals, metal productions and energy supplies are responsible for contributing the most amount of green house gases.
3.3.1.2. China has the most amount of green house gases emissions which occupies 28% of global output.
3.4. Urbanization
3.4.1. Large amount of fossil fuels are burnt to provide energy for household activities in urban areas.
3.4.1.1. Eg. Cooking, transportation.
3.4.1.2. Although cities only cover 2 percent of global land use, they account for 70% of total green house gases emission. Seoul has the greatest GHG emissions which is 276.1 footprints followed by Guangzhou which is 272.0 footprints. Waterloo in Canada that has the least amount of GHG emissions which is 4.4 footprints.
3.5. Enhanced green house effects
3.5.1. Increased concentration of greenhouse gases leading to infrared radiation being excessively trapped resulting in rise in global temperature.
3.5.1.1. Anthropogenic factors release increased greenhouse gases especially carbon dioxide at a faster rate than by natural causes.
3.5.1.2. Since industrial revolution in 1786, concentration of carbon dioxide (+39%) nitrous oxide (+20%) and methane (+158%) have increased in earth’s atmosphere.
4. Responses to climate change
4.1. Kyoto Protocol
4.1.1. Kyoto protocol is an agreement linked to the United Nation Framework Convection on Climate Change (UNFCCC) with the goal of reducing the levels of green house gases in the atmosphere. Various targets to reduce greenhouse gas emissions were set with at least 5% from 1990 onward.
4.1.2. Success
4.1.2.1. Countries like Finland (-21%/-14.8Mt) Ireland (-17%), Greece(-24%) met and exceeded targets as they monitor and administer self and peer assessment.
4.1.2.2. CDM (Clean Development Mechanism) gave Certified Emission Reduction (CER) credits to Least developed countries which carry out emission-reduction projects such as installing energy-efficient infrastructures.
4.1.3. Limitation
4.1.3.1. Not all countries met reduction targets such as Norway (+1%), Australia (+8%) and Iceland (+10%) because these recommendations are only guidelines but not legally binding hence participates are not punished for breaking pledges and countries which did not sign up the Protocol continued to contribute significantly to GHG (+35% since 1997 by China, India and USA.
4.2. National Responses
4.2.1. “Plant-a-Tree” Programme
4.2.1.1. Started in 1971 by the Garden City Fund and Singapore Environment Council aimed to plant more trees to reduce CO2 emissions. Residents are encouraged to donate money to buy a tree or take part in tree planting events that take place monthly.
4.2.1.2. Successes
4.2.1.2.1. The programme has contributed 60,000 trees planted yearly throughout Singapore by the National Parks Board.
4.2.1.2.2. Over the past decade, number of trees have doubled from 327,000 to 660,000.
4.2.1.3. Limitations
4.2.1.3.1. Trees take many years (25years) to mature, so the positive effects of planting trees will take time to materialize.
4.2.1.3.2. It is costly and labour-intensive to maintain as regular pruning is needed to remove diseases and precarious branches.
4.2.1.3.3. Trees may fall down during storms that cause deaths which had happened in Bukit Batok Nature Park and Singapore Botanic Garden.
4.2.2. Singapore Green Plan
4.2.2.1. Launched by MOE in 2002 which aimed to generate 60% of energy using natural gas by 2012 as Natural gas is a cleaner source of energy compare to coal.
4.2.2.2. Successes
4.2.2.2.1. By June 2017, 95% electricity in Singapore is produced by natural gas.
4.2.2.2.2. Compressed natural gas (CNG) vehicles rose and 24-hour CNG refueling station was opened.
4.2.2.3. Limitations
4.2.2.3.1. Natural gas requires complex treatment plants to process and pipeline to transport.
4.2.2.3.2. These pipelines have high maintenance costs because they need to be laid underground ground and have to be checked regularly for leakage.
4.2.3. Singapore Green Mark Scheme
4.2.3.1. It is adopted to encourage construction of green buildings that is energy efficient, environmentally-friendly by using solar energy. It aims to cut down GHG emissions because less fossil fuels will be burnt to generate electricity for these buildings.
4.2.3.2. Successes
4.2.3.2.1. Existing green buildings such as plaza by the park, standard chartered and national library building report 15% to 35% energy saving.
4.2.3.3. Limitations
4.2.3.3.1. Developers are less motivated to build such buildings because environmentally friendly, non-toxic and recyclable materials such as bamboo are expensive.