The Ocean of Life

by Callum Roberts

  8. Planetary wobbles, called Milankovich cycles after their discoverer, are also critical to glaciations; http://en.wikipedia.org/wiki/Milankovitch_cycles; accessed May 22, 2011. Milankovitch, Milutin (1998) [1941]. Canon of Insolation and the Ice Age Problem (Belgrade: Zavod za Udzbenike i Nastavna Sredstva).

  9. Arrhenius, S., Worlds in the Making. The Evolution of the Universe (London and New York: Harper & Brothers, 1908).

  10. www.asi.org/adb/02/05/01/surface-temperature.html.

  11. The value for 2007 was 388 ppm of CO2. IPCC, Climate Change 2007: Synthesis Report. Contribution of Working Groups I, II and III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Core Writing Team, Pachauri, R. K., and A. Reisinger, (eds.)] (Geneva: IPCC, 2007).

  12. Calculated over a time horizon of one hundred years; since methane reacts with other compounds over time, its global warming potential is high to begin with and declines as time passes. See IPCC Third Assessment Report, chapter 2: www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-chapter2.pdf; accessed December 31, 2011.

  13. There are also vast quantities of methane hydrates deep in the oceans. Past episodes of intense global warming, such as that at the great extinction at the end of the Permian period, led to their release.

  14. One kg of seawater contains about 4.13 times the heat of 1 kg of air at the same temperature and pressure. A kilogram of air has a volume of 856.2 liters at a pressure of one atmosphere and 25oC, compared to a volume of 1 liter for seawater under the same conditions. So the heat capacity of water is 3,536 times higher than air under these conditions.

  15. Schubert, R., et al., The Future Oceans—Warming Up, Rising High, Turning Sour (Berlin: German Advisory Council on Global Change, 2006), p. 110.

  16. Hoegh-Guldberg, O., and J. F. Bruno, “The Impact of Climate Change on the World’s Marine Ecosystems,” Science 328 (2010): 1523–28.

  17. Schofield, O., et al., “How Do Polar Marine Ecosystems Respond to Rapid Climate Change?” Science 328 (2010): 1520–23.

  18. www.timesonline.co.uk/tol/news/uk/article767459.ece; accessed September 26, 2011.

  19. Kerr, R. A., “Is Battered Arctic Sea Ice Down for the Count?” Science 318 (2007): 33–34.

  20. This notion of the Gulf Stream as the North Atlantic’s winter warmer has recently been questioned (Seager, R., et al., “Is the Gulf Stream Responsible for Europe’s Mild Winters?” Quarterly Journal of the Royal Meteorological Society 128 [2002]: 2563–86). The Rocky Mountains squeeze air into a thinner layer as it flows from the west and twists winds to the north in the process. As air flows east beyond the Rockies, the twist unwinds to the south, bending winds above the warm Sargasso Sea that surrounds Bermuda. There they pick up heat, which is carried northeast. Europe’s mild climate is a result of ocean warmth, but the Gulf Stream carries little of that heat, or so the authors argue. However, this view is at odds with sea surface temperature maps built up from satellite measurements that show warm ocean waters pulled far into the northeastern Atlantic by the global ocean conveyor. Because of the much greater heat capacity of water than air, far more heat would be required to warm those waters than mere winds could transfer blowing from the tropics.

  21. Rahmstorf, S., “Ocean Circulation and Climate During the Past 120,000 Years,” Nature 419 (2002): 207–14.

  22. Nesje, A., O. D. Svein, and J. Bakke, “Were Abrupt Late Glacial and Early-Holocene Climatic Changes in Northwest Europe Linked to Freshwater Outbursts to the North Atlantic and Arctic Oceans?” The Holocene 14 (2004): 299–310.

  23. Sachs, J. P., and S. J. Lehman, “Subtropical North Atlantic Temperatures 60,000 to 30,000 Years Ago,” Science 286 (1999): 756-59.

  24. Rahmstorf, “Ocean Circulation.”

  25. Water at the surface veers at about 45o to the wind direction. Friction transfers wind energy from surface to deeper layers. If you take a pack of cards, place your finger in one corner, and fan them using a finger in the opposite corner, friction moves each card a little less than the one above until the cards do not move at all. In the same way, friction moves water less as you go deeper. However, a peculiarity of the Coriolis force is that as depth increases, water twists a little farther, so the angle of flow relative to the wind increases with depth, rather than lessens. The net flow, taking into account the whole water column, is at right angles to the wind direction.

  26. Thermoclines are well developed and virtually permanent features of tropical seas, but they are poorly developed or absent from polar seas, where warming is less. In between they tend to be seasonal, forming in spring and breaking up in autumn when storms stir the sea.

  27. Bakun, A., et al., “Greenhouse Gas, Upwelling-Favorable Winds, and the Future of Coastal Ocean Upwelling Ecosystems,” Global Change Biology 16 (2010): 1213–28.

  28. Bakun, A., and S. J. Weeks, “Greenhouse Gas Buildup, Sardines, Submarine Eruptions and the Possibility of Abrupt Degradation of Intense Marine Upwelling Ecosystems,” Ecology Letters 7 (2004): 1015–23.

  29. Ibid.

  30. Bakun, A., “Global Climate Change and Intensification of Coastal Ocean Upwelling,” Science 247 (1990): 198–201.

  31. Ekau, W., et al., “Impacts of Hypoxia on the Structure and Processes in Pelagic Communities (Zooplankton, Macro-invertebrates and Fish),” Biogeosciences 7 (2010): 1669–99.

  32. Daniel Pauly, whose breadth of understanding always amazes me, has come up with an elegant theory to explain much about why fish are built the way they are and do the things they do. He articulates the case for oxygen as a limiting constraint in Pauly, D., Gasping Fish and Panting Squids: Oxygen, Temperature and the Growth of Water-Breathing Animals (Hamburg, Germany: International Ecology Institute, 2010).

  33. Bakun, A., “Afterword,” in Pauly, D. ed. Gasping Fish and Panting Squids, pp. 137–40.

  34. Field, J., “Jumbo Squid (Dosidicus gigas) Invasions in the Eastern Pacific Ocean,” CalCOFI Report 49 (2008): 79–81.

  35. Stramma, L., et al., “Expanding Oxygen-Minimum Zones in the Tropical Oceans,” Science 320 (2008): 655–58.

  36. Chan, F., et al., “Emergence of Anoxia in the California Current Large Marine Ecosystem,” Science 319 (2008): 920.

  37. www.sciencedaily.com/releases/2006/08/060812155855.htm; accessed May 22, 2011.

  38. Zeidberg, L. D., and B. H. Robinson, “Invasive Range Expansion by the Humboldt Squid, Dosidicus gigas, in the Eastern North Pacific,” Proceedings of the National Academy of Sciences 104 (2008): 12948–50.

  Chapter 5: Life on the Move

  1. de Lamarck, J.B., Philosophie zoologique, ou exposition des considerations relatives à l’histoire naturelle des animaux. (Zoological Philosophy: An Exposition with Regard to the Natural History of Animals). Translated by Hugh Elliot (London: Macmillan, 1809, reprint edition 1914).

  2. Roberts, C. M., et al., “Marine Biodiversity Hot Spots and Conservation Priorities for Tropical Reefs,” Science (2002): 1280–84; Hawkins, J. P. et al., “The Threatened Status of Restricted Range Coral Reef Fish Species,” Animal Conservation 3 (2000): 81–88.

  3. Ushatinskaya, G. T., “Origin and Dispersal of the Earliest Brachiopods,” Paleontological Journal 42 (2008): 776–91, doi 10.1134/S0031030108080029.

  4. Sepkoski, J. J., “Biodiversity: Past, Present and Future,” Journal of Paleontolgy 71 (1997): 533–39. Microbes, by contrast, seem almost immutable over vast stretches of geologic time.

  5. Perry, A., et al., “Climate Change and Distribution Shifts in Marine Fishes” Science 308 (2005): 1912–15.

  6. Brander, K., “Impacts of Climate Change on Marine Ecosystems and Fisheries,” Journal of the Marine Biological Association of India 51 (2009): 1–13.

  7. Beaugrand, G., et al., “Plankton Effect on Cod Recruitment in the North Sea,” Nature 426 (2003): 661–64; Beaugrand, G. et al., “Reorganisation of North Atlantic Marine Copepod Biodiversity and Climate,” Science 296 (2002): 1692–94.

  8. Personal communication from John Pitchford, University o
f York.

  9. Cheung, W. W. L., et al., “Large-Scale Redistribution of Maximum Fisheries Catch Potential in the Global Ocean under Climate Change,” Global Change Biology 16 (2009): 24–35.

  10. Sheppard, C. R. C., “Predicted Recurrences of Mass Coral Mortality in the Indian Ocean,” Nature 425 (2003): 294–97.

  11. Cheung, W. W. L., et al., “Application of Macroecological Theory to Predict Effects of Climate Change on Global Fisheries Potential,” Marine Ecology Progress Series 365 (2008): 187–97.

  12. Hamilton, L., et al., “Social Change, Ecology and Climate in Twentieth Century Greenland,” Climatic Change 47 (2000): 193–211.

  Chapter 6: Rising Tides

  1. Countering this spurt in wetland creation, coastal construction and reclamation has reduced wetland area in some places.

  2. With the caveat that solids like ice can take up more space than their warmer liquid phases.

  3. Lambeck, K., et al., “Sea Level in Roman Time in the Central Mediterranean and Implications for Recent Change,” Earth and Planetary Science Letters 224 (2004): 563–75.

  4. Pilkey, O., and R. Young, The Rising Sea (Washington, DC. Island Press, 2009).

  5. Nicholls, R. J., and A. Cazenave, “Sea-Level Rise and Its Impact on Coastal Zones,” Science 328 (2010): 1517–20.

  6. Jevrejeva, S., A. Grinsted, and J. C. Moore, “Anthropogenic Forcing Dominates Sea Level Rise Since 1850,” Geophysical Research Letters 36 (2009): L20706; doi:10.1029/2009GL040216.

  7. Fanos, A. M., “The Impact of Human Activities on the Erosion and Accretion of the Nile Delta Coast,” Journal of Coastal Research 11 (1995): 821–33.

  8. Bamber, J. L., et al., “Reassessment of the Potential Sea-level Rise from a Collapse of the West Antarctica Ice Sheet” (2009): doi: 10.1126/science.1169335. This study revises downward the widely reported six meter (about seven yards) rise in sea levels that melting of the West Antarctic ice shelf was expected to produce.

  9. Weiss, J. L., et al., “Implications of Recent Sea Level Rise Science for Low-Elevation Areas in Coastal Cities of the Coterminous U.S.A.,” Climatic Change 105 (2011): 635–45.

  10. Blanchon, P., et al., “Rapid Sea-Level Rise and Reef Back-stepping at the Close of the Last Interglacial Highstand,” Nature 458 (2009): 881–84.

  11. Kopp, R. E., et al., “Probabilistic Assessment of Sea Level During the Last Interglacial Stage,” Nature 462 (2009): 863–68.

  12. Nicholls, R. J., et al., “Sea-Level Rise and Its Possible Impacts Given a ‘Beyond 4oC World’ in the Twenty-first Century,” Philosophical Transactions of the Royal Society A 369 (2011): 161–81.

  13. Jenkins, A., et al., “Observations beneath Pine Island Glacier in West Antarctica and Implications for Its Retreat,” Nature Geoscience 3 (2010): 468–72: doi 10.1038/ngeo890.

  14. Connor, S., “Vast Methane ‘Plumes’ Seen in Arctic Ocean as Sea Ice Retreats,” The Independent (UK), December 13, 2011; www.independent.co.uk/news/science/vast-methane-plumes-seen-in-arctic-ocean-as-sea-ice-retreats-6276278.html.

  15. UN-HABITAT, State of the World’s Cities 2008/2009–Harmonious Cities (Nairobi, Kenya: United Nations Human Settlement Program, 2008); www.unhabitat.org/pmss/getPage.asp?page=bookView&book=2562; accessed August 18, 2011.

  16. Kabat, P., et al., “Dutch Coasts in Transition,” Nature Geoscience 2 (2009): 450–52.

  17. Subsidence rates in the Maldives are around 0.15mm per year, which is very slow compared to subsidence rates in many deltas. Fürstenau, J., et al., “Submerged Reef Terraces of the Maldives, Indian Ocean,” Geo-Marine Letters 30 (2010): 511–15.

  18. www.parliament.uk/documents/post/postpn342.pdf; accessed May 22, 2011. Two other factors explain the difference: Scotland has fewer people and more hard coastal rock than England, so it has less to defend and less need for coastal defense.

  19. Large dams are defined as those with walls higher than 15m. Syvitski, J. P. M., et al., “Impact of Humans on the Flux of Terrestrial Sediment to the Global Coastal Ocean,” Science 308 (2005): 376–80.

  20. Engelkemeir, R., et al., “Surface Deformation in Houston, Texas, Using GPS,” Tectonophysics 490 (2010): 47: doi: 10.1016/j.tecto.2010.04.016.

  21. Extremes will rise faster than the average if the extent of the variation around an average value is proportional to the value of the average.

  22. Kerr, R. A., “Models Foresee More Intense Hurricanes in the Greenhouse,” Science 327 (2010): 399.

  23. Ibid.

  24. Ericson, J. P., et al., “Effective Sea-Level Rise and Deltas: Causes of Change and Human Dimension Implications,” Global and Planetary Change 50 (2006): 63–82.

  25. Other effects of climate change, including higher temperatures and altered rainfall patterns, will also affect agricultural production.

  26. Tanaka, N., et al., “Coastal Vegetation Structures and Their Function in Tsunami Protection: Experience of the Recent Indian Ocean Tsunami,” Landscape and Ecological Engineering 3 (2007): 33–45.

  27. Analyses of satellite images show that fourteen of the world’s largest deltas lost 3 percent of their wetlands in the last fourteen years of the twentieth century. Coleman, J. M., O. K. Huh, and D. Braud, “Wetland Loss in World Deltas,” Journal of Coastal Research 24 (2008): 1–14.

  28. Alongi, D. M., “Present State and Future of the World’s Mangrove Forests,” Environmental Conservation 29 (2002): 331–49.

  29. Waycott, M., et al. “Accelerating Loss of Sea Grasses across the Globe Threatens Coastal Ecosystems,” Proceedings of the National Academy of Sciences 106 (2009): 12377–81.

  30. Pilkey and Young, The Rising Sea.

  31. Chatenoux, B., and P. Peduzzi, “Impacts from the 2004 Indian Ocean Tsunami: Analysing the Potential Protecting Role of Environmental Features,” Natural Hazards 40 (2007): 289–304.

  32. King, S. E., and J. N. Lester, “The Value of Salt Marsh as a Sea Defence,” Marine Pollution Bulletin 30 (1995): 180–89.

  Chapter 7: Corrosive Seas

  1. W. Russell, quoted in Littell, E. Littell’s Living Age, Vol. X (Boston: Waite, Pearce & Company, 1846).

  2. Hall-Spencer, J., and E. Rauer, “Champagne Seas—Foretelling the Ocean’s Future?” Journal of Marine Education 25 (2009): 11–12; Hall-Spencer, J. M. et al., “Volcanic Carbon Dioxide Vents Show Ecosystem Effects of Ocean Acidification,” Nature 454 (2008): 96–99.

  3. If you are familiar with the language of chemistry, the equations that represent the dissolution of carbon dioxide in the sea are:

  CO2 (carbon dioxide) + H2O (water) ↔ H2CO3 (carbonic acid)

  H2CO3 (carbonic acid) ↔ HCO3– (bicarbonate ion) + H+ (hydrogen ion)

  H+ + CO2– (carbonate ion) ↔ HCO3–

  4. Forest clearance and wetland drainage liberate large quantities of stored carbon, most of which ends up in the atmosphere as carbon dioxide.

  5. Secretariat of the Convention on Biological Diversity. Scientific Synthesis of the Impacts of Ocean Acidification on Marine Biodiversity, Montreal: Technical Series No. 46 (2009), 61 pages.

  6. Ridgwell, A., and D. N. Schmidt, “Past Constraints on the Vulnerability of Marine Calcifiers to Massive Carbon Dioxide Release,” Nature Geoscience (2010): doi: 10.1038/NGEO755.

  7. This assumes business as usual in growth of carbon dioxide emissions.

  8. Caldeira, K., and M. E. Wickett, “Anthropogenic Carbon and Ocean pH,” Nature 425 (2003): 365.

  9. De’ath, G., et al., “Declining Coral Calcification on the Great Barrier Reef,” Science 323 (2009): 116–19.

  10. Maier, C., et al., “Calcification Rates and the Effect of Ocean Acidification on Mediterranean Cold-Water Corals.” Proceedings of the Royal Society B (2011): doi:10.1098/rspb.2011.1763.

  11. The depth below which carbonate dissolves is shallower in the Atlantic than in the Pacific, because deep water in the Pacific is “older” (as you will remember, deep bottom water forms in the North and South Atlantic and flows around the world from there), so it has had more time to accumulate carb
on dioxide from the breakdown of organic matter.

  12. Veron, J. E. N., et al., “The Coral Reef Crisis: The Critical Importance of <350 ppm CO2,” Marine Pollution Bulletin 58 (2009): 1428–36. Some of my colleagues were pleased there was no agreement on emissions reduction in Copenhagen in 2010 because it left negotiating space for a tougher deal that could save coral reefs.

  13. Fabricius, K. E., et al., “Losers and Winners in Coral Reefs Acclimatized to Elevated Carbon Dioxide Concentrations,” Nature Climate Change (2011): doi: 10.1038/nclimate1122.

  14. Deep waters are more acid because they contain higher levels of carbon dioxide as a result of respiration by the organisms that live there and less oxygen because there is no light for photosynthesis. Manzello, D. P., et al., “Poorly Cemented Coral Reefs of the Eastern Tropical Pacific: Possible Insights into Reef Development in a High-CO2 World,” Proceedings of the National Academy of Sciences 105 (2008): 10450–55.

  15. Yamamoto-Kawai, M., et al.,“Aragonite Undersaturation in the Arctic Ocean: Effects of Ocean Acidification and Sea Ice Melt,” Science 326 (2009): 1098–1100.

  16. Tropical seas warmed about 9oF while those at the poles warmed up to 16oF. Deep bottom waters also warmed by 7-9oF. Zachos, J., et al., “Rapid Acidification of the Ocean During the Paleocene-Eocene Thermal Maximum,” Science 308 (2005): 1611–15.

  17. Kerr, R. A., “Ocean Acidification. Unprecedented, Unsettling,” Science 328 (2010): 1500–1.

  18. Carbon dioxide was removed by weathering of silicate rocks above sea level, as well as by the dissolution of carbonates in the sea.

  19. Scheibner, C., and R. P. Speijer, “Decline of Coral Reefs During Late Paleocene to Early Eocene Global Warming” (2008); www.electronic-earth.net/3/19/2008/: doi:10.5194/ee-3-19-2008. Charlie Veron thinks that there was a major reef coral extinction event as well, but the research has yet to be done to document it.

  20. Zachos, J., et al., “Rapid Acidification of the Ocean.”

  21. There is a possibility that lack of oxygen in bottom waters killed these species rather than it being a direct effect of acidification. Zachos, J. C., et al., “An Early Cenozoic Perspective on Greenhouse Warming and Carbon Cycle Dynamics,” Nature 451 (2008): 279–83.