Topic 7 - Climate change and energy production

fossil fuels

formed from dead plants and animals under pressure over millions of years.

types of fossil fuels

• coal

• oil

• natural gas

advanatges of fossil fuels

• infrastructure is set up for its use (roads and railways for transport)

• relatively cheap

• currently relatively abundant

• high energy content

disadvantages of fossil fuels

• finite resource

• extraction can result in habitat loss and loss of biodiversity

• transport of fossil fuels can produce emissions of carbon dioxide, nitrogen oxides, sulfur dioxide and particulates

• combustion of fossil fuels produces greenhouse gas emissions, carbon dioxide, nitrogen oxide, sulfur dioxide and particulates

• powerplants require large amounts of water for cooling, may compete with other users of water and may impact aquatic systems

• discharge of water can result in thermal pollution of aquatic ecosystems

coal characteristics

• solid made up of carbon, hydrogen, oxygen, nitrogen, and sulfur compounds

• most abundant fossil fuel

where is coal obtained from?

• deep mines

• open mines

mining coal human impacts

• dangerous occupation

• causes health conditions such as “black lung disease”

• deaths caused by mining accidents

impact of coal mining systems on aquatic systems

• acid mine drainage can contaminate aquatic systems

burning of coal environmental impacts

• produces ash, containing metal oxides and alkali requiring disposal

where is oil extracted from?

pumped from underground reservoirs

envrionemntal impacts of oil

• drilling can pollute underground aquafers

• transportation can cause accidental oil spillages, affecting marine life

oil refineries

separate oil into different products

different oil products and their uses

• Residue containing bitumen used in road building

• Fuel oil for ships and power stations

• Diesel for cars and lorries

• Kerosene used by aircrafts

• Gasoline (petrol) for cars

• Various additional chemicals used to make plastics and fertilizers

waste from oil refineries

slurry containing metals and toxic compounds

most to least CO2 NOx and SO2 production fossil fuel types

• Coal

• Oil

• Natural gas

natural gas characteristics

• consists of methane, ethane, butane, propane and pentane

• natual gas is odorless, tasteless and colourless

why is natural gas less harmful than coal or oil

• lower nitrogen and sulfur content than oil or coal

• results in lower harmful emissions

environmental impacts from oil extraction (through hydraulic fracking)

• pollute groundwaters

• pollute surface waters with waste products

• contribute to seismic activity

nuclear power process

• uranium mined

• uranium ore is processed and purified

• neutrons start a chain reaction, in which energy is produced from the splitting of uranium atoms (nuclear fission)

• heat that is generated from nuclear fision is used to turn water into steam

• steam travels through pipes to spin a steam turbine

• spinning of the steam turbine generates electricity

waste products from nuclear power

radioactive waste

how is radioactive waste disposed off?

• low level waste is filtered, then disposed into the environment

• solid waste is buried underground

• other waste is stored in led covered stainless steel containers

advantages of nuclear power

• Nuclear power stations do not produce carbon dioxide emissions, reducing the risk of climate change

• Compared to fossil fuels, nuclear power causes less deaths

disadvantages of nuclear power

• Generation of nuclear waste with high radioactive levels that will last thousands of years

• risk of nuclear accidents

• potential use of radioactive materials from nuclear power station to produce nuclear weapons

• high capital costs and high decommissioning cost

renewable energy sources

• solar

• wind

• hydropower

• biomass

• geothermal

• wave

• tidal

advantages of renewable resources

• production of less primary pollutants such as particulates (SO₂, NOx) and secondary pollutants (ozone)

• Reduced GHG emissions

• provide employment opportunities

• improve energy security

what factors can accelerate the use of renewable energy

• decline in fossil fuel reserves, increasing prices

• technological developments, improving efficiency of renewable energy, and capital cost

• governmental support through economic incentives

• increase awareness on impact of fossil fuels

• international set targets

types of solar panels

• solar thermal panels = used to heat water and buildings

• photovoltaic panels = used to convert sunlight energy into electrical energy

amount of solar radiation is dependent on which factors?

• tilting of the earth

• amount of cloud cover

photovoltaic panels advantages

• running costs are low

• no emissions

• Panels called heliostat can track the movement of the sun, maximising the amount of electricity produced

photovoltaic panels disadvantages

• efficiency ranges between 10 and 20%

• cost of production and installation is high

• production of panels introduces pollutants such as carbon dioxide

advantages of solar power

• can be used in remote areas

• low running cost

• once operational does not produce air pollutants

• sustainable, renewable, reliable

• silent

disadvantages of solar power

Needs sunlight which varies regionally and seasonally, also is weather dependent

Relatively high capital cost

Production of solar panels produces pollution

No electricity is produced at night and therefore electricity produces needs storing for use when required

advantages of wind power

• renewable

• abundant supply

• can be used in remote areas

• once set up does not produce pollutants

• operational cost is low

disadvantages of wind power

• Wind dependent which varies

• noise pollution

• aesthetically displeasing

• can kill birds and bats

• high capital costs

• electricity produced needs storing

offshore windpower disadvantages

• Visual impact on the sea

• Corrosion of the aerogenerator

• Potential impact of vibrations from the aerogenerator on sea life

• Potential impact on seabirds

• Disruption to shipping routes

• Reduced fishing grounds for fishermen

hydropower

energy obtained from the movement of water

hydroelectric power

produced when flowing water drives turbines connected to a generator which converts mechanical energy into electrical energy

advantages of hydropower

• Relatively low running cost

• Sustainable source of energy

• Dam construction can also increase water resources, reduce risk of flood downstream

• The reservoir can provide an ecosystem for fisheries and opportunities for recreation

• Does not produce urban air pollutants

disadvantages of hydropower

• High start-up cost

• Dam construction can lead to displacement of people, potential seismic activity, loss of habitat and loss of species biodiversity

• disruption of migratory route for river organisms

• Decomposition of the biota flooded to create the reservoir can result in emissions of methane and carbon dioxide

geothermal energy

energy from the interior of the earth that sometimes leaks through faults and fractures to the surface of the earth

advantages of geothermal energy

• Cheap to operate

• Low emissions of carbon dioxide and other GHGs

• Reliable supply in some areas

• Sustainable energy supply

disadvantages of geothermal energy

• high running cost (drilling can be expensive)

• Poisonous gases from within the earth can be released

• Historically limited to areas near volcanic activity

energy security

the uninterrupted availability of energy sources at an affordable price

energy security depends on which factors?

• An adequate supply of energy which matches demand

• Reliable supply, that is not interrupted

• Affordable supply to ensure access to all

threats to energy security

• Political instability and /or conflict in exporting country

• Accidents or natural disasters

• Risk of terrorist attacks on source or supply infrastructure

• Exhaustion of resource

factors affecting energy choices

• availability (geology and topography)

• technological innovation

• cultural attitudes

• politics

• economics

• environmental impact of an energy source

climate

average weather over the long term at a regional level

weather

refers to the conditions over a short time scale at a local level

factors affecting climate (outside the earth)

• Solar radiation emitted from the sun

• Tilting and orbit of the earth

factors affecting climate (within the earth)

• Atmospheric and ocean circulation systems

• Greenhouse gases that trap heat and warm the land, oceans and atmosphere

• Volcanic activity

• Feedback cycles

how does solar radiation from the sun change?

• 11 year cycles

• period of high and low emissions

what is the tilt of the earth

23.5 degrees

why does more solar radiation reach the equator?

due to earths curvature

how is heat distributed from the equator to the poles

atmospheric and ocean circulation systems

what causes ocean circulation systems?

• winds

• difference in water temperature

• difference in water salinity

how does wind occur?

movement of air from high to low pressure

when does low air pressure occur?

when air is warmed, it expands and rises forming clouds

when does high air pressure occur?

reduction in temperature cools the air which contracts becoming denser and descends

tricellular model

• hadley cell

• ferrel cell

• polar cell

hadley cell

• 0 - 30 latitude

• The Sun heats the air at the Equator, causing it to rise.

• As the air rises, it cools and spreads out toward 30° latitude.

• It then sinks at around 30°, creating dry, high-pressure areas (like deserts).

• The air moves back to the Equator, completing the cycle

Ferrel cell

• 30 - 60 latitude

• This cell acts like a link between the Hadley and Polar cells

• Air moves from high-pressure (30°) to low-pressure (60°), bringing storms and variable weather in this region

• Winds here are known as the westerlies, moving from west to east

Polar cell

• 60 - 90 latitude

• Cold air sinks at the poles (90°) and moves toward 60° latitude

• At 60°, the air rises, cools, and moves back toward the poles

• This creates cold, dry conditions at the poles

El nino

• “warm phase”

• Normally, trade winds blow westward (from South America to Australia), pushing warm water toward the western Pacific

• During El Niño, these winds weaken or even reverse, causing warm water to spread back toward the eastern Pacific (near South America)

effects of el nino

• Warmer ocean temperatures in the eastern Pacific

• More rain and flooding in South America

• Droughts in Australia and Southeast Asia

• Weaker upwelling (cold water rising from deep in the ocean), which reduces fish populations along the South American coast

la nina

• “cold phase”

• Trade winds strengthen, pushing even more warm water toward the western Pacific (Australia)

• This causes colder than normal water to rise in the eastern Pacific (south America)

effects of la nina?

• Droughts in South America

• Heavy rainfall and floods in Australia and Southeast Asia

• Stronger hurricanes in the Atlantic

• Cooler global temperatures overall

water vapour positive feedback loop on climate change

• higher surface temperature

• increased evaporation

• more water vapour

• enhanced greenhouse effect

Ice albedo positive feedback climate change

• ice and snow have a reflective surface, high albedo

• temperatures increase, ice and snow melt, reducing amount of solar radiation reflected

• dark surfaces which replace the ice and snow increase absorption of sunlight and contribute to global warming

• higher temperatures result in more ice and snow melting

permafrost positive feedback climate change

• increase in temperature results in melting of permafrost

• releases methane

• methane greenhouse gas increases global temperatures

carbon dioxide solubility positive feedback climate change

• temperatures increase

• solubility of carbon dioxide in oceans decreases

• release of carbon dioxide into atmosphere

• results in further warming of the planet

plant photosynthesis negative feedback climate change

• temperatures increase

• levels of plant photosynthesis rise more and more if carbon dioxide is absorbed

• reduction in overall atmospheric levels of carbon dioxide results in a reduction of global temperatures

cloud cover negative feedback climate change

• low clouds reflect some of the incoming solar radiation back into space

• heat loss

cloud cover positive feedback loop climate change

• high cloud trap heat radiated from the earth’s surface

• increases temperature

impacts of climate change

• higher temperatures

• sea level rise

• flooding

• reduced water resources

• fisheries

• agriculture

higher temperatures impact on climate

• higher temperatures will affect hydrological cycle

• rise in temperature, more water evaporates, some regions will experience more rainfall

• rainfall will not be distributed equally, water stressed areas will receive less rainfall

• extreme weather patterns are likely to be frequent

• warming oceans may impact ocean circulation systems

impact of climate change on ecosystems and biodiversity

• Increase in temperature and change in precipitation patterns

• Increased risk of flooding

• Drought conditions

• Increased risk of wild fires

• Increased spread of pests

• Ocean acidification

• change in migration patterns

shifts of biomes animals and plants due to climate change explain

• due to change in climactic conditions of temperature and rainfall, likely a general shift of biomes, animals and plants moving towards the poles and upwards in elevation

• geographical range for some species will expand which may threaten local species

• less adaptive species, or species at the top of their thermal tolerance range will decrease in number with potential risk of becoming extinct

• if change is rapid, species may not be able to adapt

impact of climate change on coastal systems

• storm intensity

• rising sea levels

perspectives on climate change

• climate sceptic view

• climate advocator view

what do climate skeptics argue

• human induced global warming is not proven, changes in climate have always occurred and warming has occurred before prior to humans changing GHG levels

• Warming is a natural phenomenon and a result of natural cycles

• Climate change models used are inaccurate and impacts are exaggerated

• Data that is technologically verifiable has been collected for only relatively short time period

• Scientists manipulate results to attract future funds for research

what do climate advocators argue?

• sufficient scientific data from a variety of sources as evidence of warming occurring

• Levels of GHG emissions from human activity since the industrial revolution correlates with rise in average global temperature

• Current rate of global temperature increase is unprecedented

• There is scientific consensus that climate change is occurring

• It is too late to avoid some problems of climate change and we also need to focus on how to adapt to changes

ecocentric course of action to deal with impacts of climate change

change in behaviour and lifestyle that reduces production of GHGs

anthropocentric course of action to deal with impacts of climate change

Use regulation to reduce GHG emissions and provide compensation to those affected

technocentric course of action to deal with impacts of climate change

Believe in market forces and technology and therefore may invest in technology to reduce emissions and adapt to changing conditions

mitigation

human intervention to reduce the sources or enhance the sinks of greenhouse gasses

ways in which greenhouse gasses emissions could be reduced

• lower energy use through improved efficiencies and conservation approaches

• replace use of fossil fuels with low emission energy sources

• decrease emissions from agriculture activity

• reducing emissions from transport

what are substitutes of fossil fuels (for fuel)

• biodiesel

• bioethanol

biodiesel

Diesel engines can use a variety of different oils (such as rapeseed, palm or sunflower oil

Bioethanol

Many crops can be fermented to produce bioethanol (sugar cane, maize or sorghum)

geo-engineering

manipulating the earth’s environmental systems to counteract the impacts of climate change

main approaches of geo-engineering

• Carbon dioxide removal from the atmosphere

• Solar radiation management

carbon dioxide removal (CDR)

• afforestation

• reforestation of degraded land

• reduced deforestation

• use of farming practices which encourages retention of carbon stores

• use of biomass

carbon capture and storage (CCS)

• chemical process to form carbonates

• compression and transport to a site of permanent storage

solar radiation management (SRM)

• methods are only theoretical

• increasing reflection of sunlight back into space and therefore reducing the amount of solar radiation absorbed by the earth

adaptation

The process of adjustment to actual or expected climate and its effects. In human systems, adaptation seeks to moderate or avoid harm or exploit beneficial opportunities

differences between mitigation and adaptation

• Effects of mitigation can be seen on a global scale whereas those of adaptation are at a local level

• Success of mitigation is relatively easy to measure, whereas the success of adaptation is more complex to measure

adaptation strategies sectors

• water resources

• agriculture and fisheries

• ecosystems

• coastal systems

• human health

adaptation strategies water resources

• reducing demand for water

• improving water supplies (through desalination)

• flood control (drainage systems, flood barriers)

• modifying infrastructure to withstand floods

adaptation agriculture and fisheries

• using crops that are adapted to new conditions (less water, salt resistant, pest resistant, flood resistant)

• using crops with high yields

• altering times of planting and harvesting to optimize yields

• water conservation techniques (micro-irrigation)

• increasing retention of soil moisture

• reduction in fishing intensity

• reduced fish catches

adaptation strategies ecosystem

• Adjusting to biome shifts by expanding conservation areas towards the poles

• Connecting protected areas with corridors to allow movement of species adapting to changing conditions

• Greater protection of vulnerable areas, protection from pollution and over exploitation

• Development of forest fire management techniques