Flashcards in Topic 6: The Carbon Cycle and Carbon Insecurity Deck (188)
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1
Q
What is the natural carbon cycle
A
- the movement and storage of carbon between the land, ocean and the atmosphere.
2
Q
What are the three forms of carbon in the Carbon Cycle?
A
- inorganic: found in rocks as bicarbonates and carbonates
- organic: found in plant material and living organisms
- gaseous: found as CO2 and CH4 (methane)
3
Q
Why is carbon important?
A
It plays a major role in regulating global climate, particularly temperature and the acidity of rain, rivers and oceans.
4
Q
How is carbon stored?
A
- Atmosphere - as carbon dioxide and compounds such as methane
- Hydrosphere - as dissolved carbon dioxide
- Lithosphere - as carbonates in limestone and fossil fuels (e.g. coal, oil and gas)
- Biosphere - in living and dead organisms
5
Q
Three components of carbon cycle:
A
- Stores - where carbon is held, e.g. atmosphere or lithosphere
- Fluxes (transfers) - the flows which move carbon between stores (from one sphere to another) measured in petagrams or gigatonnes of carbon per year. e.g. photosynthesis and respiration.
- Processes - the physical mechanisms which drive the fluxes between stores e.g. photosynthesis and diffusion
6
Q
What is the geological carbon store?
A
- natural cycle that moves carbon between land, oceans and atmosphere.
- involves a number of chemical reactions that create new stores which trap carbon for significant periods of time.
- tends to be a natural balance between carbon production and absoption. However there can be occasional disruptions and short periods before balance is restored, e.g. major volcanic eruptions emitting large quantities of carbon.
7
Q
Process of geological carbon cycle:
A
- terrestrial carbon, held within mantle, is released into the atmosphere as CO2 when volcanoes erupt. This is known as out-gassing.
- CO2 within the atmosphere combines with rainfall to produce carbonic acid that dissolves carbon-rich rocks, releasing bicarbonates. This is chemical weathering.
- rivers transport weathered carbon and calcium sediments to the oceans, where they are deposited.
- carbon in organic matter from plants and animal shells and skeletons sinks to the ocean bed when they die, building up strata of coal, chalk and limestone.
- carbon-rich rocks are subducted along plate boundaries and eventually emerge again when volcanoes erupt.
- the presence of intense heating along subduction plate boundaries metamorphoses sedimentary rock by baking, creating metamorphic rocks. CO2 is released by the metamorphism of rocks rich in carbonates during this process.
8
Q
geological stores of carbon - out-gassing:
A
- The Earth’s crust contains pockets of carbon dioxide which can be disturbed by volcanic eruptions or seismic activity
- This release of gas that has been dissolved, trapped, frozen or absorbed in rock is called outgassing
- Outgassing happens at:
+ Volcanic zones associated with plate boundaries (including subduction zones and spreading ridges)
+ Areas with no current volcanic activity, e.g., the geysers in Yellowstone National Park, USA
+Direct emissions from fractures in the Earth’s crust - The gas released by volcanic eruptions is relatively insignificant in comparison to human activity
+ Volcanoes currently emit 0-15 - 0.26 Gt carbon dioxide annually
+ Fossil Fuel use emits about 35 Gt
9
Q
geological stores of carbon - chemical weathering:
A
- chemical weathering water reacts with carbon dioxide in the atmosphere forming carbonic acid, which reaches the surface as rain dissolving surface minerals.
- rivers transport calcium ions from the land to oceans which combine with bicarbonate ions to form calcium carbonate
- deposition and burial turns the calcite sediment into limestone.
- subduction of the sea floor (tectonic uplift can expose buried limestone)
- some carbon rises back to the surface within magma which is returned to the atmosphere as carbon dioxide.
10
Q
What are the four key processes involved in the bio-geochemical carbon cycle?
A
- photosynthesis: removing CO2 from the atmosphere to promote plant growth.
- respiration: releasing CO2 into the atmosphere as animals consume plant growth and breathe.
- decomposition: breaking down organic matter and releasing CO2 into the atmosphere.
- combustion of biomass and fossil fuels - releasing CO2 and other greenhouse gases into the atmosphere.
11
Q
Variations in fluxes - fast and slow:
A
- ## if it’s too dark, hot or cold, and low levels of CO2 the speed of the cycle reduces.
12
Q
Variations in fluxes - geographical patterns:
A
- levels are always higher in the Northern hemisphere as it contains greater landmasses and greater temperature variations than in the Southern Hemisphere.
13
Q
What is carbon sequestration?
A
Sequestering is the movement of carbon into carbon stores which can lower the amount of carbon dioxide in the atmosphere
Photosynthesis (by land based plants and phytoplankton) is the main process responsible for sequestering carbon from the atmosphere
14
Q
What is ocean sequestration?
A
- 93% of carbon dioxide is stored in undersea algae, plants, coral and dissolved form, making oceans the largest carbon store on Earth
- The movement of carbon within oceans is controlled:
+Vertically by carbon cycle pumps
+Horizontally by thermohaline circulation - There are three carbon cycle pumps which move carbon dioxide to the sea floor and to the ocean surface to be released into the atmosphere
15
Q
Ocean sequestration - biological pump:
A
- The biological cycle sequesters carbon in the ocean through photosynthesis by phytoplankton and other marine animals which converts CO2 into organic matter (10GtC per year)
- This acts as a biological pump transporting carbon from the oceans’ surface to the intermediate and deep ocean stores (10 GtC per year)
- As the biological organisms die, their dead cells, shells and other parts sink into the mid and deep water
- Also, the decay of these organisms releases carbon dioxide into the intermediate and deep water stores
- Oceans regulate the composition of the atmosphere by moving carbon from the ocean’s surface (where it may vent back into the atmosphere) and storing it in the mid and deep ocean store, along with the dissolved carbon store, which regulates the carbon cycle
16
Q
Ocean sequestration - carbonate pump:
A
- Relies on inorganic carbon sedimentation
- When organisms die and starts to sink, many shells dissolve before they reach the ocean floor entering the deep ocean currents
- The solubility cycle occurs when CO2, absorbed by the oceans from the atmosphere, forms carbonic acid which in turn reacts with hydrogen ions to form bicarbonates and then further reactions form carbonates which are stored in the upper ocean
- Some organisms use these carbonates to make their shells or skeletons
- When these organisms die some material sinks to the ocean floor and forms the sea bed sediment store (1750 GtC)
- Over time, through chemical and physical processes, the carbon is transformed into rocks such as limestone
- This process locks up carbon in the long-term carbon cycle and does not allow an easy return to the ocean surface and so prevents possible venting into the atmosphere as the physical pump does.
17
Q
Ocean sequestration - physical pump:
A
- Considered the most important transfer
- Carbon dioxide (CO2) is absorbed by the ocean’s surface through diffusion
- Dissolved CO2 is then taken from the surface down to the intermediate and deep ocean stores through downwelling currents (96 GtC per year)
- The thermohaline circulation then distributes the carbon around the planet
- Cold water absorbs more CO2, therefore, as the equatorial waters move toward the poles, more CO2 is absorbed
- Salinity increases at the same time, making the water denser, therefore, the water sinks (downwelling) taking CO2 from the ocean’s surface to the deep ocean stores
- Allowing more diffusion to occur at the surface and helping to regulate the carbon stored in the atmosphere
- However, there is also the upwelling of carbon from intermediate and deep oceans to the surface oceans (105.6 GtC yr-1)
- Through upwelling currents and turbulence created by surface winds, previously stored carbon in the intermediate and deep ocean stores, return to the ocean’s surface and then back into the atmosphere
18
Q
The role of trees - carbon sequestration:
A
- 95% of a tree’s biomass is made up from the CO2 that it sequesters and converts into cellulose.
- carbon fixation turns gaseous carbon - CO2 - into living organic compounds that grow.
- the amount of carbon stored within a tree, woodland or forest depends on the balance between photosynthesis and respiration.
19
Q
Mangroves and the role of soil:
A
- mangroves are vital processors - sequestering almost 1.5 metric tonnes of carbon per hectare per year.
- their soils are anaerobic and due to this the decomposition of plant matter is slow. As a result, little of the carbon can be respired back to the atmosphere and the store remains intact.
- however if mangroves are drained or cleared, carbon is released into the atmosphere. Mangroves are being closed for tourism. Even 2% is cleared results in carbon released being 50 times the natural sequestration rate.
20
Q
Tundra soils - carbon sequestration:
A
- much of soil in the tundra is permanently frozen and contains ancient carbon.
- this locks any carbon into an icy store due to the decayed organic matter being frozen.
- tundra soils contain carbon that has been trapped for hundreds of thousands of years.
21
Q
Tropical rainforests as carbon stores:
A
- tropical rainforests are huge carbon sinks, but are fragile and can quickly disappear.
- carbon within rainforests is mainly stored in trees, plant litter and dead wood.
- as litter and dead wood decay they are recycled so quickly a soil store does not develop.
- TR absorb more atmospheric CO2 than any other terrestrial biome, accounting for 30% of global net primary production, although they cover 17% of the earth’s surface.
- if they died off the world would lose a massive carbon sink.
22
Q
What is the natural greenhouse effect:
A
- solar energy is received from the sun, fark surfaces on Earth absorb this sunlight and some is reflected back into space.
- the greenhouse gases in the atmosphere act like a ‘blanket’ to trap some of the heat and keep the earth warm (without them we would be 16 degrees Celsius). This means life on earth is sustained.
- CO2 is the most common greenhouse has and it has the highest radioactive forcing effect (RFE) - holds onto heat for longer.
23
Q
Enhanced greenhouse effect:
A
-concentration of greenhouse gases such as CO2 and CH4 in the atmosphere have increased 25% since 1750. 75% of CO2 emissions have come from burning fossil fuels.
- many believe that this is the cause of increased global temperatures and leading to enhanced greenhouse effect.
- human activities, e.g. burning fossil fuels and deforestation release natural carbon stores and nitrogen, which then combine with oxygen to form greenhouse gases. e.g. carbon combines with oxygen to form CO2.
- level of water vapour increases as well as global temperatures. Higher temps results in greater evaporation of water leading to greater condensation. This causes increased cloud cover, trapping heat in the atmosphere.
24
Q
enhanced greenhouse effect - temperature:
A
- due to the angle of the sun’s rays solar insolation is intense at the Equator, but dispersed over a wider area at the Poles.
- different characteristics of the Earth’s surface (e.g. whether it is light or dark) also affect how much heat is absorbed or reflected (albedo) snow reflects heat and dark forests absorb it.
- heat is redistributed around the globe by air movement, caused by both pressure differences and ocean currents.
25
Q
enhanced greenhouse effect - distribution of precipitation:
A
- solar radiation (insolation) is most intense over the Equator, convection and low-pressure systems dominate there. Rainfall is high all year round.
- as the air pressure rises around 30 degrees north and south of the Equator, precipitation decreases. Clouds rarely form there.
- mid latitudes: air masses of different characteristics meet, and low-pressure systems bring rainfall.
- nearer the Poles, precipitation falls as the air cools further ad us dense and dry - creating polar deserts.
26
Q
How does photosynthesis regulate the composition of the atmosphere?
A
- phytoplankton in the oceans sequester CO2 through the process of photosynthesis - pumping it out of the atmosphere and into the ocean store.
- terrestrial photosynthesis enables plants to sequester 100-120Gt of CO2 each year. This is then released back into the atmosphere through respiration and decomposition.
27
Q
Ocean and terrestrial photosynthesis:
A
- The carbon cycle is dependent on ocean and terrestrial photosynthesis in regulating the composition of the atmosphere
- Plants photosynthesising play a vital role in helping to keep carbon dioxide levels relatively constant thus helping to regulate average global temperatures
- As a result, patterns in plant productivity and carbon density are evident
- Highest productivity NPP occurs either in warm and wet regions such as the tropical rainforest or in shallow ocean waters
28
Q
Soil and carbon:
A
- carbon is vital in soils. It supports micro-organisms that maintain the nutrient cycle, break down organic matter, provide pore spaces for infiltration and storage of water, and enhance plant growth.
- without carbon, the nutrient and water cycles cannot operate properly.
29
Q
Characteristics of healthy soils:
A
- dark and porous
- sequester carbon
- retain moisture, which regulates soil temperature during heatwaves ad reduces the effects of drought.
- improve resilience to wetter weather, as they enable infiltration and percolation of water (reducing soil erosion and flood risk)
30
Q
Fossil fuel combustion - balance?
A
- earth’s carbon reservoirs act as sources (adding carbon to the atmosphere) and sinks (removing it). If the sources are equal they will be in equilibrium. This helps to stabilise global temperatures.
- however, human activities (e.g. deforestation and fossil fuel combustion) have increased CO2 inputs into the atmosphere, without any increases in the natural sinks (e.g. oceans or forests).
- process of fossil fuel combustion has altered the balance of carbon pathways and stores - with carbon being released in large amounts.
31
Q
Fossil fuel combustion - implications for climate?
A
rising levels of CO2 are leading to increased global temperatures. However the increases will vary.
- Across Europe, annual average land temperatures are predicted to increase by more than the global average. The largest increases are expected to be over Eastern Europe in winter, and southern Europe in summer.
- extreme weather events are also likely to increase in both intensity and frequency.
- annual precipitation is projects un increase in N Europe and decrease in S Europe - increasing the differences between regions that are currently wet and those which are dry.
32
Q
Fossil fuel combustion - arctic amplification?
A
- arctic region is warming twice as fast as the global average.
- melting permafrost releases CO2 and CH4, increasing the concentration of these greenhouse gases in the atmosphere leading to increased global temperatures and further melting.
- rapid warming has led to extensive melting of ice in summer months and greatly reduced snow cover and reduction in permafrost.
- shrubs and trees, previously unable to survive i tundra, have started to establish themselves.
33
Q
Fossil fuel combustion - implications for ecosystems:
A
- Ecosystems help regulate carbon and hydrological cycles as well as providing goods and services for humans and the planet
- Already, species with low population numbers, limited climatic ranges or restricted habitats are at risk
- Marine ecosystems are threatened by lower oxygen levels, higher rates of ocean acidification and food chain changes (resulting from rising temperatures)
- Coastal ecosystems are at risk from sea level rise
- Although most species will be impacted negatively, there are some that may benefit. E.g. cool, moist regions (e.g., UK) could provide habitats for more species
34
Q
Fossil fuel combustion - implications for the hydrological cycle?
A
- precipitation in the form of snow could diminish and rainfall patterns change.
- river discharge patterns may also change, with greater flooding in winter and drought in summer.
- as Alpine glaciers melt, water flows lead to increased sediment yield. Once the glaciers have retreated, discharge and sediment yields fall and water quality declines.
35
Q
What are carbon pathways?
A
- in theory, constant levels of CO2 in atmosphere are maintained if photosynthesis keeps up with the release of GHGs.
- increased thawing has accelerated the process of carbon release. Increased thawing means that methane and water are also being released as ancient vegetation decomposes and trapped gases seep to the surface. Plants and micro-organisms grow faster than before and respire CO2.
36
Q
What are the two types of carbon pathways?
A
- pathway 1: shrubs and trees invade the Arctic landscape and store more carbon than is being released into the atmosphere. A short-term balance is reached - i.e. negative feedback.
- pathway 2: the decomposition of plant material in wet soils reduces carbon stores by releasing more CO2 and CH4 into the atmosphere. Increased greenhouse gases reinforce global warming in the longer term - i.e. positive feedback. Scientists believe that this will add as much carbon to the atmosphere each year as all f the land use changes in the rest of the world combined.
37
Q
Madagascan + USA comparison - energy usage:
A
- Madagascar has a population of 23 million and uses little energy
- Manhattan (USA) has a population of 1.7 million yet consumes more energy in a year than an average Madagascan will in a lifetime.
38
Q
Urban consumption - UK:
A
- cities consume 75% of world’s energy and produce 80% of its greenhouse gas emissions.
- e.g. City of London generates 1.7 million tonnes of carbon per year and its resident population averaging 1.8 tonnes of carbon per capita.
- London’s demands are met through a web of national and international supply lines, and involve several key players.
39
Q
Rural consumption - Peru:
A
- national program of solar-panel installation made electricity available to 500,000 villages across Peru from 2006-2015.
- provides increased productivity allowing extra processing of cereals, meat, wood and cocoa. This helps to boost incomes and raise rural standards.
- increasing energy consumption is helping to bring sustainable development and a brighter future for Peru’s villagers.
40
Q
Energy security definition:
A
- being able to access reliable and affordable sources of energy. These may be domestic, but could also include energy sources from ‘friendly’ countries
41
Q
What are primary and secondary sources?
A
- primary: consumed in their raw form. They include burning fossil fuels, nuclear energy, and renewable sources. They can also be used to generate electricity.
- secondary sources: electricity - flows through power lines and infrastructure to power homes and businesses.
42
Q
Domestic and overseas sources:
A
- UK consumed less energy in 2015 than in 1998 despite population growth.
- more energy came from renewable sources
- however, declining domestic North Sea oil and gas have made the UK more reliant on imported energy.
- now the country imports more than it produces domestically and therefore has an energy deficit and is energy insecure.
43
Q
Renewable sources:
A
- e.g. solar, wind and wave power.
- these are continuous flows of nature, which can constantly be reused.
44
Q
non-renewable sources:
A
- e.g. coal, oil and gas. Exploitation and use of these stocks will eventually lead to their exhaustion.
- traditionally coal has been the major source for producing electricity.
45
Q
recyclable sources:
A
- e.g. reprocessed uranium and plutonium from nuclear power plants and heat recovery systems.
46
Q
Factors affecting energy consumption:
A
- physical availability
- cost
- technology
- political considerations
- level of economic development
- environmental priorities
47
Q
Physical availability - UK:
A
- until 1970s: UK relied heavily on domestic coal from Yorkshire, Derbyshire, South Wales and north-east England.
- also among global leaders in nuclear technology from the 1950s-70s, but lost momentum after discovery of large reserves of North Sea oil and gas which greatly altered the UK’s energy mix.
48
Q
Physical availability - Norway:
A
- mountainous, with steep valleys and plentiful rainfall, HEP is a natural energy choice.
- much of Norway’s oil and natural gas is exported (e.g. to the UK)
- coal from Svalbard is also exported.
49
Q
Cost - UK:
A
- North Sea oil is expensive to extract, so if global prices fall (like in 1997-98), it becomes less viable.
- stocks pf North Sea oil are also declining, which is forcing the UK to import more.
50
Q
Cost - Norway:
A
- Norsk Hydro runs over 600 HEP sites, supplies 97.5% of Norway’s renewable sources.
- HEP costs are low once capital investment is complete.
- however, transfer of electricity from HEP production in remote regions to urban population centres and isolated areas is expensive.
51
Q
Technology - UK:
A
- current technology and environmental policy make the extraction and use of oil unrealistic and expensive.
- last deep mine closed in 2015, although 80% of of UK’s primary energy still came from fossil fuels.
- technology exists for ‘clean coal’ but coal has lost its political support.
52
Q
Technology - Norway:
A
- deepwater drilling technology enabled both Norway and the UK to develop North Sea oil and gas extraction.
53
Q
Political considerations - UK:
A
- public concern is growing over new and proposed fracking and nuclear sites
- privatisation of UK’s energy supply industry in the 80s now means overseas companies (French EDF) decide which energy sources are used to meet UK’s demand.
54
Q
Political considerations - Norway:
A
- HEP been used since 1907 and Norwegian Water and Energy Directorate manages the nation’s power supply.
- Norwegian government has an interventionist approach, which prevents foreign companies from owning any primary energy source sites - waterfalls, mines, forests.
- royalties and taxes are paid into the government to boost the standard of living through govt spending but profits also go to a sovereign wealth fund to prepare for a future without fossil fuels.
55
Q
Level of economic development - UK:
A
- GDP per capita: $41,200 (2015)
- Energy use per capita: 2752kg oil equivalent (2014)
- Average annual household energy costs: £1300 (2015)
56
Q
Level of economic development - Norway:
A
- GDP per capita: $61,500 (2015)
- Energy use per capita: 5854kg oil equivalent (2014)
- Average annual household energy costs: £2400 (2015)
57
Q
Environmental priorities - UK:
A
-2015: committed to a 40% reduction in domestic greenhouse gas emissions by 2030, compared to 1990 levels.
- intends to broaden its energy mix with renewable sources (especially wind) and more nuclear power.
- however, in 2015, it abandoned its ‘Green Deal’ conservation and insulation schemes.
58
Q
Environmental policies - Norway:
A
- 2015: committed to a 40% reduction in domestic greenhouse gas emissions by 2030, compared to 1990 levels.
- Norway’s ‘Policy for Change’ was launched in 2016, with a domestic target of being carbon neutral by 2050.
59
Q
Changes in energy mix (UK) from 1980 - 2012:
A
- nuclear power: 6% - 9%
- renewables: remained the same at 2%
- coal: 34% - 15%
- gas: 19% - 40%
- oil: 38% - 32.5%
- biomass and waste: remained the same at 1%
- hydropower: 2% - 1%
60
Q
Changes in energy mix (Norway) from 1970 - 2010:
A
- renewables: <1% to <0.5%
- coal: 6.5% - <1.5%
- gas: 2010 - 20%
- oil: 51% - 33.5%
- biomass and waste: 2010 - 5%
- hydropower: 42.5% - 40%
61
Q
Energy pathway definition:
A
- term used to describe the flow of energy between a producer and a consumer, and how it reaches the consumer, e.g. pipeline, transmission lines, ship, rail.
62
Q
What are examples of energy players:
A
- Energy TNCs
- OPEC
- National governments
- Consumers
63
Q
Role of energy TNCs:
A
- TNCs explore, exploit and distribute energy resources
- own supply lines and invest in distribution and processing of raw materials, as well as electricity production and transmission.
- they respond to market conditions yo secure profits for their shareholders.
64
Q
Examples of energy TNCs:
A
- Old players: BP (UK) and Shell (UK-Netherlands); Exxon/Mobil (USA)
- New players: Petrobas (Brazil), Reliance (India) and Gazprom (Russia)
65
Q
What is OPEC?
A
- The Organisation of Petroleum Exporting Countries - permanent inter-governmental organisation (IGO)
- between them, OPEC producers control 81% of proven world oil reserves.
66
Q
Role of OPEC:
A
- mission is to co-ordinate and unify petroleum policies of its members, to ensure the stabilisation of oil markets.
- this is to ensure steady income for producers and efficient, economic and regular supply of petroleum to consumers.
67
Q
Role of national governments:
A
- to meet international obligations, whilst securing energy supplies for nation’s present and future, as well as supporting nation’s economic growth.
- regulating the role of private companies and setting environmental priorities.
68
Q
Examples - national governments:
A
- EDF (France) and China General Nuclear are two government-backed energy TNCs involved in developing new nuclear power plants in the UK.
- EU governments aim to fulfil CO2 emissions targets and reduce fossil fuel dependency.
69
Q
Role and factors affecting consumer attitudes:
A
- Create demand. Purchasing choices are often based on price/cost issues, e.g. petrol prices can be keenly competitive between supermarkets.
70
Q
What is the location of fossil fuels?
A
- not evenly distributed throughout the world and are determined by underlying geology.
71
Q
Geology - coal:
A
- most coal in Western Europe and North America was formed during the Carboniferous period (300-360 million years).
- successive layers of rainforest-type tress within swamp forests accumulated as they feel, and were transformed under pressure of over-lying strata into seams of coal.
72
Q
Geology - oil and gas:
A
- generally younger than coal and were formed during the Mesozoic era (250-260 million years ago)
- formed from fossil remains of plants and animals that dies and buried under alternate layers of mud.
- heat and pressure converted these fossil remains into oil and natural gas., with accumulated into porous sandstone.
73
Q
Energy pathways - ESPO:
A
- East Siberia Pacific Ocean
- 4188km long ESPO pipeline exports crude oil from Russia to China, South Korea ad Japan.
- built by Russian energy company Transneft, and was completed in 2012.
74
Q
What are other examples of pipelines?
A
- Yamal-Europe pipeline
- Keystone XL oil and Rockies Express
- Transmed
- West-East Gas Pipeline Project (WEPP)
- Kazakhstan-China
75
Q
What is the Yamal-Europe pipeline (Nordstream)?
A
- a 4107km gas pipeline that runs from Russia through Belarus and Poland into Germany.
76
Q
What are the Keystone XL oil and the Rockies Express?
A
- gas pipelines between western Canada and Nebraska and Ohio in northern USA.
77
Q
What is the Trans-Mediterranean (Transmed)?
A
- a 2475km gas pipeline from Algeria to Italy, via Tunisia and Sicily.
78
Q
What is the West-East Gas Pipeline Project (WEPP)?
A
- connects the natural gas reserves of the Tarim Basin in Xinjiang with the growing energy markets of the Yangtze and Pearl Delta regions.
79
Q
What is the Kazakhstan-China pipeline?
A
- a 2800km pipeline that trasnports crude oil from Western Kazakhstan to Xinjiang, western China.
80
Q
Examples of energy pathways that have been disrupted - Strait of Malacca:
A
- December 2015: the International Maritime Bureau reported piracy attacks along the Strait of Malacca, between Malaysia, Indonesia and Singapore.
- world’s second largest chokepoint for oil and gas transit by transfer.
- criminal gangs frequently seized ships for hostage payments-over 500 attacks occurred from 2009-2015.
81
Q
Political conflict due to energy pathways - Syrian conflict:
A
- ongoing Syrian conflict has involved two superpowers and their allies during the 2010s. On one side is Russia and its Shia non-fundamentalist allies and on the other side USA and its fundamentalist sunni allies.
- involved in the battle for control over Syrian territory. Key reason is the the proposed construction of oil and gas pipelines through Syria to supply fuel into Europe - world’s largest energy market.
- in recent decades, oil and gas have frequently been at the root of international tension, and proxy wars have been common.
82
Q
Political conflict due to energy pathways - Russia:
A
- world’s biggest supplier of both oil and gas, but Shiite Iran, an ally, wants a share of the European market, which Russia supports.
- Having Iran on side gives Russia control over European energy, while strengthening a non-fundamentalist bloc between Asia and Middle East.
83
Q
Political conflict due to energy pathways - Sunni Qatar:
A
- seeking to become Europe’s main suppliers of gas and oil respectively.
- Qatar and Saudi Arabia are US allies which explains why the USA and its allies are happy for Al Q’aeda and other jihadists to conquer a strip of Syria which US companies would build pipelines, allowing US companies such as Exxon to market Middle Eastern oil and gas in Europe.
84
Q
Energy pathways - Suez Canal:
A
- blockage in March 2021
- about 12% of global trade, around one million barrels of oil and roughly 8% of liquified natural gas pass through the canal each day.
- revenue lost: $14-15 million per day.
85
Q
What are examples of unconventional fossil fuels?
A
- deep water oil
- tar sands
- shale gas
- oil shale
86
Q
What is deep water oil?
A
- as accessible reserves run out, prospecting companies have to extract oil from deeper depths with greater risks and concerns, e.g. spills during transportation.
- e.g. the Gulf of Mexico and Brazil’s off-shore reserves.
87
Q
What are the advs of deep water oil?
A
- shale gas produces half the emissions of coal, which would reduce global emissions without completely eradicating fossil fuel use.
- large influx of readily available shale gas would drop the price of electricity.
- majority of shale gas is found in the US, which would improve the US’s economy and provide an alterative source to Russian oil (if political tensions continue)
88
Q
What are the disadvs of deep water oil?
A
- fracking faces large environmental opposition, especially as it can trigger minor tremors.
- shale gas is still more expensive to produce than conventional gas.
89
Q
What is shale gas?
A
- extracted through fracking.
- provides 25% of the US’ energy needs in 2015
- usually methane in coal seams, or natural gas trapped in fractures and pores of sandstones and shales.
90
Q
What are the advs of shale gas?
A
- less polluting than coal or oil
- could provide a boost to the economy
-in the UK, the Royal Academy of Engineers believes we can make fracking safe. - shale gas produces half the emissions of coal, which would reduce global emissions without completely eradicating fossil fuel use.
- large influx of readily available shale gas would drop the price of electricity.
- majority of shale gas is found in the US, which would improve the US’s economy and provide an alterative source to Russian oil (if political tensions continue)
91
Q
What are the disadvs of shale gas?
A
- wastewater needs treating due to chemical contents
- may pollute groundwater aquifers. In the USA the water has become flammable due to pollution by fracking
- earthquakes of low magnitude may occur - but not usually strong enough to pose a risk to humans
- the IPCC suggest it would be irresponsible to use shale gas
92
Q
What is oil shale?
A
- deposits of organic compounds (kerogen) in sedimentary rocks that have not undergone sufficient pressure, heat or time to become unconventional oil.
- USA has 77% of known global reserves.
93
Q
Disadvantages of oil shale:
A
- air and water pollution
- over-use of water resources
- disturbance of land and vegetation cover
- disposal of waste after processing
94
Q
What are tar sands?
A
- naturally occurring mixtures of sand, clay, water and bitumen.
- Canada has 73% of known global stocks
- large environmental cost but can be lucrative in profit and employment opportunities.
95
Q
What are the advs of tar sands?
A
- tar sands production creates economic growth and a large influx of jobs for rural regions.
- fastest growing industry, producing high-value bitumen for international exportation.
96
Q
What are the disadvs of tar sands?
A
- process of extracting bitumen is water and energy extensive, producing a large volume of waste.
- liquid waste is left in tailing ponds. However, tailing ponds may contain sulfate, chloride and ammonia which may infiltrate groundwater stores and other water stores
- open mining involves removing the top layer of vegetation and soils to access bitumen-sands - destroys habitats.
- estimated contribution to global warming three times higher than conventional oil.
- leaves scars on landscape.
97
Q
Canadian tar sands:
A
- Canada has the world’s largest reserves of tar sands, with three major deposits in Alberta - the Athabasca, Cold Lake and Peace River. Together they cover an area larger than England.
- extracting the oil is expensive and difficult but it helps to improve Canada’s energy security.
98
Q
How are tar sands extracted?
A
- extracted by opencast mining. The extracted material is crushed and mixed with water, and the bitumen is separated before it can be used.
- they can also be pumped out - high pressure steam is injected underground to separate the bitumen from the sand.
99
Q
Players involved in tar sands?
A
- governments
- oil companies
- environmental pressure groups
- local community groups
100
Q
Players involved in tar sands - governments:
A
- Alberta regional government and Canada’s national government promote tar sands for energy security and economic development.
101
Q
Players involved in tar sands - oil companies:
A
- local and international companies include Syncrude, Shell, Exxon, Mobil and BP.
- Syncrude has a tremendous and positive impact on the economies of Alberta and Canada.
102
Q
Players involved in tar sands - environmental pressure groups:
A
- Greenpeace called for an end to the ‘Industrialisation of indigenous territories, forests and wetlands in Northern Alberta.
103
Q
Players involved in tar sands - local communities:
A
- new jobs and local businesses benefit from trade.
However:
- fears over pollution in the Athabasca River, atmospheric toxins and increased incidence of rare cancers and auto-immune diseases
- now a housing crisis, as thousands of workers have been shipped in.
- disruption to traditional ways of life (area is inhabited by many indigenous workers)
104
Q
What are the costs of exploiting tar sands?
A
- only viable when the price of crude oil exceeds $40 a barrel. It costs $10-$20 a barrel of bitumen from tar sands compared to $2 for conventional oil
- produces huge quantities of waste - it takes 2 tonnes of mined tar sands to produce one tonne of oil.
- adds to greenhouse gas emissions
- 470km2 of Alberta’s woodlands taiga forest has been removed.
105
Q
What are the benefits of exploiting tar sands?
A
- provides an alternative source of oil
- by 2030, it could meet 16% of North America’s oil needs.
- offers energy security for Canada and the USA. 28% of Canada’s oil is used in Canada, 70% is exported to the USA.
- environmental protection is in place to ensure that mining companies are required to reclaim land disturbed by extraction.
- earns vital revenues for local and national economies.
106
Q
What are the implications for the carbon cycle?
A
- carbon emissions rise due to their extraction, production and use
- carbon absorption falls due to deforestation (removal of taiga)
107
Q
What are the consequences for the environment?
A
- extraction creates spoil heaps - dumps for waste oil and sand.
- tailing ponds are created, which contain contaminated toxic wastewater caused by oil extraction and processing
- large-scale opening mining destroys forest and peat bogs, causing a loss of ecosystems and habitats. Mining reduces the resilience of the native Taiga environment.
108
Q
The UK’s changing energy-mix:
A
- 2015: renewables and nuclear energy supplied 47% of the UK’s electricity, wind and solar farms, HEP and biomass supplied 24% and coal 22%.
- UK’s use of fossil fuels is falling and there are plans to close all traditional fired power stations by 2025.
- however the country is energy insecure - imports 6-% of its energy.
- it will increase renewable energy - especially wind and solar. Wind energy could provide 25% of the UK’s electricity needs by 2020. Solar power is also growing rapidly, however this is only expanded through large government subsidies.
- Hinkley Point C (nuclear power station) will provide 7% of the UK electricity.
109
Q
Renewable energy sources:
A
- biomass: heat energy from wood, plants, animal and general waste. Strike price £80/MwH.
- solar power: energy from the sun, generating eldctricity vai photovoltaic cells. Strike price £50-80/MwH.
- wind energy: moving air turns a propeller-driven generator. Strike price - onshore wind £80/MwH, offshore £115-120/MwH
- wave and tidal energy: moving water flows through a barrage, driving turbines. No strike price; technology is at the research stage.
- HEP: the vertical release of water turns a turbine to drive a generator. Strike price £100/MwH.
110
Q
What are advantages of renewables?
A
- create unemployment - USA nuclear sector employs 3x more than fossil fuel sector
- save money in the long term due to maintenance and operation costs are lower
- reduces country’s reliance on imported energy sources from abroad.
- won’t run out
111
Q
Disadvantages of renewables?
A
- oil prices fell in 2015 - renewable energy became less attractive due to higher costs.
- can have negative impacts on environment - e.g. flooding for HEP dams.
- many protest when there is a proposal made for a wind or solar farm close to their home.
- there are few countries where renewables will be able to replace fossil fuels completely due to the intermittency of renewable energy and limitations associated within physical geography of a country.
112
Q
What is nuclear power?
A
- the use of atomic to obtain heat, in turn heating water and generating stream to drive a turbine.
113
Q
Nuclear power examples:
A
- Japan: before EQ and tsumani of 2011, 27% of Japan’s electrcicity came from nuclear power. The Fukushima nuclear plant was severeyl damaged and released dangerous levels of radiation. Japan closed all its nuclear reactors, but nuclear energy has been reintroduced as part of Japan’s energy mix.
- UK: Hinkley Point C is an £18 billion project, which will provide energy for 60 years, and 25,000 jobs, involving French EDF and China General Nuclear.
114
Q
Advantages of nuclear power:
A
+ very low carbon footprint
+ may have fewer negative impacts than fossil fuels
+ technology becoming more accessible and affordable for NICs.
+ electricity produced is cheaper
+ large amount of energy generated from small amount of fuel.
115
Q
Disadvantages of nuclear power:
A
- large scale disasters occur and risks to do with security due to accidents and terrorism.
- produces radioactive waste which is difficult to dispose of
- very high cost
- lack of support from general public
- technology involved is complex and therefore use is only really an option in developed countries.
- costs of decommission and construction are very high.
116
Q
Wind power examples:
A
- Hornsea project 1: 190-metre-high turbines will eventually provide power for a million homes once completed in 2020. Located 121km off the coast of Yorkshire, it will create 2000 construction jobs.
- Quarrendon Fields, Aylesbury: wind turbine that will supply 2000 homes, but some local residents see it as negative, potentially harmful to birds and supply can be intermittent depending on wind.
117
Q
Advantages of wind power:
A
+ low running costs
+ can be used all year round
+ plenty of suitable sites
+ creates many jobs - 2000 construction jobs were created in Yorkshire due to the Hornsea project 1.
118
Q
Disadvantages of wind power:
A
- bird life can be affected
- weather dependent
- most renewable installations, e.g. wind turbines, require industrial processes that use energy during their construction. Therefore indirectly adding CO2 emissions.
119
Q
What is solar power?
A
- heat from the sun used to heat water, or photoelectric cells which can generate electricity directly.
- used in areas with inland temperature regions which aren’t affected by cloud cover. Also areas of high latitude.
- e.g. Germany has invested the most in solar energy.
120
Q
Solar power - examples:
A
- Chapel Lane Solar Farm, Christchurch: cost £50 million. UK’s largest solar farm, serving 60000 households. However expensive as solar and wind power still aren’t viable without a high strike price. They also consume productive farmland, which people argue should be producing food at a time when food costs are rising.
121
Q
Advantages of solar power:
A
+ costs are decreasing rapidly, therefore can be used by poorer countries
+ large potential in desert areas
+ safe, clean and non-polluting once made and installed
+ renewable - sustainable source of energy
+ flexible and modular - can be used on roofs
122
Q
Disadvantages of solar power:
A
- not very efficient yet (15-20%)
- effectiveness dependent on climate and time of day and year
- not enough research and development, especially into storage methods.
- energy needs to be stored for later use
- not effective in cloudy climates or polar latitudes.
- electricity produced is initially very expensive.
123
Q
The growth of biofuels - Brazil:
A
- first country to produce biofuel from sugar cane in 1970s.
- Brazil has since become the world’s leading producer of bio-ethanol, and leader in cutting carbon emissions.
- cars running on bio-ethanol emit 80% less CO2 than petrol-driven cars.
- the country aims to double bio-ethanol production by 2024.
- however, social unrest has also occurred. Farm workers have lost land to grow sugar cane and cannot grow food for themselves. Many farm workers end up moving to the cities.
- ‘green fuel’ has reinforced rural inequalities.
124
Q
Advantages of biofuels:
A
- can help Africa reduce carbon emissions
- renewable energy source
- lower emissions
- easily grown and does not need specialist equipment/machinery
125
Q
Why aren’t biofuels necessarily carbon-neutral:
A
- biomass requires a fuel to ‘kick-start’ burning. However, coal is needed to ‘fire-up’ the biomass and therefore produce between 150% and 400% more CO2 than coal.
- most renewable installations, e.g. wind turbines, require industrial processes that use energy during their construction - indirectly adding to CO2 emissions.
126
Q
What are other approaches to reducing carbon emissions?
A
1) carbon capture and storage (CCS)
2) hydrogen fuel cells
3) electric vehicles
127
Q
reducing carbon emissions - CCS:
A
- uses technology to capture CO2 emissions from coal-fired power stations
- gas is transported to a site where it is stored, compressed and transported by pipeline to an injection well, where its injected in liquid form into underground aquifers.
- theoretically CCS would cut global emissions by 19%. However currently not financially viable. In 2016, there was one commercial CCS plant. Also CO2 leakage affecting human health, small EQs.
128
Q
Advantages of CCS:
A
- reduce carbon emissions by 90% as by pumping CO2 underground and selling it to an oil company - makes scheme economical
- CCS is combined with bioenergy to capture CO2 produced - ensures that there is a net removal of CO2 from the atmosphere which could extend the use of fossil fuels (greater efficiency)
129
Q
reducing carbon emissions - hydrogen fuel cells:
A
- hydrogen provides an alternative to oil.
- fuel cells convert chemical energy in hydrogen to electricity, with pure water as a by-product.
- far more energy efficient than petrol engines in vehicles.
- separating hydrogen from other elements initially requires energy but this can be provided by renewable sources such as wind or solar power.
130
Q
Disadvantages of hydrogen fuel cells:
A
- processes to separate it require large amounts of energy and may emit large quantities of greenhouse gases.
131
Q
reducing carbon emissions - electric vehicles:
A
- traditionally, problems include their range and price.
- Tesla’s new electric cars extend over 200 miles (previously 80-90 miles), and are cheaper than many electric cars, although cost over £25,000.
- adv: reduce co2 emissions as they are zero carbon emissions and virtually no noise pollution.
132
Q
Disadvantages to electric cars:
A
- quiet: people have become concerned about collisions with pedestrians
- carbon emissions depend on energy profile of the country.
133
Q
Threats to the carbon and water cycles - growing demands:
A
- first two centuries of 21st century have brought extreme droughts in Brazil, Australia and the USA and torrential flooding in Europe, Japan and South Africa.
- average global temperatures are highest on record.
- growing demands for fuel, food and other resources have led to land use changes, which are threatening both water and carbon cycles.
134
Q
Threats to the carbon and water cycles - deforestation in Madagascar:
A
- since 1950s, Madagascar’s tropical forests have been cleared at a rapid rate.
- encouraged to grow cash crops to earn foreign currency to help repay country’s debts.
- before 1950: 11.6 million hectares but by 1985 this had reduced to 3.8 million hectares (loss of two-thirds).
- soil erosion now exceeds 400 tonnes per hectare per year in some areas.
- extensive logging of inland rainforests and coastal mangroves means after heavy rainfall soil is washed from hillsides into rivers and streams.
135
Q
Deforestation - impacts on the water cycle:
A
- infiltration is decreased
- runoff and erosion are increased
- flood peaks are higher and lag time is shorter
- increased discharge leads to flooding
- more eroded material is carried in the river, both as bedload and as silt and clay in suspension.
- annual rainfall is reduced and the seasonality of rainfall increases.
136
Q
Deforestation - impacts on soil health:
A
- raindrop impact washes finer particles of clay and humus away.
- coarser and heavier sands are left behind
- CO2 is released from decaying woody material
- biomass is lost, due to reduced plant growth/photosynthesis
- rapid soil erosion leads to a loss of nutrients
- increased leaching means that minerals are lost.
137
Q
Deforestation - impacts on the atmosphere:
A
- turbulence is increases as heated ground induces convectional air currents
- oxygen content is reduced and transpiration rates are lower
- reduced shading leads to more direct sunlight reaching the forest floor
- reduced evapotranspiration makes it less humid
- the air is dryer
- evapotranspiration rates from resultant grasslands are about one-third of that of the tropical rainforest.
138
Q
Deforestation - impacts on the biosphere:
A
- evaporation from vegetation is reduced
- less absorption of CO2 means a reduced carbon store
- species diversity is reduced
- ecosystem services are reduced
- decrease in habitats means few animal species survive
- biomass is lost, due to reduced plant growth /photosynthesis
139
Q
Threats to the carbon and water cycles - converting grasslands to farming:
A
- between 2007-2015 farmers were encouraged to grown corn, soya, canola, and sugar cane as part of the US Environmental Protection Agency’s Renewable Fuel Standard Policy.
- by 2013, the price of corn had trebled and states (e.g. North Dakota) were cashing in.
- over 5.5 million hectares of natural grassland disappeared across the American Midwest.
140
Q
What are the impacts of converting grasslands?
A
- when natural ecosystems are destroyed there can be serious consequences for the water and carbon cycles, as well as for soil health.
- America’s Midwest is prone to dry summers, and is at risk from wind-blown soil erosion, which would also have a detrimental effect on the soil carbon store.
141
Q
Benefits of natural grasslands?
A
- trap moisture and floodwater
- absorb toxins from soils
- maintain healthy soils
- provide cover for dry soils
- maintain natural habitats
142
Q
Disadvantages of converting grasslands?
A
- natural habitats are reduced
- cultivated soils are liable to erosion by runoff and wind
- initial removal of grasslands releases CO2 from soils into the atmosphere
- annual ploughing enables soil bacteria to release CO2.
143
Q
Afforestation:
A
- trees provide a vital carbon store - sequestering carbon through photosynthesis
- makes sense to replant trees when deforestation has occurred or establish forests on land, which were not previously forested.
- EU’s Afforestation Grant Scheme encourages the planting of forests for their value as terrestrial carbon stores and for the ecosystem services that they provide.
144
Q
Threats to the carbon and water cycles - ocean acidification:
A
- as the ocean becomes more acidic, corals cannot absorb the alkaline calcium carbonate that they need to maintain their skeletons, and reefs begin to dissolve.
- ocean acidification has lowered the pH of the ocean by about 0.1. This means it is now 30% more acidic than it was in 1750.
145
Q
Threats to the carbon and water cycles - corals:
A
- corals get their colour from algae.
- algae provide food to the coral through carbohydrates produced during photosynthesis.
- coral has a narrow temperature range within which it can live (never below 18 degrees and ideally between 23-29).
- if water becomes too warm, the algae are ejected and coral turns white (coral bleaching)
146
Q
What are the causes of coral bleaching?
A
- climate change which raises the ocean’s temperatures
- if CO2 emissions continue at their current rate, the pH of ocean surface could be lowered to 7.8 by 2100 which would dissolve coral skeletons and cause reefs to disintegrate.
147
Q
Ecosystems - supporting services:
A
- these keep ecosystems healthy by providing other services, including soil formation, photosynthesis, nutrient cycling and water cycling.
148
Q
Ecosystems - provisioning services:
A
- these are the products obtained from ecosystems, including food, fibre, fuel, genetic resources, natural medicines and pharmaceuticals
149
Q
Ecosystems - regulating services:
A
- these are the benefits obtained from the regulation of ecosystem processes, including regulating air quality, climate,, water, dieases, erosion and pollination.
150
Q
Ecosystems - cultural services:
A
- these are the non-material benefits that people obtain from ecosystems, such as spiritual well-being, recreation, education and science,
151
Q
Drought in the Amazon:
A
- Amazon Basin suffered severe droughts in 2005 and 2010, and drought of 2014-15 was worst in Brazil foe 80 years.
- the basin plays a key role in the Earth’s carbon store, holding 17% of terrestrial vegetation carbon store.
- during 2010, trees died and growth rates declined.
- the drought effectively shut down the Amazon’s function as a carbon sink.
- Forest fires broke out - burning tress and litter and releasing CO2.
- further concerns (as temps rise) that the Amazon rainforest will become a carbon source rather than a carbon sink.
152
Q
Degrading W+C cycles - forest loss:
A
- 66 million tonnes of palm oil is produced every year, with half of the palm oil imported to the EU being used as biofuel.
- huge areas of Africa, southeast Asia, and Latin America are being - or have been - bulldozed or burned to create land for palm oil plantations.
- vast amounts of carbon into the atmosphere.
- Indonesia is the world’s largest producer of palm oil, and in 2015 its GHG emissions temporarily overtook those of the USA - caused mostly by burning forests.
153
Q
Degrading W+C cycles - impacts on well-being:
A
- many living in forests are often driven away by the actions of palm oil producers.
- in Indonesia, over 700 land conflicts in 2016 were linked to the palm oil industry
- palm oil production is also tough on animals.
- the loss of biodiversity and habitat endangers species such as the orang-utan, Borneo elephant and Sumatran tiger, each of which is moving closer to extinction due to the loss land for palm oil.
154
Q
Degrading W+C cycles - protecting forest stores:
A
- ‘forest moratorium’ was declared in Indonesia in May 2011.
- received $1 billion of funding from UN and Norwegian govt.
- it stopped the issuing of permits for the clearance of primary forest or peatland for timber, wood pulp or palm oil.
- 2013: emissions recued between 1% and 2.5%. May 2015: moratorium was extended to help reduce emissions further by 26% in 2020.
- effectiveness is limited. Illegal logging remains an issue and permits issued before 2011 still went ahead. Reduced clearance by 15%.
155
Q
Forest recovery:
A
- Brazil has halved its rate of deforestation since 2000.
- China aims t increase its forested area by 23% between 2015 and 2020.
- between 2010-2015 an average of 7.6 million hectares of forest were lost every year by 4.3 million were gained - net loss of 3.3 million hectares. This was half of that in the 1990s.
156
Q
Climate change and Yukon:
A
- snowmelt now begins earlier in Yukon, and snow cover is decreasing. This alters river regimes, bringing earlier peak flows to most basins.
- across Yukon, winter precipitation increased between 1950 and 1998. Climate scientists agree that annual precipitation will increase between 5% and 20% by 2100.
- between 1958 and 2008, the total ice area in Yukon shrank by 22% and, as glaciers recede, streamflow is decreasing.
- climate change is leading to the thawing of permafrost - so water penetrates deeper into the soil, instead of forming surface runoff.
157
Q
Changing precipitation patterns:
A
1) existing patterns will strengthen. Warmer air traps more water vapour with scientists predicting more water to fall in parts that are already wet. Due to being a closed system, an increase in dry areas is also expected.
2) as atmospheric circulation changes, a shift in storm tracks will move storms further from the Equator to the Poles.
158
Q
Threats to ocean health:
A
- protecting mangrove forests
- food
- tourism
159
Q
Threats to ocean health - food:
A
- 520 million of poorest people on earth depend on fisheries for their food.
- climate change is altering the distribution and productivity pf species, food webs and biological processes
- warming waters in North Atlantic are killing plankton that North Atlantic cod eat. Arctic krill stock (food for whales) are declining by up to 75% per decade in some parts of the Southern ocean.
- ocean acidification and warming oceans are leading to coral bleaching, which affects food sources and incomes for people living in costal communities.
160
Q
Threats to ocean health - tourism:
A
- higher water temperatures (2016) caused the worst coral bleaching ever recorded i Australia’s Great Barrier Reef.
- globally, coral reefs are tourist attractions, but damage to the coral can directly impact on the income that local people derive frim tourism.
- main cause of damage has been climate change, added to reefs being lost by coastal pollution caused by industrial and agricultural runoff, as well as oil spills.
- all of these problems directly affect costal zones and reduce income from tourism.
161
Q
Factors leading to uncertainty of climate change?
A
- physical factors
- human factors
- peatlands
- permafrost
162
Q
Climate change uncertainty - physical factors:
A
- oceans and forests act as carbon sinks and store heat.
- oceans take decades of years to respond to changes in greenhouse has concentrations.
- their response to higher levels of greenhouse gases and higher temperatures will continue to affect the global climate for possibly 100s of years.
163
Q
Climate change uncertainty - human factors:
A
1) economic growth:
- after the financial crisis of 2007-08, there was concern that rising CO2 emissions would follow the recovery of global GDP.
- however after rising by 4% per year since 2000, the rate of emissions fell to 1% by 2012-13, and 0.5% by 2014.
- nevertheless total carbon emissions still reached a record high.
2) energy sources:
- energy consumption grew by 2% between 2008 and 2014.
- however renewable sources made up two-thirds of the increase in electricity production in 2015.
3) population change:
- increasing affluence in emerging economies means a potential extra billion consumers by 2050 - with spending power equal to the USA.
- changing diets and mobility mean more emissions.
164
Q
Climate change uncertainty - peatlands:
A
- most of the world’s wetlands are peat.
- peat: the accumulation of partly decayed vegetation, and stores large amounts of carbon, because of the low rate of carbon breakdown (decomposition) in cold, waterlogged soils.
- warming causes peat to dry out as water tables fall, as well as increasing the rate of decomposition.
- a warming of 4 degrees Celsius causes a 40% loss of
soil organic carbon from shallow peat, and 86% from deep peat. - peatlands tend to emit carbon in the form of methane, increasing the concentration of greenhouse gases.
165
Q
Climate change uncertainty - permafrost:
A
- when permafrost melts, it releases trapped carbon into the atmosphere as CO2 and methane - increasing atmospheric greenhouse gas concentrations and leading to increased temperatures and melting.
166
Q
Tipping points:
A
- critical threshold
- at a particular moment in time, a small change in global climate system can transform a relatively stable system into a very different state.
167
Q
What causes tipping points?
A
- forest die back
- changes to thermohaline circulation
168
Q
What is forest die back - Amazon?
A
- rainfall in the Amazon Basin is largely recycled from moisture within the forest.
- if the rainforest is subject to drought (like 2014-15) trees die back.
- tipping point could be reached, where level of die back stops the recycling of moisture within the rainforest - resulting in further die back.
169
Q
What is forest die back - Boreal forest ecosystem?
A
- stretches across Europe and Siberia
- hot, dry summers lead to water stress and cause trees to die.
- tipping point could be reached where the trees will no longer absorb enough CO2 from the atmosphere, leading to increased levels of greenhouse gases.
170
Q
Changes to thermohaline circulation
A
- the melting of northern ice sheets releases significant quantities of freshwater into the ocean, which is lighter and less salty - thus blocking and slowing the conveyor belt.
- as ice sheets let, the ocean circulation is susceptible to a critical tipping point.
171
Q
What are adaptation strategies?
A
- adopt new ways of doing things in order to live with the likely outcomes of climate change.
172
Q
What are mitigation strategies?
A
- re-balance the carbon cycle and reduce any impacts of climate change.
173
Q
What are examples of adaptation strategies?
A
- water conservation
- land-use planning and flood-risk management
- resilient agricultural systems
- Solar radiation management
174
Q
Water conservation?
A
- Israel has a range of strategies to manage its limited supplies of freshwater:
+ smart irrigation
+ recycling sewage water for agricultural use
+ reducing agricultural consumption and importing water in food as virtual water
+ adopting stringent conservation techniques
+ managing demand by charging ‘real value’ prices of water to reflect the cost of supply and of ecosystem management.
175
Q
Land-use planning and flood-risk management?
A
- technique used for flood management, where development on floodplain is limited to low-impact things like playing-fields and parks.
- low-cost approach to flood management.
- infiltration occurs naturally and surface runoff is reduced along with the risk of wider flooding.
176
Q
Resilience agricultural systems?
A
- conservation cropping is growing in use, from the USA to Syria and Iraq.
- it involved growing crops using a no-tiling approach.
- uses fewer fertilisers, retains stubble and grows cover crops.
- benefits: increased yields and incomes for farmers, plus improved soil stricture, healthier soils, water convention and erosion control.
177
Q
Solar radiation management?
A
- form of climate engineering which aims to reflect solar rays and so reduce global warming.
- examples: cloud-brightening, space-based reflectors and pumping sulphur aerosols into the upper atmosphere.
- benefits: techniques could be deployed relatively quickly and offset some of the effects of greenhouse gases.
- costs: uncertainty about how effective they would be and ethical, social and political issues surrounding their use. Also are potentially expensive.
178
Q
What are examples of mitigation strategies?
A
- carbon taxation
- energy efficiency
- afforestation and reforestation
- renewable switching
- carbon capture storage (CCS)
179
Q
Carbon taxation?
A
- carbon tax: a fee or cost paid by users of fossil fuels, which is directly linked to the level of CO2 emissions that the fuel produces.
- won’t guarantee a reduction in level of CO2 emissions, but idea is that it sends out a message to change to a from of energy which produces fewer emissions.
- UK’s carbon price floor is a tax on fossil fuels used to generate electricity, and came unto effect in 2013.
180
Q
Energy efficiency?
A
- 2014: Germany identified as a world leader in energy efficiency.
- their policies included:
+ requiring residential and commercial buildings to reduce energy consumption by 25%.
+ loans to renovate older, energy-consuming properties.
+ subsidies to improve efficiencies in manufacturing. - Germany’s economy has grown whilst still increasing its efficiency and reducing the negative environmental impacts of energy use.
- USA: ranked 13th but still wasting a lot of energy.
181
Q
Afforestation and reforestation?
A
- Canada and Sweden lead on afforestation and reforestation, but South Korea have had a remarkable turnaround.
- forest degradation increased during WW2, in addition to illegal logging, use of firewood and expansion of slash and burn agriculture added to its destruction.
- between 1961 and 1995, area of forested land increased from 4 to 6.3 million hectares, and by 2008 11 billion trees had been planted.
- about 2/3 of South Morea is now forested.
- benefits: restoration of degraded environments, prevention of soil erosion and provision of forest sinks and stores of CO2.
182
Q
Renewable switching?
A
- Sweden leads the way in switching energy sources from fossil fuels to the use of renewables.
- oil has fallen from providing 75% of Sweden’s energy in 1970, to 20% today.
- the benefits of Sweden’s move to clean and renewable energy are clear - although it consumes more energy per capita than many other countries, its carbon emissions are comparatively low.
- 83% of Sweden’s electricity is produces by nuclear and hydroelectric power.
- Combined heat and power pants produce 10% and around 7% comes from wind power.
183
Q
Carbon capture storage (CCS)?
A
- 2014: Boundary Dam in Canada’s Saskatchewan Province became the world’s first commercial carbon capture coal-fired power plant.
- aims to cut CO2 emissions by 90% by trapping it underground before it can reach the atmosphere.
- Saskatchewan’s state-owned electricity provider expects to reduce greenhouse gas emissions by about 1 million tonnes a year, equivalent of 250,000 cars.
184
Q
What was the 2015 Paris Agreement?
A
- At UN’s COP21 in December 2015, 195 countries adopted the first universally legally binding global climate deal.
- came into force in November 2016 - 96 states, accounting for 66% of global emissions, ratified the treaty.
185
Q
Aims of the Paris Agreement?
A
- limit the average global temperature increase to 1.5 degrees Celsius.
- report on the implementation of individual national plans to reduce carbon emissions.
- strengthen the ability to adapt to and be resilient in dealing with the impacts of climate change.
- provide adaptation support for developing countries
- continue to support initiatives in developing countries aimed at reducing emissions.
186
Q
Actions and attitudes - Goverments:
A
187
Q
Actions and attitudes - TNCs:
A
188
Q
Actions and attitudes - people:
A
