IB Environmental Systems and Societies SL Topic 7 Notes PDF

IB Environmental Systems and Societies SL 1 Topic 7: Climate change and energy production Shreya Mozumdar IB Environmental Systems and Societies SL Topic 7: Climate change and energy production 7.1. Energy choices and security Society get...

IB Environmental Systems and Societies SL 1 Topic 7: Climate change and energy production Shreya Mozumdar IB Environmental Systems and Societies SL Topic 7: Climate change and energy production 7.1. Energy choices and security Society gets energy from a range of sources that are both renewable and non-renewable. Energy security is the ability to secure affordable, reliable and sufficient energy supplies for the needs of a particular country. Energy security is an issue governments deal with to make the right choices between using resources available to them to produce energy and maintain national security. It may be cheaper to buy energy from another country, but in a situation of conflict, it would be risky to lose out on energy sources. Energy price fluctuations and political changes are risky for governments; thus, they diversify energy sources including domestic sources to spread the risk. Energy choices depend on many factors: o Availability of supply domestically or possibility to import from other countries o Technological developments like finding new/alternative energy sources o Politics can cause conflict over energy supplies or choices to use expensive domestic supplies for increased security o Economics: globalization of economies may make it cheaper to import energy than produce your own. o Cultural attitudes: preferences for fossil fuel-powered appliances o Sustainability o Environmental considerations like impacts of nuclear power Examples of energy security: Ukraine-Russia, shale oil in the US, wind power in Denmark We can continue to use non-renewable energy sources like coal, oil and gas that are due to run out in a few decades despite increasing population and demand for energy. We can acquire the required energy from renewable sources, however, they currently contribute only a small percentage of world energy. Research into renewable sources is less than research into find more oil and gas because: o TNCs/MNCs and heavy industry are committed to a carbon economy – all machines run on fossil fuels. This occurs at a large scale and is difficult to change. o It is cheaper to produce energy from fossil fuels. o Countries are tied to the resources they use with contracts or convenience, or energy security. o Renewable sources depend on location: § Wave and tidal are not viable for land-locked countries § Solar energy is only effective in sunny areas § Geothermal energy requires the presence of volcanic rocks. Carbon dioxide released from fossil fuel combustion contributes to the greenhouse effect. IB Environmental Systems and Societies SL 2 Topic 7: Climate change and energy production Shreya Mozumdar EVALUATING ENERGY SOURCES Sources Facts Advantages Disadvantages Coal It is formed from Plentiful supply Non-renewable fossilized plants that Easy to transport as a It releases a GHG, died in the solid carbon dioxide carboniferous Does not need Burning forms sulphur period. processing dioxide which leads to It is mined from Relatively cheap to acid deposition coal seams which mine and convert to Forms pollutants like exist between other energy particulate matter that types of rock affect human health through opencast or Mining leaves degraded deep mining land and pollution There is less energy released from coal per unit of mass Oil It is formed when There is more energy Non-renewable fossilized plants and released per unit of It releases carbon microorganisms are mass dioxide when burned compressed into a Once found, it is Danger of oil spills that liquid in porous relatively cheap to cause water pollution rocks mine and convert to It is extracted from energy oil wells – when they are under the ocean it is dangerous Natural gas Methane and other Highest amount of Non-renewable but hydrocarbons energy produced per more supply than oil trapped between unit mass It still gives off some seams of rock form Ready-made fuel carbon dioxide. natural gas Relatively cheap It is extracted by Cleaner than coal and drilling and is often oil found with oil Nuclear It is formed from Raw materials are High extraction costs power uranium – it is split cheap once the reactor Nuclear reactors are in nuclear reactors. is built and can last expensive to build and When it splits into quite a long time maintain other elements, Small amounts of There is a question of energy is released uranium produce lots what to do with It is extracted by of energy radioactive waste that mining No carbon dioxide or remains toxic for a long pollutants released time. It must be stored properly as there is danger from leakages Risk of terrorism and nuclear weapons. IB Environmental Systems and Societies SL 3 Topic 7: Climate change and energy production Shreya Mozumdar Hydroelectric Harnessed from the High quality energy Costly to build power (HEP) movement of water output compared to Floods surrounding through rivers, lakes low quality energy community and and dams through input landscape turbines to generate Creates water reserves Impacts on local electricity and energy supply hydrology, reducing Reservoirs used for downstream flow of the recreation and tourism river affecting habitat Renewable and water use downstream Silting of the dam Risk of flooding in case of dam burst. Biomass Decaying organic Cheap and readily Replaces food crops matter is used to available and cause starvation in produce methane in If crops are replanted, the remaining biogas generators or it can be a long-term population burned directly sustainable energy When burned, it still More processing source releases GHGs yields oils (rape, Unsustainable palm, cane) which agricultural practices can be used as If crops are not biofuels replanted, it is non- renewable Wood It is acquired from It is a cheap and Not much energy is cutting or coppicing readily available released for its mass trees and is burned energy source Releases GHGs when for heat/light If trees are replaced it burned can be unsustainable Non-renewable if trees are not replanted High transportation costs Solar energy Conversion of solar Infinite energy supply High costs for (photo- energy into Can be used at a manufacturing and voltaic cells) electricity through small-scale for transportation chemical energy households Only work in sunny Safe to use areas Needs maintenance Concentrated Mirrors focus solar Renewable Only works in sunny solar power energy on one point Cheap – as much as areas (CSP) where heat fossil fuel stations Relatively new generated drives a technology steam turbine to make electricity Solar: It uses buildings or Minimal cost if Requires specific type passive panels to capture properly designed of and store heat Renewable technology/professional in limited supply IB Environmental Systems and Societies SL 4 Topic 7: Climate change and energy production Shreya Mozumdar Wind Wind turbines Clean energy supply Only works in windy produce wind power Little maintenance areas Renewable Not near highly populated areas, so transportation costs exist Manufacture and construction are costly Some noise pollution, but it is decreasing Visual pollution May effect birds and their migration Tidal Movement of sea Potential to generate a Construction is costly water drives lot of energy, is also Only some estuaries are turbines sustainable suitable A tidal barrage is Can be bridge and can Can negatively impact built in estuaries prevent flooding wildlife Renewable May reduce tidal flow Wave Movement of sea Renewable Costly construction water in and out of a Can support small May be damaged by cavity on the shore local operations storms compresses trapped Only suitable for air, driving a turbine coastal areas Cannot be used on a national scale Geothermal Cold water is Infinite energy supply Expensive to set up pumped into earth Only suitable in areas and is heated by hot of volcanic activity rocks, coming out as Volcanic activity in steam. The steam rocks can reduce and powers turbines and make it difficult to use creates electricity. Dangerous gases may be released. 7.2. Climate change – causes and impacts Weather is the daily result of changes in temperature, pressure and precipitation in the atmosphere. It describes the conditions in the atmosphere over a short period of time. Climate is the average weather pattern over many years for a particular place on Earth. Weather is measured on a short timescale – day-to-day, while climate is measured for much longer over many years. Both are affected by: o Ocean and atmospheric circulatory systems o Clouds o Forest fires o Volcanic eruptions o Human activity IB Environmental Systems and Societies SL 5 Topic 7: Climate change and energy production Shreya Mozumdar Climate change is a long-term change in the climate and is a natural phenomenon. It is influenced by: o Fluctuations in solar insolation, affecting temperature o Changing proportions of gases in the atmosphere released by organisms Greenhouse gases like carbon dioxide are increased through anthropogenic activities. This is believed to have enhanced the greenhouse effect, causing climate change. Global warming potential (GWP) is a relative measure of how much heat a known mass of a greenhouse gas (GHG) traps over a number of years, compared to the same mass of carbon dioxide. CFCs are chemicals that break down ozone when they reach the stratosphere but are GHGs in the troposphere. They contribute a lot to the enhanced greenhouse effect due to their high GWP and long lifetime in the atmosphere. Since they destroy ozone quickly and in large amounts, they allow more insolation, including UV radiation, to reach the Earth. Water vapour is also a GHG which has the most significant impact on trapping hear but is often excluded because it varies a lot in concentration and is always condensing into water, snow and ice that prevents its action as a GHG. However, it still has an impact. Most GHGs (except CFCs) are in the atmosphere through natural processes, and the increase in their concentration is the concern. CLIMATE CHANGE DEBATE o Debate about the causes: § Enhanced greenhouse effect § Earth’s rotational wobble § Sunspot activity § Increased temperatures increase GHGs § Natural fluctuation, such as after the Ice Age § No climate change o Debate about the effects: who and how many will be affected o Debate about the solutions: § Prevention (Mitigation) § Cure (Adaptation) § No action HOW THE CLIMATE CAN CHANGE o Direct relationship: more change in solar radiation (forcing), more climate change o Buffering action: forcing increases but climate change does not follow linearly: no response o Responds slowly at first, then accelerates to a new equilibrium o Climate makes no response until a threshold after which it changes rapidly and reaches a new equilibrium o Can then get stuck at the new equilibrium even though forcing decreases until it reaches a new threshold and falls rapidly IB Environmental Systems and Societies SL 6 Topic 7: Climate change and energy production Shreya Mozumdar IMPACTS OF CLIMATE CHANGE Effect on Effects Oceans Sea levels rise because water expands when it heats up and increasing and sea temperatures lead ice to melt and fall into the sea, increasing the levels volume of water. Many low-lying nations will be affected, including Bangladesh, the Maldives and the Netherlands. Some like Tuvalu may disappear completely. Oceans absorb carbon dioxide which makes them acidic which may affect marine organisms like corals. Polar ice Melting ice in the North and South poles will lead to rising sea levels. caps Glaciers that melt into the sea increase sea levels. The Greenland ice sheet could melt completely and slow or stop the North Atlantic Drift Current by diluting the salt water. If it slows or shuts down, the climate near the North Pole will become much colder. Melting Arctic ice can open trade routes, ease travel and allow the exploitation of undersea minerals and fossil fuels. Methane clathrate is a type of ice under the Arctic Ocean floor that traps methane. If it melted and reached the surface, large amounts of the GHG methane would be released and trigger rapid temperature increases. On glaciers Glaciers have been decreasing in size since 1850 and some have melted completely. Loss of glacier ice leads to flooding and landslides. Summer glacier melt provides freshwater supply to people living below/downstream from glaciers. They also feed many major rivers, e.g. in Asia fed by the Himalayas On weather More heat means more energy in the climate; thus weather will pattern become more violent and sporadic with more extreme weather events. Increases in global precipitation will lead to soil erosion. Areas that lack water will lead to more irrigation and thus salinization. On food Warmer temperatures will increase the rate of photosynthesis. The production increase in respiration would lead to no significant increase in net primary productivity. In the sea, small increases in temperature can kill plankton that form the basis of marine life. Heat waves and drought kill crops and livestock. On Melting of permafrost in the tundra would release methane trapped in biodiversity the frozen soils. and Animals may adapt or move to cooler regions but plants cannot. The ecosystems distribution of plants can shift as they disperse seeds that only grow in favourable habitats which would be in different places due to climate change. This happens too slowly to prevent extinction of the plants which could impact food chains. Polar species would become extinct in the wild. IB Environmental Systems and Societies SL 7 Topic 7: Climate change and energy production Shreya Mozumdar Increased droughts can cause wildfires that can wipe out species and habitats. Increased temperature of fresh and salt water can kill sensitive species. Forest fires in peat bogs lead to carbon emissions. Increased temperatures of the sea can cause coral bleaching because the zooxanthellae algae are expelled from the coral by this. This could have significant impacts on the ecosystem. On water Increased evaporation rates due to increased temperatures can cause supplies water bodies to dry up. Extreme weather events like floods lead to economic water scarcity by contaminating water. Droughts lead to physical water scarcity. On human Heat waves lead to deaths. health Insect carriers of diseases like malaria will spread to other regions as they become warmer. Warmer seas, lakes and rivers contribute to algal blooms, some of which make water toxic and kill humans. Wetter climates will face increased fungal infections while drier ones will face asthma and other problems due to increased dust. On human Shortages of food and water will lead to migration migration Rises in sea levels and devastation from extreme weather events will also prompt migration. IB Environmental Systems and Societies SL 8 Topic 7: Climate change and energy production Shreya Mozumdar 7.3. Climate change: mitigation and adaptation TYPES OF SOLUTIONS TO CLIMATE CHANGE o Climate mitigation refers to strategies that attempt to reduce the causes of climate change – they are preventive measures. o Climate adaptation refers to strategies that attempt to manage the impacts of climate change – they are reactive measures. MITIGATION STRATEGIES Area Actions Evaluation Energy Supply Improved supply and efficiency of Difficult to implement due to distribution constraints like high costs for Switching fuel from coal to gas or developing countries and high nuclear power costs of research into and set up Using renewable energy sources of alternative energy sources Carbon capture and storage – Partiality in distributing cap-and- capturing from emissions and trade permits storing it underground Problems with nuclear power Reducing fossil fuel subsidies, Gas still releases GHGs imposing carbon taxes, cap-and- Govt may not be willing to trade subsidise energy sources that are Subsidies on renewable energy not completely developed and tax others as it may harm big businesses that contribute to the economy – trade-off between economy and environment, especially in LEDCs Transport Using fuel-efficient vehicles Difficulties in enforcing the (hybrid, clean diesel, biofuels, regulations on parking, entering electric cars) the city centre, types of fuel, etc. Shift from private cars to using Where incomes are high, these public transport, cycling or may not make a difference as walking people can just continue to pay Use of biofuels for them High-efficiency aircraft Biofuels can reduce the amount Taxes on buying vehicles used as food crops and cause Restrictions on parking, entering starvation city centre on certain days, odd- Biofuels can promote even scheme, etc. unsustainable agricultural Investing in improving public practices transport and providing more Costs of improved public attractive facilities transport, better aircraft, etc. may be high for LEDCs IB Environmental Systems and Societies SL 9 Topic 7: Climate change and energy production Shreya Mozumdar Buildings Efficient lighting and daylighting – Revision of standards and lights with motion sensors, focus monitoring and enforcement of on using natural light in the these rules are required daytime May have high costs of doing Efficient electrical appliances, this in LEDCs and research is heating and cooling devices required too Improved insulation to reduce the need for heating in winter (double glazing of windows, space between walls to trap heat) Using heat from AC and refrigerator in supermarkets to heat offices and homes Special requirements for making buildings Incentives for energy service companies Industry More efficient electronic May be expensive to develop equipment Difficult to calculate the correct Control of non-CO2 gas emissions amount of tax/correct cap or limit Use of scrubbers/ flue gas of carbon that can be released desulphurisation (FGD) Govt may be partial in giving Subsidies for renewable/clean permits technologies Large companies may pay taxes Carbon taxes, cap-and-trade and not reduce emissions schemes Consumers bear the costs of using scrubbers and FGD CO2 is most important and must be regulated Agriculture Improved crop and grazing land Difficult to enforce management to increase carbon Alternatives are not yet clear and retention potential of the soil may be difficult or expensive to Restoring peat soil and degraded develop land May involve high use of water, Agroforestry to increase tree cover like hydroponics Improved rice cultivation techniques that release less methane Subsidies/incentives from the government to improve land management Forestry/forests Afforestation Involving the local community Reforestation can help and will increase Preventing deforestation ecotourism/sustainable Use of alternative energy sources management from forests like biomass Difficult to enforce Difficult to finance IB Environmental Systems and Societies SL 10 Topic 7: Climate change and energy production Shreya Mozumdar Subsidy/incentive to reduce deforestation or to afforest areas Waste Incinerating waste and producing Difficult to enforce energy from it Difficult to finance Composting organic waste Incineration releases GHGs Treatment of wastewater Methane recovery from landfills Subsidies/incentives to do the above Regulations about composting and use of landfills ADAPTATION STRATEGIES Area Actions Evaluation Water Increased rainwater harvesting High costs of developing new Water re-use technologies Desalination Carbon emissions from Making water from air (Israel desalination does this using a technology called Watergen) Agriculture Using drought-resistant crops Cost of developing and Prevention of soil erosion implementing the technology through farming techniques Costs of government of Subsidies for doing the above providing subsidies Research into developing Longer growing seasons in efficient agricultural techniques higher latitudes Training and educating farmers Infrastructure Relocation Costs of building and Building seawalls and storm developing the infrastructure surge barriers Costs of maintenance Dune reinforcement to prevent Problems to the coastline and eroding coastline animals Land acquisition and creation of marshlands/mangroves to buffer sea level rise Protect wetlands Human Vaccination programs for new Difficult to find out about and health diseases be precise as to who will be Improved disease surveillance affected most and control Costs Improve water supply and Improved quality of life sanitation Regional and international cooperation Tourism Diversifying tourist attractions Difficulties in marketing new and revenue locations Artificial snow-making Costs IB Environmental Systems and Societies SL 11 Topic 7: Climate change and energy production Shreya Mozumdar Subsidies to improve tourism Snow-making may increase according to climate energy use Increased revenue