Carbon cycle

• Carbon Transfers (local)- photosynthesis sequestrates carbon reducing potential impacts of climate change.$Carbon Dioxide +$$Water --> Light Energy --> Oxygen +$$Glucose$
• Carbon Transfers (local)- respiration chemically opposite of photosynthesis, this is plants respiring during night but absorb more carbon than they emit thus net carbon dioxide absorbers.$Oxygen +$$Glucose --> Carbon Dioxide +$$Water$
• Carbon Transfers (local)- combustion (burning of fossil fuels or organic matter) emits carbon into atmosphere.
• Carbon Transfers (local)- decomposition of organic matter releases carbon dioxide into the atmosphere and into the soil as a carbon store.
• Carbon Transfers (local)- diffusion has meant ocean acidity has increased by 30% since pre-industrial times as more carbon is being absorbed. Puts coral reefs at threat and an increase in coral bleaching.
• Carbon Transfers (local)- Weathering and erosion - carbonation weathering is acid rain eroding limestone. Carbon then enters oceans and allows organisms to produce shells. increased carbon in atmosphere will increase weathering and erosion and eventually changing the carbon cycle.
• Carbon Transfers (local)- burial and compaction - when shell fragments compact onto ocean floor forming limestone and also forms fossil fuel deposits.
• Carbon Transfers (local)- carbon sequestration - transfer of carbon from atmosphere into other stores, photosynthesis and also in factories in the form of Carbon Capture and Storage (CCS). Transferred via pipelines to saline aquifers and depleted gas fields.
• Advantages of CCS- can be fitted to existing coal power stations, captures 90% of carbon produced, demand for carbon dioxide for drinks etc so transport systems already exist, potential to capture 1/2 the worlds carbon dioxide emmissions
• Disadvantages of CCS- High costs, increases energy demand of power stations, may not be space to have pipelines fitted, economically viable in some cases but is used to push fossil fuels out of the ground so has an adverse effect (can be sustainable though)
• Carbon cycle in a lithosphere environment

  
• Lithosphere- bare rock
• Halosphere- salty environment
• psammosphere - sand coastal environment
• Hydrosphere- freshwater environment
• Carbon Cycle on a Global Scale

  
• Carbon Stores (global) - Marine sediments and sedimentary rock is the biggest with 66,000-100,000 million billion metric tons of carbon stored.
• Carbon Stores (global)- Oceans are dynamic with 38,000 billion metric tons of carbon stored.
• Carbon Stores (global)- Fossil fuel deposits are dynamic currently storing 4000 billion metric tons of carbon currently
• Carbon Stores (global)- Soil organic matter stores 1500 billion metric tons of carbon
• Carbon Stores (global)- atmosphere has increased its carbon stores by 40% since the industrial revolution and stores 750 billion metric tons of carbon
• Carbon Stores (global) - Terrestrial plants store around 560 billion metric tons of carbon but these are under threat of climate change and deforestation.
• Natural Changes to the Carbon Cycle - wildfires (transfer carbon from biosphere to atmosphere, encourage plant growth and climate change), Volcanic activity (carbon within earth is released with eruptions but is a low contributor to the overall carbon cycle)
• Human impacts on the Carbon Cycle - fossil fuel use/combustion (transfers carbon from long-term carbon sinks to the atmosphere enhancing climate change), deforestation (rapid release of carbon stores in slash and burn whilst interrupting local forest carbon cycle), farming (animal respiration, ploughing disturbs soil stores, and machinery combusts), unprecedented flux in the levels of carbon in the atmosphere.
• Carbon Budget- balance between carbon inputs and outputs to a store at any scale or the balance of exchanges between the 4 major carbon stores. E.g. The carbon budget in the atmosphere has inputs from respiration and combustion, but outputs include the oceans and photosynthesis.
• Carbon Source- A store that emits more carbon than it absorbs. A damaged rainforest
• Carbon Sink- a store that absorbs more carbon than it emits. A virgin rainforest
• Enhanced Greenhouse Effect- The increase in the greenhouse effect due to human activities causing global warming and leading to climate change.
• Radiative forcing- the difference between incoming solar radiation absorbed by the Earth and the energy radiated back out into space.
• Carbon dioxide is the single most important anthropogenic greenhouse gas and contributes approximately 65% to radiative forcing by greenhouse gases.
• increased global temperatures (from alteration of the Carbon Cycle), leads to higher levels of evapotranspiration, makes summer storms more likely, decreases summer rainfall, increases winter rainfall.
• Causes of EGE- land use change (70% of deforestation in the Amazon is for cattle ranching removing the carbon stores and increasing the carbon emissions), fertilisers and rice padi fields (methane emissions increase from increased productivity from higher carbon levels), deforestation (accounts for 20% of global greenhouse emissions, interrupts the cycle, reduces carbon sequestration and land is now a carbon source not sink), urbanisation (replacing carbon sinks with infrastructure and account for 97% of all human caused global carbon dioxide).
• rewilding- where populated or manages human areas are being reduced or replaced with wildlife
• impacts of the carbon cycle on tropical rainforests (regional climate)- high rates of photosynthesis so greater humidity and cloud coverage and thus precipitation, deforestation reduces photosynthesis and respiration reducing humidity and cloud coverage and thus decreasing precipitation.
• Impacts of the carbon cycle on oceans (regional climate)- warming of the ocean causes more plankton growth and allows the ocean to store less carbon dioxide (carbon sequestration relies on cooler oceans) so higher temperatures lessens the effect of oceans as carbon sinks. This sets up a positive feedback loop where greenhouse effect is heightened.
• Positive feedback example: Wildfires release large quantities of carbon dioxide into the atmosphere through burning, carbon dioxide then enhances the greenhouse effect, the greenhouse effect causes more wildfires, as it creates hotter and drier climates.
• Negative feedback example: Global warming enhanced by carbon dioxide emissions, higher temperatures and higher levels of carbon dioxide increases photosynthesis rate and created new areas of vegetation ( permafrost thawing ) , carbon dioxide taken in by plants through photosynthesis, less carbon dioxide in the atmosphere reduces global warming effects, photosynthesis returns to post-warming levels (no longer accelerated by carbon dioxide and global warming).
• moorland- expanse of waterlogged, acidic soil and peat that stops oxygen from permeating creating a major carbon store.
• impacts of moorland drainage- increased flood risk in local areas as surface storage is reduced, streamflow is increased by digging drainage ditches, water table is lowered affecting the water cycle, dry peat has a high carbon content and regrades easily, air is able to aid decomposition of the peat releasing carbon dioxide.