Carbon Cycle - Topic 1

Atmosphere - CO2/other C compounds in ajr

Hydrosphere - dissolved CO2

Bisophere- organic carbon

Lithosphere- inorganic carbon eg as carbonate in limestone

Bio-chemical cycle by which C is transferred between 1 sphere to another - closed system

Photosynthesis - 123 PgC/yr

Respiration + fire - 118.7 PgC/yr

Atmosphere to Ocean - 80 PgC/yr

- involves death of marine organisms and compression to form sedimentary rock

- C stored for around 150million years

- released through weathering/volcanic eruotions

- involves photosynthesis + respiration

- C dissolved in ocean + returned via evaporation

- C to soils + vegetation via acid rain

Sedimentary rock store - 83mill PgC

Intermediate + deep ocean store - 37,100 PgC

Soil store - 1950 PgC

- shelled organisms + coral absorb CO2 from water + convert it to CaCO3 to build their shells

- remains accumulate + are layered on seabed + are compacted under high pressure + temp - undergoes lithification

-stored for 150mill yrs

- over millions of years organic sediment containing C may undergo metamorphosis to form hydrocarbons such as coal + oil through heat + pressure

-subduction at destructive margins + tectonic uplift can expose buried limestone

- carbon rich sedimentary rocks in contact with extreme heat - chemical changes - CO2 released

- outgassing also occurs from volcanic eruptions, direct emissions from fractures in crust, geysers

- deforestation

- farming cattle + rice

- burning fossil fuels for electricity + fuel

CO2 diffuses into sea surface waters + dissolves

Amount depends on eg wind, temp of water, concentration of CO2, sea surface mixing

Organic sequestration of C from atmosphere + land runoff to ocean interior + sea floor sediments

Sum of processes eg photosynthesis, respiration, excretion, decomposition

- Absorb C via photosynthesis

- consumed by eg zooplankton - consumed by higher tier organisms - C is spread through food chain - cycled in upper waters via respiration, excretion

- organisms die + decompose then form part of marine snow

Shower of organic material + biological debris falling from upper waters to deep ocean floor

Provides food for many deep sea creates - filter it from water

Small % not consumed reaches floor + forms muddy ooze - covers about 3/4 deep ocean floor

Thermohaline circulation - refers to flow of ocean water caused by changes in density due to changes in water temp + salinity

Cold water - downwelling of denser water - C that diffused into surface waters taken to deep ocean - areas of carbon sink eg Poles

Warm water - upwelling of less dense water - CO2 less soluble so harder to store - diffuses into atmosphere- areas odd carbon source eg between Tropics

More freshwater - less dense - upwelling occurs where downwelling is supposed to

Of the 3 largest rainforests only the Congo has enough left standing to have remained a strong net C sink

Congo's Tropical rainforest sequesters 600million metric tonnes more CO2 than it emits

Sequester 20-30% of global C - 2x quantity of C in the atmosphere

- weathering puts C particles into soil from rocks + minerals

- vegetation + plant roots

- stored in organic matter

- O horizon - high % organic matter, humus

- A horizon - rich in organic matter

- B horizon - subsoil - litter humus,soluble minerals

- C horizon - weathered bedrock

Permanently frozen ground - stores C ases remains of plants + animals that froze before they could decompose

- estimated to hold 1500billion tonnes of C

Warmer temp - permafrost thaw - CO2 + methane trapped is released - increased GHG in atmosphere

Humus accumulates in a watery environment without O2 + forms peat

Remove CO2 from atmosphere + store where acidic + waterlogged conditions prevent decomposition

One hectare of peat bogs stores ~5,000 tonnes of carbon

Threatened by overgrazing - exposed peat - releases C

Short-wave radiation from sun

Less outgoing long wave radiation radiated back out to space

Earth warms up

Increased concentration of GHG in atmosphere trap more radiation and heat - earth warmed more

1990- 350 PPM

2020 415 PPM

2023 418 PPM

Amount of CO2 vegetation takes in through photosynthesis take away amount vegetation release during respiration

Highest at night- plant respiration

Lower during day - photosynthesis

Greatest daily change during summer

Inhibits phytoplankton growth - inhibits CaCO3 from forming - less shell building - less C sequestered on sea floor

Ice cores - Capture air bubbles including CO2 concentrations when the ice was formed - Antarctica has ice cores going back 800,00yrs

Chemical data + fossils - can show CO2 values 60mill yrs back

Among the most biologically diverse + economically valuable ecosystems

Source of food for mills, protect coast from storms + erosion, provide habitat, spawning + nursery grounds

Warmer water - Coral expel algae living in their tissues - turn completely white - can't sequester carbon

Also caused by runoff + pollution, overexposure to sunlight or air

Flash foods + more intense rainfall events, tropical storms + hurricanes

Arctic + Antarctic ice sheets splitting + melting - less sunlight reflected by darker sea/land surfaces

Thermal expansion of oceans - sea level rise - increased erosion

Relative contribution of diff energy sources to a country's energy production/consumption

Natural resources that haven't been converted into any other form of energy

Release of one type of energy in order to transform it into another type of energy

China - 6 sources - 72% coal, 20% hydroelectric

UK - 6 sources - 32% coal, 30% gas, 19% nuclear

Saudi Arabia - 2 sources - 62% has, 38% oil

1. Physical geography

2. TNCs

3. Disruption due to piracy, political tensions, war, weather

4. Development

5. Energy mix

6. Geopolitics/reliance on imports

- specific conditions needed for oil, coal + gas to form

- those without a domestic supply have to import - relies on good political relationships - high level of infrastructure - susceptible to conflict, oil spills

- investment in technology + infrastructure to import/extract + export

- higher demand for energy - population increase + rapid urbanisation

Being able to access reliable + affordable sources of energy

ST - focuses on ability of energy system to react promptly to sudden changes + supply shocks

LT - investments to supply energy in line with economic development + environmental needs

Flow of energy between a producer - consumer

Deep water drilling enabled both to develop North Sea oil + extraction

UK - GDP/capita US$41,000 - energy use - 2752kg oil equivalent

Norway GDP US$61,500 - energy use - 5854kg oil equivalent

13-member organisation

Own 2/3 of worlds oil

1. Venezuela - 303.47 - 24.4%

2. Saudi Arabia - 267.19 - 21.5%

3. Iran - 208.6 - 16.8%

- enrich poor countries who can't afford primary investment required to produce their own energy

- responsible for exploration, extraction, production + trading

- investing in renewable energy eg biofuels + wind power - long term energy security

Provides 40% of EUs total gas supply + 32% of oil supply

However affected by geopolitics - sanctions imposed by EU in response to conflict with Ukraine

2015 - 4.7mill barrels oil equivalent per day output

- has power to significantly affect oil prices by increasing/decreasing production

- subsidise use of renewable energy to create incentives for population

- agreements eg Paris Agreement 2015

- funding on research + development for alternate sources

Country/state through which energy flows on its way from producer - consumer

90% chance of oil being extracted

Believed to be there but can't extract with certainty

Hellisheidi - geothermal power plant - one of several that in total provides hot water and electricity for about 90% of Icelandic households

2010 - BP oil rig exploded - 11 deaths

Oil leak - tech failed to stop it

Huge environmental impact - killed thousands of marine animals, contamination of fish - 1/3 of federal waters closed

Tourism industry reduced

Russia - 2nd largest producer - gas via pipelines to Europe

Political conflict between Ukraine + Russia - Ukraine = transit country

Countries with 100% of gas from Russia - eg Finland, Estonia - therefore detrimental if supply cut off

Russia relies on transit countries - they can exploit this - raise prices

- pipeline through Ukraine - gives Ukraine powers to increase price for Russia- not economically viable to bypass Ukraine

- Gives Russia lots of geopolitical power - can control prices

Alberta - 173 billion barrels recoverable crude oil - Shell,BP,Exxon Mobile

Transported to USA - don't want to import from middle-east

3x more polluting than normal oil

- threaten aboriginal community at Fort McKay + their way of life - can't hunt, can't drink from polluted water

- cleared 1mill+ acres - claimed to have reclaimed 20% - however not with natural + diverse vegetation

- particulate pollution in Alberta increased by 780% from 1999-2006

-tailings ponds - extremely toxic waste water - leak into environment

- health crisis at Fort Chipewyan - increase in rare cancers

- Alberta gov made $16.9billion in 2022-23

- produce 3mill+ barrels per day

- suitable for oil companies as supply as reliable, not affected by weather eg hurricanes, supplied by direct pipeline to US

Cost of energy increased massively and potential for disputes over foreign supplies has increased

Eg oil shale, tar sands, shale gas, deep water oil

Heavy viscous oil made from clay,sand,water + bitumen

Mined then injected with steam to make less viscous

Oil-bearing rocks permeable enough to allow oil to be pumped out directly

Ignited to light oil fractions so they can be pumped out

Natural gas trapped in fine grained sedimentary rocks

Fracking - water + chemicals pumped in

Oil found well offshore and at considerable ocean depths

Drilled from ocean rigs

Ground drilled into vertically then horizontally to get between fissures in rock where gas is

High pressure "slick water" pumped in to widen cracks

Proppants - tiny grains - pumped in to hold cracks open

Gas released and flushed to surface

- increased investment allows developments in tech of less harmful methods

- job creation + security in rural regions with few other prospects

- helps reduce energy prices + increase energy security nationally

- contaminates rivers + streams + domestic water supplies

- 5,000 gallons/well of toxic chemicals- lack of safe disposal of fracking fluid - toxic chemicals leaked into ground

- shale deposits contain uranium + radium - 267x the safe level

- potential of 10s of billions barrels of oil off coast of Rio de Janeiro - energy security

- money from sales + jobs may help to solve poverty + build better schools + hospitals

- ugly infrastructure affect tourist hotspots

- contaminates water - aquatic food supply + bay environment contaminated - fishermen lose jobs, less food

- potential catastrophe if rig explodes - could be worse than deep water horizon - reservoirs are deeper + larger so pressure and volume of oil increased

- one of the worlds riskiest drilling operations - 300km offshore, turbulent waters, very deep,reservoir includes toxic, flammable + explosive gases

- overcoming these obstacles is very costly - ~$300mill

- Petrobas promised revenue would be used to fund social programmes - $2bn instead gone to politicians, partners, executives

-As industrial production increases, so does energy used + GHG emissions

- as economy develops, manufacturing + industrial production changes to service based industry

- increased economic development - better tech, environmental awareness + enforcement - gradual decline in degradation

- physical - not all countries have coasts, "hot rocks", sunny climates, rivers

- impact on environment - eg entire valleys drowned to creat HEP reservoirs

- NIMBYism

Recyclable - can be reprocessed + reused

High energy density

- safety issues eg Chernobyl + Fukushima

- security issues in an era in international terrorism

- disposal of highly toxic radioactive waste with long decay life

- high costs of budding + decommissioning

- tech involved expensive - only really available to HICs

- 5 stations will have retired by 2024 - all 7 by 2030

- without them - job losses,200mill of extra C emissions by 2035

- only low-C energy source that can provide heat + power

-16mill tonnes of emissions/yr saved compared to gas fuelled stations

- large upfront + maintenance costs - especially for offshore

- claims of killing birds (however more killed by cats)

- NIMBYism

- renewable

- abundant

- no emissions (after construction)

Hornsea Project 1

-190m high wind turbines provide power for 1mill + homes

-2,000+ construction jobs created

- can't be used everywhere effectively - lots of space needed, not always sunny

- high upfront costs

- manufacturing results in emissions + plastic waste

- disposal requires melting - can produce harmful chemicals

- low maintenance costs

- power can be stored + used at night

- quite cheap - as tech becoming more advanced, price decreases + efficiency increases

Chapel Lane Solar Farm

- UKs largest - costs £50mill

- serves 60,000 households

Solar - 4.4%

Wind - 26.8% - second largest source of electricity

- could help UK reach target of 25% of electricity from nuclear by 2050

- each could power 1mill homes

- £210mill given to Rolls Royce to support design

- in July 2023 - gov competition to help develop the design + tech - would award 1 of 6 companies with contract

Organic matter used as fuel for generation of electricity eg woodchips

Fuel derived from biological carbon fixation eg sugar cane for ethanol

- Increased US demand for ethanol sent corn prices to highest in a decade

- increased price of mexicos national food staple

Drax Power Station N Yorkshire - switched from coal to wood pellets - 2/3 of wood pellets come from USA - carbon emissions of transport

Released more emissions than coal

Indirect land-use change - unintended consequence of releasing more C emissions due to land changes around the world induced by replacement of crop lands for ethanol production

- renewable, grown very easily, lower emissions (C-neutral?)

- provides rural inward investment + local development projects - multiplier effect

- fuel earns export income

- takes land that food can be grown on - reduce food production - food insecurity

- requires fertilisers, pesticides + large volumes of water - may contaminate water sources

- loss of C sinks - eg forests cleared - ILUC

- if biofuel also a food, price of food increase if shortages occur

- 90% of new vehicles sold have flex-fuel engines - work using combo petrol + biofuel

- large areas of south Brazil used for sugar cane-displacement of cattle fields-Amazon cut down to replace them

- sugar cane more profitable as fuel than food -but ethanol prices fluctuate greatly eg due to seasons - some towns moving back to petrol

- roughly 10% of Brazil's deforestation is for biofuel production