The Carbon Cycle

1. The Carbon Cycle

2. Carbon Dioxide and Carbonate system Why is it important? • CO2 regulates temperature of the planet • Important for life in the ocean • Regulates the pH of water

3. 100 ppm

4. CO2 TEMPERATURE 1-6°C

5. 80 ppm Glacial-interglacial CO2 and temperature change CO2 Temperature

6. 80 ppm Industrial Revolution CO2 changes in the last 300 yr

7. Oceans Biosphere Rock Weathering CO2 changes in the last 50 yr: the Keeling curve

8. How much CO2 can you sink in the ocean? Chemical Biological Physical Process that control CO2 absorption in the ocean Carbon Cycle

9. Carbon Cycle

10. O2 CO2 pH (m) acid basic

11. Dissolved Gases in the Ocean Oxygen profile

12. compensation depth low oxygen environment Respiration: Animal, plants and microbial decomposition Dissolved Gases in the Ocean Oxygen profile

13. from dissolution of Calcium Carbonate The Carbonate System sources of inorganic carbon from dissolved CO2 gas

14. CO2 in the ocean ~ 1000m

15. this is very small not found in this form Total dissolved inorganic carbon Total dissolved inorganic carbon

16. (1) formation and decomposition of organic matter (2) from dissolution of Calcium Carbonate Total dissolved inorganic carbon

17. Carbon Dioxide and Carbonate system Carbonic Acid Bicarbonate Ion Carbonate

18. - + Distribution of Carbon species in water

21. Tot: 0.59409~0.594

22. Tot: 0.59388 ~ 0.594

23. What control the absorption of Carbon Dioxide in the ocean? How can we measure it? The carbonate system chemistry in seawater The concept of alkalinity, pH …

24. Def: Alkalinity: is the net molar concentration, in charge-equivalents, of the cations of strong bases in excess of the anions of strong acids Strong base cations (less) strong acid anions in simple terms represents the degree to which a solution resists a decrease in pH when acid is added

25. Alkalinity • Alkalinity is fundamental for hard corals and coralline algae to properly secrete new skeletal material. When alkalinity levels drop, the carbonate ions needed are not available and the process slows or stops. • Alkalinity is measured in one of two units: milliequivalents per liter (meq/l), or parts per million of calcium carbonate (ppm CaCO3). • The 'ppm CaCO3' unit reports the concentration of CaCO3 in pure water that would provide the same buffering capacity as the water sample in question. This does not mean the sample contains that much CaCO3. • In natural seawater, though, carbonates make up 96% of the alkalinity so equating alkalinity with carbonate hardness isn't too far off.

26. from GLODAP climatology

27. What happens to this balance? Strong base cations (less) Strong acid anions

28. (2) Calcium Carbonate dissolution and formation Total dissolved inorganic carbon -alkalinity Total dissolved inorganic carbon +alkalinity

29. What happens if I add or remove CO2 by photosynthesis and respiration?

31. Carbon Cycle

32. Oceans Biosphere Rock Weathering CO2 changes in the last 50 yr

33. Ocean Acidification: Change in pHbetween 1751 and 1994 (up another ~10% if until 2009)

35. several important articles in 2010 summarized by Scientific American: • July 2010: William Howard (ACEC Research Center in Hobart, Tasmania) states that "the current rate of ocean acidification is about a hundred times faster than the most rapid events" in the geologic past. • August 2010: Marah J. Hardt and Carl Safina (USF) make the case that in the 15-year period 1995-2010, acidity has increased 6 percent in the upper 100 meters of the Pacific Ocean from Hawaii to Alaska

36. A summary of studies indicate that almost all calcifying species examined to date have shown reduced calcification rates at higher pCO2 levels, Today‘s world pCO2: 280-380 ppmV High-CO2 world pCO2: 580-720 ppmV Gephyrocapsa oceanica Emiliania huxleyi Calcidiscus leptoporus but only a small fraction of the natural species have been tested.

37. Consensus among the participants was that higher CO2 levels will generally be detrimental to calcifying organisms and that food web structures and biodiversity will likely change, Corals Coccolithophores Forams calcite calcite aragonite but it is not clear how this might impact overall productivity and top level predators (e.g. fish).

39. Ocean acidification: What corals are dying to tell us slides from Ken Caldeira

40. A cautionary tale from 65Ma: the Cretaceous-Tertiary extinction -huge comet blasts Yucatan -releases S into atmosphere -acid rain falls on ocean for 1-2 years -ALL surface calcifiers die for 2 million years!

41. We are changing CO2 rates faster than the geologic past

42. The surface ocean changes will lead deep ocean changes