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The bleached coral of Lorne Reef near Townsville, with Rattlesnake Island in the background during the 1998 mass coral bleaching event. Credit: GBRMPA
The implications of
CLIMATE CHANGE
FOR AUSTRALIA’S GREAT BARRIER REEF
AT RISK
People and industries
AT RISK
WWF Australia and the Queensland Tourism Industry Council
commissioned a revolutionary new study on Australia’s Great Barrier Reef.
This study explores possible ‘futures’ for the Reef, a complex task that involves
the analysis of vast sets of information ranging from the climate sciences to the
biology and economics of Australia’s coral reef industries. The analysis reveals
a range of possible futures, some of which are more desirable than others from
economic, social and environmental perspectives. Some of these futures are
disturbing and must be avoided.
This is the first study of its kind to outline how the future might unfold and
how specific actions taken today will craft tomorrow’s world. Strong action to
increase ecological resilience while simultaneously reducing greenhouse gas
emissions today will be instrumental in securing the economic and
environmental wealth of Australia tomorrow. Australia must act to influence the
global agenda, and this report provides some guidance on what to do.
The report seeks to answer the burning questions:
What will climate change do to Australia’s
Great Barrier Reef and its people, and
what
can we do to minimise future impacts?
Coral reefs like the Great Barrier Reef are severely
threatened by climate change as well as a range of local
human-induced factors. What this means for reefdependent societies requires complex analysis and
begins with questions as to what the Great Barrier Reef
might be like in 2020 and 2050.
Is the Reef going to be healthy, stressed or changed
beyond recognition? If it is dramatically different in
quality to today’s Reef, how will the many people and
industries dependent on the Reef be affected?
Will reef-dependent fisheries and tourism, in particular,
be strong, threatened or non-existent? How does change
in the ecology of the Great Barrier Reef flow onto people,
towns and regions?
Most importantly, what steps can be taken to minimise
the effects of these changes on the Great Barrier Reef so
that its dependent communities can retain and grow
regional economic and social health? Are there actions
that can be taken locally that might influence that
objective, or are regional societies passive recipients of
changes that are beyond our control?
The focus of the study was the Great Barrier Reef
World Heritage Area, which extends from the tip of
Australia at Cape York to its southern extremity north of
Bundaberg.
Five regions along the coast made it possible to
differentiate impacts of climate change within the area:
Far North Queensland, Northern, Mackay-Whitsunday,
Fitzroy and Wide Bay-Burnett. See Figure 1.
The study of how these regions will be affected by climate
change is described in three parts:
• The scientific evidence for the effect of climate change
on the Reef.
COOKTOWN
• Regional economic analysis of reef-related industries.
• Future scenarios.
FAR NORTH
Policy recommendations ranging from global to local are
CAIRNS
then provided.
TOWNSVILLE
NORTHERN
MACKAY
MACKAY
ROCKHAMPTON
FITZROY
BUNDABERG
WIDE BAY
BURNETT
BRISBANE
The Scientific Evidence
Clownfish (Amphiprion percula). The loss of corals due to bleaching may have drastic consequences for these delightful creatures. Credit: Triggerfish Images
CLIMATE CHANGE
The
earth has warmed by 0.6˚C since 1880 and will warm a further 2 to 6˚C by 2100.
Atmospheric concentrations of carbon dioxide over
the past few decades have increased at a rate several
orders of magnitude above anything seen over the past
400,000 years. It is no longer credible to claim that there
is major debate around the fact of human-driven climate
change. Human-driven climate change is here now and is
already changing our lives.
The earth’s biological systems have responded even to
the minimal warming seen so far. Among numerous
examples on land, the tree lines of alpine forests have
expanded to higher altitudes and exotic species have
invaded as the number of frost days has decreased - palm
forests are now growing in alpine Switzerland.
Rainforests, such as Australia’s Wet Tropics World
Heritage area, are severely threatened due to changes in
temperature, rainfall and cloud presence. In the sea, fish
populations are moving towards the poles, ecosystems
are changing dramatically and the earth’s polar ice caps
are melting with huge ramifications for some of the most
productive regions of the ocean.
Coral reefs have shown some of the most dramatic
impacts of climate change, with the advent of world-wide
coral bleaching events from 1979 as the thermal threshold
of many of the world’s coral populations was exceeded.
Global cycles of coral bleaching and mortality have
increased dramatically as sea temperatures have reached
higher and higher values over the last 20 years. In the last
five years, the Great Barrier Reef for example experienced
two of the worst bleaching events in its history.
Coral bleaching is a sign of stress in corals, which live
in close symbiosis with brown dinoflagellate algae
(zooxanthellae). When corals become stressed, the
brown algae are expelled turning corals a brilliant white.
In cases where stress is mild, corals can recover.
When stress is more intense, corals die, often across
huge sectors of the world’s oceans.
Recent episodes of mass coral bleaching were caused
by rising sea temperatures. In 1998, 16% of the world’s
coral died. In some regions such as the Western Indian
Ocean, more than 48% of living coral was eliminated.
The removal of these key organisms has huge
implications for the ecosystems and for people that
depend on these critically important coral reef resources.
Global climate change, however, is not alone in
causing the loss of coral reefs across the Earth. The stress
to coral reefs across the world is being aggravated by
coastal land practices, overfishing and marine based
pollution. These influences alone have been estimated to
potentially remove over 50% of coral reefs over the next
30-50 years, even before we factor in the effects of
climate change. Other influences such as changing
chemical properties of sea water are also inflicting
pressure on coral reefs, compounding the primary cause
of rising sea temperatures.
Climate change and the other human influences are
likely to have dramatic impacts on the world’s coral reefs
over the next 50 years. Under some scenarios, coral
cover degrades rapidly to less than 5% of the total cover
on a coral reef. If this happens, major changes to fish
populations and the natural values of coral reefs will
occur. This will affect millions of reef users and
associated industries such as fisheries and tourism. How
much, is the critical question. Industries clearly differ in
their vulnerability. Global fishing industries, for
example, are already in crisis as fish stocks plummet (no
fish, no industry); tourism is proving more flexible and
resilient (no coral, changed business) but remains
vulnerable as the decline of coral populations continues.
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Is the Great Barrier Reef vulnerable?
Estimates of the climate change expected over the
coming century suggest that corals on the Great Barrier
Reef will experience seas that will be 2˚C to 6˚C warmer
than today’s seas by 2100. Torres Strait temperatures will
be found at the southern Great Barrier Reef as early as
2030. As with coral reefs elsewhere, thermal stress will
increase to levels that are several times higher than in 1998.
By the middle of this century, these levels will be exceeded
every year at all sites along the Great Barrier Reef.
Integrating the best available data on coral tolerance
with current climate models indicates that change is
inevitable for coral reefs like the Great Barrier Reef. The
implications are that the flora and fauna of the Great
Barrier Reef will change dramatically as climate change
gathers impetus. Even under the best case scenarios,
coral cover is likely to decrease to less than 5% on most
reefs by the middle of the century. Reefs will be devoid
of coral and dominated by seaweed and blue-green algae.
The rapid reduction in coral cover will have major
consequences for other organisms and reef functions.
Many coral-dependent organisms will become rare and
may become locally or globally extinct. Populations of
fish and other organisms that form the basis of fisheries
will change.
Coral reefs have already deteriorated due to a
combination of human misuse and climate change
induced bleaching events such as those in 1998 and
2002. This will have further implications for the tourist
industry as more degradation occurs, for commercial
fisheries through changing fish community structure and
abundance, and other activities such as recreational
fishing, indigenous hunting and fishing, and coastal
protection. Understanding and planning for this change
should be an imperative for the Australian and
Queensland governments.
already deteriorated
due to a combination of human misuse and climate change.
Coral reefs have
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Economic Analysis of Reef-related Industries
International and domestic tourism is the major reefbased industry. This sector has been the main driver of
regional growth. It is strongly orientated towards the
Tropical North with smaller nodes elsewhere, especially
the Whitsundays north of Mackay. Tropical North
Queensland has experienced the strongest economic
growth of about 6% per annum, driven by the growth in
international tourism.
The WWF Australia and Queensland Tourism Industry
Council report has developed a new measure of the
importance of ‘reef-interested’ tourism for the five
regions - a measure that considerably increases previous
estimates. In terms of contribution to the regional
economies, $1.4 billion of a total $2.1 billion represents
the estimated reef-interested component (68%). The reefinterested component is highest in Far North Queensland
both absolutely and relative to total tourism in the region.
Because interest in the Reef is so high, tourism is
naturally vulnerable to the deterioration of coral reefs despite the well-known resilience and adaptability of the
tourism industry.
The value of commercial fisheries is small relative to
tourism but remains socially and economically
important. Recreational fisheries are important socially
rather than economically for the regions, since they
appear to be largely practised by local residents and
therefore add little to the economic base.
CLIMATE CHANGE
The five regions along the Great Barrier Reef derive
major revenue from mining and mineral processing,
tourism, sugar cane farming and processing, fruit and
vegetable growing, and cattle grazing. These industries
provide most of the economic base for the five regions.
Aquaculture is a growth industry, backed by
Commonwealth Government policy. The Queensland
component of the Australian aquaculture industry has
been small to date, mainly because of stringent
government controls. It is expected to grow strongly as
further measures are taken to control fisheries, and new
technologies for containing pollution are adopted by the
aquaculture industry.
A healthy reef, covered in a stunning array of colourful hard corals. Credit: Triggerfish Images
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Possible Futures for Australia’s Great Barrier Reef
The aim of developing future scenarios is to look at
futures that include most credible eventualities so that
we can then plan responses. One story may tell of rapid
population growth, unequal rates of economic growth,
and widening income gaps both domestically and
internationally. Another story may stress environmental
and social care, international cooperation and
technology transfer, and moderate population and
economic growth benefiting all countries and income
groups. There is no way to say whether any one of these
futures is more likely to happen than another.
Constructing these scenarios allows us
to
for the
plan
The Third Assessment Report of the
Intergovernmental Panel for Climate Change
(IPCC) developed four global futures along two
dimensions: 1 economic/environmental (A versus B)
and 1 global/regional (1 versus 2).
Economy
A2
Global
Regional
B1
B2
Environmental
Driving Forces
Figure 2: Schematic illustration of SRES scenarios. The four scenario ‘families’ are
illustrated, very simplistically, as branches of a two-dimensional tree. In reality, the
four scenario families share a space of a much higher dimensionality given the
numerous assumptions needed to define any given scenario in a particular
modelling approach. The schematic diagram illustrates that the scenarios build on
the main driving forces of greenhouse gas emissions. Each scenario family is
based on a common specification of some of the main driving forces. (Text quoted
from IPCC, Special Report on Emissions Scenarios, 2000, Chapter 1.7.2.)
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While the IPCC scenarios started with descriptions of
possible futures in narrative form (storylines), their
purpose was to serve as a basis for numerical
projections of population, GDP and greenhouse gas
emissions. See Figure 2.
From this international perspective, the WWF Australia
and Queensland Tourism Industry Council report
developed successive storylines for Australia, the Great
Barrier Reef, reef-based industries (tourism and fisheries),
and other industries driving the regional economies. The
final step was to derive numerical projections for each
scenario for tourism and fisheries and the economic
impact on each of the five regions along the Reef.
The Four Scenarios
A1
future.
Scenario A1 is driven by strong economic growth and
strong global institutions, and initially relies strongly on
fossil fuels. Population reaches a maximum of 8.7 billion
in 2050 and then declines. As time goes, however, fossil
fuels become scarcer and more expensive to extract, and
the trend in our version in the report veers towards a more
environmentally sensitive ‘B1’ world from the 2040s.
In the A2 scenario, the world is divided into separate
geopolitical trading blocks driven by economic growth
considerations but without strong unifying forces. Global
population keeps rising towards 15 billion in 2100. This
is the worst-case scenario which basically fails to cope
with the continued increase in greenhouse gases.
In the B1 scenario, global environmental concerns take
precedence over economic growth, and the outcome in
terms of reversing the increase in greenhouse gases is the
most favourable among the four scenarios. Global
population peaks at around the same level as in the A1
Scenario in 2050and then starts to decline.
Finally, scenario B2 depicts a world with strong local
community drivers rather than global environmental
cooperation. To capitalise on both local and global drivers
in order to build a best case scenario for the Great Barrier
Reef region, the B2 scenario is assumed to merge into the
more globally orientated B1 scenario towards the middle
of the century
Bleached coral at Heron Island during the 2002 mass bleaching event. This was the worst bleaching
event in the history of the Great Barrier Reef Marine Park. Credit: Ove Hoegh-Guldberg
The four bars show the total direct economic losses to
tourism and fisheries plus flow-on effects for the five
regional economies along the Reef.
CLIMATE CHANGE
The results of the four scenarios are illustrated by
Figure 3, showing the total economic cost up to 2020
associated with a degrading Great Barrier Reef.
Figure 3: Total estimated economic loss according to the four scenarios over the
first two decades of the 21st Century. Further losses will follow in subsequent
decades which will increase the differences, as the annual loss accelerates in the
A2 scenario indefinitely, and in A1 at least into the second half of the century.
Annual losses will grow at a decreasing rate in the B1 and B2 scenarios, and may
stabilise from mid-century. The chart shows industry losses only; there is no
attempt to value ecosystem services and other indirect and future use, or any
bequest and other non-use functions of the World Heritage Area.
In the global economic growth-driven A1 scenario
where environmental considerations take a relative back
seat at least over the first two decades, the total estimated
loss to local Queensland communities by 2020 amounts
to $A5.6 billion. The fragmented A2 world represents a
worst case to be vigorously avoided for the regions along
the Reef. Here the total estimated loss to local
Queensland communities amounts to $8 billion by 2020,
the highest projected loss of the four scenarios.
The two scenarios giving higher priority to
environmental matters will still see losses in economic
product as a result of climate change, because total
greenhouse gas emissions cannot be reduced overnight.
The total estimated loss under scenario B1 is $4.5
billion up to 2020. The fourth scenario, B2, adds a strong
local community input to the general environmental
priorities adopted in B1. Up to 2020, it shows the lowest
loss of $3.5 billion. Key findings for each of the four
scenarios are shown in Table 1.
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Table 1: Scenarios to 2020 in the Great Barrier Reef Region
Base
Year 2001
2020 (unadjusted for reef damage) per annum
A1
A2
B1
B2
Estimated Gross Regional Product ($million)
Tourism
Wild fisheries
Aquaculture
2,024
2,947
2,686
2,949
2,949
115
138
121
133
133
23
123
106
123
123
29,500
39,900
26,600
36,100
36,100
39,000
48,500
38,000
44,000
44,000
3,374
3,374
3,374
3,374
3,374
423
2,517
2,396
2,517
2,517
405,000
464,700
351,400
431,300
412,700
Regional flow-on (multiplier) effect
Total Gross Regional Product
Estimated employment (persons)
Tourism
Wild fisheries
Aquaculture
Regional flow-on (multiplier) effect
Total regional employment
Even the best-case scenarios involve
greater environmental concern
than we have
yet experienced despite recent government initiatives.
Bleached coral at Great Keppel Island during the 2002 mass bleaching event.
Healthy corals are a major draw for dive tourism in Australia and overseas, and the tourism industry is likely to suffer if reef degradation persists. Credit: Ove Hoegh-Guldberg
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(in constant 2001 dollars)
Projected cost of reef damage 2020
A2
B1
B2
2020 (adjusted for reef damage) per annum
A1
A2
B1
B2
288
403
177
127
2,659
2,283
2,272
2,822
42
40
51
48
96
81
82
85
–
–
50
–
123
106
73
123
264
355
222
140
594
798
500
315
39,300
25,800
35,600
35,800
4,700
5,700
2,600
1,900
43,800
32,300
41,400
42,100
1,026
1,142
1,298
1,230
2,348
2,232
2,076
2,144
–
–
1,023
–
2,517
2,396
1,494
2,517
4,581
5,474
3,937
2,504
10,307
12,316
8,858
5,634
454,400
339,100
422,400
407,100
CLIMATE CHANGE
A1
This provides
the
most important guidepost
for the policies we need to adopt.
9
Policy Implications
Making the best case scenario explored in the WWF Australia and
Queensland Tourism Industry Council report a reality will be critical to the
livelihoods and lifestyles of Australians that currently depend on a healthy
sustainable Great Barrier Reef. To get there, we must turn our policies in
the right direction now.
International Policies
The Great Barrier Reef is an international and national icon and draws millions of visitors to Australia every year.
The most likely outlook for the Great Barrier Reef over coming decades is more frequent mass coral bleaching
events due to increased sea surface temperatures. We can try to minimise the damage from these events if we keep
global temperature rise due to human activities to no more than 2 degrees.
In order to achieve this, developed countries like
Australia will need to have reduced their emissions by
80% (based on 1990 levels) by 2050. By 2100, emissions
will need to be close to zero.
• The Australian Government should actively engage
in discussion on how to achieve deeper cuts in
greenhouse gas emissions in the second commitment
period of the Kyoto Protocol.
To achieve such major reductions, we must start now.
If we are to minimise damage to the Great Barrier Reef,
then we must start with the following.
• The Australian Government can take a positive role
in promoting and helping to fund the replacement of oil
and coal-based energy technologies with clean,
renewable and affordable energy sources in developing
countries.
• The Kyoto Protocol should enter into force as soon as
possible, with Australian Government ratification. It is a
small but necessary step.
Bleached coral on reefs off Great Keppel Island, in May 2002.
Bleaching occurs when corals are stressed, usually as a result of been exposed to excessively warm water for an extended period of time. Credit: Ove Hoegh-Guldberg
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International Policies
The following actions would enable Australia to play its part in a global effort to avoid dangerous climate change:
• The Australian Government’s 2% national
Mandatory Renewable Energy Target (MRET) should
be strengthened. Burning fossil fuels for energy
contributed 48% of Australia’s greenhouse gas
emissions in 2001. A target of 10% renewable energy by
2010 would not only assist in turning the tide in the
battle with CO2 emissions but could also have net
benefits for rural and regional Australia.
• A national greenhouse gas emissions trading scheme
with a tight cap on emissions would be a very positive
step to reduce greenhouse emissions using market
mechanisms. Reform of the tax system should go even
further to include other environmentally motivated
reforms associated with water use and quality, solid and
industrial wastes, and the use of other natural amenities.
• The Australian Government should promote other
clean energy technologies that help to reduce national
greenhouse gas levels. For example a national target for
the uptake of co-generation for large industrial energy
users would provide an incentive for some of the biggest
users of coal-fired electricity to install gas fired
generators on site.
• State Governments are responsible for the future
direction of Australia’s electricity infrastructure. They
need to ensure that any new fossil fuel power stations
meet best-practice emissions intensity at the level of a
combined cycle gas turbine.
CLIMATE CHANGE
Domestic Policies
• Australia has great potential to improve the end
use efficiency of its energy. The Australian
Government is best placed to take the lead on this so
that standards are nationally consistent. The first step
could be the introduction of mandatory energy
efficiency standards for all new and existing buildings.
Energy performance standards for appliances and
equipment should also be tightened.
• The Australian, State and Territory Governments
need to substantially increase funding for public
transport and rail freight in order to better control
transport emissions. It is also important that mandatory
fuel efficiency standards for new cars and commercial
vehicles are introduced.
• A rapid end to broadscale clearing of remnant
bushland across in Queensland and Tasmania should be
delivered as soon as possible by the Commonwealth and
relevant State governments.
Policy implications
for the Great Barrier Reef
Even if global warming is constrained to 2-2.5˚C,
coral reefs are likely to experience widespread and
serious damage. To minimise the extent of damage to the
Great Barrier Reef, local efforts to increase the ecological
resilience of the Reef are vital. Resilience, or the capacity
to recover from major disturbances such as coral
bleaching, can be promoted by governments
implementing the following:
• Thirdly, the Queensland Government must put in
place fisheries management plans for those fisheries
without them in order to reduce fishing effort to
sustainable levels.Destructive fishing practices such as
seafloor trawling, which damage the seafloor and result
in large volumes of bycatch, should be phased out in
order to maintain and potentially restore ecosystem
integrity and resilience.
• The single most important initiative is to implement
a comprehensive network of no-take zones (marine
sanctuaries) throughout the Great Barrier Reef Marine
Park. The Australian Government’s new zoning plan for
the Great Barrier Reef, tabled in Parliament in December
2003, includes such a network and will enhance the
resilience of the reef ecosystem and minimise
biodiversity losses.
The full report is on line at the WWF Australia Great
Barrier Reef website: www.wwf.org.au.
• Secondly, the Reef Water Quality Protection Plan,
which aims to reduce water quality problems arising
from poor land management practices in the catchment
adjacent to the World Heritage area, needs to be
adequately funded and efficiently implemented.
Critical to the livelihoods
and lifestyles of Australians
who depend on a healthy Great Barrier Reef
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Healthy, colourful hard corals. Credit: Triggerfish Images
mission is to
conserve biodiversity in
WWF Australia's
Australia and the Oceania region.
WWF AUSTRALIA
For more information, contact:
WWF Australia
GPO Box 528
Sydney NSW 2001
Toll free: 1800 032 551
www.wwf.org.au
[email protected]
ISBN: 1 875941 59 2
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Authors: Professor Ove Hoegh-Guldberg
Hans Hoegh-Guldberg
WWF is one of the world's largest and most experience independent conservation organisations, with almost
5 million supporters and a global network active in more than 90 countries.
WWF Australia's mission is to conserve biodiversity in Australia and the Oceania region. We have 180 active
projects focussing on five priority areas that address current conservation challenges.
For in depth information on all our work, go on-line at www.wwf.org.au or call our toll free number
1800 032 551.