Carbon Cycle

• Carbon cycle needs to be balanced to support planetary health. Physical processes control movement of carbon between stores on land, oceans and atmosphere.
• Most global carbon locked in terrestrial stores as part of long-term geological cycle. But, resilience on fossil fuels has caused significant changes to carbon stores and amplified climate change.
• There is a consensus that anthropogenic climate change (caused by human activity) poses a great threat to planets health and functioning of its cycles.
• Biogeochemical carbon cycle consists of carbon stores of different sizes - the terrestrial (earth), oceans and atmosphere. There are annual variations between stores of varying sizes and rates.
• Most of earth's carbon is geological, having formed from sedimentary carbonate rocks in oceans and biologically derived carbon in shale, coal and other rocks.
• In the sea, marine animals convert some of their carbon in their diet to calcium carbonate to make shale, coal and other rocks. Overtime, these shells collect on sea bed and form limestone which become weathered and release carbon dioxide back into the atmosphere when exposed to air.
• Geological processes release carbon into atmosphere through volcanic out-gassing at outer ridges and subduction zones as well as from chemical weathering of rocks, creating global balance of carbon.
• Carbon cycle: carbon enters atmosphere as carbon dioxide from respiration and combustion. It's absorbed by producers via photosynthesis. Animals consume plants and carbon compounds travel through food chain, released via respiration. Animal dies, eaten by decomposers which return carbon to the atmosphere.
• Phytoplankton absorb atmospheric carbon during photosynthesis in surface ocean waters. Carbonate shells move into deep ocean water through carbonate pump (cycling of organic matter in ocean) and action of thermohaline circulation which is the movement of seawater according to temperature.
• Terrestrial primary produces sequester carbon during photosynthesis which is returned through respiration of consumer organisms.
• Biological carbon stored as dead organic matter in soils and returned through biological decomposition, forming final component of carbon cycle.
• Concentration of carbon in the atmosphere influences natural greenhouse effect, enhanced by fossil fuel combustion.
• Natural greenhouse effect is vital in regulating earth's temperature and precipitation but anthropogenic climate change has altered the balance of carbon pathways and stores, having impacts on climate, ecosystems and hydrological cycle.
• Ocean and terrestrial photosynthesis regulate composition of gases in atmosphere.
• Soil health influenced by stored carbon which is vital for ecosystem productivity.
• Deforestation interrupts natural regulation by causing soil erosion
• Primary energy sources are natural sources found in earth e.g coal, oil and gas. Secondary energy converts sources into other forms e.g electricity for convenience
• A rich energy mix made up of domestic and foreign sources; a country will have its own energy sources as well as importing from other nations, having diverse mix of renewable and non-renewable sources.
• Energy consumption greater for newly industrialised countries e.g India and China, whilst countries in later stages of Demographic Transition model will be more sustainable and conscious of their consumption.
• What factors influence access and consumption of energy resources?

  Physical availability, cost, technology, public perception, level of economic development, and environmental priority
• How does physical availability affect energy resources?


  It depends on location, as different energy sources require specific geographical conditions
• Why do large power stations require flat and stable land?


  To function correctly and ensure safety and efficiency
• What is a consequence of the mismatch between fossil fuel locations and demand?


  It can lead to inefficiencies in energy distribution and higher transportation costs
• How does cost affect energy resource supply?


  As supply decreases, costs increase, leading to fluctuating prices
• Which type of oil deposits are generally cheaper?

  Onshore oil deposits
• Why are HEP sites near transport routes more economical?


  They reduce transportation costs for energy distribution
• How has technology impacted oil extraction?


  New developments allow extraction from deeper and more technically difficult environments
• Where are there plans to extract oil from tar sand?


  Canada and Venezuela
• How does public perception influence energy resource consumption?


  Cultural preferences can lead to reluctance in adapting to new technologies
• What event caused doubts over nuclear power?

  The Chernobyl disaster
• How does the level of economic development affect energy sources used?

  Wealthier regions can afford advanced energy sources, while poorer regions rely on basic sources
• Energy players have different roles in securing pathways and energy supplies. Energy TNCs, e.g shell, are incredibly profitable but are challenged by recent rise of OPEC and other environmental groups.
• OPEC consists of 12 oil producing countries founded in 1960. Aim: Stabilise oil prices whilst limiting environmental damage. Though they help compensate the poor, significant energy producers e.g Russia refuse to be a part of the bloc
• Government can influence conservation through movements e.g increasing taxes for large emitting companies. Consumers have role in voicing their needs through protests e.g UK riots over mining in the 20th century.
• Energy pathways (can be pipelines, transmission lines or shipping routes) are vital in transporting energy sources from producers to consumers. These pathways are high risk areas, prone to piracy, theft, disruption and damage.
• One high-risk pathway is pipeline connecting Europe to Russia. In 2006, Russia completely stopped supplying gas , claiming Ukraine failed to pay in time, causing 2 week dispute and led to a 16% increase in gas prices for UK as gas passes through Ukraine to reach UK. Russia's energy company, Gazprom, is a state owned company and one of country's best assets
• Environmental priority: Costa Rica obtained 99% of energy from renewable sources in 2015 as they are conscious of environmental footprint.
• 2007: Belarus cut off Russia's oil pipeline as Russia demanded high prices. Thus, Germany and Poland were affected, with Poland being 96% dependent on imports.
• Accidents cause disruption e.g Buncefield Oil Depot fires. Likely that as supply decreases, more conflicts and tensions will arise, slowing flow of energy between produces and consumers
• Development of unconventional fossil fuel energy resources e.g tar sands, oil shale, shale gas and deep water oil have a plethora of costs and benefits.