Ocean acidification: a biogeological perspective Jelle Bijma (AWI, - - PowerPoint PPT Presentation

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Ocean acidification: a biogeological perspective Jelle Bijma (AWI, - - PowerPoint PPT Presentation

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Ocean acidification: a biogeological perspective Jelle Bijma (AWI, Bremerhaven, Germany) Ocean acidification: present and future . . . . . Why a biogeological perspective? Ocean acidification in the past . . . . . Consequences for

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Ocean acidification: a biogeological perspective

  • Ocean acidification: present and future . . . . .
  • Why a biogeological perspective?
  • Ocean acidification in the past . . . . .
  • Consequences for Biodiversity . . . . .

Jelle Bijma (AWI, Bremerhaven, Germany)

International Conference on Science and Technology for Sustainability

Climate Change and Biodiversity, Kanazawa, Dec. 17, 2010

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SLIDE 2

Artist Impression of the Human Perturbation of the Carbon Cycle

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SLIDE 3

Global Carbon Project 2010

Anthropogenic Global Carbon Dioxide Budget

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SLIDE 4

Updated from Le Quéré et al. 2009, Nature Geoscience

CO2 Emissions from Land Use Change (1960-2009)

LUC emissions now ~10% of total CO2 emissions

CO2 emissions (PgC y-1)

Fossil fuel & cement Land use change 10 8 6 4 2

1960 2010 1970 1990 2000 1980

Time (y)

7.7 1.1 8.8 PgC

Average (2000-2009)

[1 Pg = 1 Petagram = 1 Billion metric tonnes = 1 Gigatonne = 1x1015g]

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SLIDE 5

Fate of Anthropogenic CO2 Emissions (2000-2009)

1.1 0.7 PgC y-1

+

7.7 0.5 PgC y-1 2.4 PgC y-1

27%

Calculated as the residual of all other flux components

4.1 0.1 PgC y-1

47% 26%

2.3 0.4 PgC y-1

Average of 5 models Global Carbon Project 2010; Updated from Le Quéré et al. 2009, Nature Geoscience; Canadell et al. 2007, PNAS

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SLIDE 6

Fossil Fuel CO2 Emissions

Friedlingstein et al. 2010, Nature Geoscience; Gregg Marland, Thomas Boden-CDIAC 2010

2009: Emissions:8.4 0.5 PgC Growth rate: -1.3% 1990 level: +37% 2000-2008 Growth rate: +3.2% 2010 (projected): Growth rate: >3%

CO2 emissions (Pg C y-1) CO2 emissions (Pg CO2 y-1)

Growth rate 1990-1999 1 % per year Growth rate 2000-2009 2.5 % per year

Time (y)

[1 Pg = 1 Petagram = 1 Billion metric tonnes = 1 Gigatonne = 1x1015g]

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SLIDE 7

The marine carbonate system

CO2 (aq): aqueous carbon dioxide HCO3

  • :

bicarbonate ion CO3

2-:

carbonate ion H2CO3: carbonic acid ΣCO2 or DIC or TCO2: Total dissolved inorganic carbon

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SLIDE 8

„Bjerrum plot“

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SLIDE 9

CO2 pH DIC

Year

pH [CO2] [CO3

2-]

300 250 150 100 50 200 35 30 20 15 5 25 10 1850 1900 2100 1950 2050 2000 7.8 8.2 8.1 8.0 7.9 2400 1600 1200 800 400 2000 [DIC] [µmol kg-1] [µmol kg-1]

SWS

CO3

2-

Ocean Acidification

Wolf-Gladrow et al., 1999

30% 150% more acidic!

Changes in surface ocean chemistry based on the IS92a scenario IPCC report 1995 (linear increase from 6.3 GtC yr-1 to 20 GtC yr-1 in the year 2100).

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SLIDE 10

Courtesy: Richard A. Feely

NOAA/Pacific Marine Environmental Laboratory

275 300 325 350 375 400 1950 1960 1970 1980 1990 2000 2010 2020 8.03 8.08 8.13 8.18 8.23 8.28 8.33 8.38

pH Year CO2

What we know about ocean CO2 chemistry …from time series stations

„Mauna Loa“ curve „BATS“

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SLIDE 11

WOCE/JGOFS/OACES Global CO2 Survey

~72,000 sample locations collected in the 1990s DIC 2 µmol kg-1 TA 4 µmol kg-1

Sabine et al (2004)

…from field observations What we know about ocean CO2 chemistry

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SLIDE 12

Undersaturation is strongest in the high latitudes

*Model approach assuming a simulation with +1% increase per year (model results only) Aragonite undersaturation Δ[CO32-]Arag at 2xCO2 Jim Orr (CEA/IAEA)

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SLIDE 13
  • Decrease in pH 0.1 over the last two centuries (30% increase in

acidity; decrease in carbonate ion of about 16%)

  • How will this impact marine organisms and ecosystems?

Ocean Acidification

Corals Calcareous Plankton

http://www.biol.tsukuba.ac.jp/~inouye Photo: Missouri Botanical Gardens

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SLIDE 14

ΩA = 1.5

Green et al., 2004

Hard shell clam Mercenaria

  • Common in soft bottom

habitats Used newly settled clams

  • Size 0.3 mm
  • Massive dissolution within

24 h in undersaturated water; shell gone w/in 2 wks

  • Dissolution is source of

mortality in estuaries & coastal habitats Control ΩA = 0.3

Bivalve juvenile stages can also be sensitive to carbonate chemistry

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SLIDE 15

Adverse effects on reproductive success

  • Decreased fertilization rates (sea

urchins, bivalves)

  • Increased juvenile mortality (bivalves,

sea urchins, copepods, fish larvae) Impaired oxygen transport (squid) Reduced growth in adults (sea urchins, bivalves)

Potential impacts of high CO2 on marine fauna

Reduced metabolism/scope for activity (squid)

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SLIDE 16

Potential Ecosystem Responses

Changes in relative abundance & distribution of calcifying species

 Non-calcifying species may outcompete calcifiers  Geographical ranges of calcifying species may shift  Vertical depth distributions of calcifying species may shoal with decreasing CaCO3 saturation state

Changes in food webs and other species interactions

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SLIDE 17

Potential Effects on Open Ocean Food Webs

Barrie Kovish Vicki Fabry

ARCOD@ims.uaf.edu

Pacific Salmon Copepods Coccolithophores Pteropods

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SLIDE 18

Jacob (2005)

Weddell Sea Food Web: 489 species (incl 62 autotrophs, >16000 trophic links (Jacob, 2005)

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Potential Ecosystem Responses

Changes in relative abundance & distribution of calcifying species

 Non-calcifying species may outcompete calcifiers  Geographical ranges of calcifying species may shift  Vertical depth distributions of calcifying species may shoal with decreasing CaCO3 saturation state

Changes in food webs and other species interactions Impacts on biogeochemical cycles

 Speciation of nutrients and trace metals  Changes in cycling of carbon and CaCO3 within oceans (e.g. “ballasting”)  Changes in the “microbial loop”  Feedbacks to climate

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SLIDE 20

The global carbon cycle is largely driven by biology: How will the „biological pump“ respond to OA?

  • The biological pump stops
  • Within 250 yrs atmospheric CO2

increases 2.4 times

see: Maier-Reimer, Mikolajewicz and Winguth (1996); Zeebe and Westbroek (2003)

  • The surface-deep CO2 gradient

disappears The „Strangelove ocean“: What happens if biology is turned of?

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SLIDE 21

Wrap up ….

  • Oceans are stabilising global warming

(but very slowly) ….

  • At the same time are oceans acidifying

(very fast) ….

  • Society is facing double trouble….
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Ocean acidification: a biogeological perspective

  • Ocean acidification: present and future . . . . .
  • Why a biogeological perspective?
  • Ocean acidification in the past . . . . .
  • Consequences for Biodiversity . . . . .

Jelle Bijma (AWI, Bremerhaven, Germany)

International Conference on Science and Technology for Sustainability

Climate Change and Biodiversity, Kanazawa, Dec. 17, 2010

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SLIDE 23

Biological aspects

Real world

  • comprises the actual complexity of the chemical, biological and ecological

systems and interactions between them Real time

  • capture the time component inherent to carbonate perturbation and

physiological and ecosystem response Limitations

  • gradual change makes it difficult to identify responses
  • complexity of biology itself
  • difficulty to capture longer term processes such as ecological adaptation,

evolution and, biogeochemical cycles

  • no information on recovery processes
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SLIDE 24

Why paleo?

  • What has happened can happen (e.g. perturbation of ocean chemistry)
  • Long-term (natural) context for recent changes
  • Investigate the impact on biogeochemical cycles
  • Reduced complexity (integration of space and time)
  • Different time scales (historical/sub-recent, G-IG, deep time,….)
  • Process of recovery
  • Different scenarios as case and sensitivity studies and testbeds for models

The farther backward you can look, the farther forward you are likely to see.” Winston Churchill Limitations

  • limited biological information (hard parts and biomarkers)
  • limited by accuracy of proxy reconstructions
  • restrictions on temporal and spatial resolution
  • no perfect analogues
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SLIDE 25

Ocean acidification: a biogeological perspective

  • Ocean acidification: present and future . . . . .
  • Why a biogeological perspective?
  • Ocean acidification in the past . . . . .
  • Consequences for Biodiversity . . . . .

Jelle Bijma (AWI, Bremerhaven, Germany)

International Conference on Science and Technology for Sustainability

Climate Change and Biodiversity, Kanazawa, Dec. 17, 2010

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SLIDE 26

150 200 250 300 350 400 5 10 15 20

Tijd (duizenden jaren) pCO2 (ppmV)

pCO2 (ppmV)

De Last Ice age

280 385 180

Time (thousands of years)

Courtesy: Henk Brinkhuis

∆pH∼0.13 – 0.2 ∆pH∼0.1

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SLIDE 27

100 200 300 400 500 600 700 800 900 1000 50 100 150 200 250 300 350 400 450 500 550 600 650

Tijd (duizenden jaren) pCO2 (ppmV)

pCO2 (ppmV) IPCC

800.000 years!

Time (thousands of years) pCO2 (ppmV)

385 1000

Courtesy: Henk Brinkhuis

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SLIDE 28

200 400 600 800 1000 1200 1400 1600 1800 2000 5 10 15 20 25 30 35 40 45 50 55 60

Tijd (miljoenen jaren) pCO2 (ppmV)

pCO2 (ppmV) IPCC

25 million years

Time (millions of years)

pCO2 (ppmV)

Icehouse Earth Greenhouse Earth

45 million years

Courtesy: Henk Brinkhuis

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SLIDE 29
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SLIDE 30

Siberian traps Deccan traps; Asteroid impact

Carbon pertubation (symtoms):

  • Global warming
  • Ocean acidification
  • Anoxia

Trias-Jurasic (CAMP) Ord.-Silurian

Evidence:

  • Elevated pCO2 (global warming)?
  • Reduced pH?
  • Reduced Ω?
  • Anoxia?

PETM; 55Myr Viluy traps (Eastern Siberia)

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Response of marine biota to OA and climate change

  • Strong perturbation at a very fast rate → K/T impact (major

planktonic extinction)

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Hole 1259B 13R, 37-60 cm- boundary interval

0.5 cm Cretaceous ejecta Paleogene

reflected light

Courtesy: Brian Huber

Ca

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SLIDE 33

Courtesy: Brian Huber But benthics continue! Impact acid rain?

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SLIDE 34

Response of marine biota to OA and climate change

  • Strong perturbation at a fast rate → K/T impact (major

planktonic extinction)

  • Strong perturbation at a „moderate“ rate → PETM (major

benthic extinction)

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SLIDE 35

Zachos et al., 2001

Cenozoic long-term trends Early Eocene: warm superimposed: PETM One of the largest benthic mass Extinction in Earth history PETM

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Ocean Carbonate; Walvis Ridge ODP Leg 208

ODP 208 Walvis Ridge, Zachos et al., 2005

„Carbonate com pensation“: as lysocline is rising it destroys benthic habitats

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SLIDE 37

Zachos et al., Science 2005

Oceanic recovery. Walvis Ridge ODP Leg 208

Ca. 100ky

“Liebfrauenmilch principle”:

One night of drinking followed by 2 years of hang-over

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SLIDE 38

Response of marine biota to OA and climate change

  • Strong perturbation at a very fast rate → K/T impact (major

planktonic extinction)

  • Strong perturbation at a „moderate“ rate → PETM (major

benthic extinction)

  • Small perturbation at a slow rate → Neogene, G-IG

(acclimation/adaptation)

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SLIDE 39

∆[CO3

2-]G-IG → 100µmol kg-1

  • ca. 15% shell weight change
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SLIDE 40

∆[CO3

2-]G-IG → 100µmol kg-1

  • ca. 50% shell weight change!

Moy, 2005

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SLIDE 41

CO2 Vents: “Windows” into High CO2 Ocean to Assess Ecosystem Impacts

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SLIDE 42

CO2 Vents: “Windows” into High CO2 Ocean to Assess Ecosystem Impacts

Hall-Spencer et al. Nature (2008)

e.g. Sea grass benefit but so do invasive species Studies in the shallow waters of the Mediterranean and deep-sea show:

  • total loss of some calcareous species
  • reduced biodiversity
  • “regime shifts”: totally different

ecosystems

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SLIDE 43

Response of marine biota to OA and climate change

  • Strong perturbation at a very fast rate → K/T impact (major

planktonic extinction)

  • Strong perturbation at a „moderate“ rate → PETM (major

benthic extinction)

  • Small perturbation at a slow rate → Neogene, G-IG

(acclimation/adaptation)

  • Strong perturb. at a fast rate → Anthropocene: decrease in

species richness → breakdown of ecosystems → extinction?

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SLIDE 44

A conservative value of $100,000 km-2 y-1 (Burke and Maidens, 2004), the global economic value associated with reefs is in the order of $30 billion yr-1.

…..linked to its function as a habitat and nursery for commercial fish stocks, acting as a natural barrier for coastlines, and for the provision of recreation and tourism

  • pportunities.
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SLIDE 45
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SLIDE 46
  • ocean acidification is ongoing and future

changes are very well predictable

  • organismal response – poor knowledge but

growing (mostly calcifiers)

  • ecosystem response – not known
  • evolutionary capability – completely unknown
  • no perfect analogue to the present – rate of

change is unprecedented

  • Earth history tells us that the combination of
  • cean acidification, global warming and anoxia is

a deadly mix

Conclusions

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SLIDE 47

Is there a tipping point in

  • cean acidification which

should be avoided?

Carol Turley Joint EPOCA, BIOACID UKOARP Workshop on Ocean Acidification

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SLIDE 48

Potential Vulnerabilities in Relation to Human Life spans

Turley and Boot (in press) OUP Book on Ocean Acidification (Gattuso and Hansson d )

politician lifespan