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