Presentation is loading. Please wait.

Presentation is loading. Please wait.

Carbon Cycle. 0.2 Gtonne/year goes into solid earth 0.2 Gt/yr goes into atmosphere from outgassing Today 2012 approximately 10 Gt/yr are put into the.

Similar presentations


Presentation on theme: "Carbon Cycle. 0.2 Gtonne/year goes into solid earth 0.2 Gt/yr goes into atmosphere from outgassing Today 2012 approximately 10 Gt/yr are put into the."— Presentation transcript:

1 Carbon Cycle

2 0.2 Gtonne/year goes into solid earth 0.2 Gt/yr goes into atmosphere from outgassing Today 2012 approximately 10 Gt/yr are put into the atomosphere from Fossil fuel emission Thus natural fluxes from volcanoes and outgassing account for about 2% of the anthropogenic sources.

3 Carbon Cycle 1.6 Gt/yr from deforestation 6.4 Gt/yr from fossil fuel emission (1994) 1.6/6.4=0.25=25% (deforestation accounts for 25 % of total Carbon flux into atmosphere) Biosphere takes up (2.6 Gt /yr more ) carbon than it did in preindustrial times.

4 Preindustrial RR=120 GT/yr Now it is Gt/yr RR=Content/lifetime Preindustrial content =597 Gt Now(1994)= 763 Gt

5

6 The atmosphere contains the least amount of carbon and sediments and rocks contain the most.

7 The ultimate removal of carbon from the climate system is an extremely slow process. In nature this is balanced by the slow injection of carbon into the atmosphere by volcanoes and outgassing near mid ocean ridges. When humans bring carbon in the form of fossil fuels (coal, natural gas, oil) to the surface they rapidly disrupt this balance.

8 The annual cycle of vegetation is dominated by flucuations in the Northern hemisphere.

9 Carbon Reservoirs (stocks)

10

11 Carbon Cycle Land use changes (deforestation) contribute about 20% to the total anthropogenic emissions of carbon into the atmosphere.

12 Short Term Carbon Cycle

13

14

15 As atmospheric CO2 increases from photosynthesis or combustion, O2 decreases. O2 is presently decreasing faster than atmospheric CO2 is increasing. This indicates the importance of the oceans in removing CO2 from the atmosphere. 13 C/ 12 C ratios in atmospheric CO 2 are lower for human activity than for natural processes.

16 Seasonal Cycle is driven by Northern Hemisphere Vegetation When the atmospheric carbon dioxide increases plants are growing or decaying? Circle one. When the atmospheric carbon dioxide decreases plants are growing or decaying? Circle one.

17 Seasonal Cycle is driven by Northern Hemisphere Vegetation When the atmospheric carbon dioxide increases plants are growing or decaying ? Circle one. When the atmospheric carbon dioxide decreases plants are growing or decaying? Circle one.

18

19 From Unit 12www.learner.org/courses/envsci/

20

21

22

23 Atmospheric carbon dioxide concentrations are strongly correlated with surface temperatures on most time scales.

24 +sunlight

25 Residence Time

26 Removal Rate= outflow Source=inflow

27 Residence Time At equilibrium (steady state) inflow = outflow Removal Rate= outflow Source=inflow

28 A lake has an annual average outflow of 5 Mgallons per year (5,000,000 gal/yr) and an annual average content of 10 Mgallons. From this information estimate the residence time for the lake. If the annual mean inflow into the lake increased to 20 Mgallons/yr what would be the new steady state content of the lake?

29 A lake has an annual average outflow of 5 Mgallons per year (5,000,000 gal/yr) and an annual average content of 10 Mgallons. From this information estimate the residence time for the lake. If the annual mean inflow into the lake increased to 20 Mgallons/yr what would be the new steady state content of the lake? =20 Mgal/yr*2 yr=40 Mgal

30 CFC-12 has an atmospheric lifetime of 100 yrs. In the 1980s the emission rate of CFC-12 was 22 ppt/yr. What is the corresponding equilibrium concentration of CFC-12?

31 CFC-12 has an atmospheric lifetime of 100 yrs. In the 1980s the emission rate of CFC-12 was 22 ppt/yr. What is the corresponding equilibrium concentration of CFC-12? =22 ppt/yr*100yr=2200 ppt Note: the highest CFC -12 concentration level reached was 540 ppt. International agreements to phase out production and use of CFC-12 ( reduce emissions) were able to keep levels down.

32 CFC-12 has an atmospheric lifetime of 100 yrs. In the 1980s the emission rate of CFC-12 was 22 ppt/yr. What emission rate (source) would limit the steady state atmospheric concentration of CFC-12 to 500 ppt?

33 CFC-12 has an atmospheric lifetime of 100 yrs. In the 1980s the emission rate of CFC-12 was 22 ppt/yr. What emission rate (source) would limit the steady state atmospheric concentration of CFC-12 to 500 ppt? =22 ppt/yr*100yr=2200 ppt This is less than 25% of the 1980s emission rate.

34 The solubility of water increases with decreasing temperature.

35 Positive climate feedback

36 Phytoplankton shell: Diatom (SiO 2 )

37 Phytoplankton Shell: coccolithophorid (CaCO 3

38 Zooplankton shell: Foraminifer (CaCO 3 )

39 Zooplankton shell: Radiolarian SiO 2

40 More Ice on continents leaves more 18 O in oceans

41 Carbon Cycle Total flux from land use changes 1.6 (1.6/8) =20 % of the total flux from both Fossil Fuel and land use change ( =8.0)

42 Ocean Biological Pump. Slowly taking Carbon to the seafloor for ultimate burial. Most of this carbon is recycled back to the surface a very small fraction is removed from the ocean into the deep earth.

43

44 Coastal Zone Color scanner

45

46

47

48 Porosity: the fraction of rock that is pore space Permeability: the ability of a fluid to be able to flow through a rock formation. Gas, oil, and water are often trapped in porous rock with an impermeable cap. Gas on top, then oil, then water water

49

50

51 pH 7.0 is neutral (not acidic not alkaline) less than 7.0 is acidic greater than 7.0 is alkaline. pH of 2.0 is highly acidic.

52

53

54

55

56 Long term Carbon Cycle

57 Draw a causal loop diagram Describing the feedback structure at left. Is this a positive or negative feedback structure?

58 All loops are negative feedbacks

59 Weather of carbonate rock does not change atmospheric CO2 levels

60 Weather of silicate rock removes CO2 from the atmosphere

61 From Unit 1www.learner.org/courses/envsci/

62

63 Outgassing is the release of CO2 via volcanic activity and seafloor spreading. Over the long term (millions of years) the CO2 flux from outgassing is in near balance with the removal of carbon from the subduction of carbonate sediments.

64

65

66

67

68

69

70

71 Small fragmented rocks have much more surface area compared to large rocks and hence weather more easily.

72 80 % of chemically weathered ions in Amazon come from the Andes. The Andes have been uplifted in the past 20 Million years.

73 Most uplift in the western US region occurred 70 to 45 Myr ago

74 Biomass growth (Lichen) on rocks can enhance the weathering process.

75


Download ppt "Carbon Cycle. 0.2 Gtonne/year goes into solid earth 0.2 Gt/yr goes into atmosphere from outgassing Today 2012 approximately 10 Gt/yr are put into the."

Similar presentations


Ads by Google