Carbon stores change because of flows of carbon
Photosynthesis - atmosphere to biomass, plants and phytoplankton photosynthesise, passed through food chain and released through respiration and decomposition.
Respiration - living organisms to the atmosphere, plants and animals break down glucose which releases methane and carbon dioxide into the atmosphere (CO2 and CH4)
Combustion - transfers carbon stored in living, dead and decomposed biomass to atmosphere through burning
Decomposition - carbon from biomass to atmosphere and pedosphere as CO2 and CH4 are released
Ocean uptake and loss - dissolved from atmosphere into the ocean then taken up by organisms who can live in them
Weathering - chemical weathering takes it from the atmosphere to the hydrosphere and the biosphere, acid rain on calcium carbonate
Sequestration - carbon is captured and held in sedimentary rocks or as fossil fuels, compacted dead animals.