carbon cycle 2

• Carbon Cycle


  Largest Carbon Store = Lithosphere/ Sedimentary (100,000,000 PgC)

  Largest yearly flux = Photosynthesis (103 PgC from Atmosphere 560 to Biosphere 2,060)

  Smallest Carbon Store = Atmosphere/ Plants (both 560 PgC)

  Smallest yearly flux = Sedimentation/ fossilisation (0.2 PgC from Deep Oceans 38,000 to Fossil Fuels 4,000)
• Geological carbon formation


  1. Coal = duration and heat intensity influences %C

  2. Limestone = compaction/cementing of shells

  3. Crude Oil = chemical decomposition of dead phytoplankton
• Geological processes that release carbon


  Outgassing and Partial melting of sedimentary rocks
• Outgassing


  Release of CO2 in crust by volcanic eruptions/earthquake activity (geysers/ hot springs)
• Geological carbon cycle


  Slow (10-100 million tonnes carbon/year) , huge carbon store
• Anthropological carbon cycle


  Human caused, fast (1,000 million tonnes carbon/year)
• Biological carbon cycle


  Fast (10,000-100,000 million tonnes carbon/year), flows and sequester between oceans, vegetation and freshwater
• Phytoplankton


  Carry out photosynthesis by taking out carbon from seawater which enables more carbon to enter the sea (1,000 x more than respiration)
• Biological pump


  Organisms feed on phytoplankton and use carbon to make their shells (Calcium Carbonate). Carbon moves from shallow to deep ocean when organisms die and sink
• Carbonate pump


  Organisms remains turn into sedimentary rock
• Thermohaline Circulation


  System of surface and deep ocean currents driven by temperature and salinity differences. CO2 dissolves more readily in cold and deeper water (25% diffused in Southern Ocean).
• Physical pump


  Cold, denser seawater sinks into deep ocean, where slow moving currents hold CO2. Deep currents then return to the surface, warmed and diffuse CO2 back into the atmosphere.
• Terrestrial Carbon Cycling


  CO2 taken out of atmosphere by plants photosynthesis (1000x more than respiration), which is then eaten by consumers and later released back into the atmosphere during decomposition.

  
• Photosynthesis Equation

  
• Biological decomposition


  Decomposers (worms) feed on dead matter and break down into CO2, water and nutrients. Soils store 20-30% carbon but can emit or sequester CO2 depending on climate, soil type and management
• Greenhouse gases


  CO2, CH4, CFCs, N2O
• Natural Greenhouse effect


  Short-wave radiation passes through gases of Earths Atmosphere which is then absorbed by the Earth (warming planet). Earth gives off long-wave radiation thats mostly absorbed by atmosphere

  
• Net Primary Productivity


  Important measure of plant growth and conversion of C02 into plant store (measured in grams/metre2/year). Tropical forests have highest (16-23 PgC/year-1) and Tundra have the lowest (0.5-1 PgC/year-1)/ worst carbon store
• CO2 fertilisation


  Anthropogenic CO2 rise should speed up photosynthesis and NPP by 63% in 2100 but plants are limited by nutrients (only 20% expected)
• Soil health


  Influence by carbon stored in ground (lack can cause soil erosion and lower productivity)

  Deforestation and climate change can influence store levels/ fertility (1/2 carbon in litter and soil gone after 2 years deforested)
• Implications of enhanced greenhouse on climate


  Ice shelves melt, change ocean currents

  Stronger storms

  Wetter in North and South America, Northern Europe

  Drier in Sahel, Mediterranean, Southern Africa and Asia
• Implications of enhanced greenhouse on ecosystems


  Extinction rates rise 15-40%

  Habitats shift pole-ward or deeper/higher

  Marine diversity lost

  80% corals bleached
• Implications of enhanced greenhouse on water cycle


  Rivers dry up in arid areas

  20-30% decline in water in Mediterranean

  Higher humidity

  Small glaciers melt

  Extreme precipitation events
• Energy security influenced by


  Physical = exhausted supply/ hazard (Fukushima)

  Environment = protests (Horizon 2010)

  Economic = price hikes from supply issues (Gulf 91)

  Geopolitical = conflict/instability within producers (Arab Spring 2011)
• Energy mix


  Range of energy sources used by a country
• China Energy mix


  Heavy fossil fuel dependence (over 75%), over 50% coal, 2% Nuclear
• Energy players


  Involve meeting energy demands with energy pathways (TNCs, OPEC, Govt, Consumers)
• Energy player objectives


  Energy security, equity (affordable) and environmental sustainability
• Energy pathway


  route taken from source to consumer
• Energy pathway issues


  Natural = vast distances and tough terrain (Trans-Alaskan)

  Human = technical problems (leaks in Siber), supply run out (North Sea), diversion for more profit (to China)
• Nations that produce large energy reserves


  Indonesia, Australia, China, Russia, UAE
• Reasons for energy imports


  Physical = some regions have lower supply than others/ lack of resources (UK, Japan)

  Human = level of development and supply outstrips demand in some countries (Russia, Saudi)
• Politically unstable producer locations


  Oil in Niger Delta - locals threaten blocked access due to oil spills

  Container ships attacked by Somali pirates

  Gas pipelines in Europe - Russia cut Ukraine's gas in 2014
• Growth of renewables


  6% worldwide electricity

  Solar increased 38.2%

  Wind energy slow and HEP uncertainty
• Solar Energy


  Benefits = safe, clean, flexible usage, available by L.I.Cs

  Costs = not effective in cloudy condition and lack of research
• Wind Energy


  Benefits = safe, clean and non-pollutant

  Costs = need certain wind speed and large amount of land
• Geothermal Energy


  Benefits = safe, clean and non-pollutant

  Costs = high capital, sometimes blamed for quakes
• HEP Energy


  Benefits = instant electricity and potential tourism/recreation

  Costs = flooded land, fish and drought disruption
• Nuclear Energy


  Benefits = high energy, cheap once running and 'green' energy

  Costs = safety (leaks), waste disposal and security of dangerous materials
• Bioenergy


  Made by biomass in form of renewable, thermal or transport fuels (biofuels)

  Problems = food security environmental conservation threatened and change of land ownership (Nomads to govt)