carbon case studies

Slow carbon cycle

Formation of geological carbon stores, and geological processes releasing carbon: sedimentary carbonate rocks, and biologically derived carbon stores e.g. coal, shale

fast carbon cycle

Biological processes that sequester carbon: 1) oceanic sequestering (biological, carbonate, and physical pump), 2) terrestrial sequestering (plants and animals), 3) biological carbon (soil, which is the largest carbon store on land. Stores 20-30% of global carbon. But the amount depends on climate, soil type, and land use)

Impact of fossil fuel combustion on fluxes

Fossil fuels= slow carbon cycle. However, human interference shifts this flux to fast carbon cycling, quickly releasing carbon to the atmosphere

Impact of fossil fuel combustion on stores

½ the additional CO2 emissions since Industrial Revolution are still in the atmosphere.

There’s been no corresponding increase in natural sink sequestering to counteract the increasing atmospheric store. However, atmospheric store is the most sensitive to small changes.

Other ½ increased fluxes to biological store, with increased soil carbon storage in high latitudes. however, of storage in unfreezing permafrost.

8 factors affecting energy consumption

Physical availability,

Technology,

Cost,

Economic development, public perceptions, standard of living,

Climate,

Environmental policies- renewables aren’t always environmentally friendly e.g. in manufacture

UK vs Norway physical availability

UK. 37% energy in 2022 was imported, so vulnerable to dependency and global fluctuating prices. However, this was down from 50% in 2010, due to diversifying their energy mix.

Norway. Diverse energy mix from fossil fuels e.g. oil and coal. Reliance in HEP producing surplus to export. No imports, reducing costs due to shorter energy pathway. However, transport from rural sources of HEP to urban sinks may be expensive, but still cheaper than internationally importing.

UK vs Norway technology and environmental policy

UK. Current tech and environmental policy makes coal expensive, leading to the last coal mine closing in 2015. However, the rising costs could reduce pressure by reducing consumption, potentially increasing energy security.

Norway. Deep water drilling tech has aided them to develop North Sea gas extraction.

UK vs Norway political and environmental policy

UK. Privatisation of energy in 80s means more stakeholders, with foreign interests have a say in energy mix. Energy mix and prices dependant in global factors.

Norway. Energy is state owned. Royalties, taxes, go to gov towards preparation for a future without fossil fuels. More sustainable long term approach for long term energy security, than the UK’s short term energy security.

Why there’s a mismatch for oil between regions of conventional fossil fuel supply, and regions of high demand

Fossil fuel supply is due to geological and physical factors such as geology, climate, and relief, that influence formation, preservation, and accessibility of fossil fuels.

E.g. Asia supplies 8% of global oil, but consumes 38%.

There’s a large mismatch because oil is essential for transport, needed for the movement of commodities for economic activity. Deep global market for oil

Why is there less of a mismatch for gas and coal, as to oil

Gas and coal reserves are more globally distributed. Coal is commercially mined in over 70 countries, while 80% of the worlds oil reserves are found in the 11 OPEC countries.

Many major coal and gas consuming nations are also major producers. Coal has high transport costs either a low energy density, so it isn’t worth it financially for nations without it to import it.

Physical disruptions to energy pathways

Chokepoints.

½ the worlds oil goes through chokepoints. Blockage can lead to supply delays and higher shipping costs, resulting in higher world energy prices.

Closure of the Strait of Hormuz in 1973 and 1797 led to a 300% surge in oil prices. There were no economy feasible options to avoid the strait of Hromuz at the time.

Human disruption to energy pathways- Russia vs Ukraine

Conflict in transient states. E.g Russian gas to Europe.

2021 80% Gazprom’s pipeline gas exports were to Europe. 2024, 11%.

3 of 4 of their pipelines went through Ukraine. If Ukraine joined EU/ NATO, EU may had enforced EU energy policies, reducing Russia’s ability to control flow and pricing. Ukraine could’ve aligned with EU energy in tests, increasing competition against Russian gas with renewable. If Ukraine gained energy independence, Russia would have less political leverage from gas supplies on them.

Jan 2025, Russian gas no longer flows through Ukraine

Human disruption to energy pathways, disruption as conventional fossil fuel sources deplete- Syrian conflict

The Syrian conflicts have involved a proxy war between Russia and USA in s battle for control over Syrian territory.

USA and Russia involvement because of the proposed construction of oil and gas pipelines through Syria to Europe.

What is energy security and how may unconventional energy sources (theres 4 of them) affect it- intro

Energy security= the reliable, affordable access of energy to meet the needs of present and future generations.

As conventional fossil fuels decline, unconventional sources (oil shale, shale gas, tar sands, and deep water oil) have become more economically attractive.

While it improves short term security, long term is limited due to environmental, economic, and sustainability issues. So their contribution to an energy secure future partial and context- dependant.

How do unconventional energy sources increase energy supply and reduce import reliance- short term benefits (point 1)

Tar sands- Canada has 73% global stocks. By 2030 could meet 15% North America’s oil needs. Generates revenue for local gov (NE Alberta whose main industry is oil/ gas, so the money this industry provides is essential) and national for positive multiplier effect. HOWEVER owning most of global supply puts pressure on gov to extract it, causing potential tension between environmental/ local groups vs gov.

Oil shale- USA investment in new technologies for extraction such as freeze wall technique which prevents groundwater contamination, increases efficiency by isolating the extraction zone, and has minimal land disruption. Allows for increased oil shale extraction, delaying reaching the peak oil point, diversifying their energy mix.

How do unconventional energy sources have environmental and social drawbacks- (point 2)

Deep water oil- in Brazil, future drought risk would reduce their HEP which they are dependant on, so need the energy mix diversification deep water oil provides. But has risks e.g. 2010 Deepwater Horizon Spill in the Gulf of Mexico causing massive ecological damage and public backlash. Had long term environmental impacts of habitat loss disrupting migration patterns. And death of coastal veg increasing coastal erosion. Risks undermine long term energy security by threatening ecosystems and public trust.

Shale gas- its carbon footprint is ½ that of coal, however fracking to access still can cause contamination of surface water, and minor earth tremors.

Tar sands- influx of workers to Alberta led to housing shortages and infrastructure drain.

How are unconventional fuels finite and economically uncertain- sustainability concerns (point 3)

Despite tech improvements, still finite resources of fossil fuels. So use increases carbon emissions during extraction, production, and usage. Carbon sequestration falls from deforestation.

As climate commitments tighten globally, unconventional energy sources may face regulatory, reputational, and financial risks that may limit future investment. Energy return on investment is low for oil shale/ tar sands from their expensive extraction. So long term affordability/ sustainability limited, threatening future energy security.

Tar sands- deforestation of boreal Forrest’s which sequester the most for open cast mining.

Oil shale- heat energy inout required to extract it.

Shale gas- methane gas may leak during extraction, adding to the greenhouse effect.

How unconventional fossil fuels compare to renewables (point 4)

Renewables aren’t finite, so provide security. E.g. solar reducing insecurity in LICs without adequate grid or pipeline systems as it can meet specific needs. But strike prices for renewables are high. But energy return on investment is low for oil shale/ tar sands from their expensive extraction.

Unconventional fossil fuels- conclusion

Short term security especially for countries with the tech and physical availability.

The long term path to energy security lies in renewables, supported by tech innovation, and policy shifts, rather than in the continued reliance on high risk unconventional sources.

Pros of biofuels in Brazil

90% of new passenger vehicles sold in Brazil contain flex- fuel engines that use any combo of petroleum and sugarcane ethanol, significantly reducing their carbon emissions.

Diversifying their energy mix, increasing energy security, development of economy.

Biofuel industry provides 11 jobs/ ton of oil produced. Said jobs are better paid/ more formalised than that if other agricultural workers.

Cons of biofuels in Brazil

Displacement of other types of agriculture, mainly cattle pasture. Causing large scale deforestation of Amazon to replace cattle pastures. Deforestation cancelling out reduced CO2 emissions from increased bio-ethanol use

There are 2 radical technologies= 1) carbon capture and storage, and 2) alternative energy sources (including hydrogen fuel cells, electric cars, and nuclear fission).

Advantages and uncertainties of carbon capture and storage

It catches and buries CO2 from fossil fuel combustion underground. OR scrubbing CO2 out of natural gas.

Advantages= scrubbing CO2 out natural gas already widely used. Coal use will never stop as it’s abundant and cheap so beneficial for LICs. So promises the greatest savings in emissions where coal is being used to generate electricity.

Uncertainties= expensive from complex tech so may not actually be feasible for LICs. Can’t be certain the CO2 would remain underground and not gradually seep to the surface to the atmosphere.

There are 2 radical technologies= 1) carbon capture and storage, and 2) alternative energy sources (including hydrogen fuel cells, electric cars, and nuclear fission).

Advantages and uncertainties of alt energy sources- hydrogen fuel cells

Hydrogen and oxygen make water, heat, and electrical energy.

Advantages= Little disruption to carbon cycle as waters the only byproduct when generating energy, unlike in combustion where you get CO2, a greenhouse gas, additionally.

Uncertainty= H fuel cells expensive to manufacture, and transport of H is very dangerous from changes of spontaneous combustion.

There are 2 radical technologies= 1) carbon capture and storage, and 2) alternative energy sources (including hydrogen fuel cells, electric cars, and nuclear fission).

Advantages and uncertainties of alt energy sources- electric cars

Advantages= 0 CO2 emissions. Helps cities reduce air and noise pollution.

Uncertainty= tech developments needed in distances they can travel before charging. Public charging difficult e.g. European narrow roads. More expensive. So quiet there’s concerns of crashes. If the electricity isn’t created sustainably, there’s no point, so success depends on development + energy mix of the country.

There are 2 radical technologies= 1) carbon capture and storage, and 2) alternative energy sources (including hydrogen fuel cells, electric cars, and nuclear fission).

Advantages and uncertainties of alt energy sources- nuclear fusion

2 atomic nuclei joining, releasing energy.

Advantages= no greenhouse emissions or radioactivity. Can use common elements.

Uncertainty= long way from becoming reality

growing demand → more resources needed → FOOD → contrasting regional trends in land use cover: 1) deforestation, 2) afforestation, 3) conversion of grassland to farmland.

Deforestation impact on carbon cycle, hydrological cycle, and soil health

Impact on carbon cycle= less CO2 sequestration from photosynthesis, reducing it as a carbon store. Loss of biomass, CO2 released from decomposing wood and dead animals from less producers to eat.

Impact on soil health= reduced shading so more direct sunlight reaching Forrest floor causing soil to dry out reducing amount of sequestration. Rapid soil erosion, minerals lost as leeching (loss of nutrients form infiltration) increases. Ecosystem services reduced.

Impact on hydrological cycle= increased surface runoff causing silt deposition in rivers. Reduced evapotranspirstion so less humid. Infiltration, groundwater recharge decreased. Flood peaks higher, lag time shorter. Localised deforestation may increase rain due to formation of heat islands from increased convection). Extensive deforestation can disrupt ppt and seasonality and cause drought

growing demand → more resources needed → FOOD → contrasting regional trends in land use cover: 1) deforestation, 2) afforestation, 3) conversion of grassland to farmland.

Afforestation impact on carbon cycle, hydrological cycle, and soil health

negatives= monocultures if commercial trees often store less carbon (reduced biodiversity. Diverse Forrest’s have species with a range of root depths and biomass productivity, enhancing total carbon storage) and use more water (uniform canopy and root structure means less efficient use of water at different soil depths. Monocultures are often fast growing species so high water demand too), and disease prone.

growing demand → more resources needed → FOOD → contrasting regional trends in land use cover: 1) deforestation, 2) afforestation, 3) conversion of grassland to farmland.

Grassland conversion impact on carbon cycle, hydrological cycle, and soil health

There are 2 types of grassland covering ¼ of global land area:

Temperate grasslands= no trees, seasonal growth patterns related to a wide annual temp range. Contain fertile soils important for carbon store, so are prized for agriculture and subsequently suffer degradation.

Tropical grasslands= have scattered trees. Land conversion is increasing despite often infertile soils.

Carbon cycle= when grassland converted to crop land, the soil is disrupted e.g. through plowing, accelerating decomposition of organic matter, releasing stored carbon as CO2 to the atmosphere. Grassland to crop land reduces soil carbon by 60%

growing demand → more resources needed → FUEL → combustion releasing carbon → ocean acidification due to the ocean being a carbon sink → Health of corals.

Ocean acidification threatening health of corals, marine ecosystems, that provide vital ecosystem services

Oceans as sinks= oceans saturated with CO2 so can’t sequester as much. Acidification most likely to occur at west coast USA due to cold water upwelling from the deep ocean.

Corals and ecosystem services= if the coral is stressed, it expels the symbiotic algae that live in its tissues that provides the coral food through photosynthesis.

Corals are home to 25% of all marine creatures.

Corals disrupt wave energy, preventing coastal erossion.

90% corals will be gone by 2050

growing demand → more resources needed → WATER → enhanced greenhouse effect shifting climatic belts → drought → Forrest health.

Why drought frequency is increasing, what’s happening to Forrest’s as carbon stores (Forrest health), Amazon

3 ways the health of Forrests as carbon stores is being challenged: deforestation, poleward shift of climatic belts, increasing drought. (The first 2 encourage the 3rd).

Amazon=

Acts as a giant climate regulator pumping 20 billion tonnes of water into the atmosphere/ day.

Since 90s, a more extreme cycle of drought and flooding occurs here. Wetter reading seasons associated with shifts in ITCZ. Decreased rainfall in deforested areas.

Since 1911, droughts here have occurred every 10 yrs. But the 2005 mega drought was followed by another in 2010. The 2 have degraded much of the Forrest already stressed by large scale deforestation.

Less water has been available for rainforest plants, introducing stress to the ecosystem, worsening 2005:drought impacts.

In 2005, the trees damaged weren’t recovered by 2010, causing half the Amazon to be affected in 2010.

Diminished health of tropical rainforest means: dryer leading to it becoming a net carbon emitter, as to a major carbon store. Sequestering less CO2 from atmosphere, thereby exacerbating greenhouse effect. Plating a diminishing role in hydrological cycle

3 implications Forrest loss has on human wellbeing

1) Goods/ providing services= food, fuel, medicine, timber. Reduced access would harm local livelihoods, economies, food security.

2) Supporting services (fundamental ecological processes)= soil formation/ fertility as Forrest’s contribute organic matter/ prevent erosion. Nutrient cycling. Biodiversity habitat. Loss would reduce overall ecosystem resilience, reducing food production.

3) Cultural services= indigenous identity, recreation and tourism, inspiration and education. Loss would erode cultural identity, diminish mental health benefits, and reduce economic tourism income.

4) regulating earths systems= they help stabilise the global environment. Climate regulation by sequestering carbon mitigating climate change. Regulate rainfall. Disease regulation- healthy Forrest’s reduce spread of zoonotic diseases by maintaining a balanced ecosystems. Forrest loss accelerates climate change, worsens flood/ drought, increases air pollution, heightens pandemic risks

Trends in Forrest loss 1990-2000 as to 2010-2020.

Net Forrest loss has declined by 40% between 1990-2000 and 2010-2020, leading to some countries having a net Forrest gain.

What’s the environmental kuznets’ curve

Environmental Kuznetsk curve suggests societies reach a turning point where exploitation of resources shifts to protection.

Factors affecting when the turning point is are: GDP/capita, knowledge in the role of the environment on human well-being, if aid had been provide to the LIC to choose sustainable options without considering how much it’d cost, environmental laws, participation of locals, power of TNCs.

Features of model= GDP/capita on x axis, level of environmental degradation on y axis. Split into 3 sections: pre industrial economies, industrial economies (turning point in this section), post industrial/ service economies

3 ways threats to ocean health poses a threat to human well-being: resources, tourism, coastal protection.

RESOURCES

Changes (ocean acidification, rising sea levels, loss of sea ice) affect the distribution, abundance, breading cycles, and migration of marine plants and animals that ppl directly rely on.

90% of those who fishing supports, are in developing countries. China depends on fish export so will be affected by depleting stock. Only nations with large industrial fishing cleats e.g. UK, Japan, will be able to follow the fish that are able to shift their location to adapt to cloak warming.

3 ways threats to ocean health poses a threat to human well-being: resources, tourism, coastal protection.

TOURISM

20% Maldives GDP is tourism. Damage to corals may reduce number or tourists

3 ways threats to ocean health poses a threat to human well-being: resources, tourism, coastal protection.

COASTAL PROTECTION

Coral reefs shelter 25% marine species.

200 million ppl live in coastal areas protected from waves by corals

Why mangrove Forrest’s are important for human well-being

Are found along tropical coasts. Their prop roots have benifit of: stabilising coastal erossion, collecting nutrient rich sediments by trapping them in their prop roots, protection/ shelter against weather and tsunamis by absorbing and dispersing surges, providing nurseries for coastal fish away from predators.

However, ½ all mangrove Forrest’s have been lost since 50s, and clearing mangroves for tourist development or shrimp aquaculture has accounted for ¼ this loss

3 factors causing uncertainties for future CO2 levels and climate change: physical factors, human factors, feedback mechanisms.

PHYSICAL FACTORS: ocean sink, terrestrial sink

Ocean sink= Increased store in sea grasses/ algae, however, overall reduction as a sink for 2 reasons: 1) reduced sequestration in tropical oceans as they’re warning increase in temperature. 2) ocean acidification/ temp rise is slowing down and reducing efficiency of biological pump.

Terrestrial sink= when saturation is reached, they begin to act as sources

3 factors causing uncertainties for future CO2 levels and climate change: physical factors, human factors, feedback mechanisms.

HUMAN FACTORS: economic growth, energy sources, population change

Economic growth= it was thought that after 2007-8 global financial crisis, CO2 emissions would increase as global GDP recovered and increased. However that’s not the case. The rate of CO2 emissions has fallen.

Energy sources= energy consumption has grown, but in 2015 2/3 of this increase was from renewable sources.

Population change= growth of middle class.

3 factors causing uncertainties for future CO2 levels and climate change: physical factors, human factors, feedback mechanisms.

FEEDBACK MECHANISMS: 1) positive feedback, 2) negative feedback, 3) climate tipping point points

1) Positive feedback= peatlands and permafrost. Peat stores carbon because of low decomposition in cold waterlogged soils. Warming will dry it, increasing decomposition rates, emitting CH4.

2) Negative feedback= high temps, so more plant growth, more carbon sequestration, less greenhouse gasses, reducing enhanced greenhouse effect, reducing temperatures.

3) A climate tipping point is a critical threshold. A small change in the global climate system can transform a relatively stable system to a very different state. E.g. Forrest die back, e.g. changes to thermohaline circulation, which are north capable of creating tipping points.

Forrest die back= drought in rainforests causing trees to die back. The tipping point is when levels of die back stops the recycling of moisture in rainforests, resulting in further die back.

Changes to thermohaline circulation= The tipping point is when a collapse in the thermohaline circulation e.g. failure of the Gulf Stream, would affect global temperatures

5 adaption strategies to deal with impacts of climate change, which are varies between different countries

Water conservation and management,

resilient agricultural systems,

land use planning,

flood risk management,

solar radiation management

5 mitigation strategies to rebalance the carbon cycle

Carbon taxation,

Renewable switching,

Energy efficiency,

Afforestation,

Carbon capture and storage