Carbon cycle

• carbon is stored as CO2, CH4 and CO in the resovior the atmosphere
• Carbon is stored as hydrogen carbonate ions, dissolved CO2 in the hydrosphere resovoir
• Carbon is stored in carbohydrates, proteins, lipids in the biosphere
• Carbon is stored in carbonaceous rocks such as limestone in the lithosphere
• Photosynthesis captures light energy using chlorophyll pigment
• Photosynthesis converts low energy CO2 and H2O into high energy carbohydrate
• Respiration releases energy captured in photosynthesis
• Aerobic respiration releases CO2 to the atmosphere, returning carbon
• Aerobic respiration breaks down organic compounds releasing higher energy that anaerobic respiration
• Food webs: some ,olé uses like carbohydrate and proteins are synthesised by plants, these are eaten creating feeding relationships
• Fossilisation: incomplete decomposition of dead organic matter (under anaerobic conditions) produces long term carbon stores known as fossil fuels
• Some organisms produce exoskeletons including calcium carbonate, this may produce rocks such as limestone
• Combustion: burning of organic materials releases CO2
• Human activities alter rates of movements of carbon, unbalancing natural dynamic equilibrium and stores in reservoirs
• Changes in phtosynthesis can be caused by deforestation: it reduces movement of carbon from atmosto biomass
• Changes in photosynthesis may be caused by afforestation: increased movement of carbon from atmosphere to biomass
• Changes in photosynthesis may be caused by marine pollution containing toxic materials: decreased phytoplankton population decreases absorption of dissolved oxygen
• Algae live on the underside of Antarctica sea ice, carbon absorbed in photosynthesis sinks to the seabed in faeces of krill that eat algae.
• respiration By anaerobic soil organisms release methane gas, methane is gradually oxidised to CO2
• Anaerobic environments can be produced by humans in rice padi fields, landfill sites, anaerobic sediments in reservoirs, livestock intestines
• Drainage of marshlands, peat bogs, waterlogged fields destroy anaerobic conditions
• Dissolved CO2 is in equilibrium with carbonic acid, this disassociates to form hydrogen carbonate and hydrogen ions
• Hydrogen ions alter pH of the sea
• As carbon dioxide increases in the atmosphere dissolved carbon dioxide increases and there’s an increase in hydrogen ions
• Methane can be released during fossil fuel extraction
• Combustion of fossil fuels realease carbon dioxide into the atmosphere
• Conservation of biomass carbon stores involves the protection of habitats containing high amounts of carbon such as peat bogs and forests
• Alternative use to fossil fuels means using renewable energy resources and nuclear power as they release lower carbon emissions
• Grown tree is a carbon reservoir, there is no more net storage of carbon
• Pre combustion technology relating to carbon capture and storage involves changing fuel used or the way it is combusted
• Changing fuels or way they are combusted can be expensive but often makes removal of CO2 easier
• Gasification converts fuel such as coal to gaseous hydrogen and carbon dioxide. CO2 is removed for storage. Gaseous hydrogen is distributed for use in vehicles etc
• Oxy-fuel combustion uses pure oxygen so capture of carbon is easier
• Post combustion technology of carbon capture and storage, carbon dioxide can be removed from exhaust gases of fossil fuel combustion by dissolving it in a solvent, high pressure membrane filtration, grapheme absorbtion
• Areas such as depleted aquifers, oil fields and gas fields can be used for carbon storage
• Carbon can be injected into oil reservoirs