Editing The Global Carbon Cycle (section)

== Atmospheric Accumulation and Human Impact ==

Under natural, pre-industrial conditions, the fluxes of the global carbon cycle were in a state of dynamic equilibrium; the amount of carbon entering the atmosphere roughly equaled the amount being absorbed by the oceans and terrestrial sinks. 

Human activities have fundamentally disrupted this equilibrium. By extracting and combusting fossil fuels (coal, oil, and natural gas), humanity is taking carbon that was locked away in the slow geological cycle for hundreds of millions of years and injecting it directly into the fast atmospheric cycle in a matter of decades.

Furthermore, widespread land-use changes, particularly the deforestation of tropical rainforests, have severely reduced the capacity of the terrestrial sink while simultaneously releasing the carbon stored in the cut biomass. 

While the oceans and terrestrial sinks currently absorb about half of all anthropogenic carbon emissions, their capacity is finite. As the oceans warm, their ability to dissolve CO2 decreases, and as terrestrial biomes experience increased drought and heat stress, their photosynthetic capacity drops. The remaining carbon that is not absorbed accumulates in the atmosphere, driving the rapid increase in greenhouse gas concentrations and propelling anthropogenic climate change.