1. Global Carbon Cycle Sabine et al. (2004) SCOPE Ocean sequester ~30% of fossil fuel CO 2 Human perturbations overlay large natural background C cycle Climate responses and feedbacks of ocean C sink not well known Feb 2004 Chemical Oceanography Seminar

2. 3

3. 4

6. Average Surface Water DIC Increase in 2000 ~ 1.2 µmol kg -1 yr -1 Under IPCC “Business as Usual”the pH of surface sea water drops by 0.4 pH units by 2100. CO 3 = in surface water drops by 54% from pre- industrial values. 2004 Hatfield Seminar   = [Ca 2+ ][CO 3 2- ] Ksp '  a > 1 ~ Supersaturated

7. Air Increase = 1.48 ± 0.05 µatm yr -1 ; Seawater Increase = 2.48 ± 0.28 µatm yr -1 Dore et al., (2003) Dore et al., (2003)

8. WOCE/JGOFS/OACES Global CO 2 Survey ~72,000 sample locations collected in the 1990s DIC ± 2 µmol kg -1 TA ± 4 µmol kg -1 Sabine et al (2004).

11. Because the ocean mixes slowly, half of the anthropogenic CO 2 stored in the oceans is found in the upper 10% of the ocean. Sabine et al. Science (2004) Global Anthropogenic CO 2 Inventory = 118±19 Pg C

12. Column inventory of anthropogenic CO 2 that has accumulated in the ocean between 1800 and 1994 (mol m -2 ) Mapped Inventory 106±17 Pg C + marginal seas 6± 6 Pg C + Arctic Ocean 6± 6 Pg C Total Inventory 118±19 Pg C Sabine et al. Science (2004)

13. Over the past 200 years, the ocean has been the only reservoir to consistently take up anthropogenic CO 2 from the atmosphere. Carbon Changes Between 1800 and 1994 Sabine et al. Science (2004)

14. Aragonite and Calcite Saturation Depths in the Global Oceans

15. From Riebesell et al. Nature (2001) Scanning electron micrographs of Emiliania huxleyi (left) and Geophyrocapsa oceanica (right) under conditions of 300 (top) and 780 - 850 ppm (bottom) pCO 2 showing malformed coccospheres at the higher CO 2 levels. 2004 Hatfield Seminar

16. Coccolithophores calcite Corals NOAA Forams Calcareous algae Nancy Sefton T. Tyrrel calcite High-Mg calcite aragonite 2004 Hatfield Seminar

17. Pteropods Clio pyramidata Victoria J. Fabry R. W. Gilmer and G. R. Harbison Cavolinia tridentata aragonite R. W. Gilmer and G. R. Harbison The effects of increased levels of CO 2 on the dissolution of Clio pyramidata shells after 4 and 48 hours of exposure. 2004 Hatfield Seminar

18. From: R. Buddemeier