3.4 Energy and water resources
Candidates should be able to:
• Describe the significance of fuelwood in LEDCs and of non-renewable fossil fuels in terms of their availability in certain areas and in terms of the contribution made by coal, oil, natural gas and wood in supplying vast amounts of energy.
• Describe the growing significance of renewable energy supplies (geothermal, wind, running water, solar, biofuels) to reduce dependence upon fossil fuels, to alleviate the world’s energy crisis, and to offer opportunities for the development of alternative energy sources.
• Describe the factors influencing the siting of different types of electrical power stations with reference to those listed in the syllabus (thermal, hydro-electric power, nuclear).
• Describe the uses made of water for agriculture, domestic and industrial demand. Candidates should also recognise that in certain areas there are water shortages which impact upon the local people and the potential for development. This leads to competition for the use of the available water resources and requires careful management.
All these aspects would benefit from the selection of appropriate case studies.
3.5 Environmental risks and benefits: resource conservation and management
Candidates should be able to:
• Demonstrate the need for sustainable development, resource conservation and management in different environments. It is not intended that candidates should be familiar with a wide variety of illustrations here. Rather that by the use of well selected case studies, possibly integrated with the study of other concepts referred to above, candidates become familiar with general principles and can illustrate from these examples.
• Identify and describe the benefits associated with the development of agriculture, mining and quarrying, energy production, manufacturing industries, transport and tourism. This could be incorporated with the studies outlined above (3.1–3.4).
• Describe how these developments may also pose threats to the environment when natural ecosystems are interfered with including: soil erosion, global warming, and pollution (air, water, noise and visual).
• Identify areas at risk from these threats to the environment and describe attempts made to maintain, conserve or improve the quality of the environment.
Energy
Non-renewable energy: Energy that can not be reproduced in the time that it takes to consume it e.g. coal.
Renewable energy: Energy that is naturally occurring and potentially infinite.
Fossil fuels: Any combustible organic matter that is made from the remains of former flora and fauna.
Raw material: Any unprocessed material.
Global Energy
As the world's population continues to grow and as peoples level of development continues to grow, so does the demand for energy. In traditional less developed societies the main source of energy tends to be fuelwood. Fuelwood can be used for heating, cooking and even scaring away wild animals.
As countries begin to develop they can begin to afford to buy raw materials and to build power stations. Most commonly fossil fuels are burned because the technology exists and at the moment they are widely available.
However, as countries develop further their sources of energy may change again. They will probably still be heavily dependent on fossil fuels, but will begin to use more renewable energy and probably more nuclear. The reasons for the change include:
Greater concern for the environment
Rising prices of fossil fuels
The knowledge that fossil fuels are finite
Aim to reduce reliance on fossil fuel exporting countries
Improvements in renewable technology
The hope of developing and selling renewable technology
Better technology and increased stability allowing nuclear development
There are always some exceptions to the rule. For example Costa Rica gets the majority of its power from renewable sources and countries like Lithuania and France get nearly all of theirs from nuclear.
Primary Energy Consumption in Major Countries (British Petroleum)
Type on non-renewable energy (fossil fuel)
Advantages
Disadvantages
Coal
Energy production using coal can be increased or decreased according to demand
The technology to burn coal to generate electricity already exists
Coal is finite so will eventually run out.
Many existing reserves are becoming harder to extract or are in environmentally sensitive areas
Coal releases large amounts of greenhouses gases when burnt
Mining deep underground coal is very dangerous
Coal is very baulky and expensive to transport around the world
Oil
Energy production using oil can be increased or decreased according to demand
The technology to burn oil to generate electricity already exists
Technology is improving to extract deeper reserves as well oil in tar sands (Canada).
Oil is finite so will eventually run out
A lot of oil is located in politically unstable countries or environmentally sensitive areas e.g. Libya and Iraq.
Oil can cause widespread pollution when spilt
Oil releases large amounts of greenhouse gases when burnt
Oil is vulnerable to large scale changes in its price
The production of oil refineries is expensive
Gas
Energy production using gas can be increased or decreased according to demand
The technology to burn gas to generate electricity already exists
Burning gas releases less greenhouses gases then coal and oil
It is now possible to compress gas and transport it more easily.
Gas is finite so will eventually run out
A lot of gas is located in politically unstable countries or environmentally sensitive areas.
Gas is vulnerable to leaks and explosions
Type of Renewable Energy
Advantages
Disadvantages
Solar: Using the power of the sun to heat water or generate electricity.
It is a clean form of energy
It is a infinite resource
Panels can be used locally e.g. on top of someones house
It can be used to heat water and generate electricity.
It is expensive to make solar panels
The sun does not shine all the time
Not every country gets adequate levels of sun
They can't be used at night
It is hard store surplus energy
Supply does not always equal demand
Wind: Using the power of the wind to drive a turbine to generate electricity.
It is a clean form of energy
It is an infinite resource
It can be used on a local scale e.g. in your back garden
Technology is proven
They can be placed at sea on in mountains away from settlements
Visual pollution (NIMBY - see below)
Noise pollution
Wind is unreliable
They are expensive to install, especially offshore
It is hard to store surplus energy
They have to be turned off in very strong winds
Tidal: Using the incoming and outgoing motion of the tide to generate electricity.
It is a clean form of energy
It is an infinite resource, tides happen twice a day.
Ideal for island countries.
It can block important shipping routes
May interfere with some animals e.g. sea otters and seals
Limited number of sites
Useless for landlocked countries
High start up costs. The technology is still being developed
May be damaged by tropical storms
Wave: Using the motion of waves to generate electricity.
It is a clean form of energy
It is a infinite resource
Ideal for island countries.
Again it can block shipping routes and interfere with animals
Again not suitable for landlocked countries
The strength of waves can vary
May be damaged by tropical storms
The technology is still being developed.
HEP (Hydroelectric power): Using the power of falling water in rivers to drive generators. At the moment dams have to be built to create HEP power.
It is a clean form of energy
It is finite as long as rivers are managed properly.
The built dam can also prevent flooding.
The reservoir behind the dam can be a store of water.
Only a limited number of suitable rivers
Can hamper navigation up and down river
Reservoirs may force resettlement
Migration patterns of animals maybe disrupted
Dams reduce the deposition of alluvium downstream
Dams can flood large areas of land.
Biofuels: The use of biological matter to create energy. It is a renewable form of energy, but because the mater is often burnt it still releases greenhouse gases.
It is a renewable form of energy as long as people replant crops.
It is cheap and the resources can be grown locally
It can still release greenhouse gases.
Areas can be deforested to grow crops for energy generation.
If crops are used for energy production it can lead to an increase in food prices.
Geothermal: Geothermal uses thermal energy from the earth to heat water. The water can be used as a source of hot water or the steam released can be used to drive turbines.
It is a clean renewable form of energy.
It is a finite resource.
Can be used to heat water and generate electricity.
Geothermal energy can be created constantly and is not dependent on the weather.
Not every country has geothermal potential.
Installation and start up costs are expensive
Drilling can release harmful gases.
Geothermal activity can change which can make the production of energy harder
NIMBY: Not in my backyard is a phenomenon where people support ideas, but do not want those ideas implemented in their neighbourhood or near their house. For example most people support wind energy, but do not want a wind turbine built near their house.
Nuclear Energy
Some people consider nuclear energy to be a renewable energy. However, because nuclear energy uses uranium and uranium is non-renewable, then nuclear energy should also be considered to be non-renewable. Although the first man-made reactor was first operated in 1942 in the US, the first electricity producing nuclear power station was not completed until 1951.
It is estimated that nuclear power provides about 14% of the world's electricity (6% of its energy). Japan (all nuclear reactors are temporarily closed after the Fukashima Disaster), US and France combined account for about 50% of the world's nuclear power produced although the IAEA say that there are 439 nuclear power stations in 31 countries (IAEA, 2007).
Nuclear power has created widespread debate, because some people see it as a solution to declining fossil fuels while others worry about the waste produced, the technology falling into the wrong hands and accidents.
The world's two biggest nuclear accidents happened in Chernobyl (Ukraine) in 1986 and Fukushima (Japan) in 2011. The Fukushima accident was caused by a giant earthquake and tsunami that hit the east coast of Japan on 11th March 2011. The tsunami broke the generators connection to the power grid and flooded emergency generators. This meant that water could not be pumped into the reactors to cool them - this resulted in a meltdown of reactors 1, 2 ad 3. The result of the disaster has been contamination of the land and sea near the plant and the enforcement of a 20km exclusion zone. Japan has also said that it will start to reduce its dependence on nuclear power and look for alternatives.
Although all countries reserve the right to develop nuclear power technology, many countries in the world have signed the 'Nuclear Non-Proliferation Treaty'. The treaty forbids the development of nuclear weapons. The UN and many other countries are worried that Iran and North Korea are developing nuclear technology for the use in weapons.
IAEA: The International Atomic Agency is a UN organisation that seeks to promote the peaceful use of nuclear energy.
The technology to make nuclear power already exists.
There is a plentiful supply of uranium, enough to last hundreds of years.
Nuclear energy releases very low amounts of greenhouse gases.
It reduces the dependency on oil, coal and gas producing countries
Nuclear waste can be safely stored underground
The supply of electricity can be altered depending on the demand.
There is always the risk of nuclear accidents like the Chernobyl accident in the Ukraine
There is a risk that nuclear power stations will become terrorist targets or that nuclear material will fall into the hands of terrorists.
Countries can use nuclear technology to make nuclear weapons. North Korea and Iran have both been accused of doing this.
Transporting nuclear material and nuclear waste is risky and expensive.
Nuclear power stations only have a limited life period and the cost of decommissioning them is expensive.
There is a belief that living next to nuclear power stations can increase the risk of cancers (leukemia).
People don't want nuclear power stations built near where they live i.e. NIMBY
Mining for uranium is dangerous and can be polluting.
Nuclear waste remains radioactive for thousands of years (it has a very long half life)
Fuelwood
Fuelwood is the most common source of energy for people living in LEDCs - it is estimated that about 40% of the world's population rely on fuelwood. Fuelwood is often the main source of energy because countries either can't afford to buy raw materials to produce energy, don't have the technology or money to build and operate powers stations and certainly don't have a national grid to distribute energy. Fuelwood has multiple functions, it can be used for cooking, heating and scaring away wild animals. Although using fuelwood is essential for many people it can cause environmental and social problems. Problems include:
Deforestation
Biodiversity loss (vegetation is removed and animals lose their home)
Desertification and reduced rainfall
Increased soil erosion and increased sandstorms
Increased time spent looking for wood
Children taken out of school to look for wood
Dangers posed by collecting wood (wild animals and criminals)
Dangers of breathing in smoke inside houses
Risk of fire within houses
Location of Power Stations
Three Gorges Dam
The Three Gorges Dam is the largest hydroelectric power station in the world. The dam is over 2km wide and it produces 22,500 MW of electricity. The HEP is located on the Yangtse River in Central China. China is the most populated country in the world and the Yangtse is the third longest river in the world. The site of the Three Gorges Dam was chosen over 15 other sites in China. Its location was picked for the following reasons:
As the third largest river in the world the river offered huge hydroelectric potential
The river valley was wide and flat making building easier
The bedrock was firm with limited cracks and fissures making it stronger
There was a small island in the river channel which made it easy to create a diversion channel during building
Despite large parts of China being seismically active, the area around the dam has not suffered any recent major quakes
There were towns and cities that needed to be relocated, but in communist China it was easy to purchase homes and relocate people e.g. Fengdu
China has a huge population (over 1.3 billion) so it was easy to mobilise workers
For information about the Three Gorges Hydroelectric power station go to: IGCSE Rivers
Sizewell A and B, UK - Nuclear Power Station
Sizewell A and B are locate near the village of Sizewell in Suffolk. Suffolk is county of England located in the east in a part of England called East Anglia. Sizewell is located on the coast next to the North Sea. Although Sizewell A is now being decommissioned (shut down), Sizewell B is still in use and there are proposals for a third. The location of Sizewll was chosen for the following reasons:
Close to the sea so seawater can be used for cooling
Close to the coast so raw materials (uranium) can be imported and waste exported.
Away from major population centres who may fear impacts of nuclear power (NIMBY)
It has a nearby rail link and road links - nuclear waste is actually transported by train to Sellafield (a different nuclear site)
Flat ground with plenty of extra land available for expansion
It is on a slight plateau so sited about the level of coastal flooding
Connections to the national grid
Ratcliffe-on-Soar, UK - Thermal Power Station (coal)
A thermal power station is any power station that uses fossil fuels as its fuel. The Ratcliffe-on-Soar power station is located in the county of Nottinghamshire in central England. The power station was initially commissioned in 1968 and generates about 2,000 MW of electricity which can meet the needs of about 2 million people. The power station generates electricity using coal. The location of the power station was chosen because:
It is close to the River Trent so waster can be easily obtained for cooling
It is close the M1 motorway so raw materials can be transported to the power station easily.
When built it was close to the Derbyshire and Nottinghamshire coal mines - although most have now closed.
It was connected to the national grid
It was close to the major population centres of Derby, Leicester and Nottingham - supply of workers
It was located outside of any major cities to reduce protests (NIMBY)
It has a railway nearby to help with transportation of workers and materials
It was built on flat land (floodplain)
Changing Energy Use in the UK (1940-Present)
In the 1950's the main source of UK energy was coal. This was because the UK had huge reserves of coal in the NE, in the Midlands and in South Wales. In just two counties (Northumberland and Durham) there were nearly 1000 coal mines. In the 1940's nearly 90% of energy was supplied by coal and in 1960 its still stood at over 76%. From the 1960's the reliance on coal started to fall down to its present total of about 34%. The reason that the reliance on coal fell, is because British reserves began to decline and became more expensive to extract (deep underground and rising labour and health and safety costs) and because of the development of nuclear energy.
The UK's first nuclear power station opened in 1956 leading to an increase in its use. The peak of nuclear production was in 1997 when 26% of UK energy was produced by nuclear. Nuclear became popular because it reduced reliance on imports of foreign raw materials and was seen as a cleaner energy. The UK currently has 9 operational nuclear power stations producing about 15% of energy. It is unclear how this figure will change in the future. There are plans for further nuclear power stations, but the risk of accidents, problems of waste disposal and expensive construction costs may mean alternatives are sought.
Gas is currently the biggest supplier of UK energy. The use of gas increased with the discovery of gas in the North and Irish Sea and because it was seen as been cleaner than coal. There are currently about 45 gas fired power stations producing about 43% of the UK's energy needs. However, because gas is finite and because the UK now has import over 40% of its gas, its importance may change in the future.
Because of the debate over nuclear usage, the declining supplies over fossil fuels and increased environmental awareness, the UK hopes to produce more renewable energy in the future. By 2020 the UK aims to produce about 15% of its energy from renewables. The overall European Union target is 20% by 2020. As an island nation it has great potential for tidal, wave and wind power. Because of its climate solar is never going to play a major role and because of the size of its rivers, hydroelectric is always going to be small scale. Biomass and biogas are going to be used, but because they still release greenhouse emissions they are not going to help the UK meeting carbon reduction targets.
In 2011 the UK had 296 wind farms and over 3,400 turbines. There are proposals for hundreds of more wind farms but because of protests (NIMBY) many have been delayed or are being forced offshore which is very expensive. Tidal and wave technology is still in its infancy, but the UK leads the research in both fields so hopes to see increased production in the future. Tidal power needs very specific conditions for it to work and only about 20 ideal sites have been found around the world, 8 of which are in the UK.
The majority of the world's water is seawater (about 97%). This leaves only 3% that is potentially useful for humans. However, out of this freshwater the majority is frozen (about 69%) or under the ground (about 30%). This means that only about 0.01% of the earth's water is useful and easily accessible.
In terms of surface water, the large continents of North America, Asia and Africa have the most. Australia that has a very arid climate, especially towards the centre has very little surface water. Every continent has a large supply of groundwater. However, groundwater can be hard to extract because it can be deep underground and often large distances from where it is needed - this makes extraction and transport expensive. Although groundwater is useful, unless it is managed properly and replaced, it can cause problems like salinisation and ground subsidence.
Even though the world has a lot of frozen water (glaciers and ice caps) the water is not useful because you would have to melt it, releasing large amounts of greenhouse gases and altering local ecosystems and then you would have to transport it large distances to where it is needed.
Groundwater: Water found underneath the surface of the earth.
Surface water: Water found above the surface of the earth.
How is Water Used?
Agriculture is by far the World's biggest user of water. Water is used for animals, but the majority is used for irrigation. The amount being used by agriculture is also increasing as the World's population increases and the demand for food increases. Household or domestic use in the next biggest user. The most water is usually used in toilets, but also washing machines and shower/baths use significant percentages. Industry and energy production also uses large percentages in manufacturing and cooling processes. The fourth biggest user is actually water lost through evaporation and leaks in reservoirs.
Groundwater
Groundwater is water stored under the ground. Water can be held in porous rocks called aquifers. With increasing demand for water, groundwater is being demanded more and more.
Aquifer: Rocks that can hold water. Aquifers are called ''confined'' if they are surrounded and contained by aquitards and aquicludes. Unconfined are not contained by aquitards and aquicludes and instead their upper limit is the water table. Aquiclude: Rock that will not hold water or allow its movement i.e. they are non-porous and impermeable. Aquitard: A layer of rock that limits the movement of groundwater. It may be non-porous and has low hydraulic conductivity e.g. it is a clay that water finds it hard to pass through. Water table: The boundary between saturated and unsaturated ground.
If groundwater is not used sustainable i.e. more is taken than is replaced, then it can cause a number of problems including:
Salinisation: An increase in the salinity (salt content) of water. Salinisation may happen if more water is being removed from an aquifer than is being replaced causing the concentration of salt to increase. Saltwater intrusion: When aquifers near the coast are depleted and saltwater leaks into the aquifer changing its salinity. Subsidence: This is the collapsing of ground. Ground may collapse if water has been abstracted (removed) from an aquifer underground. Parts of Mexico City are subsiding because of over abstraction.
Economic water scarcity: This is when water is available, but for some reason it is inaccessible or unusable. This might because it is groundwater that is expensive to extract or that the cost of transporting it is too expensive or simply that the supply of water has become polluted.
Physical water scarcity: This is when there is not enough water available. The most common reason for this is low precipitation rates.
Water stress: This is when the demand for water exceeds the supply of water causing water shortages. Water shortages are known as droughts.
Water stress basically happens when demand exceeds supply. Below are some of the main reasons why demand is increasing and supply falling.
GROWING DEMAND
FALLING SUPPLY
Population Growth: As with many of the world's resources, they are coming under increasing pressure as the world's population grows. The world's population now stands at 7 billion, all of whom are placing increasing pressure on water resources as they develop and get richer.
Domestic Demand: The demand from households is not only increasing because there are more households in the world, but also because the amount of water they want is increasing with development. For example as peoples income increases and they move into permanent residences, they demand flush toilets, bath/showers, washing machines, dishwashers and green gardens, all of which use large amounts of water.
Agricultural Demand: As can be seen below, agricultural places by far the biggest demand on water. With a growing population, global warming and the movement in to less favourable agricultural regions, the demand from agriculture is only likely to increase in the future.
Industrial Demand: As the world's population grows and becomes richer our demand for industrial products grows. Many industrial products, particular things like metal making use huge quantities of water and place increasing demand on resources. Also mining for the raw materials used in manufacturing use large quantities of water.
Energy Production: Although HEP is the most obvious form of energy that uses water, this water is released into rivers once it has passed through the dam. Other types of energy that uses large amount of water for cooling e.g. coal and nuclear power, may pollute water or see it evaporated removing it from local use.
Climate Change: Climate change is impacting the availability of water in many ways. Global warming maybe releasing freshwater from glaciers and ice shelves,but unfortunately much of it is running directly into the oceans. The subsequent rising sea levels are threatening many coastal freshwater wetlands as well as increasing the risk of saltwater intrusion into aquifers. Warmer temperatures are increasing the amount of evaporation from rivers and surfaces stores.
Groundwater Depletion: If water used unsustainable i.e. more is taken out than is being recharged then aquifers can suffer from salinisation and saltwater intrusion. If you increase the concentration of water it can become too salty for human to use. Also if you drain aquifers near coastal areas, then they can become full of saltwater, again making them useless.
Sewage: With rapid urbanisation taking place in many cities around the world, infrastructure often does not keep up with new arrivals. The growth of informal settlements without proper sewage treatment can mean that human waste is often pumped directly into water sources. However, this is not only a problem in LEDCs, in London the sewer system can not cope and an estimated 39 million tonnes of sewage are dumped in the River Thames annually.
Pollution: As the world's population grows so does the demand for agricultural and industrial products. Our thirst for agricultural products is increasing the use of fertilisers and pesticides which often run off into rivers and lakes or leach down to groundwater stores. Like wise our increasing demand for industrial and at times relaxed environmental regulations mean more chemicals and metals are being released into our water sources. Sewage treatment also often lags behind population growth so increasingly our rivers and lakes are being polluted by sewage.
Political: In many countries or regions, water sources are shared e.g. the River Nile flows through eleven countries. At times some countries control large percentages of the shared resource, leading to shortages for other countries. Egypt and Sudan historically control much of the Nile's water and refuse to let other countries along the Nile use it.
Mismanagement: If water is not used sustainably or used inappropriately then water shortages can occur. One of the most famous examples is the Aral Sea. The Aral Sea is located on the border of Kazakhstan and Uzbekistan. Water was taken from the two rivers that fed the Aral Sea to irrigate the desert and grow cotton. Unfortunately so much water was needed to grow cotton in the desert, that no water reached the Aral Sea and it began to dry up, causing huge water shortages.
The map above shows that North America, Europe and Northern Asia are unlikely to experience any water shortages in the future. This is because they have the technology to access water supplies and they have fairly reliable sources (mostly precipitation). Although large parts of South America, Africa and SE Asia have very wet rainy seasons, they are forecast to have water shortages in the future. This is because demand is increasing, but also because they don't have the technology or infrastructure to store, transport and treat large quantities of water. As you would expect the fairly arid areas on North Africa, the Middle East and South Asia that have low levels of precipitation, but growing populations are likely to suffer from physical water scarcity. Water map shows billions at risk of 'water insecurity' - BBC article
Problems Caused by Water Shortages and Water Pollution
Possible Solutions to Water Shortages and Water Pollution
Drought: If there are economic or physical water scarcity and water stress exists then drought can occur. Drought is below average supply of water over a prolonged period. Because drought is below average supply of water, even relatively wet country's like the UK can suffer from drought.
Crop Failure: If there is a shortage of water and farmers can not irrigate their crops then they begin to die.
Livestock Deaths: If livestock don't have enough water to drink they will begin to die.
Famine: If cops are failing and livestock are dieing then people will become undernourished and suffer from famine.
Groundwater Depletion (subsidence and saltwater intrusion): If aquifers begin to dry up or are used unsustainably, then the ground above can subside (collapse) or the aquifer can suffer from salinisation or saltwater intrusion.
Conflict: If there is a limited supply of water and water resources are shared conflict can arise. The ongoing border dispute between Israel and Palestine is often blamed on water shortages
Refugees: If there is drought and famine then people are forced to relocate or face death. Unfortunately many of the countries that suffer from drought and famine have poor neighbours so refugees will be arriving in countries that are least able to cope.
Disease: Dirty water can attract mosquitoes which can increase diseases like dengue and malaria. Dirty water can also cause the spread of diseases like hepatitis A and typhoid as well things like diarrhea.
Eutrophication: Run-off from farms containing fertiliser can lead to eutrophication. Eutrophication is the excess growth of algae causing water to not oxygenate properly or receive enough light. This can cause plants and animals to suffocate and die.
Biodiversity Loss: Dirty water and eutrophication can cause loss of biodiversity in wetland environments, but also just like humans can die of thirst and starvation, so can animals. Big animals like elephants which require large amounts of water often die in African droughts.
Irrigation Projects: Countries that have regional shortages of water or variable rainfall can use irrigation systems to redistribute water and water the land. More efficient forms of irrigation, like drip irrigation can also be used.
Reduced Leakage: Leakage is a huge problem, especially in countries with old pipe networks. In the UK it is estimated that 460 million litres of water is lost everyday through leaks. In the UK there are targets for water companies to reduce leakages, unfortunately many companies are currently missing these targets. (Enough water for 22m people leak from firms' pipes EVERY DAY - Daily Mail Article)
Dam Construction: Dams are controversial because they can bring many disadvantages as well as advantages but if they are built sustainable they can create artificial stores that can collect water in rainy seasons and distribute during drier periods.
Water Metering: Charging people per unit of water used, rather than charging a flat fee can drastically reduce wastage and make people consider how and when they use water.
Construction of Wells: Many countries cannot afford to have piped water to every residence so wells become important in accessing groundwater supplies. As long as wells are used sustainably they can be a vital source of water in many LEDCs and arid countries.
International Cooperation: When water is shared, it is necessary to have sustainable policies to reduce the tragedy of the commons, when all countries or regions take water for their needs and forget about overall impacts. The countries along the Nile are trying to create such agreements, but Egypt is hostile to any plans to redistribute.
Sewage Treatment: This is the removal of contaminants from waste water and household sewage. It requires physical, chemical and biological processes to remove all the contaminants and make safe.
Virtual Water: Many products (agricultural and industrial) use large amounts of water to produce. For example it is estimated that 4500 litres are needed to produce just one beef steak. It has therefore been suggested that arid countries should specialise in producing products that need less water to produce, while countries with an access of water should produce products that need a lot of water to produce. The products cold then be traded between each other, so instead of water been traded, products with large amount of water used in their production are being traded - this is virtual water.
Desalination: With the growing shortage of freshwater, attempts have been made to desalinate seawater more efficiently. Traditionally the processes has involved evaporation water off to remove salt (thermal desalination), but increasingly reverse osmosis is being used to forces water through semi-permeable membrane to remove salts. Although the second process uses less energy, both are energy intensive and require high levels of technology so have been criticised and have not been widely adopted yet.
Conservation and Education: Residents and water users can be educated about basic conservation methods which can reduce water wastage. Basic conservation methods may include: half flush toilets, showering instead of bathing, watering the garden after sunset and recycling grey water (shower water, etc). to use in the garden
The UK is trying to save water by using the following methods:
Lake Biwa is the largest freshwater lake in Japan, covering an area of 670km2. It is located on the island of Honshu, north east of the cities of Kyoto and Osaka.
After the end of World War II, Japan demilitarised and concentrated on rebuilding its economy and population. Between 1945 and 2010 Japan's population grew from 72 million to 128 million. Japan's economy was regarded as an economic miracle, growing at 10% a year in the 1960's and 5% a year in the 1970's. Japanese companies like Toyota, Nissan, Mitsubishi, Sony and Toshiba started to grow rapidly. The area around Lake Biwa became one of the most densely populated and most industrialised in the country. Osaka on its own contains about 2.7 million people. As well as population and industrial growth, agriculture was also having to grow rapidly to meet growing demand.
The rapid growth meant that a lot of land reclamation took place around Lake Biwa in order to accommodate new factories, growing cities and to create new farmland. During this period of economic growth, the economy was more important than environment so household, industrial and agricultural waste was allowed to run-off into the lake. These pollutants caused a series of problems including:
In the 1960's agricultural chemical poisoned and killed aquatic life
In the 1970's heavy metals poisoned and killed aquatic life
Also in the 1970's agricultural fertilisers caused eutrophication to take place.
Eutrophication is an ecosystems response to large quantities of phosphates and nitrates being added. In Lake Biwa it caused rapid growth of algae, which prevented sunlight from reaching the lake and prevented proper oxygenation. This caused widespread death of aquatic plants and animals.
There have been a number of responses to the pollution including:
1960's - "Direction for Safe Use of Agricultural Chemicals'' - this meant that chemicals could not be used within 6km of the lake.
1969 - "Pollution Control Ordinance" - introduction of strict effluent controls
1970's - Japanese housewives started an organisation to eliminate synthetic detergents.
1979 - "Ordinance Relating to the Prevention of Eutrophication in Lake Biwa"
In reality for much of the time that Lake Biwa was being polluted, economic growth was much more important and it was not until the economy started to grow, people had secure jobs, growing incomes and increased leisure time, did people start thinking about the environment.
The Colorado River
The Colorado River is located in South-West USA and North-West Mexico. It is over 2,300km and has its source in the Rocky Mountains and its mouth in the Gulf of California. Its drainage basin covers an area of 640,000km2. The Colorado River and its tributaries pass through the US states of; Wyoming, Nevada, Utah, California, Arizona, Colorado and New Mexico. The climate across the river basin is very varied, in the Rockies temperatures can fall to -50 degrees Celsius an experience precipitation in excess of 1000mm, whereas some areas in the Mojave Desert can experience temperatures of nearly 50 degrees Celsius and precipitation as low as 15mm. About 12.7 million people live within the drainage basin of the Colorado River, although some people outside the drainage basin (especially in California) use water from the Colorado River. In total it is estimated that about 40 million rely on the river for domestic, agricultural, industrial and energy needs.
To cope with the massive demand, the Colorado River has become one of the most managed river's in the world. The river has over 29 major dams built along its and hundreds of miles of artificial canals. The Hoover Dam was one of the first major dams built along the river (and certainly the most famous), it was completed in 1936 and created Lake Mead - this is still the US's largest artificial lake.
Colorado River Aqueduct (CRA): This is 389km of tunnels, pipes and canals taking water from the Colorado River to California. The water is taken from the Parker Dam and is pumped up over the Rockies ending up at Los Angeles. Work on the project began in 1933 and water was first pumped in 1939. On average 1.5km3 of water is pumped through the aqueduct each year.
Central Arizona Project (CAP): This is 541km diversion canal. The canal was designed to provide water for irrigation of 405,000 hectares (1.85 trillion litres a year) and for domestic use in cities like Phoenix and Tuscon. Construction of the project began in 1973 and it was completed in 1993. The canal starts at Lake Havasu and eventually finishes at Tucson. The scheme cost about $4 billion to build.
California State Water Project (SWP): The project aimed to provide water for 23 million people and 6.6 million MWh of electricity to people living in Southern California. The project began in the 1950's.
Environmental Impacts
It is impossible to manage a river so much and not create some environmental problems. Problems include:
The Colorado River used to carry about 90 million tonnes of sediment (alluvium) a year down to its mouth. However, the majority of this now gets trapped behind dams, damaging the delta and wetland ecosystem at the river's mouth.
Salinity in the lower Colorado has increased changing the ecosystem.
The number of fish shrimps and sea mammals have all reduced around the mouth of the river.
Evaporation rates have increased behind the river's many dams. About 15% of water is evaporated.
The deep water in the reservoirs behind the dams has reduced the temperature of the river in many areas.
Management Strategies
In an attempt to reduce environmental damage while allowing continued economic and population growth, a number of management strategies have been implemented and/or suggested, including:
Reduced leakage: It is estimated that 25% of all water is currently lost through leaking pipes and canals. Recycling Water: Using more grey water in domestic homes. Sewage Treatment: Recycling industrial and domestic waste more efficiently. Domestic Conservation: Improving education and introducing things like half flush toilets. Drip Irrigation: Use more efficient irrigation techniques. Changing Crops: Growing crops or varieties that need less water. Metering and Pricing: Increasing the price of water and metering its use. Cloud seeding: Using chemicals to create artificial rain has been talked about. Desalination: With the Pacific Ocean on California's door step the technology of desalination could be improved. Groundwater: Increase extraction of groundwater supplies.
The Aral Sea
The Aral sea is an inland lake on the border of Kazakhstan and Uzbekistan. The Aral Sea used to be the fourth largest inland lake in the world, with a surface area of 68,000km2. The sea is fed by two rivers, the Amu Darya and the Syr Darya. Since the 1960's the sea has been shrinking because the two rivers have been diverted to irrigate the desert. The USSR decided to irrigate the desert because they wanted to increase their production of melons, rice, wheat and cotton. Rice and cotton both need extremely high amounts of water to grow. Because the irrigation canals were built quickly, it has been estimated that up to 75% got lost through evaporation or leakage. Even today, only 12% of Uzbekistan's irrigation canals are lined to stop leakage.
Between 1960 and 1988 the surface of the Aral Sea shrank by nearly 60% and its volume by up to 80%. By 1998 its surface area was only 26, 687km2 making it the eighth largest lake. At the same time the salinity of the lake changed from 10 g/L (grams per litre) to about 45 g/L. In 2004 the Aral Sea was only 17,160km2 or 25% of its original size. By 2007 it was only 10% of its original size and its salinity had increased to 100 /L (normal seawater is only about 35 g/L).
The rapidly increasing salinity has largely killed the sea's ecosystem. Huge salt plains have appeared as more water is evaporated. The salt on the plains is often whipped up in storms, killing crops and also cooling winters and warming summers. The fishing industry has collapsed and residents health worsened due to inhalation of salt, a lack of clean water and food shortages.
The greenhouse effect is a natural process and one that is vital to the existence of humans. Without the greenhouse effect the earth will be significantly colder and unable to support large scale life. The greenhouse effect acts as a kind of blanket. As energy is reflected or released by the earth it moves into the atmosphere where it is trapped and reflected back by a layer of greenhouses gases. The reflected energy returns to earth and is absorbed warming global temperatures. The problem of global warming is caused by humans enhancing the greenhouse effect. We are releasing more greenhouse gases into the atmosphere which is trapping an ever increasing amount of reflected or released energy which returns to earth and warms us further.
Greenhouse gasses (GHG): Any gas that absorbs and emits radiation in the thermal infrared range. The gases include: Carbon monoxide, carbon dioxide, methane, sulphur dioxide, Nitrous Oxide, water vapour and ozone.
Sources of greenhouse gases include:
Transport (cars and planes)
Animals (cow release large amounts of methane)
Burning fossils fuels (especially oil and coal)
Melting Permafrost (methane is released when permafrost melts)
Industry
Domestic use (wood fires)
There are some natural causes of changes in climate including:
Changes in the sun's solar radiation
Gases (sulphur dioxide) released from volcanoes
Dust and ash from volcanoes and meteorites blocking incoming solar radiation
Changes in the earth's orbit/axis, making earth close to or further from the sun
PROBLEMS CAUSED BY GLOBAL WARMING
SOLUTIONS TO GLOBAL WARMING
Rising Sea Levels
Coastal Flooding (cost of defences)
Climate Refugees
Loss of Biodiversity: As temperatures warm and sea levels rise, the habitats of many plants and animals will alter. Although some animals may be able to migrate to new areas, other plants and animals lose their habitats forever and become extinct.
Changes in the Gulf Stream: The Gulf Stream that warms Europe could stop if the salinity of water changes around Northern Europe.
Desertification
Loss of Industry: Coastal industries like tourism and fishing will be effected as sea level rise and destroy holiday resorts (or even whole islands) and engulf fishing ports and communities.
Flash Floods: Rising temperatures will in turn mean more water is evaporated into the atmosphere. Because of the amount of evaporation rainfall (especially convectional) will become more intense an cause more flash floods.
Increased Tropical Storms: Some scientists believe that warming temperatures are increasing the magnitude and frequency of tropical storms.
Heatwaves and Forest Fires
Melting Permafrost: The melting permafrost not only releases large amounts of methane in the atmosphere increasing the greenhouse effect, but also releases freshwater into the seas which may affect some of its ocean currents.
Droughts and Famines (crop failure)
Skin Cancer (diseases)
Mitigation: Trying to reduce the effects of something happening.
Renewable Energy
Hybrid Cars
Reduce, Reuse, Recycle
Afforestation and Reforestation
Carbon Sequestration: This is the capture of carbon dioxide from the atmosphere or emission chimneys.
International Agreements: International agreements like the Kyoto Protocol that came into force in 2005 (minus a US ratification) should help limit the amount of greenhouse gases being released into the atmosphere.
Adaptation: Changing lifestyles to suit new conditions.
Build More Sea Defences
Air con and/or Heating
Improved Meteorology: Predict and track events (hurricanes, droughts, etc.) so that populations can be warned and therefore prepare.
Disease Treatment: If the strength of the sun's rays intensify diseases like skin cancer and eye cataracts will increase. We will have to improve prevention (slip, slap, slosh) and improve treatment.
Desalination
Resettlement: Rising sea levels will create climate refugees in countries like the Maldives and Bangladesh.
Are there any Positive Impacts of Global Warming?
Improved Arctic Navigation: Global warming will mean that the amount of Arctic ice steadily decreases. As the ice melts navigation across the North Pole will become safer and quicker. Trade between Scandinavia, Russia, Canada and US will all be a lot easier.
Increased Agricultural Land: As permafrost melts and temperatures start to rise it will be possible to grow more crops on more land. With a rising global population this might be vital in the fight to reduce global famine.
Reduction in Cold Deaths: Old, young and sick people are very vulnerable to the cold. If global temperatures start to rise then latitudes further north and south will become more hospitable and less people will die from the cold.
Release of Freshwater: Currently a lot the world's freshwater is held in glaciers or as permafrost. As global temperatures rise, we might be able to capture and use some of this freshwater to reduce the effects of drought.
Accessibility of Resources: It is believed that places like Greenland, Alaska, Siberia and Antarctica contain a lot of resources (oil, gas, etc.). As global warming causes large areas of ice to melt they will become more accessible for human exploitation.
Reduced Heating: If global temperatures rise people will have to heat their properties less. Not only will this save money but it will also reduce the demand for gas and electricity and therefore reduce the amount of greenhouse gases being released.
Acid Rain
Acid rain was first discovered in Manchester, UK in 1852, but it was not properly studied until the 1960's. Acid rain can take two forms, wet deposition and dry deposition. Wet deposition is when pollutants mix with rain water and fall to the ground as acidic precipitation. Dry deposition is when pollutants and particulates fall to the ground without mixing with rain water. Some acid rain has had pH levels as low as 2
Sulphur dioxide and nitrous oxides are the two main chemicals that react with water to make acid rain. The chemicals are commonly released from power stations, factories and transport. Traditionally sulphur dioxide has been the biggest contributing chemical, accounting for about two thirds and nitrous oxides the other third. However, in most areas of the world the importance of sulphur dioxide is decreasing and nitrous oxides increasing. Acid rain can cause many problems including:
Damage to buildings
Metals (iron, aluminum, etc.) dissolved by acid rain can be washed into water courses
Vegetation can be damaged and growth reduced
Lakes and rivers can become acidic harming the ecosystem and aquatic life
Soil acidity increases
Acid rain is known as a transboundary pollutant because it can be blown from one country to another - it does not obey national boundaries and in fact it is often non polluting countries that are most seriously impacted. Because it is a transboundary polluter acid rain tends to be worst in the direction of the prevailing wind from major industrial locations. The map to the right shows that the east coast of the US suffers badly from acid rain, its rain has an average pH of 4. Large parts of Europe and also the east coast of China are also badly affected.
Acid rain can be reduced by reducing the amount of fossil fuel burnt or at least burning coal with a lower sulphur content, by using a greater proportion of renewable energy, by using more public transport and cleaner forms of transport and by removing pollution at source with the use of scrubbers.
Dry Deposition: When acid falls directly back to earth without mixing with precipitation. This tends to happen close to source.
Wet Deposition: When acids are dissolved in precipitation and fall to the ground as acid rain.
The ozone layer is a layer of gas (mainly ozone O3) high in the Earth's atmosphere (20-30km up). The ozone layer helps to protect humans from the sun's harmful ultraviolet solar radiation (it absorbs up to 99%). The existence of the ozone layer was first discovered in 1913. The ozone layer can be damaged by chemicals and gases including; nitrous oxide, bromine and chlorine. Although all occur naturally the amount of chlorine and bromine were increasing because of the human use of CFCs (chlorofluorocarbons) and bromofluorocarbons. CFCs were being used in products like:
aerosols
packaging
fridges and refrigerators
air con
solvents
Even though it was known that the ozone layer could be damaged, it was not until 1985 when holes were discovered over the poles that serious action was taken. This meant that more of the sun's harmful ultraviolet radiation was reaching Earth causing more disease (skin cancers and cataracts) and damage to vegetation. Because of the the depletion of the ozone layer, countries started to ban the use and production of CFCs. USA and Norway were the first to ban in 1978 and then in 1985 the Montreal Protocol (now signed by 160 countries) severely limited the production of CFCs. After 1996 only recycled CFCs could be used. Since the banning of CFCs the rate of depletion is believed to have slowed.
Sidoarjo Mudflow
Sidoarjo is on the island of Java in Indonesia, 20km south of Surabaya. Indonesia sits on a destructive plate boundary (the Indo-Australian plate is subducting under the Eurasian plate). As well as earthquakes and volcanoes being present at destructive plate boundaries, mud volcanoes are also common, especially in East Java.
East Java has also got large oil and gas reserves. In order to try and access these reserves PT Lapindo Brantas had started exploratory drilling. On the 28th May PT Lapindo Brantas drilled two boreholes. The second borehole was deeper reaching a depth of 2,834 metres. However, the drill used for this borehole did not have a protective casing which allowed water, steam and a small amount of gas to be released triggering an explosion. The first explosion was about 200 metres from the drill sites, further explosions on the 2nd and 3rd June happened 800-1000 metres from the drill site.
The explosions caused fractures to the surface and by 5th June locals noticed mud escaping. In the first three months the daily flow of mud was between 7,000 and 150,000 cubic metres. 240 hectares of rice paddies were lost, along with eight villages and 25 factories. In total 11,000 people were displaced. On the 23rd December ground subsidence caused a gas leak and explosion killing 11. 18 months after the initial explosions 20km2 of land had been lost, 11 towns buried, 16,000 displaced, the local railways line had been covered along with the Porong-Gempol toll road.
Dams and barriers were created to try and contain the flow, concrete balls were dropped into the fractures and mud pumped into the Porong River and Java Sea. Despite efforts to stop the flow, scientists have estimated that the flow could continue for up to 40 years.
The company involved initially blamed an earthquake for the accident. However, courts have already ordered the company to pay $400 million in clean up costs and compensation. The fear is that with clean-up costs like to exceed $1 billion, PT Lapindo Brantis will just declare bankruptcy.
IGCSE and GCSE Energy, Water and the Environment
Specification:
3.4 Energy and water resources
Candidates should be able to:
• Describe the significance of fuelwood in LEDCs and of non-renewable fossil fuels in terms of their availability in certain areas and in terms of the contribution made by coal, oil, natural gas and wood in supplying vast amounts of energy.
• Describe the growing significance of renewable energy supplies (geothermal, wind, running water, solar, biofuels) to reduce dependence upon fossil fuels, to alleviate the world’s energy crisis, and to offer opportunities for the development of alternative energy sources.
• Describe the factors influencing the siting of different types of electrical power stations with reference to those listed in the syllabus (thermal, hydro-electric power, nuclear).
• Describe the uses made of water for agriculture, domestic and industrial demand. Candidates should also recognise that in certain areas there are water shortages which impact upon the local people and the potential for development. This leads to competition for the use of the available water resources and requires careful management.
All these aspects would benefit from the selection of appropriate case studies.
3.5 Environmental risks and benefits: resource conservation and management
Candidates should be able to:
• Demonstrate the need for sustainable development, resource conservation and management in different environments. It is not intended that candidates should be familiar with a wide variety of illustrations here. Rather that by the use of well selected case studies, possibly integrated with the study of other concepts referred to above, candidates become familiar with general principles and can illustrate from these examples.
• Identify and describe the benefits associated with the development of agriculture, mining and quarrying, energy production, manufacturing industries, transport and tourism. This could be incorporated with the studies outlined above (3.1–3.4).
• Describe how these developments may also pose threats to the environment when natural ecosystems are interfered with including: soil erosion, global warming, and pollution (air, water, noise and visual).
• Identify areas at risk from these threats to the environment and describe attempts made to maintain, conserve or improve the quality of the environment.
Energy
Non-renewable energy: Energy that can not be reproduced in the time that it takes to consume it e.g. coal.
Renewable energy: Energy that is naturally occurring and potentially infinite.
Fossil fuels: Any combustible organic matter that is made from the remains of former flora and fauna.
Raw material: Any unprocessed material.
Global Energy
As the world's population continues to grow and as peoples level of development continues to grow, so does the demand for energy. In traditional less developed societies the main source of energy tends to be fuelwood. Fuelwood can be used for heating, cooking and even scaring away wild animals.
As countries begin to develop they can begin to afford to buy raw materials and to build power stations. Most commonly fossil fuels are burned because the technology exists and at the moment they are widely available.
However, as countries develop further their sources of energy may change again. They will probably still be heavily dependent on fossil fuels, but will begin to use more renewable energy and probably more nuclear. The reasons for the change include:
There are always some exceptions to the rule. For example Costa Rica gets the majority of its power from renewable sources and countries like Lithuania and France get nearly all of theirs from nuclear.
Type on non-renewable energy (fossil fuel)
Advantages
Disadvantages
Type of Renewable Energy
Advantages
Disadvantages
Nuclear Energy
Some people consider nuclear energy to be a renewable energy. However, because nuclear energy uses uranium and uranium is non-renewable, then nuclear energy should also be considered to be non-renewable. Although the first man-made reactor was first operated in 1942 in the US, the first electricity producing nuclear power station was not completed until 1951.
It is estimated that nuclear power provides about 14% of the world's electricity (6% of its energy). Japan (all nuclear reactors are temporarily closed after the Fukashima Disaster), US and France combined account for about 50% of the world's nuclear power produced although the IAEA say that there are 439 nuclear power stations in 31 countries (IAEA, 2007).
Nuclear power has created widespread debate, because some people see it as a solution to declining fossil fuels while others worry about the waste produced, the technology falling into the wrong hands and accidents.
The world's two biggest nuclear accidents happened in Chernobyl (Ukraine) in 1986 and Fukushima (Japan) in 2011. The Fukushima accident was caused by a giant earthquake and tsunami that hit the east coast of Japan on 11th March 2011. The tsunami broke the generators connection to the power grid and flooded emergency generators. This meant that water could not be pumped into the reactors to cool them - this resulted in a meltdown of reactors 1, 2 ad 3. The result of the disaster has been contamination of the land and sea near the plant and the enforcement of a 20km exclusion zone. Japan has also said that it will start to reduce its dependence on nuclear power and look for alternatives.
Although all countries reserve the right to develop nuclear power technology, many countries in the world have signed the 'Nuclear Non-Proliferation Treaty'. The treaty forbids the development of nuclear weapons. The UN and many other countries are worried that Iran and North Korea are developing nuclear technology for the use in weapons.
IAEA: The International Atomic Agency is a UN organisation that seeks to promote the peaceful use of nuclear energy.
Japan earthquake triggers nuclear shutdown - BBC article
Iran nuclear: UN voices deep concern over plans - BBC article cerns
North Korea Conducts Nuclear Test - BBC article
ADVANTAGES OF NUCLEAR ENERGY
DISADVANTAGES OF NUCLEAR ENERGY
Fuelwood
Fuelwood is the most common source of energy for people living in LEDCs - it is estimated that about 40% of the world's population rely on fuelwood. Fuelwood is often the main source of energy because countries either can't afford to buy raw materials to produce energy, don't have the technology or money to build and operate powers stations and certainly don't have a national grid to distribute energy. Fuelwood has multiple functions, it can be used for cooking, heating and scaring away wild animals. Although using fuelwood is essential for many people it can cause environmental and social problems. Problems include:
Location of Power Stations
Three Gorges Dam
The Three Gorges Dam is the largest hydroelectric power station in the world. The dam is over 2km wide and it produces 22,500 MW of electricity. The HEP is located on the Yangtse River in Central China. China is the most populated country in the world and the Yangtse is the third longest river in the world. The site of the Three Gorges Dam was chosen over 15 other sites in China. Its location was picked for the following reasons:
For information about the Three Gorges Hydroelectric power station go to: IGCSE Rivers
Sizewell A and B, UK - Nuclear Power Station
Sizewell A and B are locate near the village of Sizewell in Suffolk. Suffolk is county of England located in the east in a part of England called East Anglia. Sizewell is located on the coast next to the North Sea. Although Sizewell A is now being decommissioned (shut down), Sizewell B is still in use and there are proposals for a third. The location of Sizewll was chosen for the following reasons:
Ratcliffe-on-Soar, UK - Thermal Power Station (coal)
A thermal power station is any power station that uses fossil fuels as its fuel. The Ratcliffe-on-Soar power station is located in the county of Nottinghamshire in central England. The power station was initially commissioned in 1968 and generates about 2,000 MW of electricity which can meet the needs of about 2 million people. The power station generates electricity using coal. The location of the power station was chosen because:
Changing Energy Use in the UK (1940-Present)
In the 1950's the main source of UK energy was coal. This was because the UK had huge reserves of coal in the NE, in the Midlands and in South Wales. In just two counties (Northumberland and Durham) there were nearly 1000 coal mines. In the 1940's nearly 90% of energy was supplied by coal and in 1960 its still stood at over 76%. From the 1960's the reliance on coal started to fall down to its present total of about 34%. The reason that the reliance on coal fell, is because British reserves began to decline and became more expensive to extract (deep underground and rising labour and health and safety costs) and because of the development of nuclear energy.
The UK's first nuclear power station opened in 1956 leading to an increase in its use. The peak of nuclear production was in 1997 when 26% of UK energy was produced by nuclear. Nuclear became popular because it reduced reliance on imports of foreign raw materials and was seen as a cleaner energy. The UK currently has 9 operational nuclear power stations producing about 15% of energy. It is unclear how this figure will change in the future. There are plans for further nuclear power stations, but the risk of accidents, problems of waste disposal and expensive construction costs may mean alternatives are sought.
Gas is currently the biggest supplier of UK energy. The use of gas increased with the discovery of gas in the North and Irish Sea and because it was seen as been cleaner than coal. There are currently about 45 gas fired power stations producing about 43% of the UK's energy needs. However, because gas is finite and because the UK now has import over 40% of its gas, its importance may change in the future.
Because of the debate over nuclear usage, the declining supplies over fossil fuels and increased environmental awareness, the UK hopes to produce more renewable energy in the future. By 2020 the UK aims to produce about 15% of its energy from renewables. The overall European Union target is 20% by 2020. As an island nation it has great potential for tidal, wave and wind power. Because of its climate solar is never going to play a major role and because of the size of its rivers, hydroelectric is always going to be small scale. Biomass and biogas are going to be used, but because they still release greenhouse emissions they are not going to help the UK meeting carbon reduction targets.
In 2011 the UK had 296 wind farms and over 3,400 turbines. There are proposals for hundreds of more wind farms but because of protests (NIMBY) many have been delayed or are being forced offshore which is very expensive. Tidal and wave technology is still in its infancy, but the UK leads the research in both fields so hopes to see increased production in the future. Tidal power needs very specific conditions for it to work and only about 20 ideal sites have been found around the world, 8 of which are in the UK.
Changing Energy Use in the UK - BBC Bitesize
Water
Where is the Earth's Water?
The majority of the world's water is seawater (about 97%). This leaves only 3% that is potentially useful for humans. However, out of this freshwater the majority is frozen (about 69%) or under the ground (about 30%). This means that only about 0.01% of the earth's water is useful and easily accessible.
In terms of surface water, the large continents of North America, Asia and Africa have the most. Australia that has a very arid climate, especially towards the centre has very little surface water. Every continent has a large supply of groundwater. However, groundwater can be hard to extract because it can be deep underground and often large distances from where it is needed - this makes extraction and transport expensive. Although groundwater is useful, unless it is managed properly and replaced, it can cause problems like salinisation and ground subsidence.
Even though the world has a lot of frozen water (glaciers and ice caps) the water is not useful because you would have to melt it, releasing large amounts of greenhouse gases and altering local ecosystems and then you would have to transport it large distances to where it is needed.
Groundwater: Water found underneath the surface of the earth.
Surface water: Water found above the surface of the earth.
How is Water Used?
Agriculture is by far the World's biggest user of water. Water is used for animals, but the majority is used for irrigation. The amount being used by agriculture is also increasing as the World's population increases and the demand for food increases. Household or domestic use in the next biggest user. The most water is usually used in toilets, but also washing machines and shower/baths use significant percentages. Industry and energy production also uses large percentages in manufacturing and cooling processes. The fourth biggest user is actually water lost through evaporation and leaks in reservoirs.
Groundwater
Groundwater is water stored under the ground. Water can be held in porous rocks called aquifers. With increasing demand for water, groundwater is being demanded more and more.
Aquifer: Rocks that can hold water. Aquifers are called ''confined'' if they are surrounded and contained by aquitards and aquicludes. Unconfined are not contained by aquitards and aquicludes and instead their upper limit is the water table.
Aquiclude: Rock that will not hold water or allow its movement i.e. they are non-porous and impermeable.
Aquitard: A layer of rock that limits the movement of groundwater. It may be non-porous and has low hydraulic conductivity e.g. it is a clay that water finds it hard to pass through.
Water table: The boundary between saturated and unsaturated ground.
If groundwater is not used sustainable i.e. more is taken than is replaced, then it can cause a number of problems including:
Salinisation: An increase in the salinity (salt content) of water. Salinisation may happen if more water is being removed from an aquifer than is being replaced causing the concentration of salt to increase.
Saltwater intrusion: When aquifers near the coast are depleted and saltwater leaks into the aquifer changing its salinity.
Subsidence: This is the collapsing of ground. Ground may collapse if water has been abstracted (removed) from an aquifer underground. Parts of Mexico City are subsiding because of over abstraction.
Economic water scarcity: This is when water is available, but for some reason it is inaccessible or unusable. This might because it is groundwater that is expensive to extract or that the cost of transporting it is too expensive or simply that the supply of water has become polluted.
Physical water scarcity: This is when there is not enough water available. The most common reason for this is low precipitation rates.
Water stress: This is when the demand for water exceeds the supply of water causing water shortages. Water shortages are known as droughts.
Water stress basically happens when demand exceeds supply. Below are some of the main reasons why demand is increasing and supply falling.
GROWING DEMAND
FALLING SUPPLY
Water map shows billions at risk of 'water insecurity' - BBC article
Problems Caused by Water Shortages and Water Pollution
Possible Solutions to Water Shortages and Water Pollution
The UK is trying to save water by using the following methods:
Lake Biwa, Japan
Lake Biwa is the largest freshwater lake in Japan, covering an area of 670km2. It is located on the island of Honshu, north east of the cities of Kyoto and Osaka.
After the end of World War II, Japan demilitarised and concentrated on rebuilding its economy and population. Between 1945 and 2010 Japan's population grew from 72 million to 128 million. Japan's economy was regarded as an economic miracle, growing at 10% a year in the 1960's and 5% a year in the 1970's. Japanese companies like Toyota, Nissan, Mitsubishi, Sony and Toshiba started to grow rapidly. The area around Lake Biwa became one of the most densely populated and most industrialised in the country. Osaka on its own contains about 2.7 million people. As well as population and industrial growth, agriculture was also having to grow rapidly to meet growing demand.
The rapid growth meant that a lot of land reclamation took place around Lake Biwa in order to accommodate new factories, growing cities and to create new farmland. During this period of economic growth, the economy was more important than environment so household, industrial and agricultural waste was allowed to run-off into the lake. These pollutants caused a series of problems including:
Eutrophication is an ecosystems response to large quantities of phosphates and nitrates being added. In Lake Biwa it caused rapid growth of algae, which prevented sunlight from reaching the lake and prevented proper oxygenation. This caused widespread death of aquatic plants and animals.
There have been a number of responses to the pollution including:
In reality for much of the time that Lake Biwa was being polluted, economic growth was much more important and it was not until the economy started to grow, people had secure jobs, growing incomes and increased leisure time, did people start thinking about the environment.
The Colorado River
The Colorado River is located in South-West USA and North-West Mexico. It is over 2,300km and has its source in the Rocky Mountains and its mouth in the Gulf of California. Its drainage basin covers an area of 640,000km2. The Colorado River and its tributaries pass through the US states of; Wyoming, Nevada, Utah, California, Arizona, Colorado and New Mexico. The climate across the river basin is very varied, in the Rockies temperatures can fall to -50 degrees Celsius an experience precipitation in excess of 1000mm, whereas some areas in the Mojave Desert can experience temperatures of nearly 50 degrees Celsius and precipitation as low as 15mm. About 12.7 million people live within the drainage basin of the Colorado River, although some people outside the drainage basin (especially in California) use water from the Colorado River. In total it is estimated that about 40 million rely on the river for domestic, agricultural, industrial and energy needs.
To cope with the massive demand, the Colorado River has become one of the most managed river's in the world. The river has over 29 major dams built along its and hundreds of miles of artificial canals. The Hoover Dam was one of the first major dams built along the river (and certainly the most famous), it was completed in 1936 and created Lake Mead - this is still the US's largest artificial lake.
Colorado River Aqueduct (CRA): This is 389km of tunnels, pipes and canals taking water from the Colorado River to California. The water is taken from the Parker Dam and is pumped up over the Rockies ending up at Los Angeles. Work on the project began in 1933 and water was first pumped in 1939. On average 1.5km3 of water is pumped through the aqueduct each year.
Central Arizona Project (CAP): This is 541km diversion canal. The canal was designed to provide water for irrigation of 405,000 hectares (1.85 trillion litres a year) and for domestic use in cities like Phoenix and Tuscon. Construction of the project began in 1973 and it was completed in 1993. The canal starts at Lake Havasu and eventually finishes at Tucson. The scheme cost about $4 billion to build.
California State Water Project (SWP): The project aimed to provide water for 23 million people and 6.6 million MWh of electricity to people living in Southern California. The project began in the 1950's.
Environmental Impacts
It is impossible to manage a river so much and not create some environmental problems. Problems include:
Management Strategies
In an attempt to reduce environmental damage while allowing continued economic and population growth, a number of management strategies have been implemented and/or suggested, including:
Reduced leakage: It is estimated that 25% of all water is currently lost through leaking pipes and canals.
Recycling Water: Using more grey water in domestic homes.
Sewage Treatment: Recycling industrial and domestic waste more efficiently.
Domestic Conservation: Improving education and introducing things like half flush toilets.
Drip Irrigation: Use more efficient irrigation techniques.
Changing Crops: Growing crops or varieties that need less water.
Metering and Pricing: Increasing the price of water and metering its use.
Cloud seeding: Using chemicals to create artificial rain has been talked about.
Desalination: With the Pacific Ocean on California's door step the technology of desalination could be improved.
Groundwater: Increase extraction of groundwater supplies.
The Aral Sea
The Aral sea is an inland lake on the border of Kazakhstan and Uzbekistan. The Aral Sea used to be the fourth largest inland lake in the world, with a surface area of 68,000km2. The sea is fed by two rivers, the Amu Darya and the Syr Darya. Since the 1960's the sea has been shrinking because the two rivers have been diverted to irrigate the desert. The USSR decided to irrigate the desert because they wanted to increase their production of melons, rice, wheat and cotton. Rice and cotton both need extremely high amounts of water to grow. Because the irrigation canals were built quickly, it has been estimated that up to 75% got lost through evaporation or leakage. Even today, only 12% of Uzbekistan's irrigation canals are lined to stop leakage.
Between 1960 and 1988 the surface of the Aral Sea shrank by nearly 60% and its volume by up to 80%. By 1998 its surface area was only 26, 687km2 making it the eighth largest lake. At the same time the salinity of the lake changed from 10 g/L (grams per litre) to about 45 g/L. In 2004 the Aral Sea was only 17,160km2 or 25% of its original size. By 2007 it was only 10% of its original size and its salinity had increased to 100 /L (normal seawater is only about 35 g/L).
The rapidly increasing salinity has largely killed the sea's ecosystem. Huge salt plains have appeared as more water is evaporated. The salt on the plains is often whipped up in storms, killing crops and also cooling winters and warming summers. The fishing industry has collapsed and residents health worsened due to inhalation of salt, a lack of clean water and food shortages.
Dam project aims to save Aral Sea - BBC article
Environmental Problems
Greenhouse Effect and Global Warming
The greenhouse effect is a natural process and one that is vital to the existence of humans. Without the greenhouse effect the earth will be significantly colder and unable to support large scale life. The greenhouse effect acts as a kind of blanket. As energy is reflected or released by the earth it moves into the atmosphere where it is trapped and reflected back by a layer of greenhouses gases. The reflected energy returns to earth and is absorbed warming global temperatures. The problem of global warming is caused by humans enhancing the greenhouse effect. We are releasing more greenhouse gases into the atmosphere which is trapping an ever increasing amount of reflected or released energy which returns to earth and warms us further.
Greenhouse gasses (GHG): Any gas that absorbs and emits radiation in the thermal infrared range. The gases include: Carbon monoxide, carbon dioxide, methane, sulphur dioxide, Nitrous Oxide, water vapour and ozone.
Sources of greenhouse gases include:
There are some natural causes of changes in climate including:
PROBLEMS CAUSED BY GLOBAL WARMING
SOLUTIONS TO GLOBAL WARMING
Adaptation: Changing lifestyles to suit new conditions.
Are there any Positive Impacts of Global Warming?
Improved Arctic Navigation: Global warming will mean that the amount of Arctic ice steadily decreases. As the ice melts navigation across the North Pole will become safer and quicker. Trade between Scandinavia, Russia, Canada and US will all be a lot easier.
Increased Agricultural Land: As permafrost melts and temperatures start to rise it will be possible to grow more crops on more land. With a rising global population this might be vital in the fight to reduce global famine.
Reduction in Cold Deaths: Old, young and sick people are very vulnerable to the cold. If global temperatures start to rise then latitudes further north and south will become more hospitable and less people will die from the cold.
Release of Freshwater: Currently a lot the world's freshwater is held in glaciers or as permafrost. As global temperatures rise, we might be able to capture and use some of this freshwater to reduce the effects of drought.
Accessibility of Resources: It is believed that places like Greenland, Alaska, Siberia and Antarctica contain a lot of resources (oil, gas, etc.). As global warming causes large areas of ice to melt they will become more accessible for human exploitation.
Reduced Heating: If global temperatures rise people will have to heat their properties less. Not only will this save money but it will also reduce the demand for gas and electricity and therefore reduce the amount of greenhouse gases being released.
Acid Rain
Acid rain was first discovered in Manchester, UK in 1852, but it was not properly studied until the 1960's. Acid rain can take two forms, wet deposition and dry deposition. Wet deposition is when pollutants mix with rain water and fall to the ground as acidic precipitation. Dry deposition is when pollutants and particulates fall to the ground without mixing with rain water. Some acid rain has had pH levels as low as 2
Sulphur dioxide and nitrous oxides are the two main chemicals that react with water to make acid rain. The chemicals are commonly released from power stations, factories and transport. Traditionally sulphur dioxide has been the biggest contributing chemical, accounting for about two thirds and nitrous oxides the other third. However, in most areas of the world the importance of sulphur dioxide is decreasing and nitrous oxides increasing. Acid rain can cause many problems including:
Acid rain is known as a transboundary pollutant because it can be blown from one country to another - it does not obey national boundaries and in fact it is often non polluting countries that are most seriously impacted. Because it is a transboundary polluter acid rain tends to be worst in the direction of the prevailing wind from major industrial locations. The map to the right shows that the east coast of the US suffers badly from acid rain, its rain has an average pH of 4. Large parts of Europe and also the east coast of China are also badly affected.
Acid rain can be reduced by reducing the amount of fossil fuel burnt or at least burning coal with a lower sulphur content, by using a greater proportion of renewable energy, by using more public transport and cleaner forms of transport and by removing pollution at source with the use of scrubbers.
Dry Deposition: When acid falls directly back to earth without mixing with precipitation. This tends to happen close to source.
Wet Deposition: When acids are dissolved in precipitation and fall to the ground as acid rain.
Third of China 'hit by acid rain' - BBC article
The Hole In The Ozone Layer
The ozone layer is a layer of gas (mainly ozone O3) high in the Earth's atmosphere (20-30km up). The ozone layer helps to protect humans from the sun's harmful ultraviolet solar radiation (it absorbs up to 99%). The existence of the ozone layer was first discovered in 1913. The ozone layer can be damaged by chemicals and gases including; nitrous oxide, bromine and chlorine. Although all occur naturally the amount of chlorine and bromine were increasing because of the human use of CFCs (chlorofluorocarbons) and bromofluorocarbons. CFCs were being used in products like:
Even though it was known that the ozone layer could be damaged, it was not until 1985 when holes were discovered over the poles that serious action was taken. This meant that more of the sun's harmful ultraviolet radiation was reaching Earth causing more disease (skin cancers and cataracts) and damage to vegetation. Because of the the depletion of the ozone layer, countries started to ban the use and production of CFCs. USA and Norway were the first to ban in 1978 and then in 1985 the Montreal Protocol (now signed by 160 countries) severely limited the production of CFCs. After 1996 only recycled CFCs could be used. Since the banning of CFCs the rate of depletion is believed to have slowed.
Sidoarjo Mudflow
Sidoarjo is on the island of Java in Indonesia, 20km south of Surabaya. Indonesia sits on a destructive plate boundary (the Indo-Australian plate is subducting under the Eurasian plate). As well as earthquakes and volcanoes being present at destructive plate boundaries, mud volcanoes are also common, especially in East Java.
East Java has also got large oil and gas reserves. In order to try and access these reserves PT Lapindo Brantas had started exploratory drilling. On the 28th May PT Lapindo Brantas drilled two boreholes. The second borehole was deeper reaching a depth of 2,834 metres. However, the drill used for this borehole did not have a protective casing which allowed water, steam and a small amount of gas to be released triggering an explosion. The first explosion was about 200 metres from the drill sites, further explosions on the 2nd and 3rd June happened 800-1000 metres from the drill site.
The explosions caused fractures to the surface and by 5th June locals noticed mud escaping. In the first three months the daily flow of mud was between 7,000 and 150,000 cubic metres. 240 hectares of rice paddies were lost, along with eight villages and 25 factories. In total 11,000 people were displaced. On the 23rd December ground subsidence caused a gas leak and explosion killing 11. 18 months after the initial explosions 20km2 of land had been lost, 11 towns buried, 16,000 displaced, the local railways line had been covered along with the Porong-Gempol toll road.
Dams and barriers were created to try and contain the flow, concrete balls were dropped into the fractures and mud pumped into the Porong River and Java Sea. Despite efforts to stop the flow, scientists have estimated that the flow could continue for up to 40 years.
The company involved initially blamed an earthquake for the accident. However, courts have already ordered the company to pay $400 million in clean up costs and compensation. The fear is that with clean-up costs like to exceed $1 billion, PT Lapindo Brantis will just declare bankruptcy.