caie-igcse-environment-management-0680-theory-v2.pdf

ZNOTES.ORG UPDATED TO 2022-2024 SYLLABUS CAIE IGCSE ENVIRONMENT MANAGEMENT SUMMARIZED NOTES ON THE THEORY SYLLABUS CAIE IGCSE ENVIRONMENT MANAGEMENT 1.2. Extraction of rocks and minerals 1. Rocks and minerals and...

ZNOTES.ORG UPDATED TO 2022-2024 SYLLABUS CAIE IGCSE ENVIRONMENT MANAGEMENT SUMMARIZED NOTES ON THE THEORY SYLLABUS CAIE IGCSE ENVIRONMENT MANAGEMENT 1.2. Extraction of rocks and minerals 1. Rocks and minerals and from the Earth their exploitation 1.1. Formation of rocks The rock cycle: a representation of the changes between the three rock types and the processes causing them. Exploring for minerals: Prospecting: a process of searching for minerals by examining the surface of the rocks Ore: A rock with enough important mineral to make it worth mining Methods of exploration Remote sensing: a process in which information is gathered about the Earth’s surface from above. Types of Rocks Photographs of the area are taken from air. The images are carefully analysed for mineral Igneous rocks: presence. Made when liquid magma cools to form solid rock. Aerial photography can cover more ground than a Molten rock below the surface is called magma, person on the surface. and lava when it reaches the surface. Satellite signals: Extrusive igneous rock: if the rock cools quickly, small Some satellites send signals to the Earth’s surface and crystals are formed e.g. basalt. collect the reflected signals, indicating the presence of Intrusive igneous rock: if the rock cools slowly, large minerals. crystals are formed e.g. granite. The unique radiation pattern is processed and Examples: Granite and Basalt analyzed by computers Sedimentary rocks: The system works in all weather conditions. Formed by the weathering of existing rocks at the The GPS gives the exact location Earth’s surface. Large area covered in low cost Fossils may be present. Most efficent method Sediments (small particles of rocks) accumulate into Geochemical analysis and feild surveys layers and get pressurized due to the newer deposits Geochemical analysis: analyzing the chemical properties above them. of rocks (by taking samples). The sediments are transported by water and wind The samples can be taken from stream sediments, soil or (erosion). rocks (using shallow drilling). Particles like clays, silts, sands, gravels, and small The location of the sample points can be accurately found boulders are found in sediments. using the Global Positioning System (GPS). Examples: limestone, sandstone, and shale. Metamorphic rocks: Formed from the existing rock when heat and/or pressure causes changes in the rock crystals without melting it. The changes can be physical, chemical, or both. Examples: marble and slate. WWW.ZNOTES.ORG CAIE IGCSE ENVIRONMENT MANAGEMENT The vegetation is cleared and topsoil removed. Geophysics: method to identify mineral ores present in rocks using their physical properties. A series of vibrations (seismic waves) are sent through the Earth’s surface. Several sensors are placed at different distances from the source of vibrations on the surface. The vibrations create shock waves that travel down into the rock layers. They are reflected back to the sensors on the surface. The shock waves record different patterns depending on the mineral present in the rock layers. The rocks are broken up and loosened with explosives. The loose rock is removed using diggers. The rock or mineral is tipped into trucks or railway wagons. Building materials such as sand, gravel, and stone are removed from open pits called quarries. Strip mining is used to mine a seam of mineral. The overburden (the unwanted overlying rock and soil) is removed as a thin strip. \n Methods of extraction: There are two methods of extraction Surface mining Sub- surface mining Surface mining: includes open-cast (open-pit, open-cut) and strip mining. Open-pit mining is used when a valuable deposit is located near the surface. It is mainly used to mine coal and lignite Sub-surface mining: includes deep and shaft mining. A vertical shaft is sunk to the rock layer containing minerals. A horizontal tunnel is made, following the mineral layer. WWW.ZNOTES.ORG CAIE IGCSE ENVIRONMENT MANAGEMENT If the demand falls, working mines may get into a loss due to the transport and extraction expenses. 1.3. Impact of rock and mineral extraction Environmental impacts: Ecological impacts: Loss of habitat as the vegetation is cleared ∴ plants The minerals are extracted by digging (by machines do not have a place to grow,so the animals depending on them for food and shelter are affected. and miners). The loose rock is brought from the mine and piled up Pollution: on waste heaps on the surface. Noise pollution: due to machinery and explosives ∴ The minerals are brought to the surface and disturbs the behavior of animal species and causes transported in trucks or trains hearing problems for people. Resources: Gold and Diamonds Water pollution: water supplies may also be polluted, making it unsafe for people to drink. Factors that affect the decision to extract rocks The water may become acidic and dissolve toxic metal ions-this combination kills many aquatic and minerals: organisms. Geology: Bioaccumulation: organisms absorb the ions and High-grade ores yield more of the required chemical retain them in their body, reaching a concentration elements than low-grade ores. higher than that in water. Small deposits of high-grade ore are worth mining. Biomagnification: the concentrations increase Small deposits of low-grade ore that cannot be mined higher up in the food chain and cause the death of top consumers. at a profit is left as reserves. Land pollution: toxic nature of the waste doesn’t allow Accessibility: Transporting the ore from the mine to processing plant growth even years after the mining is stopped. Air pollution: dust particles settle on the vegetation, plants can be difficult and expensive. The cost of building road or rail links to the processing not allowing sunlight to reach the leaves and thus, plant or to the nearest port for export has to be reducing the rate of photosynthesis. considered. Breathing in dust that remains in the lungs can Carrying out some processing at the mine reduces cause serious lung diseases. transport costs. Visual pollution: the landscape is damaged. The mining company must be given a licence before extracting a deposit. Economic impacts: A long-term agreement between the government and Jobs are created in the extraction and transporting of mining companies must be reached to avoid rapid minerals rises in the tax, which makes mining unprofitable. Increase in the Country’s economy Environmental impact assessment: Earn foreign exchange. For the license application to be approved, the The income earned can be used for buying goods and company must have a plan to keep the loss of habitat services and investing in infrastructure projects. minimal, followed by the restoration of land Improvements to transport proceeding with the completion of mining. The choice of site for mine waste should also be Social Impacts: considered. Supply and demand: the relation between how much of a Positive: commodity is available and how much is needed or Better standard of life due to economic gain wanted by the consumers. Improvements to services, like healthcare and An increase in world demand for any mineral ore will education elevate the prices. Investing in infrastructure projects can help the The profit from a working mine depends on changes in country in building more well-designed communities. supply and demand. \ If the demand is too high, mines that were not Negative: profitable before becoming worth mining. Affects health of the labour workers WWW.ZNOTES.ORG CAIE IGCSE ENVIRONMENT MANAGEMENT Affects health of civillans due to pollution the ground becomes less toxic. Lack of safety Making lakes and natural reserves: 1.4. Managing the impact of rock and Several tree and herb species are introduced. This will mineral extraction help maintain the biodiversity As their populations grow, they create habitats for many Safe disposal of mining waste: species. These nature reserves become valuable green spaces for Mine waste must be stored to prevent collapse. human recreation and help in maintaining biodiversity. The site of the mine must prevent the chances of water If the rock lining the hole (created by the extraction) is pollution. non-toxic and impervious to water, it can be filled with The waste must be monitored to detect any movement or water to form a reservoir or lake. further pollution. It is used for irrigating farmland or processing to provide clean, safe drinking water for humans. Land restoration: Soil improvement: 1.5. Sustainable use of rocks and After (sanitary) landfilling, mine waste can be covered minerals by a layer of soil, that can be enriched with fertilizers. Sustainable resource: a resource that can be continuously replenished e.g. agriculture, forestry, etc. Sustainable development: development that meets the needs of the present, without compromising the ability of future generations to meet their own needs. Landfilling: the waste is tipped into a hole; from time to Strategies for the sustainable use of rocks and time it is leveled off and compacted. minerals: Sanitary landfilling: As in landfilling, the waste is used to fill the hole, but alternating layers of waste and Increasing the efficiency of the extraction of sand are used. Tree planting: rocks and minerals: After improving soil fertility, plants and trees can be Mine wastes must be processed for the second time. grown in that area, helping an ecosystem to be This allows the valuable minerals to be recovered reborn. and reduces the risk of pollution due to mine Bioremediation: waste. It is a process of removing pollutants from waste using Chemical treatment of the waste and biological living organisms. treatment (using microorganisms) extracts much of In situ treatment: treatment of contaminated waste the valuable mineral still within it. where it’s left. Improvements in the performance of the machines Ex-situ treatment: removal of contaminated waste used in mining and processing. from a site to a treatment plant. Greater use of data analysis by computers (to predict Often happens slowly (can be sped up by providing geological conditions). oxygen and nitrogen). Increasing the efficiency of the use of rocks and minerals: Engineering solutions e.g. design of steel beams with the same strength but using less steel. The need to recycle rocks and minerals: Microorganisms, like bacteria, can absorb pollutants and metabolize them into less harmful Recycling uses less energy than processing the ores. substances. Recycling also produces less waste and thus, reduces Some plants have the ability to bioaccumulate the risk of pollution. toxic metals. After these plants grow for a while, the parts of the Legislation: plants aboveground are removed so the waste in WWW.ZNOTES.ORG CAIE IGCSE ENVIRONMENT MANAGEMENT The governments pass laws that require 2.2. Energy resources and the manufacturers to become responsible for recycling and reuse. generation of electricity The demand for energy is increasing worldwide due to: 2. Energy and the Increasing population size. Increasing industrialisation and urbanisation. environment Improvements in standards of living and expectations. Types of energy sources: 2.1. Fossil fuel formation Non-renewable Renewable Can be used over and over Fossil fuels: carbon-based fuels, formed over millions of Limited again years ago from the decay of living matter. Coal: formed from plants. Take millions of years to get Can be replenished in a short Oil and natural gas: formed from sea creatures. replenished period of time Formation of coal: Fossil fuels (coal, oil and Geothermal power Huge forests grew millions of years ago covering most natural gas) of the Earth. Nuclear power (using Hydro-electric power uranium) Tidal power Wave power Wind power Solar power Biofuels e.g. bioethanol, biogas and wood Nuclear fuels last for centuries and are a good replacement for fossil fuels, but the source material The vegetation died and formed peat. (uranium) is limited. The peat was compressed between layers of Biofuels may become limited, but it can be renewed by sediments to form lignite (low-grade coal). replacing the cut-down trees with new ones to obtain Further compression formed coal. bioethanol and wood. Formation of oil and natural gas: Biogas can be obtained by recycling waste products. Small animals and plants die and fall to the bottom of How energy sources are used to generate electricity: the sea. Turbine: a machine, often containing fins, that is made to Their remains are covered by sediments. revolve by gas, steam or air (it is connected to a As the sediments start forming layers, they start to generator). change into sandstone as the temperature and Generator: a machine that converts mechanical energy pressure increase. into electrical energy. Fossil fuels and biofuels: The heat and pressure turn the remains into crude oil and natural gas. They separate and rise through the sandstone, filling in the pores. The rock above the oil and gas is impervious (non- These produce a massive amount of energy during porous). combustion that is used to heat water and convert it So, they get trapped underneath it. into steam, which thereby drives the turbines. Nuclear power: WWW.ZNOTES.ORG CAIE IGCSE ENVIRONMENT MANAGEMENT Uranium, a radioactive element, releases huge amounts of energy when nuclear fission (splitting of the atom) occurs. This energy is used to heat the water, produce steam, and rotate the turbines. Geothermal power: Uses photovoltaic cells that produce a small electric charge when exposed to light. A bank of cells organised into solar panels produce a significant amount of electricity. Cold water is pumped under pressure into a layer of Tidal power: hot rocks. The rocks heat the water. The hot water returns to the surface under pressure and heats the second supply of water using a heat exchanger. The steam produced in the second supply moves the turbine, generating electricity. Wind power: Uses the natural rise and fall in the level of water in an area. When the levels drop, water is held back by a tidal barrage (a small dam that releases water back through a turbine). Wave power: Also uses turbine and generator. Uses the smaller differences in water levels that are caused by wind. Hydro-electric power: Wind turbines have shafts (blades) that rotate due to wind. Gearbox maximises the rotation of the shaft. Brakes slow down or stop the rotor in very windy conditions, preventing damage to the blade. As the turbine rotates, the generator produces electricity. Solar power: Uses a dam on a river to store water in a reservoir. Water is released from the reservoir that flows through the turbine, rotating it. The turbine then activates a generator that generates electricity. Advantages and disadvantages of: Fossil fuels: WWW.ZNOTES.ORG CAIE IGCSE ENVIRONMENT MANAGEMENT Advantages Disadvantages Increase in demand for the product; Carbon dioxide and toxic Increase in demand for energy (for production). gases are released when If economic conditions are poor: Plentiful supply; Families have less money to spend on luxury items; burnt contributes to global warming; Need to make savings; Reduce the use of fuel; Provides job opportunities Damages local area; Reduce the purchase and use of electrical items; (mining and processing); Decrease in the demand for energy. The technology used is well- Decline in the economy of one country can have a global Limited supply (non- known and the methods of impact. renewable). extraction are well-practised. Reduction in the economy of China meant a worldwide: Reduction in production of steel. Biofuels: Decrease in the amount of manufactured goods (transported by ships). Advantages Disadvantages Decrease in the price of oil (energy source). Carbon dioxide and toxic Climate: Renewable source; gases are released when The demand for energy with regard to climate depends burnt; on the country. Lot of land needed. People living in a temperate climate are likely to Growing more plants uses Shortage of land for experience colder winters, so the energy demand for carbon dioxide; agriculture ‫؞‬ heating would be far higher. Removal of natural They also experience fewer hours of daylight. Plentiful supply. This increases the usage of electrical lighting. ecosystems ‫؞‬ Climate change (excessive heat or cold) increased the energy consumption (particularly in urban areas). 2.3. Energy demand Need for additional heating. Installation and operation of air-conditioning units. Domestic demand: Created by affordability, availability and social status. 2.4. Conservation and management of Most of the purchases that are considered as necessities now increase the demand for energy supplies, notably energy sources electricity. Example: Strategies for the efficient management of energy Fruits and vegetables, that aren’t naturally available in resources: the season locally, are produced in glasshouse or in Reducing consumption: areas with a favourable climate and are then transported. Reducing the amount of energy used to heat a In both the scenarios (glasshouse operation and building. transport), the energy cost is significant. Industrial demand: Manufacturing requires the use of large amounts of energy throughout the production e.g. iron and steel production. Advanced manufacturing techniques made the products, that were once luxury items, cheaper. So, more people want to buy them. The demand for the product increases. The demand for energy (needed for production) also increases. Transport: Manufacturers supply customers across the globe. Insulation: constructing using material with good This decreases production costs in countries that import, insulation properties prevents loss of heat. but increases the transport costs as they require large Loft insulation: adding an insulation layer into the roof amounts of fossil fuels to operate. space. Personal and national wealth: Underfloor insulation: adding an insulation layer on If economic conditions are good: the floor e.g. carpet. Higher employment; More money to spend on luxury items; WWW.ZNOTES.ORG CAIE IGCSE ENVIRONMENT MANAGEMENT Cavity wall insulation: a gap between inside and Scrapping older, inefficient cars, that emit more outside walls is filled with an insulating material, pollutants. causing the heat to pass through more slowly. Exploiting existing energy resources: Double glazing: two panes of glass with a gap in the The type of energy source used depends on social, middle to act as an insulator. environmental and economic factors. This sealed gap is usually filled with air or an inert gas e.g. argon. The current solution is to use a renewable resource as Triple glazing can also be used, but it is too expensive. a primary energy source when possible and have a Electrical devices must be turned off when not in use. fossil-fuel (or biofuel) powered station available as a Devices can be left in ‘standby’ mode and can be backup when weather conditions are not suitable. accessed rapidly. More energy-efficient devices must be bought. Developing alternative fuels for vehicles and further development in engine technology. ‘Scrappage’ schemes: remove inefficient machines from use (electrical appliances or vehicles). Energy from waste: Reusing existing materials to extract energy from them before they are disposed. Anaerobic digestion: breaking down of organic matter (waste food and vegetation) using bacteria. This process takes place in a sealed container and releases methane (a flammable gas) that can be used for heating purposes. The composted waste can be used as organic matter to improve soil structure. Household rubbish can be incinerated (burnt) to This is a reliable source for industry and households produce heat, that can be used to generate electricity; and reduces the amount of fossil fuels used. Transport policies: Advantages Disadvantages Regulations regarding the quality of exhaust gases Waste from burning (ash) is from vehicles; Produces poisonous gases small in volume. Thus, it Check on the fuel efficiency; during combustion. doesn’t take up much space. Restrictions on where vehicles may go; Taxation on fuels; Vegetable oils, once used, should be disposed; Surcharges for travelling to certain places at peak These oils can be collected and recycled into biofuels times; suitable for running vehicles; Improving public transport so it is easier and cheaper It can be used exclusively or as an additive. than using cars; Improving routes for cyclists and pedestrians; Education: Encouraging car-sharing; Benefits of the technology must be communicated to Restricting when cars can be used e.g. odd even rule others; in Delhi; Promote new ways of thinking; Providing incentives to buy more fuel-efficient vehicles The message must be that significant savings in and for vehicles using cleaner technology. energy bills can be made over the longer term, Development of new resources: reducing energy use; Fracking: obtaining oil or gas from shale rock by splitting Energy-efficiency ratings must be provided for new them open using water, sand and chemicals. products to compare with the old ones. A vertical hole (2-3 km deep) is drilled to reach the fuel- Laws passed by the government to make changes rich rocks (shale rocks). rapidly: Stricter building regulations: new constructions must be more energy efficient. Preventing the sales of inefficient types of electrical devices. Incentives to encourage the purchase of more efficient technologies: Insulating older houses that are energy efficient; Replacing older, inefficient electrical devices; WWW.ZNOTES.ORG CAIE IGCSE ENVIRONMENT MANAGEMENT Organism or habitat Impact of oil Shortage of food as fish and other Birds creatures die; May consume oil when eating fish (toxic); When hunting for food, feathers get covered with oil, affecting their ability to fly. Mammals Food sources are depleted; Mammals may also swallow oil while feeding (toxic); Coating of oil will affect their skin. Complete devastation of the reef Reefs Water, sand and chemicals are pumped down into the due to lack of oxygen (species die); shale rock layer. Areas may be covered in oil. This causes the rock to fracture, releasing oil and natural Beaches Oil (washed by tides) coats rocks; gas, which are forced back to the surface and collected. Organisms in shallow water and Purpose of the three components: rock pools may die due to toxic Water: easy to handle (in high pressure). effects of the oil; Chemicals: stop the blockage of pipes. Sand: keeps the cracks in the rock open. Animal food sources and tourism are affected. Advantages Disadvantages Access to more oil and gas; Risk of toxins entering the 2.6. Management of oil pollution water table; Less pollution than burning Chemicals are toxic and may Reducing oil spills in marine environments: coal; affect local residents; MARPOL (Marine Pollution): International Convention for Uses a lot of water; may the Prevention of Pollution from Ships. The need to import reduces; Regulations of the MARPOL: cause water scarcity; Supervise the transport of oil at sea; Noise pollution; All tankers must be certificated to show they have Natural areas damaged; Provide many jobs locally. appropriate systems in use; May cause additional Earth Else, it can result in a heavy fine or the ship may not tremors. be permitted to leave port. Tanker design: 2.5. Impact of oil pollution Oil spill can be caused by damage to the hull (a hole in the hull of the boat causes its contents to leak). Main causes of marine oil spills: Increase in the number of compartments within the Offshore oil extraction: leakage from the rigs. hull of the ship: if one of the compartment’s damaged, Oil pipelines: leaks in the oil pipework. the contents of the whole ship aren’t lost. Shipping: risk of collision or damage to oil tankers. Double-hulled tankers: if the outer layer’s damaged, Effects of an oil spill: the contents are still secure by the inner plate. Organism or habitat Impact of oil Oil floats on the surface of the water and blocks the sunlight from Phytoplankton entering. The phytoplankton can’t photosynthesise, so they die. Shortage of food; reduction in Fish phytoplankton. Oil floating on the surface prevents Though double-hulled tankers cost more than single- gas exchange. Fish become short of hulled, the risks of oil spill are far less. oxygen and die; Direct contact of Minimising the impact of oil spills: the fish with oil affects their gills. Floating booms: a floating barrier is used to surround the oil slick, preventing it from spreading. WWW.ZNOTES.ORG CAIE IGCSE ENVIRONMENT MANAGEMENT This process works well when the spill covers a Air enters the soil by diffusion. relatively small area and the sea is calm. Detergent sprays: detergents help break down the oil slick into smaller droplets, that eventually degrade, and disperse it. They are effective on smaller spills, but cause damage to the coral reefs themselves as they’re not tolerant to detergents. Skimmers: clean the water using a material that oil easily attaches to. Water: held within the pore spaces (water that is available for plant growth). Water enters the soil when there’s precipitation or when the soil is irrigated. The proportion of these components depends on: Type of soil; Way it has been managed; The skimmer drags oil off the seawater surface, that is Local climatic conditions; then scrapped off into a container. Size of the mineral particles. This system is used when oil slick is contained within a Soil can be classified into three groups: boom and the sea is calm. When the oil reaches beaches, it can only be removed Type Size Texture by hand (difficult and time-consuming). Sand 2.0-0.02 mm Gritty Silt 0.02-0.002 mm Silky or soapy 3. Agriculture and the Sticky when wet and Hard when clay