Carbon Cycle

Natural Carbon Cycle

The natural Carbon Cycle is influenced by atmosphere, biosphere, pedosphere, hydrosphere and lithosphere. The Carbon release and the Carbon sinks standing Equilibrium

The natural earth system is a closed system with a constant carbon content. The following table shows the time duration of the release and storage in the individual spheres:

SphereReleaseStorage
AtmosphereImmediately up to yearsShort-term
BiosphereDays to yearsYears to centuries
HyrosphereYears to centuries Decades to millennia
LithosphereMillion yearsMillion years
PedosphereYears to decadesDecades to centuries

Carbon Cycle under anthropogenic influence

Humans are changing the natural relationship between carbon emissions and carbon reductions

Source: Carbon cycle – Wikipedia
Development of the remaining CO2 in the atmosphere after an emission pulse
Stocker et al., 2014, p.96
Results calculated by a range of coupled models
Line: the multi-model mean
Shaded: the uncertainty interval (maximum model range)

5000 petagrams of carbon (PgC), or gigatonnes of carbon (GtC), are about 10 times the CO2 emitted so far since pre-industrial time
(Ciais et al., 2014, p.545)

Schematic representation of carbon fluxes between atmosphere, land, ocean and geological reservoirs

Different system conditions are shown: (a) an unperturbed Earth system; and changes in carbon fluxes for (b) an Earth system perturbed by fossil fuel carbon dioxide (CO2) emissions; (c) an Earth system in which fossil fuel CO2 emissions are partially offset by carbon dioxide removal (CDR); (d) an Earth system in which CDR exceeds CO2 emissions from fossil fuels (‘net negative’ CO2 emissions). Carbon fluxes depicted in (a) (solid and dashed black lines) also occur in (b–d). The question mark in the land-to-ocean carbon flux perturbation in (c) and (d) indicates that the effect of CDR on this flux is unknown.
Source: IPCC AR6 WGI (Chapter 5; p 758)