IB HL Biology 4.3 Carbon Cycling 4.4 Climate Change

Carbon Cycle

Sinks: Fuels, fossils, animals, plants, ocean, CaCO3, atmosphere

Fluxes: Pollution, respiration, photosynthesis, dissolving, extraction, feeding, sedimentation, decomposition, fossilisation

Sink

Store of carbon

Flux

Movement of carbon between sinks and the atmosphere(e.g. respiration, photosynthesis, combustion), measured in gigatonnes(GT)

Spheres

Atmosphere(air), lithosphere(earth), hydrosphere(water), biosphere(living things)

Methanogenic Archaea

extremophiles, live in the guts of ruminants + waterlogged areas + deep ocean sediment, convert acetic acid into methane

Peat

Organic matter is not fully decomposed in waterlogged soils, carbon-rich molecules remain in the soil and form peat

Combustion

A chemical process in which a hydrocarbon-rich substance exothermically reacts with oxygen to produce water and carbon dioxide

CaCO3

CO2 dissolves in water to form carbonic acid(H2CO3), which dissociates to form bicarbonate ions and hydrogen, carbonate ions in the ocean are used to build shells and skeletons for organisms, excess hydrogen ions react with carbonate ions and remove them from the environment

Warming Impact

• How much long-wave radiation it absorbs compared to CO2 as 1(methane 21, NOx 310)

• The greater the concentration of a gas, the greater its warming impact will be within the atmosphere

• The concentration of a gas will be determined by both its rate of release and persistence within the atmosphere

• Atmospheric lifetime(water vapour 1-5 days, methane 12 year, NOx 120 years)

Wavelength

Earth absorbs short-wave energy from the sun and re-emits longer wavelengths

Pre-Industrial CO2 Levels

280ppm