P.1 Book E3 Section 3.2 Environmental impact of energy consumption 3.2Environmental impact of energy consumption Venus Impact on environment and society Greenhouse gases and global warming Energy consumption patterns Check-point 6

P.2 Book E3 Section 3.2 Environmental impact of energy consumption Venus However, unlike earth, the surface temperature of Venus is over 460  C.  Hotter than Mercuryeven if it is twice Mercury’s distance from the sun Why is Venus such a hot planet? Venus and earth are similar in size, gravity, etc.

P.3 Book E3 Section 3.2 Environmental impact of energy consumption 1 Impact on environment and society All energy sources should undergo some processes before their energy become ‘usable’: extraction distribution conversion consumption

P.4 Book E3 Section 3.2 Environmental impact of energy consumption 1 Impact on environment and society a Extraction Energy sources have to undergo extraction. E.g.fossil fuels are extracted underground or under the seabed. Mining for fuels may involve deforestation.  Induces erosion and landslides  Destroys the habitat for animals and plants

P.5 Book E3 Section 3.2 Environmental impact of energy consumption a Extraction Mining produces loose debris.  Carried by wind and water to streams and rivers nearby  Water pollution Mining may release toxic chemicals & heavy metals (e.g. coal mining releases ~20 toxic chemicals).  Serious pollution Mining results in land occupancy.  Land development hindered

P.6 Book E3 Section 3.2 Environmental impact of energy consumption 1 Impact on environment and society b Conversion The energy in energy sources usually needs to be converted into other forms of energy before it can be used by the end-users. E.g.Burning fossil fuels: chemical energy of fuels  internal energy of water (  electrical energy) E.g.Using wind power: KE of air particles  electrical energy

P.7 Book E3 Section 3.2 Environmental impact of energy consumption b Conversion However, power stations use water as coolant.  Hot used water discharged to rivers or seas  Thermal pollution  Marine life endangered

P.8 Book E3 Section 3.2 Environmental impact of energy consumption b Conversion Burning fossil fuels releases pollutants. global warming acid rain CO 2 and methane (greenhouse gases) sulphur dioxide + water nitrogen oxides + sunlight smog

P.9 Book E3 Section 3.2 Environmental impact of energy consumption b Conversion Renewable energy sources (e.g. wind, hydroelectric & solar power) do not apply combustion to generate electricity.  Do not produce air pollutants  Wind turbines may cause noise pollution.  In building hydroelectric power stations, land may be drowned.  People have to move; animals and plants may lose their habitat. However, renewable energy also affect the environment:

P.10 Book E3 Section 3.2 Environmental impact of energy consumption 1 Impact on environment and society c Distribution The electricity generated by power stations are usually transmitted and distributed by overhead and underground power cables at high tension.  Produce strong EM fields  May increase the chance of getting leukemia (blood cancer)

P.11 Book E3 Section 3.2 Environmental impact of energy consumption 1 Impact on environment and society d Consumption We cannot use energy without control. Energy cannot be destroyed  All used energy will finally change into heat (internal energy).  Heat island effect  Higher temperature in urban areas

P.12 Book E3 Section 3.2 Environmental impact of energy consumption d Consumption Using more electricity  More electricity generation  More serious pollution Furthermore, non-renewable energy sources like fossil fuels are running out. How long can they last depends largely on the way we use energy. Nuclear power Example 8

P.13 Book E3 Section 3.2 Environmental impact of energy consumption Example 8 Nuclear power Some countries invest heavily in the development of nuclear energy to meet their surging power demands. Find out the various impacts of the extraction and conversion of nuclear power on environment and society.

P.14 Book E3 Section 3.2 Environmental impact of energy consumption Example 8 Nuclear power Extraction Uranium is extracted from mines.  The waste may contaminate groundwater and surface water resources with heavy metals and traces of radioactive uranium. Machines powered by fossil fuels are used for mining, enrichment and transportation of uranium.  Emits air pollutants

P.15 Book E3 Section 3.2 Environmental impact of energy consumption Example 8 Nuclear power Conversion Water is used as coolant.  Hot water is released back to rivers or seas.  Thermal pollution A large amount of water is needed for producing steam and cooling.  Damage the aquatic resources that animals and plants require

P.16 Book E3 Section 3.2 Environmental impact of energy consumption Example 8 Nuclear power Conversion Accidents may occur in nuclear reactors.  Leakage of radiation Radioactive nuclear wastes are have to be buried underground for a very long time.  Prevent the land from future uses

P.17 Book E3 Section 3.2 Environmental impact of energy consumption 2 Greenhouse gases and global warming a Greenhouse effect The earth’s atmosphere behaves like a greenhouse.  Greenhouse effect

P.18 Book E3 Section 3.2 Environmental impact of energy consumption a Greenhouse effect The earth’s surface absorbs solar energy and emits infra-red radiation.  Greenhouse gases (e.g. CO 2, methane, water and ozone) absorb the radiations and re-radiate.  Some radiation returns to the earth  Keep the earth warm (~15  C) (would drop to –18  C without atmosphere)

P.19 Book E3 Section 3.2 Environmental impact of energy consumption 2 Greenhouse gases and global warming b Global warming The greenhouse effect is essential for life on earth. However, our atmosphere contains more and more greenhouse gases.  Greenhouse effect enhanced  Earth’s surface temperature   Global warming 3.1 Greenhouse effect and global warming Video

P.20 Book E3 Section 3.2 Environmental impact of energy consumption b Global warming Results of global warming: 1.Rise in sea levels Warmer earth  ice sheets at the poles melt  sea level rise  more coastal flooding

P.21 Book E3 Section 3.2 Environmental impact of energy consumption b Global warming Results of global warming: 2.Changes in climate The world rainfall patterns change.  More extreme weather conditions (e.g. rainstorm or drought) 3.Spread of diseases A warmer climate favours the spread of diseases like dengue fever.

P.22 Book E3 Section 3.2 Environmental impact of energy consumption b Global warming The fast increase in greenhouse gases is due to the following human activities: 1.Burning of fossil fuels releases a lot of greenhouse gases (e.g. CO 2 and methane)

P.23 Book E3 Section 3.2 Environmental impact of energy consumption b Global warming 2.Destruction of forests Plants absorb CO 2. However, some forests are burnt and cleared for development.   CO 2 in the atmosphere

P.24 Book E3 Section 3.2 Environmental impact of energy consumption b Global warming 3.Growth in population Population   Demand of energy   Greenhouse gases  Need of food   More livestock like cattle and sheep are reared.  More greenhouse gases are given out. Greenhouse gases Example 9

P.25 Book E3 Section 3.2 Environmental impact of energy consumption Example 9 Greenhouse gases (a)What are greenhouse gases? Name two examples of such gases that exist naturally. Greenhouse gases  Contribute to the greenhouse effect  Absorb the radiation emitted by the earth   heat loss through radiation  Makes the earth warmer Examples: CO 2 and water vapour

P.26 Book E3 Section 3.2 Environmental impact of energy consumption Example 9 Greenhouse gases (b)Discuss the effect of uncontrolled greenhouse gas emission. Greenhouse gases are emitted without control.  Concentration in the atmosphere   More radiation emitted by the earth absorbed  More energy retained in the earth  Global warming  Climate change and rise in sea levels

P.27 Book E3 Section 3.2 Environmental impact of energy consumption 3 Energy consumption patterns In HK, fossil fuels act as the main source of energy.  Include coal, natural gas and oil  Coal and natural gas  Generation of electricity  Coal and oil  Refined into products like gasoline, diesel, town gas and liquefied petroleum gas (LPG) for transportation, residential and industrial uses.

P.28 Book E3 Section 3.2 Environmental impact of energy consumption 3 Energy consumption patterns Consumption of different types of fuel: Consumption of electricity, town gas and LPG   Overall consumption  However, the use of coal and oil products 

P.29 Book E3 Section 3.2 Environmental impact of energy consumption 3 Energy consumption patterns Electricity end-uses in 1997 and 2007:  Main use: air-conditioning & lighting  A significant drop in the industrial sector ∵ Industrial processes move to the mainland.

P.30 Book E3 Section 3.2 Environmental impact of energy consumption 3 Energy consumption patterns Oil and coal products end-uses in 1997 and 2007:  Main use: transportation  A significant increase in the car sector ∵ The growth of population and commerce  A significant drop in the industrial sector ∵ Industrial processes move to the mainland

P.31 Book E3 Section 3.2 Environmental impact of energy consumption 3 Energy consumption patterns Town gas and LPG end-uses in 1997 and 2007:  Main use: cooking and heating water  A significant increase in the transportation ∵ Replacement of some diesel taxis with LPG ones (which emit less air pollutants)

P.32 Book E3 Section 3.2 Environmental impact of energy consumption 3 Energy consumption patterns Summary:  Relocation of industrial processes to the mainland  consumption of oil and coal products and electricity  The steady increase of consumption  demand of energy in the commercial and residential sectors

P.33 Book E3 Section 3.2 Environmental impact of energy consumption A oxygen B carbon dioxide C sulphur dioxide D water vapour E ozone F methane Check-point 6 – Q1 Which of the following are greenhouse gases?

P.34 Book E3 Section 3.2 Environmental impact of energy consumption Check-point 6 – Q2 The greenhouse gases in the atmosphere cause greenhouse effect. Why is greenhouse effect good to us? Why is the enhanced effect bad to us? Give a point for each side. Good:Keeping the earth’s surface at a temperature suitable for life Bad:Causing more extreme weather conditions

P.35 Book E3 Section 3.2 Environmental impact of energy consumption Check-point 6 – Q3 A power station uses coal fuel. Suggest two environmental problems caused in the conversion process. (1) Global warming (2) Acid rain

P.36 Book E3 Section 3.2 Environmental impact of energy consumption The End