STORES:
- Lithosphere: over 99.9% of the carbon on earth is stored in sedimentary rock such as limestone
- Fossil fuels: 50 00 – 10000 pt
- Atmosphere: CO2, CH4, enters through respiration, removed by photosynthesis
- The atmosphere contains 0.001% of carbon
- Hydrosphere: Carbon dioxide is dissolved in rivers and lakes and oceans
- Oceans the second largest carbon store on earth containing 0.04% of the earths carbon.
- Surface Ocean: 725pt
- Biosphere: Carbon is stored in the tissues of living things, transferred to soil via decomposition
- Contains approximately 0.004% of the earths carbon
- Plants: 560pt
- Cryosphere: most of the carbon in the Cryosphere is in the soil in areas of permafrost where decomposing plants and animals have frozen into the ground.
- Contains less than 0.01% of the earths carbon
FLOWS:
Flux: refers to the movement or transfer of carbon between stores, they create cycles and feedbacks
Biggest Fluxes per year:
- Photosynthesis: plants and phytoplankton use energy from the sun – 120 pt
- Plant respiration – 59 pt
- Litter fall – 59 pt
- Soil decomposition: bacteria and fungi break down, CO2 and methane are released- 58pt
- Ocean uptake: carbon dissolved directly into oceans or taken up by organisms- 92 pt
- Ocean loss: carbon rich water from the deep oceans rise to the surface and release co2- 90pt
- Burning fossil fuel s – 7.7 (10 giggatonnes of carbon from fossil fuels annually)
- Deforestation and land use – 1.1
- Weathering: Transfers carbon from the atmosphere into the hydrosphere and biosphere
- Volcanoes – 0.1
Fast and Slow Carbon Flows
- Fast flows quickly transfer carbon between sources, it only takes minutes, hours or days
- Photosynthesis, respiration, combustion and decomposition
- Slow carbon flows slowly transfer carbon between sources, they can take years
- Sequestration
Natural Processes and Changes to the Carbon Stores:
- Wildfires: Rapidly transfer large quantities of carbon from biomass to the atmosphere
- BUT in long term can an encourage the growth of new plants, which take in carbon = Neutral
- Volcanic Activity: carbon stored within the Earth in magma is released during volcanic eruptions
Human Activity and Changes to the Carbon Stores:
- Hydrocarbon extraction and use: 40% more CO2 in atmosphere since 1750 because of humans burning fossil fuels
- Farming: animals release carbon dioxide and methane when they respire and digest food
- Ploughing releases carbon dioxide stored in soil and rice paddies releases lots of methane
The Carbon budget: the difference between the inputs and outputs of carbon – Source or Sink?
The Effects of Carbon: Keeling curve
- Climate: greenhouse gases trap some of the sun’s energy, keeping some of the heat in
- IPCC predict by 2100 there will be a 4OC increase
- Land: Effects vegetation, permafrost, wildfires
- Oceans:
- Acidity due to absorbing more CO2
- Phytoplankton, may not be able to survive at higher temperatures
Warmer water is less able to absorb CO2, so as temperatures rise