Issue 1
Climate change:

It's now or never to save coral reefs
Coral reefs are increasingly coming
Three scenarios
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under pressure from human activities,
The CRTR Program has forecast
arising from over-exploitation,
future scenarios for coral reefs with
destructive fishing, pollution,
increased CO (measured in parts
2
eutrophication and the extensive
per million, ppm) in the Earth's
i
so
modification of coastlines adjacent
atmosphere and mean temperature
to coral reefs. Recent evidence
above today's associated with
suggests that climate change, by
climate change.

increasing sea temperatures and
ocean acidity, may interact with and
Scenario A - 380 ppm
worsen the plight of coral reefs. This

Today's situation; 10-60% coral
has serious consequences for tens of
cover, a diversity of marine life;
mil ions of people and bil ion-dol ar
Adv
mass bleaching impacts continue
lume 2
fishing and tourist industries.
o
and coral dominated reefs struggle
A recent report in the international
V
to survive. The formation of
journal, Science Magazine, from
calcium carbonate is slower than
the Coral Reef Targeted Research &
100 years ago but can still keep
Capacity Building for Management
up with reef erosion. (This image
(CRTR) Program has analyzed the
shows a rich coral community on
evidence and has concluded that
the southern Great Barrier Reef)
climate change is now the biggest
threat to coral reefs.
Scenario B - 450-500 ppm
Global projects such as the CRTR

Reef structures reach a tipping
Program are essential to our ability
point and reef erosion in most
to understand and respond to
parts of the world exceeds reef
The Coral Reef Targeted Research &
the problems posed by the
Capacity Building for Management
calcification. The structure of coral
Program (CRTR) is a leading
increasing stress on coral reefs
reefs begins to crumble. Coral
international coral reef research
for many nations.
initiative that provides a coordinated
bleaching events occur almost
approach to credible, factual and
annually and coral cover declines
scientifically-proven knowledge for
Key Points
improved coral reef management.
as a result to less than 10% of what
ˇ Coral reefs may not survive
it was previously. Coral dominated
The CRTR Program is a proactive
research and capacity building
the rapid increases in global
reefs are rare but still exist in a few
partnership that aims to lay the
temperatures and atmospheric
places. (This image was taken from
foundation in filling crucial knowledge
gaps in the core research areas of Coral
CO that are forecast this century
the inshore Great Barrier Reef)
2
Bleaching, Connectivity, Coral Diseases,
ˇ The livelihoods of 100 mil ion
Coral Restoration and Remediation,
Scenario C - >500 ppm
Remote Sensing and Modeling and
people living along the coasts of
Decision Support.
tropical developing countries and

The concentration of carbonate
Each of these research areas are
those businesses earning bil ions
ions decreases well below the
facilitated by Working Groups
of dollars from reef-related tourism
carbonate threshold; coral-
underpinned by the skills of many of the
may be the first casualties
dominated reef ecosystems are
world's leading coral reef researchers.
The CRTR also supports four Centers of
rare or non-existent. Those few
Excellence in priority regions, serving as
ˇ There needs to be drastic action
corals that exist grow very slowly
important regional centers for building
from world leaders to urgently
confidence and skills in research,
and do not produce the amount of
training and capacity building.
reduce CO emissions
2
carbon required to maintain reef
ˇ Policy-makers and reef managers
The CRTR Program is a partnership
structures. Coral reefs collapse
between the Global Environment
need to immediately address over-
into rubble. (This image shows a
Facility, the World Bank, The University
fishing, pollution and unsustainable
of Queensland (Australia), the
reef that once grew on the inshore
United States National Oceanic and
coastal development - many
region of the Great Barrier Reef)
Atmospheric Administration (NOAA) and
coastal management tools already
approximately 50 research institutes &
other third parties around the world.
exist - they require broader
application in earnest
July 2008
Product code: CRTR 004/2008

Figure 1 rev1, Hoegh-Guldberg/Science
Figure 1 rev1, Hoegh-Guldberg/Science
A
BB
Atmo
At sp
mo he
sp ri
h c
eri C
c O
CO content (ppm)
2 co
2 ntent (ppm)
200
200
300
300 400
400 600 800
600
1
800 20
1 0
2 0
88
t
h th C C
r r a
e
a
e r
s s b
C)
r
b
C)
o o
6
h h o
6
o
o o n n
l
d 480 ppm ld 480 ppm a
Ree
R f
e s
e n
f o
s t
not
t a
e te
dominated
dominated
Th
Ter
h m
er al
mal
C
by corals
C
by corals
CO
CO
4
threshold
4
threshold
0.2
0.p
2H
pH
22
(+2oC)
(+2oC)
22
'
s temperature ( 's temperature (
Interglacial
Interglacial
B
Non-carbonate reef
B
Non-carbonate reef
AA
coral communities
coral communities
00
)
-
)
-
800
CO
CO + H O => HCO
+ H O => HCO + H+
800
+ H+
2 2
22
3
-1
3
-1
Today
Today
600
- 2
- 2
400
+
2-2-
- -
] (ľmol kg
H+
H + CO
+ CO => HCO
] (ľmol kg
3
=> HCO
3
33
2- 2-
200
- 4
- 4
3 3
Glacial
0
Glacial
0
Deviation from today
[CO
Deviation from today
[CO
0 200 400
400 600
600 800
800
2+
2-
- 6
- 6
[CO
2-
[CO ]
(ppm)
CaCO =>
CaCO
Ca2+
=> Ca + CO
(ppm)
+ CO
3
3
400
300
2020
100
1 0
0
2
00
0
2 atm
3
3
400
300
atm
(coral)
(coral)
Ca
Crb
a o
rbn
oa
nte
at i
eon
io co
n nce
con nt
ce ra
nt tio
rat n
io (
n (mol kg-1
mol
)
kg-1)
Figure 1. Approximately 25% of the CO emitted by humans in the period 2000 to 2006
Figure 2. Temperature and carbonate ion concentrations related to calcification rates
2
was taken up by the ocean where it combined with water to form carbonic acid.
reconstructed for the past 420,000 years. A, B, and C refer to scenarios depicted in page 1.
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The facts and conclusions
risk. It is essential that we reduce
collected by the CRTR Program
the risk of these occurring by
When corals
are as follows:
helping and buffering the ability
ˇ Sea temperatures and ocean
of coral reefs to rapidly return
i
so
get too warm
acidity are now outside the values
from climate shocks.
experienced by coral reefs during
ˇ Best case scenarios arise if we
the past 420,000 years, at least.
can keep carbon dioxide below
ˇ Conditions surrounding coral
450 ppm and increase our efforts
reefs are changing at rates
to build the ecological resilience
which exceed even the most
of coral reefs by reducing the
Adv
rapid changes over the past
impact of other stresses, such as
420,000 years. Rates of change
pollution, sedimentation, over
in conditions are now 100 to
exploitation and destructive
1000 times higher than those
fishing practices.
experienced during the ice age
ˇ Worst-case scenarios arise if
transitions, in which the planet
we do not take stern action
underwent great physical and
on emissions today. In these
biological change.
scenarios (greater than 450 ppm),
ˇ Our current understanding of
extensive coral reef ecosystems
coral reefs is that they have
will not be present in the rapidly
specific limits with respect to
warming and acidifying seas.

sea temperature and acidity.
ˇ Given the trend of increasing
first
it
There is little evidence that these
global stress, it has become
Change
te
thresholds will change rapidly
increasingly important to reduce

where
enough to keep pace with
the impact of other stresses on
Clima
climate change.
coral reefs. This alone, will not
pid
Magazine,
Ra
ˇ Increases in atmospheric carbon
be enough to save coral reefs if
dioxide above 450 ppm will
we do not deal with the carbon
Bleached corals on southern Great Barier Reef in January 2002.
Science
under
largely eliminate carbonate
dioxide emission problem.
Photo: Ove Hoegh-Guldberg, Centre for Marine Studies,
Reefs
coral reefs.
ˇ The current scientific consensus
The University of Queensland
prestigious
2007.
ˇ Corals are central to coral reef
is that the highly-biodiverse coral

Coral
When corals get too warm, The
the
ecosystems. If corals are unable
reefs of today will be relics of the
symbiosis with brown plant-like
from
Crisis:
to build reef structures, 50% of
past if we do not act globally to
organisms known as zooxanthellae
the estimated million species
rapidly reduce global emissions
breaks down. The result is coral
Carbon
that live in and around coral reefs
of carbon dioxide and other
bleaching as shown here. The
reproduced
,
on December 14,
,

The
will disappear.
greenhouse gases.
tion
beautiful blue colors are due to
been
paper
ˇ Analysis of the potential impact
animal pigments while the pale
has
the
of increased sea temperature
brown color remaining at the base
in
Acidifica
and acidity indicate a series of
of the branches is due to remaining
material
potential negative feedback loops
zooxanthellae.
This
appeared
and Ocean
to date which increase the level of