Carbon exchange Photosynthesis Respiration Decay Soil Organic Matter Vegetation Weathering & Runoff Rock Formation Sedimentary Rock Coal, Oil and Gas Phytoplankton Ocean surface Deep circulation Sinking Sediments Burning / of Fossil fuels Deep ocean Origin Reservoir & FLuxes Geological C-Cycle Biomarker/Isot opes Recent Research

C-Cycle Photosynthesis

Available oxygen Aerobic Respiration Anaerobic Respiration C-Cycle

Outgassing of Primordial CO2 At mid ocean ridges Metamorphosis Of subducted carbonate And outgassing of volcanic arcs Respiration PhotosynthesisWeathering Burial of organic carbon Storage in Carbonate rock Erosion and Exposure of Carbon bearing sediments C-Cycle

CO 2 (g) + H 2 O  H 2 CO 3 H 2 CO 3 +H 2 O  H 3 O + + HCO 3 - HCO 3 - +H 2 O  H 3 O + + (CO 3 ) 2- Ca 2+ + (CO 3 ) 2-  CaCO 3 (s) CaCO 3 + H 2 CO 3  Ca HCO 3 - Primary Silicates + CO 2  Clay + Dissolved metals +H 4 SiO 4 + HCO 3 - 2KAlSi 3 O 8 (Kspar) + 2H + + 9H 2 O  Al 2 Si 2 O 5 (OH) 4 (kaolinite) + 4H 4 SiO 4 (aq) + 2K + 2KAlSi 3 O 8 (Kspar) + 2CO H 2 O  Al 2 Si 2 O 5 (OH) 4 (kaolinite) + 4H 4 SiO 4 (aq) +2K + + 2HCO 3 - Basaltic Oceanic Crust + HCO 3  CaCO 3 + Altered Oceanic Crust. CO 2 absorption by surface ocean ~1 yr Mixing to deep ocean ~300 yr Carbonate dissolution ~6000 yr Silicate-rock weathering ~300,000 yr

C-Cycle Global estimates of land area, net primary productivity (NPP), and carbon stocks in living plants and soil organic matter for ecosystems of the world Soil C values are for the top 1 m of soil only, except for peatlands, in which case they account for the total depth of peat. Pg = Petagram = Gigatonne. Amthor, J.S. and 21 others Terrestrial ecosystem responses to global change: a research strategy. Oak Ridge National Laboratory, Oak Ridge, TN, ORNL/TM-1998/27.

Components of Soil Organic Matter Components of soil organic matter and their functions C-Cycle

Global carbon cycle (units are PgC. Role of organisms and contribution of organic inputs to soil organic matter and soil biota C-Cycle5

Carbon sequestration by mineral carbonation or Mineral sequestration 2.1 tonnes serpentine is formed per tonne of CO2 sequestered Source C-Cycle Assuming that coal is 7% carbon

Burial of organic carbon C-Cycle

Levels (proved reserves) Coal: 905 billion metric tonnes Oil: 1,119 billion barrels (177.9 km 3 ) to 1,317 billion barrels (209.4 km 3 ) Natural gas: 6,183–6,381 trillion cubic feet (175–181 trillion cubic metres) Flows (daily production) during 2006 Coal: 16,761,260 metric tonnes Oil: 84,000,000 barrels per day Natural gas: 104,435 billion cubic feet (2,963 billion cubic metres), C-Cycle

Atmospheric CO 2 Dissolved CO 2 Carbonic Acid (H 2 CO 3 ) CO3-- H2OH2O H+H+ HCO 3 - Less Acidic More Acidic C-Cycle

C-Cycle

Carbon Emission Estimate C-Cycle embook/globalwarmA4.html nal/v488/n7409/full/nature11299.h tml?WT.ec_id=NATURE s/glo.html

warming/impact_ocean_acidification.html C-Cycle

Geological timescale with important biological events, and observations of well-preserved Precambrian biomarkers (gray) and crude oil (black Elsevier' Treatise on Geochemistry C-Cycle

720 gT 2000 gT gT gT Gaseous Exchange Decomposition Photosynthesis Sedimentation & Erosion Fossil Fuel Burning 78 gT 0.2 gT 65 gT 5 gT Global carbon system main reservoirs and fluxes. Units are gigatons C for amounts, and gigatons C per year for fluxes. Steady state assumed. C-Cycle

Atmosphere. Lithosphere Hydrosphere, Biosphere Mantle B POC, B CH4 D POC W POC A POC E POC, Inorg. C Org. C DMDM A OC WCWC DCDC B BC + B AC ACAC EC,EC, Conti.. C OceaN C S POC BCBC C-Cycle Next

C-Cycle NextPrevious Atmosphere. Lithosphere Hydrosphere DMDM DCDC D POC B BC B AC B CH4 B POC W POC w C-Sil W C-SIL WCWC

Sink of Carbon W c + W C-SIL + W O-SIL + B POC + B AC +B CH4 Source of Carbon D M + D C + D POC + W POC + B AC Previous C-Cycle

Typical δ 13 C org and C/N tot ranges for organic inputs to coastal environments C-Cycle

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