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IMPACTS OF CLIMATE CHANGE ON THE WORLD’S
MARINE ECOSYSTEMS
Ove Hoegh-GuldbergGlobal Change Institute
University of QueenslandQLD 4072 [email protected]
www.climateshifts.org
CLIMATE CHANGE AND THE GLOBAL OCEAN:
HAVE WE GONE TOO FAR?
Ove Hoegh-GuldbergGlobal Change Institute
University of QueenslandQLD 4072 Australia
Gene Feldman
“We are on the precipice of climate tipping points beyond which there is no redemption”
Dr James Hansen, Executive Director, NASA Goddard Institute for Space Studies
1. Physical and chemical changes in the ocean.2. Biological consequences
• General patterns• Case study: coral reef ecosystems
3. Points of no return: When does change become dangerous?• Limiting change to 450 ppm and below• Is this possible physically, technically and politically?
4. Conclusion: has dangerous change begun in our oceans?
Hansen, J., R. Ruedy, M. Sato, and K. Lo, 2010: Global surface temperature change, Rev. Geophys., accepted.
NASA Goddard Institute for space studies
GLOBAL TEMPERATUREConsensus among measurements of surface temperature
Hansen, J., R. Ruedy, M. Sato, and K. Lo, 2010: Global surface temperature change, Rev. Geophys., accepted.
1. 2/3rds of the warming since 1975.
2. The past 12 months are the hottest in the instrumental record.
3. The rate is accelerating. • Last decade = Previous 2
decades of warming
1970s
1990s
1980s
2000s
Surface temperature
NASA Goddard Institute for space studies
BEST
WORST
Ocean Acidification
Doney et al. 2009
1. 0.1 pH unit decrease (since 1870)
2. Represents 26% increase in the concentration of Hydrogen ions
3. Much reduced concentration of carbonate ions (‐ 30 mol/kg water)
Pelejero, Calvo and Hoegh‐Guldberg (2010)
Paleo-reconstructions (2) from boron isotopes in foraminifera
atmosphere–ocean–sediment carbon cycling model
Today
Sea Level Rise Sea Level Rise, Global mean
Storms Ice volume
Hoegh‐Guldberg and Bruno 2010
Biological consequences?Biological consequences?
Impacts of climate change on ocean ecosystems. General themes:
1.Migrating species: Invasive species and disease
2.Changes to ecosystem function
3.Loss of habitat forming species
Impacts of climate change on ocean ecosystems. General themes:
1.Migrating species: Invasive species and disease
2.Changes to ecosystem function
3.Loss of habitat forming species
1. Migrating species: Invasive species and disease
Continuous Plankton Recorder (CPR) studiesin North Sea (1958‐2002)
Northward shift of warm‐adapted plankton assemblages
Loss of cold adapted assemblages
From a changing climate to cod recruitment
Northern Hemisphere temperature
Northern hemisphere sea surface temperature
Phytoplankton
Holoplankton
Meroplankton
Cod
Just in ...
Small changes can precipitate large scale change
Kelp communities (no urchins) After arrival of Centrostephanus
Ling et al. (2009) Global Change Biology
300 km extension of East Australian current
Survival of urchin larvae and adults
Loss of kelp
Fisheries, diversity
Open Ocean:50% of primary productivity and oxygen
“Planetary heart and lungs”
2. Changing Ecosystem function
Polovina et al. (2008):
Nutrient‐poor “ocean deserts” of the Pacific and Atlantic increased by 6.6 million km2, or 15%, over the period 1998 to 2006.
Increased stability of the water column – less nutrients in photic zone?
Boyce et al. 2010, Nature Observed “declines in 8 out of 10 ocean regions, and estimate a global rate of decline of ~1% of the global median per year.”
Back to 1899 using Secchi disk data
Critical habitats for over a million species ... yet all are all in decline
3. Loss of Habitat forming species and processes
DinoflagellateDinoflagellateSymbiodiniumSymbiodinium
Extremely specific and highly co-evolved symbiosis
Within species
Deep
Shallow
Host genotype
Sym
bion
tgen
otyp
ye
LaJeunesse, Hoegh-Guldberg, Schmidt, Fitt (2003)
Between species
Seriatopra hystrixLizard Island
Bongaerts P, Ridgway T, Riginos C, Englebert N, Sampayo E, VermeulenF, Hoegh-Guldberg O (in review)
Epidermis
Endodermis
SymbiodiniumIntracellular
Waste nutrients
Photo‐synthates
Fluorescence in situ hybridization
Percent coral cover
Percent coral cover
Bruno and Selig (2007) Meta‐analysis of over 6000 studies reporting coral cover
Bruno and Selig 2007, PLoS ONE 2, e711. doi:10.1371/journal.pone.0000711
CONCLUSION: CONCLUSION: Around 40Around 40‐‐50% of 50% of corals have been corals have been
lost from reefs over lost from reefs over the past 40 years!the past 40 years!
Overexploitation Coastal development
Climate change
What is causing this decline of coral reefs?
Elevated temperatureElevated temperatureImpact of 2oC increase in sea temperature over 4-6 weeks
Mass coral bleaching
Impacts are global:e.g. Loss of corals during global cycle of
mass bleaching events in 1998
Global loss: 16%Global loss: 16%
Western Indian Western Indian Ocean: 46%Ocean: 46%
GCRMN
Hoegh-Guldberg (1999, Mar Freshwater Research)
The latest?www.climateshifts.org
Mass coral bleaching is driven by thermal stress
• Small excursions above thresholds (1oC) result in bleaching
• Basis for a highly predictive SST program at NOAA (HotSpots, 0.9oC):
1998
2002
Bleaching Severe Bleaching Mass Mortality
Bleaching events
AnomalySize oC
The future?Mass
mortality
Sea tempe
rature (oC)
YearHoegh‐Guldberg (1999) – doubling of CO2 by 2100
1860 1900 1950 2000 2050 2100
Bleaching threshold
Will coral reefs survive beyond 2050?
Ocean Acidification
• Gatusso et al. (1998)
• Kleypas et al. (1999)
• Langdon et al. (2001)
• Leclercq (2002)
• Langdon et al. (2003)
• Guinotte et al. (2003)
• Caldeira and Wickett (2003)
• Feely et al. (2004)
• Orr et al. (2005)
• Raven et al. (2006)
• Kleypas and Langdon (2007)
Effect on coral calcification
-15% to - 45% change in calcification rate with a doubling of CO2
Carbonate balance
Ero
sion
Ero
sion
Reef accretionCoral growth (10-300 mm/year)
Reef growth(1-3 mm/year)Davies (1985)
Cal
cific
atio
nC
alci
ficat
ion
Caldeira et al. 2007
Coral reefs and aragonite saturation at 500 ppm CO2
3.3 (limit for carbonate coral reefs)
Long Cao and Ken Caldeira Stanford Univ
Hoegh-Guldberg et al. 2007 (Science Vol 318)
Calcification rate of GBR Calcification rate of GBR PoritesPoritescorals has slowed by 14.5% since corals has slowed by 14.5% since 1990 1990 –– unprecedented in 400 years unprecedented in 400 years of record (of record (DeDe’’athath et al. 2009 Science)et al. 2009 Science)
1990
Remaining questions• Acidity X temperature
interaction ...
• Are lab experiments a good proxy for what is going on in the field?
• Free Ocean Carbon Enrichment experiment
David Kline
387 ppm+1.0oC
450 ppm+2oC
>500 ppm> +2oC
The future of coral reefs?
Present day analogies to future conditions?
Hoegh-Guldberg et al. 2007 (Science)
Not just about coralsNot just about corals
1. Physical and chemical changes in the ocean.2. Biological consequences
• General patterns• Case study: coral reef ecosystems
3. Points of no return: When does change become dangerous?• Limiting change to 450 ppm and below• Is this possible physically, technically and politically?
4. Conclusion: has dangerous change begun in our oceans?
Avoiding dangerous climate change
“to achieve in accordance with the relevant provisions of the convention, stabilisation of greenhouse gas concentrations in the
atmosphere at a level that would prevent dangerous anthropogenicinterference with the climate system” UN FCCC 1992
450 ppm
+2°C
• Is this possible physically, technically and politically?
Meinshausen et al. (2009)
Today
Physically possible to constrain CO2 to <450 ppm?
50% chance of exceeding 2oC
Conclusion:
If we constrain emissions to 1,000 GT CO2 over the period 2000‐2050,
we can avoid unmanageable dangerous climate change
Ambitious but technically feasible.
http://beyondzeroemissions.org/zero-carbon-australia-2020
$8 per household per week
Economic?
Military burden 1939‐44 as a percent of national income.
1939 1940 1941 1942 1943 1944
USA 1 2 11 31 42 42
UK 15 44 53 52 55 53
Germany 23 40 52 64 70
Japan 22 22 27 33 43 76
From Harrison M (2000) The economics of the second world war: six great powers in international comparison , Cambridge University Press(from Code Red, Spratt and Sutton 2008)
IPCC estimates of cost of acting: <1% of GDP growth over next 50 years
Depends on how committed we are.
Possible physically, technically.What about politically?
Over 300 political leaders from federal, state & local government
Polled anonymously over past 6 months
Full survey results can be found at: www.climateshifts.org
Where do you go for advice on climate change?
The science behind “Climate change is absolute crap.”Tony Abbott, leader LNP in opposition, Nov 2009
What constitutes dangerous climate change to some Australian politicians?
www.climateshifts.org
1. The ocean is changing at a speed which is largely unprecedented.2. Major changes are occurring within marine ecosystems upon
which much of humanity depends. 3. These changes qualify as evidence of dangerous climate change
by the definition of the UNFCCC. Dangerous climate change is occurring within the global ocean.
4. Concentration of carbon dioxide become critical somewhere between today's concentrations and 450 ppm.
5. Responding to this crisis is physically and technically feasible.6. Whether or not have the political will is highly questionable at
this point.
www.coralecosystems.org2005‐2010
Dr Simon Dunn
Dr Scarla Weeks Dr Ken Anthony
Dr Mathieu Pernice
Dr Linda Tonk
Dr Nela Rosic
Dr David Kline
Dr Paulina Kaniewska
Dr Guillermo Diaz-Pulido
Mr Pim BongaertsMs Alicia Crawley
Mr Jez Roff Mr Juan Carlos Ortiz
Ms Rachel Middlebrook
Ms Narinratana Kongjandtre
Mr Cameron Veal Mr Chris Roffsema
Ms Angela Lawton
Ms Meegan Henderson
Ms Annamieke Van Den Heuvel
Mr Siham Afatta Ms Lotte Kvennefors
Mr David Harris
Mr Udo Engelhardt Ms Maxi EckesMs Ana Redondo-Rodriquez
Mr Ayax Diaz-Ruiz
Dr Sophie Dove
Assoc Prof.
Senior research fellows
Postdoctoral Fellows
Graduate students
Ms Tracy Ainsworth
ARCGBRF World BankGEFQLD government
B2+3oC, 450 ppm
A1FI+6oC, 800 ppm
TODAY0oC, 380 ppm
Pre‐industrial‐1oC, 280 ppm
Rep1 Rep2 Rep3 Rep4 2 m3
Heron Island mesocosms
30 m3
Mixing sumpsComputer controlled
Free Ocean Carbon Enrichment
• Dosing a living coral reef with CO2 enriched water.
• Began in June
• Will run for 12 months (possibly more)
David Kline
pH in the environment
7.8
7.9
8
8.1
8.2
8.3
8.4
8.5
12/17/090:00
12/17/0912:00
12/18/090:00
12/18/0912:00
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12/19/0912:00
12/20/090:00
12/20/0912:00
12/21/090:00
12/21/0912:00
12/22/090:00
Date/Time
-1
0
1
2
3
4
5
TId
e h
eig
ht
(m)
pH Tides
Preliminary data
pH in Control FOCE
7.7
7.8
7.9
8
8.1
8.2
8.3
8.4
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12/18/090:00
12/18/0912:00
12/19/090:00
12/19/0912:00
12/20/090:00
12/20/0912:00
12/21/090:00
12/21/0912:00
12/22/090:00
Date/Time
0
0.05
0.1
0.15
0.2
0.25
pH
an
om
aly
Open Inc.Coral Inc. Sed Inc. Algae
pH in Control FOCE
7.7
7.8
7.9
8
8.1
8.2
8.3
8.4
12/17/090:00
12/17/0912:00
12/18/090:00
12/18/0912:00
12/19/090:00
12/19/0912:00
12/20/090:00
12/20/0912:00
12/21/090:00
12/21/0912:00
12/22/090:00
Date/Time
0
0.05
0.1
0.15
0.2
0.25
pH
an
om
aly
Open Inc.Coral Inc. Sed Inc. Algae
Adaptation options:Adaptation options:
Local alleviation of climate stressLocal alleviation of climate stressCan we reduce the global stresses Can we reduce the global stresses at a local level?at a local level?
Restoring reef ecosystemsRestoring reef ecosystemsReRe‐‐establishing reefs populationsestablishing reefs populations
Moving species and ecosystemsMoving species and ecosystemsCan we move species and ecosystems?Can we move species and ecosystems?
Reduction of local stress factorsReduction of local stress factorsIncrease resilience of reefs to impacts Increase resilience of reefs to impacts of climate change through reducing of climate change through reducing impacts of local stressors (e.g. impacts of local stressors (e.g. Overfishing, poor water quality)Overfishing, poor water quality)
Quicksilver ConnectionsQuicksilver Connections
Light-dependent exacerbation of bleaching and mortality2006 – less bleaching under shaded sections of reef (proof of concept)2007 – scale up to commercial model?
Potential for operators to retain coral growth around platformsSmall yet economically important effect – could be worth doing …
Alleviating global stress at local levels
Restoring reef ecosystems
Probably can only be done in Probably can only be done in a limited number of a limited number of
situations.situations.
Likely to be to expensive or Likely to be to expensive or impossible at scale of reefs impossible at scale of reefs
and forests and forests
Moving species and ecosystems
FishFish
No FishNo Fish
Caged versus Non‐caged reef areas + 2002 Bleaching Event
Reef areas that contained normal fish grazers recovered coral populations 3 times faster than those which did not.
Current Biology 17, 1–6, 2007
Reducing impacts of water Reducing impacts of water quality and overquality and over‐‐exploitation exploitation present a number of viable present a number of viable options for delaying impacts options for delaying impacts
of climate change of climate change
Reducing impact of local stressors
Does this work?
The secret of effective medicine
Things we should do while we aggressively reduce with emissions
• Protect ecosystems processes that maintain coral dominated reef systems (e.g. herbivores)
• Improve land management and coastal water quality.
• Maintain topological complexity by reduce physical impacts on coral reefs (e.g. anchoring)
The Great Barrier Reef Marine Park
History
1.Great Barrier Reef Marine Park declared in 1975
• Multi-use park• 5% in total protection areas
2.GBR World Heritage listed in 1981• Stewardship on behalf of
world – increased protection
3.Rezoned in 2004 • Concern of decline in GBR
health and growing climate change threat.
• Increased in size• Complex process to include
all users and stake-holders but with 34% now totally protected.
Is it working?
