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Climate Change and Ocean Acidification

Kevin Noone Sida-SRC Conference on Oceans and Climate Change

Stockholm, 12 October 2010

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Outline

•  The basics of ocean acidification •  Ocean acidification impacts •  Connections to development

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Acknowledgments

•  Terry Garcia, National Geographic •  Alex David Rogers, Zoological Society of London •  Carol Turley, Plymouth Marine Laboratory

for providing material and inspiration for this presentation

The oceans comprise huge ecosystems

• Oceans cover 71% of Earth’s surface

• Average depth ~ 3,800m • 88% oceans beyond

continental shelves are >1km deep

• 90% of habitable volume for life

• Contains 90% of Earth’s biomass

Every second breath you take comes from the ocean…..

•  Oxygen is produced as a by-product of photosynthesis by microscopic plants •  Overall oceans produce nearly half of the atmosphere’s oxygen

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The basics of ocean acidification

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Carbonate chemistry in the oceans

Climate Change Science Compendium, UNEP 2009

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pH in the deep past

Turley et al, 2006. Cambridge University Press, 8, 65-70

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Anthropogenic CO2 in the oceans

Sabine, et al., Science 305, 367-371, 2004

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Changing ocean pH

Source: Guinotte, et al., Coral Reefs 22, 551-558, 2003

pCO2 = 280 ppmv

pCO2 = 375 ppmv

1870

2000-2009

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Changing ocean pH

pCO2 = 415 ppmv

pCO2 = 465 ppmv

2020-2029

2040-2049

Source: Guinotte, et al., Coral Reefs 22, 551-558, 2003

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Changing ocean pH

Source: Guinotte, et al., Coral Reefs 22, 551-558, 2003

pCO2 = 517 ppmv

2060-2069

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Impacts

The most diverse marine ecosystems on Earth

Coral reefs are ancient ecosystems Cover <1% of Earth’s surface but harbour 1.5 - 2 million species Includes quarter of all marine fish Species Coral reefs confer a net value of approximately $29.8 billion per year Tourism & recreation $9.6 billion; coastal protection $9 billion; fisheries $5.7 billion; biodiversity $5.5 billion Feed about 1 billion people per year

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Coral reefs

Bellwood, D.R., et al., 2004. Confronting the coral reef crisis. Nature, 429(6994): 827-833.

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Coral reefs

Kleypas & Yates, Oceanography, 22(4), 108-117, 2009.

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Ocean acidification: implications?

Orr et al. Nature 437, 681-686, 2005

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Ocean acidification and development

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Population growth & ocean acidification

S. R. Cooley, et al., Oceanography, 22(4), 172-181, 2009.

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Coral reefs

S. R. Cooley, et al., Oceanography, 22(4), 172-181, 2009.