Carbon Cycle

• Carbon


  Called the main ‘building block of life’, present in the stores of the atmosphere, hydrosphere, lithosphere, and biosphere
• Stores of Carbon

  • The atmosphere (as carbon dioxide and compounds like methane), The hydrosphere (as dissolved CO2), The lithosphere (as carbonates in limestone and fossil fuels), The biosphere (in living and dead organisms)
• Photosynthesis


  The process by which green plants and some other organisms use sunlight to synthesize nutrients from carbon dioxide and water, involving the green pigment chlorophyll and generating oxygen as a by-product
• Decomposition


  The state or process of rotting; decay
• Respiration


  The action of breathing
• Carbon sink


  A forest, ocean, or other natural environment viewed in terms of its ability to absorb carbon dioxide from the atmosphere
• Carbon pool


  A system that has the capacity to store or release carbon
• Closed system


  Must be equal, cannot increase or decrease, just stored differently
• System feedback loops

  • Any change is cancelled out, maintains equilibrium
  • Positive feedback occurs when a small change in one component causes change in another component
• Geological carbon cycle

  Centred on huge carbon stores in rocks and sediments, involving weathering, decomposition, transportation, sedimentation, metamorphosis, mechanical, chemical, and biological processes
• Major stores of carbon

  • Hydrosphere (water, ocean), Lithosphere (rock, upper layers of earth's crust), Biosphere (animals, plants, soil), Atmosphere (gaseous form like CO2/CH4)
• Lithosphere

  Inorganic stores like fossil fuels and limestone, as well as organic stores like peat and humic substances
• Hydrosphere


  Involving oceans, dissolved CO2, organisms like fish, plankton, and plants, with stores in surface plants, intermediate deeper water, and living organic matter like fish/plankton
• Biosphere


  Involving living vegetation, plant litter, soil humus, peat, and animals
• Atmosphere


  Involving human activities, greenhouse gases, global warming, CO2 concentration, and control of Earth's temperature
• Thermohaline circulation

  Involving phytoplankton, plankton bloom, photosynthesis, decomposition, and carbon cycle pumps
• Marine snow is a shower of organic material falling from upper waters to the deep ocean, including biological debris that falls from higher in the water column
• Marine snow is a shower of organic material falling from upper waters to the deep ocean
• Biological debris that falls from higher in the water column is also known as marine snow. Some flakes fall for weeks before finally reaching the ocean floor
• As plants and animals near the surface of the ocean die and decay, they fall toward the seafloor, just like leaves and decaying material fall onto a forest floor. In addition to dead animals and plants, marine snow also includes fecal matter, sand, soot, and other inorganic dust
• Carbonate pump: white cliffs of dover
• How does atmosphere carbon affect the greenhouse?
• The carbon stores of the atmosphere, ecosystems, and soils are in constant exchange. The carbon balance in soils is regulated by plant productivity, microbial activity, geology, erosion, climate, and the amount of upward and downward (leaching) water movement in the soil
• The Anthropocene began 8000 years ago, with farming changing the world's processes
• Ocean and atmosphere are connected by rain. Adding the two numbers together gives one combined value which is larger
• 31% of greenhouse effect is reflected by clouds, 69% is absorbed. 50% is at the earth's surface, especially the oceans. 69% of the surface absorption is re-radiated to space as longwave radiation
• Net primary production = Gross primary production - Respiration
• Energy security is a key goal for countries as it is vital to the functioning of a country, particularly its economy and the well-being of its people
• Energy is essential as it powers most forms of transport, lights settlements, warms or cools homes, powers domestic appliances, is vital to modern communications, and drives most forms of manufacturing
• Hydroelectricity does not fall under renewable energy
• Nuclear energy is small and people are scared of it
• Energy mix is the combination of different available energy sources used to meet a country's total energy demand
• Key players in energy security include Shell and OPEC
• Development of unconventional fossil fuels is a key aspect of energy pathways
• Key Energy Pathways

  • Oceans are currently at risk
  • Ecosystems are at risk- the ocean
  • Not all go through the ocean- some through pipes, lorries and rail- liquid gas
• Case Study: Tar sands- Alberta State, Canada
• Characteristics of Tar sands

  • Boreal forest- Hundreds of millions of acres in size
  • Goes across the northern hemisphere
  • Large size and Scale
  • Crucial regulator of the world's climate
  • One of the worst carbon exports in the world
  • Alberta oils sands complex
  • 3rd biggest oil deposits
  • Hundreds of square miles in size
  • Used to mine tar to turn into oil to then turn into petrol
  • Enormous carbon emissions
  • Toxic sludge/ lakes
  • Largest and most destructive project in human history
  • Separating the oil requires a huge amount of energy and water
  • The revenue will fuel the countries change towards greener energy
  • Cash cow for Canada- makes lots of money
  • Contribute £1trillion to Canada’s economy within a year
  • ‘Petro State’- increasing dependence on it
  • Benefits include Employment, Taxes, Land compensation schemes
• However, some don't feel these benefits outweigh the cons
• Some communities are being left behind
• Indigenous people are the poorest out there