Unit 7

Question 1

Fossil fuels

Answer 1

Coal, oil,natural gas. Formed from dead plants and animals under pressure over millions of years.

Question 2

Advantages vs disadvantages of fossil fuels

Answer 2

advantages
- Infrastructure is set up for its use in most countries e.g. road and rail links and connection to electricity grid are well established.
- High energy content.
- Relatively cheap.
- Currently relatively abundant.

disadvantages
- Finite resource, which is not sustainable.
- Extraction can destroy habitats and reduce biodiversity in an area.
- Transport of fossil fuels can produce emissions of carbon dioxide, NOx, SO2 and particulates.
- Combustion of fossil fuels also produces CO2 (greenhouse gas),
- Power plants require relatively large amounts of water which may compete with other users of water and also have a detrimental impact on aquatic ecosystems.
- Discharge of waste water can result in thermal pollution of aquatic ecosystems.

Question 3

Nuclear power

Answer 3

Nuclear power is a lowcarbon low-emission non-renewable resource but is controversial due to the
radioactive waste it produces and the potential scale of any accident

Question 4

Advantages and disadvantages of nuclear power

Answer 4

ad
- Nuclear power stations do not produce carbon dioxide emissions, reducing the risk of climate change.
- Compared to fossil fuels, nuclear power causes less deaths e.g. from coal mining accidents or premature death from urban air pollution.

disv
- Generation of nuclear waste with high radioactive levels that will last thousands of years.
- Risk of nuclear accidents e.g. Chernobyl
- Potential use of radioactive material from nuclear power station to produce nuclear weapons.
- High capital cost and high decommissioning cost (when power plant is closed and dismantled).

Question 5

Renewable energy sources

Answer 5

solar, wind, hydropower, biomass, geothermal, wave and tidal

Question 6

advantages and disadvantages of solar power

Answer 6

ad
- used in remote areas
- low running cost
- does not produce pollutants
- silent

disv
- sun vaies so its weather dependant
- high capital cost
- production of solar panels produces pollution
- no energy at night (storing required)

Question 7

Advantages and disadvantags of wind power

Answer 7

adv
- Renewable (inexhaustible), sustainable energy source.
- large supply
- remote areas used
- low cost
- no pollutants

disv
- winds varies from place to place
- noise pollution
- aesthetically displeasing
- can kill birds and bars
- high capital cost

Question 8

adv and disv of hydropower

Answer 8

adv
- low running cost
-sustainable
- dam construction can also increase water resources
- can provide opportunities for fishing or recreation
- no urban air pollutants

disv
- high capital cost
- dislacement of people loss of habitat and species
- decomposition of biota flooded can cause emissions of methane and carbon dioxide

Question 9

adv and disv of geothermal energy

Answer 9

adv
Cheap to operate.
Low emissions of carbon dioxide and other GHGs.
Reliable supply in some areas.
Sustainable energy supply.

disv
High capital cost (drilling can be expensive).
Poisonous gases from within the earth can be released e.g. methane, hydrogen sulphide, ammonia and carbon dioxide (quantities are low compared to use of fossil fuels).
Historically limited to areas near volcanic activity (boundary of tectonic plates).

Question 10

energy security

Answer 10

The International Energy Agency defines energy security as ‘the uninterrupted availability of energy sources at an affordable price’.

Question 11

energy security depends on

Answer 11

An adequate supply of energy which matches demand.
Reliable supply, that is not interrupted e.g. by conflict.
Affordable supply to ensure access to all.

Question 12

threats to energy security

Answer 12

Political instability and /or conflict in exporting country.
Accidents or natural disasters e.g. Fukushima accident.
Risk of terrorist attacks on source or supply infrastructure.
Exhaustion of resource.

Question 13

risks to these threats can be reduced by

Answer 13

Reducing imports and becoming more self-sufficient in energy supply. This may involve:
Diversifying sources of energy, increasing alternatives to fossil fuels such as renewable sources.
Exploiting indigenous resources.
Reducing demand by increasing energy efficiency and energy conservation measures.
Reducing reliance on one or two exporting countries and using multiple exporters i.e. spreading out the risk.

Question 14

Factors affecting energy choices

Answer 14

Availability
Geology e.g. some countries have an abundance of fossil fuels or relatively easy access to geothermal power.
Topography e.g. hillsides suitable for wind power and rivers for hydropower.

Sustainability
Many countries are beginning to consider energy choices over the long term and investing in renewable resources rather than non-renewable fossil fuels which will eventually run out

Scientific and technological developments
Developments in science and technology are increasing the choices of affordable alternative sources of energy e.g. technology development has decreased the cost of photovoltaic panels. Scientific discoveries may provide new options for the future.

Cultural attitudes
Some communities have a more nature centered environmental value system and are more proactive in changing their behaviour to reduce energy use and moving to less polluting energy sources.

Economics
Energy sources need to be economically viable as they must be affordable to all to ensure full access. The economic wealth of a country may limit the choice of energy source e.g. nuclear power stations are expensive to build.

Question 15

Climate vs weather

Answer 15

Climate is the ‘average’ weather over the long term (e.g. years) often at a regional level, whereas weather refers to the conditions over a short time scale (e.g. day to day) at a local level.

Question 16

Factors affecting climate

Answer 16

Factors outside the earth:
Solar radiation emitted from the sun.
Tilting and orbit of the earth.

Factors within the earth:
Atmospheric and ocean circulation systems.
Greenhouse gases that trap heat and warm the land, oceans and atmosphere.
Volcanic activity.
Feedback cycles.

Question 17

Causes of climate change

Answer 17

Atmospheric and ocean circulation systems (tricellular model)
El Nino
Green house effect
Volcanic activity

Question 18

Climate feedback

Answer 18

Positive and negative feedback can either enhance or reduce warming respectively

Question 19

Impacts of climate change

Answer 19

an increase in the mean global temperature
increased frequency and intensity of extreme weather events
the potential for long-term changes in climate and weather patterns
rise in sea level.

Question 20

Impacts of climate change on water reosurces

Answer 20

climate change is chaning the quantity and quality of water available

this can lead to
- lakes and rivers running out
- increase in desertificayion
- loss of crops
- conflict over water resources
- flooding
- contamination of water supplies
-displacements of people

-

Question 21

Impact of climate change in agriculture and fisheries

Answer 21

Agriculture
- some regions more favorable, others affected
- increase in mid to high latitude regions
- decrease in low lattude reguons

fisheries rise in tempreature
- death of some species
- migration toward cooler waters
- damage

Question 22

Impact of climate change on ecosystems and biodiversity

Answer 22

Increase in temperature and change in precipitation patterns.
Increase risk of flooding.
Drought conditions.
Increase risk of wild fires.
Increase spread of pests.
Ocean acidification.

Question 23

range shifts by climate change

Answer 23

Range shifts
With a change in climatic conditions of temperature and rainfall, there is likely to be a general shift of biomes with animals and plants moving towards the poles and upwards in elevation.
The geographical range for some species will expand which may threaten local species. For instance, Boreal forest expansion into tundra threatens tundra ecosystem and species such as snowy owl and caribou.
Less adaptive species or those already near the top of their thermal tolerance range will decrease in number with a potential risk of becoming extinct.
If change is rapid, species may not be able to move quickly enough and therefore die out.

Question 24

Impact of climate change on coastal systems and low lying areas

Answer 24

Storm intensity
Rising sea levels (salinization of agriculture)
- insufficient water and resources
- heat waves result in cardiovasculat problems

Question 25

Action taken examples based on EVS to deal with impacts of climate change

Answer 25

Question 26

Mitigation definition

Answer 26

A human intervention to reduce the sources or enhance the sinks of greenhouse gases (GHGs)

Mitigation involves reduction and/or stabilization of GHG emissions and their removal from the atmosphere.

Question 27

Variety of wats in which GHG can be reduced

Answer 27

reduction of energy consumption
reduction of emissions of oxides of nitrogen and methane from agriculture (by using less fertilizers) (by selecting cattle that produces less methane)
use of alternatives to fossil fuels
geo-engineering (manipulating the earths environmental systems to counter act climate change) (by removing carbon dioxide from the atmosphere or by a solar radiation management)

Question 28

Mitigation strategies for carbon dioxide removal (CDR techniques) include:

Answer 28

protecting and enhancing carbon sinks through land management;
for example, through the UN collaborative programme on reducing emissions from deforestation and forest degradation in developing
countries (UN-REDD)

using biomass as a fuel source (replace the use of fossil fuel)

using carbon capture and storage (CCS) very expensive (air can be filtred and CO2 removed)

enhancing carbon dioxide absorption by the oceans through either
fertilizing oceans with compounds of nitrogen, phosphorus and iron
to encourage the biological pump, or increasing upwellings to release
nutrients to the surface.

Question 29

Solar radiation management (SRM)

Answer 29

only theoretical. Focus on increasing the reflection back into space and therefore reducing the amount of solar radiation absorbed by the earth.
- painting rooftops white
- growing plants with high reflexivity
- covering areas with reflectve materials

Question 30

Adaptation vs mitigation

Answer 30

Whereas mitigation addresses the causes of climate change by reducing emissions of greenhouse gases (GHG), adaption is focused on dealing with the effects.

Effects of mititagion can be seen at a global scale but adaptation at local level.
Mitigation is easier to measure

Question 31

adaptation strategies

Answer 31

water resources
- improving water supplies/desalination plants
- sustainable urban drainage
-include flood defences

agriculture and fisheries
- changing crop varieties to high yields
- water conservation techniques like micro-irrigation

health
- prepared for climate related treatments
- public education programme which covers actions to take during floods, specific diseases etc

ecosystems
- more protected areas with corridors to allow the movement of speces.
- forest management techniques