The Carbon Cycle Tyler Szwarc and Eliana Manangon

http://www.physicalgeography.net/fundamentals/images/carboncycle.jpg

Atmosphere• Primarily in the form of CO2 and smaller

amounts of CH4

• Reservoir: ~ 6 x 1014 kg

• Flux: 1.25 x 1012 kg/yr

• Residence time: 4 x 102 2 yryr– Residence time is highly variable due to

nature of atmosphere and its relationship to other reservoirs

http://www.newworldencyclopedia.org/entry/Carbon_cycle

HydrosphereInorganic carbon exchange controls the pH

C is exchanged between the hydrosphere and atmosphere

Dissolved Ca+2 and carbonate ions are used by shells and crustaceous to build their skeletons

Oceans have 3.8 x1016 kg C Flux = ~2.2 x 1012 kg/yr Residence Time = 1.7 x 104 yr

Takahashi et.al, Global sea–air CO 2 flux based on climatological surface ocean pCO2 , and seasonal biological and temperature effects, Deep-Sea Research, volume II issue 49, 2002, pp 1601–1622.

Lithosphere• Reservoirs: Sedimentary rock, fossil

fuels, and plants (1 x 1020 kg total)• Flux assumptions:

– Carbon rich sedimentation occurring on 25% of Earth’s surface

– Accumulates at 0.2 mm/yr, 2710 kg/m3

– Carbon accounts for ~12% of total rock mass

– Flux = ~8.2 x 1012 kg/yr

• Residence Time = 1.2 x 107 yr

Reservoir Size (1016 kg)Flux (1012 kg/yr)

Residence Time (yr)

Atmosphere 0.05-0.08 1.25 4 x 102

Ocean 3.80 2.2 1.7 x 104

Lithosphere 6,600 – 10,000 8.2 1.2 x 107

Fossil Fuel 0.40 ^ ^

Soil 0.15 ^ ^

Plants 0.05 ^ ^

Reservoirs, Flux, and Residence Times

Pidwirny, M. (2006). "The Carbon Cycle". Fundamentals of Physical Geography, 2nd Edition. Date Viewed. http://www.physicalgeography.net/fundamentals/9r.html