1. 1 CARBON CYCLING THROUGH ECOSYSTEMS Presented by Scott Weir, Air Quality Coordinator Kickapoo Tribe in Kansas

2. CARBON CYCLING THROUGH ECOSYSTEMS CARBON (FROM LATIN: CARBO "COAL")  chemical element  nonmetallic  tetravalent — four electrons available to form covalent chemical bonds FOURTH MOST ABUNDANT ELEMENT IN THE UNIVERSE

3. 3 DIAMONDS AND COAL: NATURALLY OCCURRING FORMS OF CARBON

4. 4 CARBON: ESSENTIAL TO LIFE ON EARTH Organic compounds contain carbon All living things need carbon for structure for energy

5. 5 THE CARBON CYCLE Carbon is always on the move From Atmosphere to plants Plants to animals Plants and animals to the ground Living things to the atmosphere Fossil fuels to the atmosphere Atmosphere to the oceans

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7. 7 CARBON MOVES FROM THE ATMOSPHERE TO PLANTS Photosynthesis Carbon dioxide (CO 2 ) pulled from air by plants Solar energy used to make plant food for energy Carbon incorporated into plant structure

8. 8 CARBON MOVES FROM PLANTS TO ANIMALS Food Chains Carbon in plants moves to animals that eat them Predators get carbon from their prey

9. 9 CARBON MOVES FROM PLANTS AND ANIMALS TO GROUND Death and Decomposition Decay of structure releases carbon to soil If buried deep underground, some become fossil fuels after millions of years

10. 10 CARBON MOVES FROM LIVING THINGS TO THE ATMOSPHERE Aerobic Respiration Animals breathe in oxygen CO 2 (resulting from oxidation of carbohydrates) is exhaled Plants also release CO 2 from oxidation of carbohydrates

11. 11 COMPARISON OF PHOTOSYNTHESIS AND RESPIRATION PhotosynthesisRespiration Produces sugars from light energy Stores energy Occurs only in cells with chloroplasts Releases oxygen Uses water Uses carbon dioxide Requires light Burns sugars for energy Releases energy Occurs in most cells Uses oxygen Produces water Produces carbon dioxide Occurs in dark and light

12. 12 CARBON MOVES FROM FOSSIL FUELS TO THE ATMOSPHERE Combustion Fossil fuels burned to release energy CO 2 is result of combustion (rapid oxidation) Releases 5,500,000,000 tons of carbon per year 3,300,000,000 tons remain in air 2,200,000,000 tons dissolve in seawater

13. 13 CARBON MOVES FROM THE ATMOSPHERE TO THE OCEANS Dissolved CO 2 Oceans and other bodies of water “soak up” atmospheric carbon

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15. 15 ATMOSPHERIC CYCLE CO 2 leaves atmosphere through photosynthesis CO 2 also dissolves directly into water (oceans, lakes, etc.), as well as falling raindrops Human activity over past 200 years has increased amount of atmospheric carbon Mainly as CO 2 Ecosystems extraction of CO 2 from atmosphere has been reduced agricultural activity deforestation Increased direct emission of CO 2 burning fossil fuels and manufacturing concrete

16. 16 TERRESTRIAL BIOLOGICAL CYCLE Terrestrial biosphere includes: organic carbon in all land-dwelling organisms 500 gigatons (500 billion tons) carbon stored in soils 1,500 gigatons 1/3 is inorganic (e.g., CaCO 3 ) Carbon uptake in terrestrial biosphere depends on biotic factors follows diurnal and seasonal cycles strongest in Northern Hemisphere Less land mass in Southern Hemisphere

17. 17 TERRESTRIAL BIOLOGICAL CYCLE (CONT.) Carbon leaves terrestrial biosphere in several ways Combustion or respiration of organic carbon releases it rapidly to atmosphere Carbon stored in soil can remain there for thousands of years before it is washed into rivers by erosion Released to atmosphere through soil respiration increasing temperatures = faster rates of decomposition of organic matter resultant increase in flow of CO 2

18. 18 OCEANIC CARBON CYCLE Oceans contain the greatest quantity of actively cycled carbon on Earth surface layer holds large amounts of dissolved organic carbon Rapid exchange with atmosphere deep layer concentration of dissolved inorganic carbon (DIC) is about 15% higher than surface layer DIC is stored in deep layer for much longer periods

19. 19 OCEANIC CARBON CYCLE (CONT.) Ocean receives carbon via dissolution of atmospheric CO 2 converted by organisms to organic carbon via photosynthesis Also enters via rivers as dissolved organic carbon exchanged throughout food chain or precipitated into ocean's deeper carbon rich layers as dead soft tissue in shells as calcium carbonate (CaCO 3 )

20. 20 OCEANIC CARBON CYCLE (CONT.) Oceanic absorption of CO 2 is important form of carbon sequestering Limiting human-caused rise of atmospheric CO 2 Increased CO 2 absorption makes water more acidic affects ocean ecosystems increasing oceanic acidity reduces biological precipitation of calcium carbonate decreases the ocean's capacity to absorb carbon dioxide damages coral reefs Less CO 2 absorbed Reduced biodiversity

21. 21 GEOLOGICAL CARBON CYCLE Operates slowly compared to other parts of global carbon cycle Important determinant of atmospheric carbon Thereby determinant of global temperatures

22. 22 GEOLOGICAL CARBON CYCLE (CONT) Organic carbon stored in geosphere remains for millions of years Most of Earth's carbon is stored inertly in lithosphere Some carbon in earth's mantle has been there since Earth formed 80% in geosphere is limestone From sedimentation of CaCO 3 stored in shells of marine organisms 20% is stored as kerogens formed via sedimentation and burial of terrestrial organisms under high heat and pressure

23. 23 GEOLOGICAL CARBON CYCLE (CONT.) How carbon leaves the geosphere CO 2 is released during metamorphosis of carbonate rocks when they are subducted into mantle Released to atmosphere and ocean through volcanoes and hotspots Removed by humans through extraction of kerogens (fossil fuels) fossil fuels are burned to release energy stored carbon is emitted to atmosphere

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25. 25 HUMAN DISRUPTION OF CARBON CYCLING Human activity has modified carbon cycle by affecting its component's functions by directly adding carbon to atmosphere Human-caused land use/land cover change (LUCC) has led to loss of biodiversity lowers ecosystems‘ ability to remove carbon from atmosphere directly leads to release of carbon from terrestrial ecosystems to atmosphere

26. 26 HUMAN DISRUPTION OF CARBON CYCLING (CONT) Deforestation removes forests holding large amounts of carbon replaces them with agricultural or urban areas store comparatively small amounts of carbon more carbon stays in atmosphere

27. 27 HUMAN DISRUPTION OF CARBON CYCLING (CONT.) Other human-caused changes Air pollution damages plants damages soils Agriculture and land use higher erosion rates lower soil carbon decreased plant productivity

28. 28 HUMAN DISRUPTION OF CARBON CYCLING (CONT.) Higher atmospheric CO 2 levels Higher temperatures Increased decomposition in soil More rapid return of CO 2 to atmosphere

29. 29 HUMAN DISRUPTION OF CARBON CYCLING (CONT.) Higher ocean temperatures more CO 2 and acidic run-off change ocean chemistry damage coral reefs Less CO 2 absorbed Reduced biodiversity

30. 30 HUMAN DISRUPTION OF CARBON CYCLING (CONT.) Burning fossil fuels transfers carbon from geosphere to atmosphere Began on large scale 150-200 years ago (start of “industrial revolution”) Much of fossil fuel reserves already consumed Demand and amount burned are constantly increasing Rapid release of carbon stored up over 400 million years

31. 31 AN EXAMPLE…

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33. 33 ANNUAL EMISSIONS FROM THIS EGU (1 METRIC TON = 2,200 POUNDS) Total Facility Emissions in metric tons CO 2 e (excluding Biogenic CO 2 ) 12,687,836 (27,913,239,000 pounds per year) Emissions by Gas in metric tons CO 2 e Carbon Dioxide (CO 2 ) 12,591,661 (27,701,654,000 pounds per year) Methane (CH 4 ) 30,557 (67,225,400 pounds per year) Nitrous Oxide (N 2 O) 65,618 (144,359,600 pounds per year)

34. 34 27,913,239,000 POUNDS CO 2 E PER YEAR SOURCE: HTTP://GHGDATA.EPA.GOV/GHGP/MAIN.DO

35. 35 CAUSE FOR CONCERN… China burns more coal than rest of world combined India rapidly becoming industrialized As coal consumption decreases in U.S., coal companies are exporting coal to Asia Reduced consumption in U.S. and Europe is offset by increased consumption in Asia