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