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25
Australasia
Coordinating Lead Authors:
Andy Reisinger (New Zealand), Roger L. Kitching (Australia)
Lead Authors:
Francis Chiew (Australia), Lesley Hughes (Australia), Paul C.D. Newton (New Zealand),
Sandra S. Schuster (Australia), Andrew Tait (New Zealand), Penny Whetton (Australia)
Contributing Authors:
Jon Barnett (Australia), Susanne Becken (New Zealand), Paula Blackett (New Zealand),
Sarah Boulter (Australia), Andrew Campbell (Australia), Daniel Collins (New Zealand),
Jocelyn Davies (Australia), Keith Dear (Australia), Stephen Dovers (Australia), Kyla Finlay
(Australia), Bruce Glavovic (New Zealand), Donna Green (Australia), Don Gunasekera
(Australia), Simon Hales (New Zealand), John Handmer (Australia), Garth Harmsworth
(New Zealand), Alistair Hobday (Australia), Mark Howden (Australia), Graeme Hugo
(Australia), Sue Jackson (Australia), David Jones (Australia), Darren King (New Zealand),
Miko Kirschbaum (New Zealand), Jo Luck (Australia), Yiheyis Maru (Australia), Jan McDonald
(Australia), Kathy McInnes (Australia), Johanna Mustelin (Australia), Barbara Norman
(Australia), Grant Pearce (New Zealand), Susan Peoples (New Zealand), Ben Preston (USA),
Joseph Reser (Australia), Penny Reyenga (Australia), Mark Stafford-Smith (Australia),
Xiaoming Wang (Australia), Leanne Webb (Australia)
Review Editors:
Blair Fitzharris (New Zealand), David Karoly (Australia)
This chapter should be cited as:
Reisinger
, A., R.L. Kitching, F. Chiew, L. Hughes, P.C.D. Newton, S.S. Schuster, A. Tait, and P. Whetton, 2014:
Australasia. In: Climate Change 2014: Impacts, Adaptation, and Vulnerability. Part B: Regional Aspects.
Contribution of Working Group II to the Fifth Assessment Report of the Intergovernmental Panel on Climate
Change [Barros, V.R., C.B. Field, D.J. Dokken, M.D. Mastrandrea, K.J. Mach, T.E. Bilir, M. Chatterjee, K.L. Ebi,
Y.O. Estrada, R.C. Genova, B. Girma, E.S. Kissel, A.N. Levy, S. MacCracken, P.R. Mastrandrea, and L.L. White
(eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, pp. 1371-1438.
25
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Executive Summary ......................................................................................................................................................... 1374
25.1. Introduction and Major Conclusions from Previous Assessments ........................................................................ 1377
25.2. Observed and Projected Climate Change ............................................................................................................. 1377
25.3. Socioeconomic Trends Influencing Vulnerability and Adaptive Capacity .............................................................. 1379
25.3.1. Economic, Demographic, and Social Trends .................................................................................................................................... 1379
25.3.2. Use and Relevance of Socioeconomic Scenarios in Adaptive Capacity/Vulnerability Assessments .................................................. 1382
25.4. Cross-Sectoral Adaptation: Approaches, Effectiveness, and Constraints .............................................................. 1382
25.4.1. Frameworks, Governance, and Institutional Arrangements ............................................................................................................. 1382
25.4.2. Constraints on Adaptation and Leading Practice Models ............................................................................................................... 1382
Box 25-1. Coastal Adaptation—Planning and Legal Dimensions .............................................................................................. 1384
25.4.3. Sociocultural Factors Influencing Impacts of and Adaptation to Climate Change ........................................................................... 1385
25.5. Freshwater Resources ........................................................................................................................................... 1387
25.5.1. Observed Impacts ........................................................................................................................................................................... 1387
25.5.2. Projected Impacts ........................................................................................................................................................................... 1387
25.5.3. Adaptation ..................................................................................................................................................................................... 1389
Box 25-2. Adaptation through Water Resources Policy and Management in Australia ............................................................ 1389
25.6. Natural Ecosystems ............................................................................................................................................... 1390
25.6.1. Inland Freshwater and Terrestrial Ecosystems ................................................................................................................................. 1390
25.6.1.1. Observed Impacts ............................................................................................................................................................ 1390
25.6.1.2. Projected Impacts ............................................................................................................................................................ 1390
25.6.1.3. Adaptation ...................................................................................................................................................................... 1391
25.6.2. Coastal and Ocean Ecosystems ...................................................................................................................................................... 1392
25.6.2.1. Observed Impacts ............................................................................................................................................................ 1392
25.6.2.2. Projected Impacts ............................................................................................................................................................ 1392
25.6.2.3. Adaptation ...................................................................................................................................................................... 1392
Box 25-3. Impacts of a Changing Climate in Natural and Managed Ecosystems .......................................................... 1394
25.7. Major Industries .................................................................................................................................................... 1393
25.7.1. Production Forestry ......................................................................................................................................................................... 1393
25.7.1.1. Observed and Projected Impacts ..................................................................................................................................... 1395
25.7.1.2. Adaptation ...................................................................................................................................................................... 1396
25.7.2. Agriculture ...................................................................................................................................................................................... 1396
25.7.2.1. Projected Impacts and Adaptation—Livestock Systems .................................................................................................. 1396
25.7.2.2. Projected Impacts and Adaptation—Cropping ................................................................................................................ 1397
Table of Contents
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25
Box 25-4. Biosecurity ..................................................................................................................................................... 1397
Box 25-5. Climate Change Vulnerability and Adaptation in Rural Areas ....................................................................... 1398
25.7.2.3. Integrated Adaptation Perspectives ................................................................................................................................. 1399
Box 25-6. Climate Change and Fire ................................................................................................................................ 1400
25.7.3. Mining ............................................................................................................................................................................................ 1399
25.7.4. Energy Supply, Transmission, and Demand ..................................................................................................................................... 1400
25.7.5. Tourism ........................................................................................................................................................................................... 1401
25.7.5.1. Projected Impacts ............................................................................................................................................................ 1401
25.7.5.2. Adaptation ...................................................................................................................................................................... 1401
25.8. Human Society ...................................................................................................................................................... 1402
25.8.1. Human Health ................................................................................................................................................................................ 1402
25.8.1.1. Observed Impacts ............................................................................................................................................................ 1402
25.8.1.2. Projected Impacts ............................................................................................................................................................ 1402
Box 25-7. Insurance as Climate Risk Management Tool ................................................................................................ 1403
Box 25-8. Changes in Flood Risk and Management Responses ..................................................................................... 1404
25.8.1.3. Adaptation ...................................................................................................................................................................... 1405
25.8.2. Indigenous Peoples ......................................................................................................................................................................... 1405
25.8.2.1. Aboriginal and Torres Strait Islanders .............................................................................................................................. 1405
25.8.2.2. New Zealand Māori ......................................................................................................................................................... 1405
25.9. Interactions among Impacts, Adaptation, and Mitigation Responses .................................................................. 1406
Box 25-9. Opportunities, Constraints, and Challenges to Adaptation in Urban Areas .............................................................. 1406
25.9.1. Interactions among Local-Level Impacts, Adaptation, and Mitigation Responses ........................................................................... 1406
25.9.2. Intra- and Inter-regional Flow-on Effects among Impacts, Adaptation, and Mitigation .................................................................. 1408
Box 25-10. Land-based Interactions among Climate, Energy, Water, and Biodiversity ............................................................. 1409
25.10.Synthesis and Regional Key Risks ......................................................................................................................... 1410
25.10.1. Economy-wide Impacts and Potential of Mitigation to Reduce Risks ............................................................................................ 1410
25.10.2. Regional Key Risks as a Function of Mitigation and Adaptation ................................................................................................... 1410
25.10.3. The Role of Adaptation in Managing Key Risks, and Adaptation Limits ......................................................................................... 1412
25.11.Filling Knowledge Gaps to Improve Management of Climate Risks .................................................................... 1412
References ....................................................................................................................................................................... 1414
Frequently Asked Questions
25.1: How can we adapt to climate change if projected future changes remain uncertain? ................................................................... 1386
25.2: What are the key risks from climate change to Australia and New Zealand? ................................................................................. 1412
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Executive Summary
The regional climate is changing (very high confidence). The region continues to demonstrate long-term trends toward higher surface air
and sea surface temperatures, more hot extremes and fewer cold extremes, and changed rainfall patterns. Over the past 50 years, increasing
greenhouse gas concentrations have contributed to rising average temperature in Australia (high confidence) and New Zealand (medium
confidence) and decreasing rainfall in southwestern Australia (high confidence). {25.2; Table 25-1}
Warming is projected to continue through the 21st century (virtually certain) along with other changes in climate. Warming is
expected to be associated with rising snow lines (very high confidence), more frequent hot extremes, less frequent cold extremes (high
confidence), and increasing extreme rainfall related to flood risk in many locations (medium confidence). Annual average rainfall is expected to
decrease in southwestern Australia (high confidence) and elsewhere in most of far southern Australia and the northeast South Island and
northern and eastern North Island of New Zealand (medium confidence), and to increase in other parts of New Zealand (medium confidence).
Tropical cyclones are projected to increase in intensity but remain similar or decrease in numbers (low confidence), and fire weather is projected
to increase in most of southern Australia (high confidence) and many parts of New Zealand (medium confidence). Regional sea level rise will
very likely exceed the historical rate (1971–2010), consistent with global mean trends. {25.2; Table 25-1; Box 25-6; WGI AR5 13.5-6}
Uncertainty in projected rainfall changes remains large for many parts of Australia and New Zealand, which creates significant
challenges for adaptation. For example, projections for average annual runoff in far southeastern Australia range from little change to a
40% decline for 2°C global warming above current levels. The dry end of these scenarios would have severe implications for agriculture, rural
livelihoods, ecosystems, and urban water supply, and would increase the need for transformational adaptation (high confidence). {25.2, 25.5.1,
25.6.1, 25.7.2; Boxes 25-2, 25-5}
Recent extreme climatic events show significant vulnerability of some ecosystems and many human systems to current climate
variability (very high confidence), and the frequency and/or intensity of such events is projected to increase in many locations
(medium to high confidence).
For example, high sea surface temperatures have repeatedly bleached coral reefs in northeastern Australia
(since the late 1970s) and more recently in western Australia. Recent floods in Australia and New Zealand caused severe damage to infrastructure
and settlements and 35 deaths in Queensland alone (2011); the Victorian heat wave (2009) increased heat-related morbidity and was associated
with more than 300 excess deaths, while intense bushfires destroyed more than 2000 buildings and led to 173 deaths; and widespread drought
in southeast Australia (1997–2009) and many parts of New Zealand (2007–2009; 2012–2013) resulted in substantial economic losses (e.g.,
regional gross domestic product (GDP) in the southern Murray-Darling Basin was below forecast by about 5.7% in 2007–2008, and New
Zealand lost about NZ$3.6 billion in direct and off-farm output in 2007–2009). {25.6.2, 25.8.1; Table 25-1; Boxes 25-5, 25-6, 25-8}
Without adaptation, further changes in climate, atmospheric carbon dioxide (CO
2
), and ocean acidity are projected to have
substantial impacts on water resources, coastal ecosystems, infrastructure, health, agriculture, and biodiversity (high confidence).
Freshwater resources are projected to decline in far southwest and far southeast mainland Australia (high confidence) and for rivers originating
in the northeast of the South Island and east and north of the North Island of New Zealand (medium confidence). Rising sea levels and increasing
heavy rainfall are projected to increase erosion and inundation, with consequent damages to many low-lying ecosystems, infrastructure, and
housing; increasing heat waves will increase risks to human health; rainfall changes and rising temperatures will shift agricultural production
zones; and many native species will suffer from range contractions and some may face local or even global extinction. {25.5.1, 25.6.1-2, 25.7.2,
25.7.4; Boxes 25-1, 25-5, 25-8}
Some sectors in some locations have the potential to benefit from projected changes in climate and increasing atmospheric CO
2
(high confidence). Examples include reduced winter mortality (low confidence), reduced energy demand for winter heating in New Zealand
and southern parts of Australia, and forest growth in cooler regions except where soil nutrients or rainfall are limiting. Spring pasture growth in
cooler regions would also increase and be beneficial for animal production if it can be utilized. {25.7.1-2, 25.7.4, 25.8.1}
Adaptation is already occurring and adaptation planning is becoming embedded in some planning processes, albeit mostly at the
conceptual rather than implementation level (high confidence).
Many solutions for reducing energy and water consumption in urban
areas with co-benefits for climate change adaptation (e.g., greening cities and recycling water) are already being implemented. Planning for
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Australasia Chapter 25
reduced water availability in southern Australia and for sea level rise in both countries is becoming adopted widely, although implementation
of specific policies remains piecemeal, subject to political changes, and open to legal challenges. {25.4; Boxes 25-1, 25-2, 25-9}
Adaptive capacity is generally high in many human systems, but implementation faces major constraints, especially for
transformational responses at local and community levels (high confidence). Efforts to understand and enhance adaptive capacity and
adaptation processes have increased since the AR4, particularly in Australia. Constraints on implementation arise from: absence of a consistent
information base and uncertainty about projected impacts; limited financial and human resources to assess local risks and to develop and
implement effective policies and rules; limited integration of different levels of governance; lack of binding guidance on principles and priorities;
different attitudes toward the risks associated with climate change; and different values placed on objects and places at risk. {25.4, 25.10.3;
Table 25-2; Box 25-1}
Indigenous peoples in both Australia and New Zealand have higher than average exposure to climate change because of a heavy
reliance on climate-sensitive primary industries and strong social connections to the natural environment, and face particular
constraints to adaptation (medium confidence).
Social status and representation, health, infrastructure and economic issues, and engage-
ment with natural resource industries constrain adaptation and are only partly offset by intrinsic adaptive capacity (high confidence). Some
proposed responses to climate change may provide economic opportunities, particularly in New Zealand related to forestry. Torres Strait
communities are vulnerable even to small sea level rises (high confidence). {25.3, 25.8.2}
We identify eight regional key risks during the 21st century based on the severity of potential impacts for different levels of
warming, uniqueness of the systems affected, and adaptation options (high confidence). These risks differ in the degree to which they
can be managed via adaptation and mitigation, and some are more likely to be realized than others, but all warrant attention from a risk-
management perspective.
Some potential impacts can be delayed but now appear very difficult to avoid entirely, even with globally effective mitigation and planned
adaptation:
Significant change in community composition and structure of coral reef systems in Australia, driven by increasing sea surface
temperatures and ocean acidification; the ability of corals to adapt naturally to rising temperatures and acidification appears limited
and insufficient to offset the detrimental effects. {25.6.2, 30.5; Box CC-CR}
Loss of montane ecosystems and some native species in Australia, driven by rising temperatures and snow lines, increased fire risk, and
drying trends; fragmentation of landscapes, limited dispersal, and limited rate of evolutionary change constrain adaptation options. {25.6.1}
Some impacts have the potential to be severe but can be reduced substantially by globally effective mitigation combined with adaptation,
with the need for transformational adaptation increasing with the rate and magnitude of climate change:
Increased frequency and intensity of flood damage to settlements and infrastructure in Australia and New Zealand, driven by increasing
extreme rainfall although the amount of change remains uncertain; in many locations, continued reliance on increased protection
alone would become progressively less feasible. {25.4.2, 25.10.3; Table 25-1; Box 25-8}
Constraints on water resources in southern Australia, driven by rising temperatures and reduced cool-season rainfall; integrated
responses encompassing management of supply, recycling, water conservation, and increased efficiency across all sectors are available
and some are being implemented in areas already facing shortages. {25.2, 25.5.2; Box 25-2}
Increased morbidity, mortality, and infrastructure damages during heat waves in Australia, resulting from increased frequency and
magnitude of extreme high temperatures; vulnerable populations include the elderly and those with existing chronic diseases; population
increases and aging trends constrain effectiveness of adaptation responses. {25.8.1}
Increased damages to ecosystems and settlements, economic losses, and risks to human life from wildfires in most of southern
Australia and many parts of New Zealand
, driven by rising temperatures and drying trends; local planning mechanisms, building
design, early warning systems, and public education can assist with adaptation and are being implemented in regions that have
experienced major events. {25.2, 25.6.1, 25.7.1; Table 25-1; Box 25-6}
For some impacts, severity depends on changes in climate variables that span a particularly large range, even for a given global temperature
change. The most severe changes would present major challenges if realized:
Increasing risks to coastal infrastructure and low-lying ecosystems in Australia and New Zealand from continuing sea level rise, with
widespread damages toward the upper end of projected sea level rise ranges
; managed retreat is a long-term adaptation strategy for
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25
human systems but options for some natural ecosystems are limited owing to the rapidity of change and lack of suitable space for
landward migration. Risks from sea level rise continue to increase beyond 2100 even if temperatures are stabilized. {25.4.2, 25.6.1-2;
Table 25-1; Box 25-1; WGI AR5 13.5}
Significant reduction in agricultural production in the Murray-Darling Basin and far southeastern and southwestern Australia if scenarios
of severe drying are realized; more efficient water use, allocation, and trading would increase the resilience of systems in the near term
but cannot prevent significant reductions in agricultural production and severe consequences for ecosystems and some rural communities
at the dry end of the projected changes. {25.2, 25.5.2, 25.7.2; Boxes 25-2, 25-5}
Significant synergies and trade-offs exist between alternative adaptation responses, and between mitigation and adaptation
responses; interactions occur both within Australasia and between Australasia and the rest of the world (very high confidence).
Increasing efforts to mitigate and adapt to climate change imply an increasing complexity of interactions, particularly at the intersections
among water, energy, and biodiversity, but tools to understand and manage these interactions remain limited. Flow-on effects from climate
change impacts and responses outside Australasia have the potential to outweigh some of the direct impacts within the region