Carbon and energy Flashcards
What are the 3 carbon stores?
Inorganic (in rock as bicarbonate/carbonate)
Organic (in plant material)
Gaseous (eg: CO2, CH4, CO)
What are the 2 biggest stores of carbon?
Marine sediments + sedimentary rock (100 mil Gt)
Ocean (40,000 Gt)
What are some medium sized stores of carbon?
Fossil fuels
Soil organic matter
Permafrost/ice
What are the 2 smallest stores of carbon?
Atmosphere + terrestrial plants
What are 8 fluxes in the carbon cycle?
Burning fossil fuels
Plant/soil respiration
Photosynthesis
Volcanoes
Litterfall
Rivers
Deforestation/land use change
Ocean uptake/loss
What is the role of latitude in flux speed of CO2?
Levels of photosynthesis + respiration greater in northern hemisphere as greater landmass, greater temperature variations
What is the geological carbon cycle?
Slowest part of the carbon cycle (millions of years)
What are the 5 steps to the geological carbon cycle?
- Mechanical + chemical + biological weathering
- Decomposition of carbon-storing plants and animals
- Rivers carry particles to ocean where deposited
- Sediments accumulate, burying older sediments below (shale/limestone)
- Metamorphosis, layering builds pressure so deeper sediment -> rock eg: shale -> slate. limestone -> marble, volcanoes release CO2 to atmosphere
What are the 3 key processes in the geological carbon cycle?
Chemical weathering
Fossil fuel formation
Volcanic outgassing
How does chemical weathering play a role in the geological carbon cycle?
H2O + CO2 -> carbonic acid, which dissolves rock into calcium ions
Ions transported by river to ocean, where combines with bicarbonate ions and carbonates
Precipitates out as minerals eg: calcite, which turns to limestone via deposition and burial
Then subducted at plate margins, outgassed by tectonic activity
How does fossil fuel formation play a role in the geological carbon cycle?
Gas + oil: 300 mil years ago dead organisms sank to ocean floor, buried deeper + changed to kerogen under heat + pressure + no oxygen, generates oil/gas over millions of years
Coal: remains of plants covered 100 mil years ago, forms peat, eventually solidified into coal
How does volcanic outgassing play a role in the geological carbon cycle?
Outgassing of CO2 from pockets in crust at subduction zone with extreme tectonic pressure
Degassing of CO2 from magma at divergent hotspots/geysers
-> eruptions return CO2 to atmosphere (negative feedback)
What is the speed of the oceanic carbon pump?
Much faster
What does phytoplankton do?
Account for half of all photosynthetic activity
Lives at well-lit surface of water
Sequesters (removes and stores) atmospheric carbon
What are the 3 types of oceanic carbon pump?
Biological carbonate pump
Carbonate pump
Physical pump: thermohaline circulation
How does the biological carbonate pump work in the carbon cycle?
Phytoplankton sequester 2Gt of CO2 to ocean /y
At base of food chain, so consumed by other marine organisms who respire, returning CO2 to water + atmosphere
How does the carbonate pump work in the carbon cycle?
Calcium carbonate shells/skeleton sinks to ocean floor,building up seabed (sedimentary rock)
Subducted + emitted via volcanoes as part of geological carbon cycle (creates global carbon equilibrium)
What is both the biological carbonate pump and the carbonate pump reliant on?
Mainitainence of ocean temperature + currents + recycling of nutrients
How does the physical pump/thermohaline work in the carbon cycle?
Global system of surface/deep ocean currents driven by temperature/salinity differences
Downwelling results in cold, dense water sinking at poles. bringing dissolved CO2 to slow, deep ocean current for hundreds of years
Returns to surface by upwelling and warmer water rises at equator, holding less CO2 -> some dissolved CO2 returns to atmosphere
What are terrestrial primary producers?
Land-based green plants that use solar energy to produce biomass
What are 3 differences in terrestrial carbon stores?
Forest biomes hold most global carbon (1146 Gt)
Then temperate grassland, tropical savannah
More stores in soil than vegetation
How does temperature affect net primary productivity?
Higher temp = high NPP as high rate of photosynthesis
What are the 3 carbon terrestrial fluxes?
Diurnal (more sequestration in day)
Seasonal (more sequestration summer)
Anthropogenic (forest burning releases carbon)
What is soil?
Thin surface of the crust containing organic and inorganic matter
What are the 4 layers of the soil profile?
Litter layer
Top soil (with humus)
Sub-soil (mostly rock)
Parent material (bedrock)
Where does most carbon cycling occur in soil?
Litter layer and top soil
What 3 factors affect the capacity of soil to store organic carbon?
Climate (hot/wet cycles quicker + stores less)
Soil type (clay has lots of water so less decomposition, sandy lower store of carbon)
Use (selling, deforestation -> soil erosion)
What are 4 examples of soil stores and where they can be found?
Tundra: Siberia
Tropical rainforest: Indonesia
Mangrove: Mauritius
Peat: Scotland
What is the capacity of tundra soil to store carbon?
Soil permanently frozen with ancient carbon
Decomposing only on active surface layer (1-2m) when thaws in summer
CC causing warming, sub-soil (permafrost) thaws, so decomposers release carbon
What is permafrost?
Continually frozen ground in periglacial areas
What is the capacity of tropical rainforest soil to store carbon?
Soil thin, constantly decomposing due to constant hot + wet conditions
Carbon stored in deep layers
Deforestation reduces soil store as no roots to bind, exposed
What is the capacity of mangrove soil to store carbon?
High levels of carbon as waterlogged for much of day (high tide)
So, respires anaerobically, decomposers can’t survive without oxygen, decomposition slow so little carbon respires to atmosphere
If deforested/drained, will release carbon
What is the capacity of peat soil to store carbon?
Colder, but similar to mangroves, covered in water so decomposers can’t survive + respire
Will decompose in warmer climate from CC
Extracting for agriculture/domestic use releases carbon
What is the natural greenhouse effect?
Warming of atmosphere as greenhouse gases absorb heat energy that is radiated from earth
Why is the natural GHE important?
Sustains life, would be 30ºc colder without
What is climate forcing/radiative forcing effect?
Potential of each GHG to cause climate change
What is the enhanced greenhouse effect?
Increase in the natural GHE due to human activities increasing the quantity of GHGs in the atmosphere, increasing temperature
What are the human sources of carbon dioxide (CO₂)?
Combustion of FF (domestic electricity + factories)
Transportation
Deforestation
What are the human sources of methane (CH₄)?
cattle ranching (cows)
Rice farming
What are the human sources of nitrous oxide (N₂O)?
Chemical processes in factories
Aircraft
Sewage processes
What are the human sources of halocarbons?
Factory use as a solvent + cooling equipment
What is the atmospheric composition of the GHG?
CO₂ - 89% -> 20% stays in atmosphere for 20y
CH₄ - 7%
N₂O - 3%
Halocarbons - 1%
What is the radiative forcing effect of the GHG in comparison to carbon dioxide?
CH₄ - 21x
N₂O - 250x
Halocarbons - 3000x
How has the use of the 3 main GHG changed?
CO₂ + N₂O - Relatively low increase since industrial
CH₄ - Massive increase since industrial
Explain the water vapour positive feedback loop
Global temp increases → air holds more WV → increases temperature → increased evap + condensation → increased clouds to trap heat
Give 2 ways in which the EGHE has changed the global temperature distribution?
Arctic amplification: temp rise at poles
Potential collapse of the Gulf Stream: temp decrease at mid-latitudes (although currently small rise)
How has the EGHE posed a risk of potential collapse of the Gulf stream?
Melting arctic ice increases freshwater
reduces salinity + density, reduced sinking of cold water
N-Atlantic loses pulling effect on warmer water from tropics
Give 2 ways in which the EGHE has changed the global precipitation distribution?
More frequent + intense storms
Changing jet stream
How has the EGHE changed the jet stream?
Arctic warming 2x as fast as rest of world
Air mass pushes down over UK, so meeting of cold Arctic air and warm equatorial air can get stuck over south UK for longer than usual, increases rain
What are 3 general implications that the EGHE has on ecosystems?
10% land species will be extinct as fail to adapt, could be up to 40% in high-risk regions
Biomes shifting northwards, up to 85% species migrating
Reduced biodiversity
What are 2 ecosystems that have been affected by the EGHE?
Melting of Arctic’s permafrost
Decline in UK deciduous woodland
What are the impacts on animal ecosystems from the melting of the Arctic’s permafrost?
Alaska red fox spread northwards, competing
with Arctic fox
Krill feeds + lives on bottom of ice sheets, up to 80% decline → 50% decline penguin → decline in orca whale
What are the impacts on plant ecosystems from the melting of the Arctic’s permafrost?
Tree line moves north
CO2 may help plants establish
Why may the + feedback of the Arctic’s permafrost actually be negative feedback? (eval)
CO2 released fuels plant growth to sequester as much CO2 as initially released
Tundra thawing replaced with Boreal forest (carbon sink)
Why has there been a decline in the UK’s deciduous woodland, particularly in the south?
More heat waves → trees lack water → replaced by grassland
What is the impact on animal ecosystems due to the decline in UK’s deciduous woodland?
Sharp decline in birds as rely on trees
Eg: yellow wagtail 70% decline
What is a positive ecosystem impact due to the decline in UK’s deciduous woodland?
Increase in temp may increase new species (unless there is rapid urbanisation)
What impacts can the EGHE have on the hydrological cycle?
Warming
Storms
ENSO
Sediment balance (increased erosion)
Wet season ITCZ
What is Hubbert’s peak oil theory?
As a non-renewable resource, oil will reach max production, and then sources decline as it becomes increasingly difficult/expensive to extract
What is evidence for and against peak oil already passing?
2 million gallons/min consumed, almost everything uses oil
BUT
Haven’t mapped all supplies, still new discoveries
What is the model suggesting that energy demand increases with development (and then reduces)?
Energy transition model
Describe the 6 stages of the energy transition model?
Biomass
Coil + oil
Gas
Renewables
Nuclear power
Reduction of dirty FF
Why is biomass used as an energy resource at the lowest development level?
Poverty
Off-grid, lacks access to other resources
Why is coil/oil used as an energy resource as countries begin to develop?
Easy + cheap for lamps and transport
Why is gas used as countries develop?
Access to grid grows
Less polluting
Technically challenging + expensive
Why are renewables used as countries develop further?
Less polluting
Technically challenging + expensive
Intermittent
Why is nuclear power used in developed countries?
Carbon free + reliable
Expensive
Why do developed countries reduce usage of dirty fossil fuels?
To meet carbon goals
What is an energy mix?
Proportion of country’s energy that comes from each source
What are global trends in energy mixes?
Global demand increasing as middle class increasing (use tech, travel, food)
Consumption/capita decreasing as efficiency increases, and increased poverty offsets use
What is primary energy?
Energy consumed in raw form
What is secondary energy?
Electricity, as it is generated from primary energy
What is the overall trend for the UK’s total consumption of energy?
Increasing, hasn’t decrease yet like ETM predicts
How has the UK’s use of coal changed?
Lots was mined underground, but now expensive as surface coal used
Poor working conditions
Thatcher closed mines 1980s
Less popular as heavily polluting
How has the UK’s use of oil changed?
Much extracted from North Sea via rigs, connected to land via undersea pipes
Still very used + relied on
How has the UK’s use of gas changed?
Thatcher closed mines and privitised energy sector with goal of profit -> ‘Dash for Gas’
Combined Cycle Gas Turbine Generator is very efficient
Least polluting of fossil fuel
How has the UK’s use of nuclear power changed?
Increase as no carbon emissions
Then decrease as unpopular due to safety risks from accident/hard to store harmful radioactive waste
How has the UK’s use of renewables changed?
Little use, less than ETM predicts
Accepted as the future, but opposition due to NIMBY + intermittence
What are the 2 countries used as national comparison of access/consumption of energy?
UK- mostly oil/gas, reduced coal, increasingly renweable
Norway- widespread HEP, then oil, decreasing use of renewable
What are the 6 factors that affect access to/consumption of energy resources depends on?
Physical availability
Cost
Technology
Public perception
Level of economic development
Environmental policies
How does physical availability affect access/consumption of energy in the UK and Norway?
UK- heavily reliant on coal and leader in nuclear until 70s, now North Sea oil + gas discovery
Norway- mountainous, rainy (HEP), lots from territorial waters + Svalbard is exported
How does cost affect access/consumption of energy in the UK and Norway?
UK- north sea expensive to extract from, less viable if global E price decreases, stocks declining -> more imports
Norway- over 600 HEP sites supplying 97.5% E, after investment, low cost, but transfer from remote regions to urban is costly
How does technology affect access/consumption of energy in the UK and Norway?
UK- 150y worth of coal available but tech too expensive, is ‘clean coal’ tech (but lost political support)
Both- deep water drilling tech helped develop oil + gas extraction
How does public perception affect access/consumption of energy in the UK and Norway?
UK- string support for renewables, concerns over nuclear + fracking eg: Frack Off
Norway- strong connection to landscape, HEP source of national pride
How does level of economic development affect access/consumption of energy in the UK and Norway?
UK- lower GDP/capita and consumption/capita
£1300 average annual household E cost
Norway- higher GDP/capita and consumption/capita
£2400 average annual household E cost
How do environmental policies affect access/consumption of energy in the UK and Norway?
Both- target of 40% decrease in domestic GHGE by 2030
UK- intends to broaden E mix, CO2 emissions decreasing
Norway- domestic target of carbon neutral by 2050, CO2 emissions increasing
What is energy security?
Access to reliable + affordable sources of energy
What is an energy pathway?
Flow of energy between producer and consumer
What are 4 energy players that play a role in securing pathways and energy supplies?
Organisation of Petroleum Exporting Countries (OPEC)
TNCs
Governments
Consumers
How does OPEC play a role in securing pathways and energy supplies?
15 member countries own 79% of worlds reserves
Stabilise global prices by setting production quotas in response to supply and demand
Protects interests of oil-producing countries as profits remain in countries, as opposed to TNCs (tax, vital for socioeconomic wellbeing)
What are 2 reasons as to why the role of OPEC is reduced?
Rise of unconvetionals (N-Am) reduces reliance, so OPEC reduce prices to make them unprofitable: tensions within OPEC: Saudi can afford, Venezuela can’t
Finite supply + carbon 0 pledges -> accelerating shift to renewables
How do energy TNCs play a role in securing pathways and energy supplies?
Explores, exploits, and distributes energy through supply lines
Powerful role in building energy infrastructure in predominantly FF-driven economy
Give some examples of energy TNCs
Older TNCs eg: BP, Shell- respond to market conditions to secure profit
Some are state owned eg: Aramco (Saudi), Gazprom (Russia, may be held back by Ukraine conflict)- focused on global power/ energy security
What is the case study for the environmental consequences of TNCs?
Shell, Niger Delta, Nigeria
What are some environmental consequences of Shell in the Niger Delta?
20% oil stolen, causes mass devastation to mangroves
Fish die- ruins livelihoods
Shell blame locals, won’t compensate for leaks and protect pipelines
What is Shell’s green plan?
Electric car charging port investment
Wind + biofuel investment
What are energy TNCs accused of?
greenwashing
eg: BP ‘Beyond Petroleum’
How does the government play a role in securing pathways and energy supplies?
Powerful in regulating energy sector
Allocates planning permission
Environmental commitments
Evaluate the government’s role in securing pathways and energy supplies
Can be complicit with thieves eg: Shell with corrupt Nigerian government
Voted in in democracies -> can easily lose power
How do consumers play a role in securing pathways and energy supplies?
Influences other 3 players by…
Purchasing
Protests/boycott
Voting
What does BAU mean?
Business as usual in the energy trade: continued reliance on fossil fuels
Where are some of the world’s most abundant coal reserves?
US
Russia
China
Australia
Where are some of the world’s most abundant oil reserves?
Saudi Arabia
Venezuela
Iraq
Iran
(OPEC countries)
Where are some of the world’s most abundant gas reserves?
Russia
Quatar
US (fracking)
Iran
Give 3 examples of notable mismatches between the locations of conventional fossil fuel supply, and regions where demand is highest?
Japan (5th largest consumer, few reserves)
Middle-east (top reserves, lower consumption)
Australia (lots of coal, lower consumption)
What is a transit state?
Country where energy flows on the way from producer to consumer
What is a choke point?
Concentration of transit routes, narrow, so easily disrupted
If disruped, energy price increases
How many major chokepoints are there in the world?
8 eg: Suez canal
What are 4 energy pathways?
Oil/gas pipelines
Oil tankers
Liquid natural gas( LNG) tankers
Coal shipping (road + rail)
What is an example of a gas pipeline?
Yamal Europe: 4107km
Russia -> Belarus -> Poland -> Germany
What are 3 examples of disruptions to pathways?
Piracy
Accidents
Armed conflict
Explain how piracy in the coast of Somalia disrupts pathways
2011- pirates held 209 oil vessels + 681 hostages, held for ransom
Takes a long time to bring back energy security from stealings
BUT has fallen (although rising elsewhere eg: Gulf of Guinea)
Explain how the BP deep water horizon oil rig explosion (accident) disrupted pathways
11 workers killed
4.9 mil barrels of oil leaks into Gulf of Mexico
Took almost 3 months to close leaking well
Cost US $42bil, largest legal settlement in history
Consequence- 20% of GoMexico no fish zone due to ecological damage -> decline for fishermen
Explain how the Yom Kippur War armed conflict disrupted pathways
Arab oil embargo (trade restriction) on US + Netherlands + South Africa for supporting Israel
US + west reduced dependence on middle eastern oil -> global oil price + recession threat
What are unconventional fossil fuels?
Oil/gas reserves technically difficult, so expensive to extract
How do unconventionals have to be economically viable?
Must be cheaper/same as conventional sources
How is the world’s oil prices affected by changes in production?
Less production = increased price
More production = decreased price
How is the world’s oil prices affected by changes in demand?
Reduced demand = decreased price
Increased demand = increased price
What is the trend of world oil price currently?
After COVID recession, price now rising as demand increases
What are 4 types of unconventional fossil fuel energy resources?
Tar sands: Canada
Oil shale: Colorado
Shale gas/fracking: USA
Deep water drilling: Gulf of Mexico
How does tar sands work as an unconventional resource in Canada?
Open-case mining, extracted material mixed with water, oil seperated from sand
How does oil shale work as an unconventional resource in Colorado?
Open/underground mining of sedimentary rock- rich in kerogen
Heated to release gas, condensed for oil
How does shale gas fracking work as an unconventional resource in the US?
Rocks with gas blasted by explosives
Water with chemicals pushed into rock under high pressure, releasing gas
How does deep water drilling work as an unconventional resource in the Gulf of Mexico?
Rigs drilled way below seabed, deposits lie under salt
What are the implications of tar sands in Canada on the carbon cycle?
Energy intensive (needs 1 barrel of oil to produce 3)
470km2 removal of forests
What are the implications of oil shale in Colorado on the carbon cycle?
3x dirtier than conventional oil
Energy intensive, requires fossil fuels to extract
What are the implications of shale gas fracking in the USA on the carbon cycle?
May displace renewables investment: hinders sustainable transition
What are the implications of deep water drilling in the Gulf of Mexico on the carbon cycle?
Pollutants contribute to EGHE
Same impact as European industrial revolution
What are the social benefits of tar sands in Canada?
Energy security (by 2030, to meet 16% of oil needs in North America
Well paid jobs in rural areas (multiplier)
What are the social costs of tar sands in Canada?
Relies onhigh world oil price ($40/barrel)
Increases rare cancers + autoimmune diseases near mines
What is a social benefit and cost of oil shale in Colorado?
Job creation in rural Colorado
Limited use as oil price not high enough for profit
What is a social benefits and cost of shale gas fracking in the US?
Energy security as decreased reliance on imports
Jobs + investments in deindustrialised rural areas
Pollution impacts health
What is a social benefit and costs of deep water drilling in the Gulf of Mexico?
Good source when in need
Only viable at $130/barrel
Accidents (eg: BP)
Flammable/explosive gases
How does using tar sands in Canada have consequences for the resilience of fragile environments?
High water use
Huge waste
Destruction of taiga forests
How does using oil shale in Colorado have consequences for the resilience of fragile environments?
Potential for spills/leaks
Transport impacts environment
How does shale gas fracking in the US have consequences for the resilience of fragile environments?
Lots of water used, pollutes aquifers
Toxic chemicals -> air pollution
How does deep water drilling in the Gulf of Mexico have consequences for the resilience of fragile environments?
No longer scenic coasts
Water polluted (death of fish)
What are renewables?
Energy produced from an infinite natural process
What is recyclable energy?
A type of renewable which needs human support to continue (nuclear, biofuels)
What is carbon neutrality, and how is it achieved?
Net 0 carbon emissions by balancing carbon emissions with carbon removal, or elimination
Achieved via decarbonisation
What is decoupling?
Allowing economic growth to continue while switching to alternative energy (a paradigm shift)
What is the IPCC’s target for global warming?
To keep global warming to 1.5ºC above pre industrial levels
Already over 1ºC, but uneven as in tropics already 1.5ºC
With this, sea levels will rise 10cm
BAU leads to 5ºC rise, so sea level rise 60-200cm
Has the UK reduced carbon emissions?
Not overall reduction, but replacement with cleaner energy
Compare the % of energy mix in the UK?
37% renewable
35% fossil fuel
How does the UK’s energy consumption vary seasonally?
More electricity consumption in winter
How can government policies support decarbonisation? Evaluate this
Innovations, ambitions, targets
Often inconsistent, changes depend on political needs of power
What are 3 benefits of nuclear power?
Low-no carbon emissions
Excellent baseload supply
Raw material (uranium) extremely plentiful
What are 3 costs of nuclear power?
radioactive waste is toxic to people + environment
Expensive, limited to developed
Fears over safety (eg: Fukashima) -> but now lots of monitoring
What are 4 benefits of solar/wind power?
Carbon emissions low-no
Tech now more affordable (used across development spectrum)
Builds energy security in country (although in UK, reliant on FDI)
Develops green jobs in green economies
What are 3 costs of solar/wind power?
Intermittent + climate dependent
On/offshore wind farms have NIMBY issues
Requires large area of land, gov my be unwilling to sacrifice other needs (eg: food)
What are biofuels?
Fuels produced from organic matter (biomass)
What is the global use of biofuels?
Increasing
9.6 million hectares in Europe
Give examples of primary and secondary biofuels?
Primary- fuelwood/chips burned
Secondary- bioethanol/biodiesel/biomethane
What are 2 socioeconomic benefits of biofuels?
Easily grown with no specialist machinery, still offers infrastructure improvements eg: piped water
Fuel earns export income
What are 2 environmental benefits of biofuels?
Cars running on bioethanol emit 80% less CO2, use in Brazil decreased emissions by over 350 mil tonnes
Renewable source
What are the implications of biofuels on food supply?
Takes investment + land away from food production
Contaminates water resources with pesticides + fertilisers
What is the uncertainty over how carbon neutral biofuels are?
Needs pesticides + fertilisers which use FF in their production
Large land deforested
Requires kick-start to burning with traditional fossil fuels
What is the current development of radical technologies?
In research phase of use, so costly
Small scale
Not widely available
What are 3 types of radical technologies?
Carbon Capture and Storage
Hydrogen fuel cells
Electric vehicles
How does CCS work?
Captures CO2 from industrial processes
Solidified and buried
What is the benefit of CCS?
Can continue use of abundant + reliable FF as baseload for electricity grids during transition to renewables
What are 2 costs of CCS?
Expensive complex tech
Unsure if CO2 could gradually leak to atmosphere
What is the UK’s investment into CCS?
2 to be built by mid 2020s
£20bil budget for it in next 20y
How do hydrogen fuel cells work?
Renewables generate electricity for electrolysis (breaks H2O into H2 + O2)
O2 released to atmosphere (non-polluting)
H2 makes batteries for transport/cooking with just water emissions
Give an example of a car using a hydrogen fuel cell?
Toyota Mirai- 270 mile range
What are 3 benefits of HFCs?
Low/no carbon emissions
Improves local air quality eg: London 444 bus
More efficient than petrol engines
What are 3 limitations of HFCs?
Initial creation of cell requires renewable energy to be truly CO2 free
Highly flammable
Expensive, requires new infrastructure (so needs TNC + political will)
What are 3 benefits of EVs?
Running car emits less CO2, especially if connected to renewable energy source
Local air quality improved, noise pollution reduced
Cheap to run
What are 3 limitations of EVs?
Battery requires cobalt (exploitative process eg: DRC)
Limited infrastructure: charging points, eg in flats
Expensive to buy eg: Tesla model Y £44,000
What % of the earth is land? Of that, what % is habitable? Of that, what % is agriculture?
29%
71%
50%
How does land conversion vary by level of development?
Developing- pockets of high land conversion (farming + mining)
Emerging- high land conversion (farming)
Developed- some large eg: UK 90%, some inhospitable eg: Scandinavia
What is land conversion?
Change from natural ecosystem to alternative use
What are 3 examples of land use cover, resulting from growing demand for food/fuel/other resources?
Deforestation
Afforestation
Grasslands to farming
Where is deforestation happening due to growing demand for food/fuel/other resources?
Madagascar 2/3 forests cleared
Why is Madagascar continuing to clear forests? How is this done?
Debt repayments + growing population
Tropical rainforests cleared by slash and burn -> converted to farmlands + plantations
Why is deforestation in Madagascar unsustainable?
Heavy rainfall has no natural sponge → surface run off + soil erosion → floods
What is afforestation?
Replanting trees where deforestation occured/establising forests
What are 2 examples of afforestation projects?
Great Green Wall 8000km
New York Declaration on Forests (350 mil hectares globally)
What are the benefits of afforestation?
Sequestration counters negative impacts of deforestation and protects nutrient cycling
What are some limitations of afforestation?
Commercial trees (eg: palm oil) store less carbon and use more water
Monoculture = more disease prone
Where are grasslands being converted for farming? Why?
American midwest
Biofuel rush in 2000s to…
- boost rural economy
- reduce dependence on exports
- reduce CO2 emitted from transport
What are the limitations of converting grasslands to farming?
Natural grasslands are important
- habitats
- carbon sink
- maintains healthy soil
Conversion has negative consequences
- biofuels have high water consumption
- initial CO2 release
- crops use fertilisers
What is the impact of land-use conversion on carbon stores?
Reduces soil storage as biomass as carbon unlocked
Burning + decomposing adds to atmosphere
Reduced CO2 sequestration
What is the impact of land-use conversion on water cycling?
Infiltration + interception reduced
Flood peaks higher and lag shorter → flood
Annual rainfall decreases as water moves downwind
What is the impact of land-use conversion on soil health?
Initial raindrop impact washes finer particles, leaves heavy behind
Less plant growth means soil is exposed, so erodes
Leaching (less interception, more infiltration, so nutrients lost) -> pH change
What is the usual nutrient cycle called?
Gersmehl’s nutrient cycle
What is ocean acidification?
Decrease in the pH of Earth’s oceans from uptake of CO2 from atmosphere
Use statistics to show that the ocean plays a crucial role
Absorbs 30% of anthropogenic CO2
3 billion rely on for food/livelihood
How has the pH of the oceans changed?
Dropped 8.2 → 8.1
As it is a logarithmic scale, acidity has increase by 30%
How does the acidity of oceans increase when oceans take up CO2?
H+ ions form
What are the threats to marine organisms from ocean acidification?
Threat to those that rely on stable pH for forming shells/skeletons
eg: Coral Polyps struggle to build hard exoskeletons, so reefs stop growing/shrink
Weaker, more vulnerable coral threatens foundation of food chain
What is a critical threshold?
Damage becomes permanent
Eg: coral stops growing when pH <7.8 - due to happen with BAU by 2100, already in Arctic
Will marine organisms be able to adapt to ocean acidification?
Ability to adapt depends on how slow the change is
What is the + feedback loop regarding ocean acidification?
Warming oceans store less carbon -> more in atmosphere
Where in particular is there an increase in drought risk?
Sahel
India
Eastern Europe + central Asia
What is the shifting climate belt using stats?
2ºC rise means 5% of land shifts to new climate
An additional 2ºC rise means an additional 10% shifts
How has the Amazon rainforest been stressed as a crucial carbon store?
Extreme drought/flood cycle due to shifts in ITCZ
Decreased rainfall in deforested areas
+ feedback: increased temp → increased fires → increase CO2 released, exacerbating EGHE
What are 3 global trends regarding forest loss?
High, in correspondence with population growth
Extent to which loss is reduced depends on development (Kuznet’s curve)
Mostly due to cattle ranching/other agriculture
How many people depend on forests for survival?
1.6 billion
Give 4 reasons why forests are essential to human survival
Climate change mitigation (sequestering carbon and regulating rainfall)
Cultural significance (psychological wellbeing/art/religious practices)
Economic contributions (timber, medicine, tourism)
Recreation/leisure (hiking, birdwatching, camping)
What are 3 supporting functions of forests?
Nutrient cycling
Soil formation
Primary producers
Who are a group of indigenous people of whom forests are essential to?
Bayaka group in the Congo
Who are the Bayaka group, and why are forests important to them?
Craft from forest resources
Men hunt, women gather fruit/nuts
Very small ecological footprint: only take what is needed
Shifting cultivators: burns land to farm and live, moves on in 5y
What are 2 issues with Kuznet’s curve in explaining deforestation rates across development levels?
Consumption post-industrial hasn’t improves, just decreased demand
Degradation just shifted to other countries
What is happening to Indonesian forests?
Growth of palm oil plantations (food, cosmetics, biofuel)
Results in huge rainforests burned: carbon released
What is the issue with the destruction of Indonesian rainforests?
Many dependent on rainforests to survive
Indigenous pushed from land
Loss of biodiversity, destruction of habitats endangers species eg: orangutan
What is the solution to the destruction of Indonesian forests? Evaluate
Receives US$1 bil from UN + Norwegian gov to stop issuing clearance permits
Permits already issues and illegal logging = only 15% reduction in clearance
What does increased temperature from EGHE leading to higher evaporation and humidity have implications for?
Precipitation patterns
River regimes
Water stores
How does increased temperature from EGHE leading to higher evaporation and humidity have implications for precipitation patterns?
Wet become wetter
Dry become drier
How does increased temperature from EGHE leading to higher evaporation and humidity have implications for river regimes?
Flashier discharge
Earlier snowmelt
Dry areas/glaciers already melted - spring melt disappears, drought
How does increased temperature from EGHE leading to higher evaporation and humidity have implications for water stores?
Cryosphere reduced
Thawed permafrost
Less in lakes/reservoirs from evap, could increase with rainfall
Decreased soil moisture = increased runoff
How is the Arctic the fastest warming area?
2.5 average due to Arctic Amplification
How does pollution exacerbate the albedo effect?
Soot on snow
How are evaporation rates/water vapour impacted in the Arctic?
20% increase in evaporation rates, atmosphere holds more water vapour
How are precipitation patterns impacted in the Arctic?
Increased rain replacing snowmelt, to increase 5%-20% by 2100
How are river regimes impacted in the Arctic?
Spring starts earlier, summer ends later -> earlier discharge peaks
eg: Yukon discharge increase 39% as more water in river from permafrost thawing
How are water stores impacted in the Arctic
Spring starts earlier, summer ends later -> increased cryosphere melt (permafrost + ice)
Lower and later refreeze in winter
What is the global impact of the changes happening to the Arctic warming?
Fresh non-saline water impacts food chain that depends on saline waters
Cold water reduces warm currents to Europe (gulf stream)
What are the human impacts of the changes happening to the Arctic warming?
Thawing -> infrastructure collapse eg: pipelines, transport
Floods
Increased shipping routes + oil gas exploration (although pollution)
What are the 3 categories of ocean ecosystem services?
Provision of goods
Regulation of Earth’s systems
Cultural value
What are the 3 ways in which global warming is threatening human wellbeing via threats to ocean health?
Food supplies
Tourism
Coastal protection
How are food supplies threatened via threats to ocean health?
Fish move polewards, impacting tropical fisheries
Krill declines 70% as phytoplankton declining (food chain)
Aquaculture (subsidence + commercial) impacted (food security) BUT: commercial fishing boats travel further (more resilient to change)
How is tourism threatened via threats to ocean health?
Don’t visit, impacting multi-billion dollar industry
Especially in SIDS eg: Maldives have 1 mil annual tourists 23% of GDP
BUT: tousim = travel - high carbon footprint (warming contributes to ocean ecosystem damage)
How is coral reef coastal protection threatened via threats to ocean health?
90% of coral reefs to die by 2050 from bleaching (algae die as too warm, reveals white skeleton)
Can’t absorb ocean energy before hitting coast
How is mangrovecoastal protection threatened via threats to ocean health?
Deforested- 50% loss
Dense prop roots buffer strong waves, also traps nutrients (nursery for fish)
Evaluate the threat on human wellbeing from the threats to ocean health?
Bigger threat on developing countries: economies reilent on JUST tourism/fishing, less resilent to change
Soultion: Marine protected Areas, conservation- gives ecosystems time to adapt = restore, also recharges neighbouring ecosystems
Future conflict on location?
What are the 2 natural factors resulting in the uncertainty of future emissions, atmospheric concentration levels and climate warming?
Carbon sinks:
Oceans
Forests
In terms of human uncertainty of emissions, what are the 2 pathways?
Low emissions pathway- 1.5º rise
High emissions pathway (BAU)- 5º rise
What are the 3 human factors resulting in the uncertainty of future emissions, atmospheric concentration levels and climate warming?
Economic growth
Population
Energy sources
In terms of economic growth, where is there uncertainty?
Decoupling + green economy OR greenwashing
Afforestation OR industrialisation + land conversion
In terms of population, where is there uncertainty?
Large middle class growth OR small growth/stable population
In terms of energy sources, where is there uncertainty?
Investment in unconventionals OR renewables + decarbonisation efforts
Who plays a role in the uncertainty of global projections?
Personal will (paradigm shift)
Political commitment to decarbonisation policies
What 2 positive feedback loops create uncertainty over global projections?
Peatlands- extent restoration continues successfully?
Permafrost- extent active layer melts? range of spacial loss predictions
What are 2 possible tipping points?
Forest die back
Alterations to thermohaline circulation
What is climate adaptation?
Adopting new ways of living with the effects of climate change
What is climate mitigation?
Rebalancing the carbon cycle to reduce the effects of climate change
What does the IPCC suggest regarding mitigation vs adaptation?
‘Aggressive’ mitigation + international cooperation needed for most optimistic future
What are the 4 climate adaptation strategies?
Water conservation + management
Resilient agricultural systems
land use planning + flood risk management
Solar radiation management
What are the 5 climate mitigation strategies?
Carbon taxation
Renewable switching
Energy efficiency
Afforestation
CCS
Where is the only large scale working CCS scheme?
Canada Boundary Dam, cut emissions 90%
What are 2 global scale climate agreements?
Kyoto protocol 1997
Paris Agreement 2015
What was the Kyoto protocol 1997?
85 signatures
First major international effort to encourage mitigation
Aim to cut emissions 5%
What was 3 successes of the Kyoto Protocol 1997?
Beginning of regular COP
Supports developing in green tech
22% decrease in emissions by 2012
What was 3 limitations of the Kyoto Protocol 1997?
Huge increase in emissions by 2015
Limited ratification
Biggest emitters USA + China didn’t sign
What are INDCs from the 2015 Paris Agreement?
Intended Nationally Determined Contributions
- all have a dif contribution to reach <2ºC goal
- reviewed every 5y
What are the INDCs of the US EU and China to reduce emissions by?
US- 26%
EU- 40%
China- 60%
What are 2 limitations of INDCs?
Not bindings
No holistic awareness of carbon cycle (too concerned with burning, less with sequestration)
What are 2 examples of climate national actions?
Green New Deal USA
Costa Rica
What are the 2 features of the Green New Deal USA?
Fast decarbonisation (pro-mitigation)
Creation of new green economy whilst protecting people from economic threats from transition
What is some of the infrastructure created by the Green New Deal USA?
EVs
High-speed rail
Interconnected state renewable national grid
What are 3 limitations of the USA’s Green New Deal?
Not legally bindings
Requires huge paradigm shift
Republicans don’t like gov intervention in private sector: accused of socialism
Although the GND failed to agree nationally across the US, what were some principles adopted by California?
All new homes net 0
Green job apprenterships
What are 3 national actions of Costa Rica to rebalance the carbon cycle?
Investment in EV infrastructure + 0 emissions public transport
Afforestation after previous heavy deforestation
Lawful ban on oil exploitation
How could Costa Rica become sufficient in meeting climate targets?
Improve agriculture targets (methane emissions)
Better monitoring
What are 6 players with different attitudes to mitigation and adaptation?
Developing countries
Developed countries
People
Economists
Climate scientists
TNCs
