Editing IPCC:AR6/WGII/Chapter-11 (section)

=== 11.3.1 Terrestrial and Freshwater Ecosystems ===

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==== 11.3.1.1 Observed Impacts ====

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Widespread and severe impacts on ecosystems and species are now evident across the region ( ''very high confidence'' ) (Table 11.4). Climate impacts reflect both ongoing change and discrete extreme weather events ( [[#Harris--2018|Harris et al., 2018]] ), and the climatic change signal is emerging despite confounding influences ( [[#Hoffmann--2019|Hoffmann et al., 2019]] ). Fundamental shifts are observed in the structure and composition of some ecosystems and associated services (Table 11.4). Impacts documented for species include global and local extinctions, severe regional population declines and phenotypic responses (Table 11.4). In terrestrial and freshwater ecosystems, land use impacts are interacting with climate, resulting in significant changes to ecosystem structure, composition and function ( [[#Bergstrom--2021|Bergstrom et al., 2021]] ), with some landscapes experiencing catastrophic impacts (Table 11.4). Some of the observed changes may be irreversible where projected impacts on ecosystems and species persist (Table 11.5). Of note is the global extinction of an endemic mammal species, the Bramble Cay melomys ( ''Melomys rubicola'' ), from the loss of habitat attributable in part to sea level rise (SLR) and storm surges in the Torres Strait (Table 11.4).

Natural forest and woodland ecosystem processes are experiencing differing impacts and responses depending on the climate zone ( ''high confidence'' ). In Australia, an overall increase in the forest fire danger index, associated with warming and drying trends (Table 11.2a), has been observed particularly for southern and eastern Australia in recent decades (Box 11.1). The 2019–2020 mega wildfires of south eastern Australia burnt between 5.8 and 8.1 million hectares of mainly temperate broadleaf forest and woodland, but with substantial areas of rainforest also impacted, and were unprecedented in their geographic location, spatial extent and forest types burnt ( [[#Boer--2020|Boer et al., 2020]] ; [[#Nolan--2020|Nolan et al., 2020]] ; [[#Abram--2021|Abram et al., 2021]] ; [[#Collins--2021|Collins et al., 2021]] ; [[#Godfree--2021|Godfree et al., 2021]] ). The human influence on these events is evident ( [[#Abram--2021|Abram et al., 2021]] ; [[#van%20Oldenborgh--2021|van Oldenborgh et al., 2021]] ) (Box 11.1). The fires had significant consequences for wildlife ( [[#Hyman--2020|Hyman et al., 2020]] ; [[#Nolan--2020|Nolan et al., 2020]] ; [[#Ward--2020|Ward et al., 2020]] ) (Box 11.1) and flow-on impacts for aquatic fauna ( [[#Silva--2020|Silva et al., 2020]] ). In southern Australia, deeply rooted native tree species can access soil and groundwater resources during drought, providing a level of natural resilience ( [[#Bell--2020|Bell and Nikolaus Callow, 2020]] ; [[#Liu--2020|Liu et al., 2020]] ). However, the Northern Jarrah forests of south western Australia have experienced tree mortality and dieback from long-term precipitation decline and acute heatwave-compounded drought ( [[#Wardell-Johnson--2015|Wardell-Johnson et al., 2015]] ; [[#Matusick--2018|Matusick et al., 2018]] ). While there is limited information on observed impacts for New Zealand, increased mast seeding events in beech forest ecosystems that stimulate invasive population irruptions have been recorded ( [[#Schauber--2002|Schauber et al., 2002]] ; [[#Tompkins--2013|Tompkins et al., 2013]] ).

'''Table 11.2a |''' Observed climate change for Australia.

{| class="wikitable"
|-
! Climate variable

! Observed change

! References

|-
| Air temperature over land

| Increased by 1.4°C from 1910 to 2019, with 2019 being the warmest year; 9 of the 10 warmest on record have occurred since 2005; clear anthropogenic attribution.

| ( [[#BoM%20and%20CSIRO--2020|BoM and]] [[#CSIRO--2020|CSIRO, 2020]] ; [[#Trewin--2020|Trewin et al., 2020]] ; BoM, 2021a; [[#Gutiérrez--2021|Gutiérrez et al., 2021]] )

|-
| Sea surface temperature

| Increased by 1.0°C from 1900 to 2019 (0.09°C/decade), with an increase of 0.16°C–0.20°C/decade since 1950 in the southeast. Eight of the 10 warmest years on record have occurred since 2010.

| ( [[#BoM%20and%20CSIRO--2020|BoM and]] [[#CSIRO--2020|CSIRO, 2020]] )

|-
| Air temperature extremes over land

| More extremely hot days and fewer extremely cold days in most regions. Weaker warming trends in minimum temperatures in southeast Australia compared to elsewhere during 1960–2016. Frost frequency in southeast and southwest Australia has been relatively unchanged since the 1980s. Very high monthly maximum or minimum temperatures that occurred around 2% of the time in the past (1960–1989) now occur 11–12% of the time (2005–2019). Multi-day heatwave events have increased in frequency and duration across many regions since 1950. In 2019, the national average maximum temperature exceeded the 99th percentile on 43 days (more than triple the number in any of the years prior to 2000) and exceeded 39°C on 33 days (more than the number observed from 1960 to 2018 combined).

| ( [[#Perkins-Kirkpatrick--2016|Perkins-Kirkpatrick et al., 2016]] ; [[#Alexander--2017|Alexander and Arblaster, 2017]] ; [[#Pepler--2018|Pepler et al., 2018]] ; [[#BoM%20and%20CSIRO--2020|BoM and]] [[#CSIRO--2020|CSIRO, 2020]] ; [[#Perkins-Kirkpatrick--2020|Perkins-Kirkpatrick and Lewis, 2020]] ; [[#Trancoso--2020|Trancoso et al., 2020]] )

|-
| Sea temperature extremes

| Intense marine heatwave in 2011 near western Australia (peak intensity 4°C, duration 100 days). The likelihood of an event of this duration is estimated to be about five times higher than under pre-industrial conditions. Marine heatwave over northern Australia in 2016 (peak intensity 1.5°C, duration 200 days). Marine heatwave in the Tasman Sea and around southeast mainland Australia and Tasmania from September 2015 to May 2016 (peak intensity 2.5°C, duration 250 days)—likelihood of an event of this intensity and duration has increased about 50-fold. Marine heatwave in the Tasman Sea from November 2017 to March 2018 (peak intensity 3°C, duration 100 days). Marine heatwave on the GBR in 2020 (peak intensity 1.2°C, duration 90 days)

| ( [[#BoM%20and%20CSIRO--2018|BoM and]] [[#CSIRO--2018|CSIRO, 2018]] ; [[#BoM--2020|BoM, 2020]] ; [[#Laufkötter--2020|Laufkötter et al., 2020]] ; [[#Oliver--2021|Oliver et al., 2021]] )

|-
| Rainfall

| Northern Australian rainfall has increased since the 1970s, with an attributable human influence. April to October rainfall has decreased 16% since the 1970s in southwestern Australia (partly due to human influence) and 12% from 2000–2019 in south-eastern Australia. The lowest recorded average rainfall in Australia occurred in 2019.

| ( [[#Delworth--2014|Delworth and Zeng, 2014]] ; [[#Knutson--2018|Knutson and Zeng, 2018]] ; [[#Dey--2019|Dey et al., 2019]] ; [[#BoM%20and%20CSIRO--2020|BoM and]] [[#CSIRO--2020|CSIRO, 2020]] ; BoM, 2021a)

|-
| Rainfall extremes

| Hourly extreme rainfall intensities increased by 10–20% in many locations between 1966 to1989 and 1990 to 2013. Daily rainfall associated with thunderstorms increased 13–24% from 1979 to 2016, particularly in northern Australia. Daily rainfall intensity increased in the northwest from 1950 to 2005 and in the east from 1911 to 2014 and decreased in the southwest and Tasmania from 1911 to 2010.

| ( [[#Donat--2016|Donat et al., 2016]] ; [[#Alexander--2017|Alexander and Arblaster, 2017]] ; [[#Evans--2017|Evans et al., 2017]] ; [[#Guerreiro--2018|Guerreiro et al., 2018]] ; [[#Dey--2019|Dey et al., 2019]] ; [[#BoM%20and%20CSIRO--2020|BoM and]] [[#CSIRO--2020|CSIRO, 2020]] ; [[#Bruyère--2020|Bruyère et al., 2020]] ; [[#Dowdy--2020|Dowdy, 2020]] ; [[#Dunn--2020|Dunn et al., 2020]] ; [[#Gutiérrez--2021|Gutiérrez et al., 2021]] )

|-
| Drought

| Major Australian droughts occurred in 1895–1902, 1914–1915, 1937–1945, 1965–1968, 1982–1983, 1997–2009 and 2017–2019. Fewer droughts have occurred across most of northern and central Australia since the 1970s, and more droughts have occurred in the southwest since the 1970s; drought trends in the southeast have been mixed since the late 1990s.

| ( [[#Gallant--2013|Gallant et al., 2013]] ; [[#Delworth--2014|Delworth and Zeng, 2014]] ; [[#Alexander--2017|Alexander and Arblaster, 2017]] ; [[#Dai--2017|Dai and Zhao, 2017]] ; [[#Knutson--2018|Knutson and Zeng, 2018]] ; [[#Dey--2019|Dey et al., 2019]] ; [[#Spinoni--2019|Spinoni et al., 2019]] ; [[#Dunn--2020|Dunn et al., 2020]] ; [[#Rauniyar--2020|Rauniyar and Power, 2020]] ; BoM, 2021b; [[#Seneviratne--2021|Seneviratne et al., 2021]] )

|-
| Wind speed

| Wind speed decreased 0.067 m/s/decade over land in the period 1941–2016, with a decrease of 0.062 m/s/decade over land from 1979 to 2015, and a decrease of 0.05–0.10 m/s/decade over land from 1988 to 2019. Wind speed increased 0.02 m/s/year across the Southern Ocean during 1985–2018.

| ( [[#Troccoli--2012|Troccoli et al., 2012]] ; [[#Young--2019|Young and Ribal, 2019]] ; [[#Blunden--2020|Blunden and Arndt, 2020]] ; [[#Azorin-Molina--2021|Azorin-Molina et al., 2021]] )

|-
| Sea level rise

| Relative SLR was 3.4 mm/year from 1993 to 2019, which includes the influence of internal variability (e.g., ENSO) and anthropogenic greenhouse gases.

| ( [[#Watson--2020|Watson, 2020]] )

|-
| Fire

| An increase in the number of extreme fire weather days from July 1950 to June 1985 compared to July 1985 to June 2020, especially in the south and east, partly attributed to climate change. More dangerous conditions for extreme pyro convection events since 1979, particularly in south-eastern Australia. Extreme fire weather in 2019–2020 was at least 30% more likely due to climate change.

| ( [[#Dowdy--2018|Dowdy and Pepler, 2018]] ; [[#BoM%20and%20CSIRO--2020|BoM and]] [[#CSIRO--2020|CSIRO, 2020]] ; [[#van%20Oldenborgh--2021|van Oldenborgh et al., 2021]] )

|-
| Tropical cyclones and other storms

| Fewer tropical cyclones since 1982, with a 22% reduction in translation speed over Australian land areas in the period1949–2016. No significant trend in the number of East Coast Lows. From 1979 to 2016, thunderstorms and dry lightning decreased in spring and summer in northern and central Australia, decreased in the north in autumn, and increased in the southeast in all seasons. Convective rainfall intensity per thunderstorm increased by about 20% in the north and 10% in the south. An increase in the frequency of large to giant hail events across southeastern Queensland and northeastern and eastern New South Wales in the most recent decade. Seven major hail storms over eastern Australia from 2014 to 2020 and three major floods over eastern Australia from 2019 to 2021.

| ( [[#Pepler--2015b|Pepler et al., 2015b]] ; [[#Ji--2018|Ji et al., 2018]] ; [[#Kossin--2018|Kossin, 2018]] ; [[#BoM%20and%20CSIRO--2020|BoM and]] [[#CSIRO--2020|CSIRO, 2020]] ; [[#Dowdy--2020|Dowdy, 2020]] ; [[#ICA--2021|ICA, 2021]] ; [[#Bruyère--2020|Bruyère et al., 2020]] )

|-
| Snow

| At Spencers Creek (1830 m elevation) in NSW, annual maximum snow depth decreased 10% and length of snow season decreased 5% during 2000–2013 relative to 1954–1999. At Rocky Valley Dam (1650 m elevation) in Victoria, annual maximum snow depth decreased 5.7 cm/decade from 1954 to 2011. At Mt Hotham, Mt Buller and Falls Creek (1638–1760 m elevation), annual maximum snow depth decreased 15%/decade from 1988 to 2013.

| ( [[#Bhend--2012|Bhend et al., 2012]] ; [[#Fiddes--2015|Fiddes et al., 2015]] ; [[#Pepler--2015a|Pepler et al., 2015a]] ; [[#BoM%20and%20CSIRO--2020|BoM and]] [[#CSIRO--2020|CSIRO, 2020]] )

|-
| Ocean acidification

| Average pH of surface waters has decreased since the 1880s by about 0.1 (over 30% increase in acidity).

| ( [[#BoM%20and%20CSIRO--2020|BoM and]] [[#CSIRO--2020|CSIRO, 2020]] )

|}

'''Table 11.3b |''' Projected climate change for New Zealand. Projections are given for different RCPs (RCP2.6 is low, RCP4.5 is medium, RCP8.5 is high) and years (e.g., 20-year period centred on 2090). Uncertainty ranges are 5th–95th percentiles, and median projections are given in square brackets where possible. Preliminary projections (10th–90th percentiles) based on CMIP6 models are included for some climate variables from the [[#IPCC--2021|IPCC (2021)]] WGI report.

{| class="wikitable"
|-
! Climate variable

! Projected change (year, RCP) relative to 1986–2005

! References

|-
| Air temperature

| Annual mean temperature

* +0.2–1.3°C [0.7°C] (2040, RCP2.6), +0.5–1.7°C [1.0°C] (2040, RCP8.5), +0.1–1.4°C [0.7°C] (2090, RCP2.6), +2.0–4.6°C [3.0°C] (2090, RCP8.5)
* More warming in summer and autumn, less in winter and spring
* More warming in the north than the south
* Preliminary CMIP6 projections: +0.4°C–1.1°C (2050, SSP1-RCP2.6), +0.9°C–1.7°C (2050, SSP5-RCP8.5), +0.5°C–1.5°C (2090, SSP1-RCP2.6), +2.2°C–4.1°C (2090, SSP5-RCP8.5) relative to 1995–2014

| ( [[#MfE--2018|MfE, 2018]] );

( [[#IPCC--2021|IPCC, 2021]] )

|-
| Sea surface temperature

| * +1.0°C (2045, RCP8.5),
* +2.5°C (2090, RCP8.5).

| ( [[#Law--2018b|Law et al., 2018b]] )

|-
| Air temperature extremes

| * Annual frequency of days over 25°C may increase 20–60% (2040, RCP2.6) to 50–100% (2040, RCP8.5), and 20–60% (2090, RCP2.6) to 130–350% (2090, RCP8.5)
* Annual frost frequency may decrease 20–60% (2040, RCP2.6) to 30–70% (2040, RCP8.5), and 20–60% (2090, RCP2.6) to 70–95% (2090, RCP8.5).

| ( [[#MfE--2018|MfE, 2018]] )

|-
| Rainfall

| Annual mean rainfall

* Waikato, Auckland and Northland: −7 to +7% (2040, RCP2.6), −8 to +5% (2040, RCP8.5), −5 to +11% [+2%] (2090, RCP2.6), −15 to +12% [−2%] (2090, RCP8.5)
* Hawke’s Bay and Gisborne: −8 to +8% [−1%] (2040, RCP2.6), −12 to +7% [−2%] (2040, RCP8.5), −9 to +4% [−2%] (2090, RCP2.6), −15 to +15% [−3%] (2090, RCP8.5)
* Taranaki, Manawatū and Wellington: −4 to +9% [+1%] (2040, RCP2.6), −6 to +10% [+1%] (2040, RCP8.5), −6 to +15% [+3%] (2090, RCP2.6), −14 to +14% [+2%] (2090, RCP8.5)
* Tasman-Nelson and Marlborough: −3 to +5% [+1%] (2040, RCP2.6), −3 to +8% [+1%] (2040, RCP8.5), −4 to +8% [+2%] (2090, RCP2.6), −3 to +15% [+5%] (2090, RCP8.5)
* West coast and Southland: −4 to +12% [+3%] (2040, RCP2.6), −4 to +12% [+4%] (2040, RCP8.5), −2 to +18% [+5%] (2090, RCP2.6), −8 to +23% (2090, RCP8.5)
* Canterbury and Otago: −7 to +15% [+3%] (2040, RCP2.6), −7 to +19% [+3%] (2040, RCP8.5), −6 to +18% (2090, RCP2.6), −9 to +28% [+8%] (2090, RCP8.5)

| ( [[#Liu--2018|Liu et al., 2018]] ; [[#MfE--2018|MfE, 2018]] )

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| Rainfall extremes

| Intensity of daily rain with 20-year recurrence interval

* +2.8 to 7.2% [5%] (2040, RCP2.6)
* +4.2 to 10.4% [7%] (2040, RCP8.5)
* +2.8 to 7.2% [5%] (2090, RCP2.6)
* +12.6 to 31.5% [2%] (2090, RCP8.5)

| ( [[#MfE--2018|MfE, 2018]] )

|-
| Drought

| Increase in potential evapotranspiration deficit

* Northern and eastern North Island: 100–200 mm (2090, RCP8.5)
* Western North Island: 50–100 mm (2090, RCP8.5)
* Eastern South Island: 50–200 mm (2090, RCP8.5)
* Western South Island: 0–50 mm (2090, RCP8.5)

| ( [[#MfE--2018|MfE, 2018]] )

|-
| Wind speed

| 99th percentile of daily mean wind speed

* Northern North Island: 0 to −5% (2090, RCP8.5)
* Southern North Island: 0 to +5% (2090, RCP8.5)
* South Island: 0 to +10% (2090, RCP8.5)

| ( [[#MfE--2018|MfE, 2018]] )

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| Sea level rise

| * 23 cm (2050, RCP2.6)
* 28 cm (2050, RCP8.5)
* 42 cm (2090 RCP2.6)
* 67 cm (2090 RCP8.5)

These projections have not been updated to include an Antarctic dynamic ice sheet factor which increased global sea level projections for RCP 8.5 by approx. 10 cm. Preliminary CMIP6 projections indicate 40–50 cm (2090, SSP1-RCP2.6) and 70–90 cm (2090, SSP5-RCP8.5).

| ( [[#MfE--2017a|MfE, 2017a]] ; [[#IPCC--2019b|IPCC, 2019b]] )

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| Sea level extremes

| For a rise in sea level of 30 cm, the 1-in-100-year high water levels may occur about

* Every 4 years at the port of Auckland
* Every 2 years at the port of Dunedin
* Once a year at the port of Wellington
* Once a year at the port of Christchurch

| ( [[#PCE--2015|PCE, 2015]] )

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| Fire

| * Seasonal Severity Rating (SSR) increases 50–100% in coastal Marlborough and Otago, 40–50% in Wellington and 30–40% in Taranaki and Whanganui, 0–30% elsewhere (2050, A1B).
* Number of days with very high or extreme fire weather increase &gt;100% in coastal Otago, Marlborough and the lower North Island, 50–100% in Taupō and Rotorua, 20–50% in the rest of the North Island, and little change in the rest of the South Island (2050, A1B).

| ( [[#Pearce--2011|Pearce et al., 2011]] )

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| Tropical cyclones and other storms

| Poleward shift of mid-latitude cyclones and potential for a small reduction in frequency

| ( [[#MfE--2018|MfE, 2018]] )

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| Snow and ice

| * Maximum snow depth on 31 August may decline by 0–10% (2040, A1B) and 26–54% (2090, A1B).
* Annual snow days may be reduced by 5–15 days (2040, RCP2.6), 10–25 days (2040, RCP8.5), 5–15 days (2090, RCP2.6) and 15–45 days (2090 RCP8.5).
* Relative to 2015, New Zealand glaciers are projected to lose 36%, 53% and 77% of their mass by the end of the century under RCP2.6, RCP4.5 and RCP8.5, respectively.
* Over the period 2006–2099, New Zealand glaciers are projected to lose 50 to 92% of their ice volume for RCP2.6 to RCP8.5.

| ( [[#Hendrikx--2013|Hendrikx et al., 2013]] ; [[#MfE--2018|MfE, 2018]] ; [[#Marzeion--2020|Marzeion et al., 2020]] ; [[#Anderson--2021|Anderson et al., 2021]] )

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| Ocean acidification

| pH is projected to drop by about 0.1 (2090, RCP2.6) to 0.3 (2090 RCP8.5).

| ( [[#CSIRO%20and%20BOM--2015|CSIRO and BOM, 2015]] ; [[#Hurd--2018|Hurd et al., 2018]] ; [[#Law--2018b|Law et al., 2018b]] )

|}

'''Table 11.4 |''' Observed impacts on terrestrial and freshwater ecosystems and species in the region where there is documented evidence that these are directly (e.g., a species thermal tolerances are exceeded) or indirectly (e.g., through changed fire regimes) the result of climate change pressures.

{| class="wikitable"
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! Ecosystem

! Climate-related pressure

! Impact

! Source

|-
| colspan="4"| Australia

|-
| Forest and woodlands of southern and southwestern Australia

| 30-year declining rainfall

| Drought-induced canopy dieback across a range of forest and woodland types (e.g., northern jarrah)

| ( [[#Matusick--2018|Matusick et al., 2018]] ; [[#Hoffmann--2019|Hoffmann et al., 2019]] )

|-
|
| Multiple wildfires in short succession resulting from increased fire risk conditions, including declining winter rainfall and increasing hot days

| Local extirpations and replacement of dominant canopy tree species and replacement by woody shrubs due to seeders having insufficient time to reach reproductive age (alpine ash) or vegetative regeneration capacity is exhausted (snow gum woodlands)

| ( [[#Slatyer--2010|Slatyer, 2010]] ; [[#Bowman--2014|Bowman et al., 2014]] ; [[#Fairman--2016|Fairman et al., 2016]] ; [[#Harris--2018|Harris et al., 2018]] ; [[#Zylstra--2018|Zylstra, 2018]] )

|-
|
| Background warming and drying created soil and vegetation conditions that are conducive to fires being ignited by lightning storms in regions that have rarely experienced fire over the last few millennia

| Death of fire-sensitive trees species from unprecedented fire events (Palaeo-endemic pencil pine forest growing in sphagnum, Tasmania, killed by lightning-ignited fires in 2016)

| ( [[#Hoffmann--2019|Hoffmann et al., 2019]] )

|-
| Australian Alps Bioregion and Tasmanian alpine zones

| Severe winter drought; warming and climate-induced biotic interactions

| Shifts in dominant vegetation with a decline in grasses and other graminoids and an increase in forb and shrub cover in Bogong High Plains, Victoria, Australia

| ( [[#Bhend--2012|Bhend et al., 2012]] ; [[#Hoffmann--2019|Hoffmann et al., 2019]] )

|-
|
| Snow loss, fire, drought and temperature changes

| Changing interactions within and among three key alpine taxa related to food supply and vegetation habitat resources: The mountain pygmy-possum ( ''Burramys parvus'' ), the mountain plum pine ( ''Podocarpus lawrencei'' ) and the bogong moth ( ''Agrostis infusia'' )

| ( [[#Hoffmann--2019|Hoffmann et al., 2019]] )

|-
|
| Retreat of snow line

| Increased species diversity in alpine zone

| ( [[#Slatyer--2010|Slatyer, 2010]] )

|-
|
| Reduced snow cover

| Loss of snow-related habitat for alpine zone endemic and obligate species

| ( [[#ACE%20CRC--2010|ACE CRC, 2010]] ; [[#Pepler--2015a|Pepler et al., 2015a]] ; [[#Thompson--2016|Thompson, 2016]] ; [[#Mitchell--2019|Mitchell et al., 2019]] )

|-
| Wet Tropics World Heritage Area

| Warming and increasing length of dry season

| Some vertebrate species have already declined in both distribution area and population size, both earlier and more severely than originally predicted

| ( [[#Moran--2014|Moran et al., 2014]] ; [[#Hoffmann--2019|Hoffmann et al., 2019]] )

|-
| Sub-Antarctic Macquarie island

| Reduced summer water availability for 17 consecutive summers, and increases in mean wind speed, sunshine hours and evapotranspiration over four decades

| Dieback in critically endangered habitat-forming cushion plant ''Azorella macquariensis'' in the fellfield and herb field communities

| ( [[#Bergstrom--2015|Bergstrom et al., 2015]] ; [[#Hoffmann--2019|Hoffmann et al., 2019]] )

|-
| Mass mortality of wildlife species (flying foxes, freshwater fish)

| Extreme heat events; rising water temperatures, temperature fluctuations, altered rainfall regimes including droughts and reduced in-flows

| Flying foxes—thermal tolerances of species exceeded; fish—amplified extreme temperature fluctuations, increasing annual water basin temperatures, extreme droughts and reduced runoff after rainfall

| ( [[#AAS--2019|AAS, 2019]] ; [[#Ratnayake--2019|Ratnayake et al., 2019]] ; [[#Vertessy--2019|Vertessy et al., 2019]] )

|-
| Bramble Cay melomys (mammal)

''Melomys rubicola''

| SLR and storm surges in Torres Strait

| Loss of habitat and global extinction

| ( [[#Lunney--2014|Lunney et al., 2014]] ; [[#Gynther--2016|Gynther et al., 2016]] ; [[#Waller--2017|Waller et al., 2017]] ; [[#CSIRO--2018|CSIRO, 2018]] )

|-
| Koala, ''Phascolarctos cinereus''

| Increasing drought and rising temperatures, compounding impacts of habitat loss, fire and increasing human population

| Population declines and enhanced risk of local extinctions

| ( [[#Lunney--2014|Lunney et al., 2014]] )

|-
| Tawny dragon lizard, ''Ctenophorus decresii''

| Desiccation stress driven by higher body temperatures and declining rainfall

| Population decline and potential local extinction in Flinders Ranges, south Australia

| ( [[#Walker--2015|Walker et al., 2015]] )

|-
| Birds

| Changing thermal regimes including increasing thermal stress and changes in plant productivity are identified as being causal

| Changes in body size, mass and condition and other traits linked to heat exchange

| ( [[#Gardner--2014a|Gardner et al., 2014a]] ; [[#Gardner--2014b|Gardner et al., 2014b]] ; [[#Campbell-Tennant--2015|Campbell-Tennant et al., 2015]] ; [[#Gardner--2018|Gardner et al., 2018]] ; [[#Hoffmann--2019|Hoffmann et al., 2019]] )

|-
| colspan="4"| New Zealand

|-
| Forest birds

| Warming

| Increasing invasive predation pressure on endemic forest birds surviving in cool forest refugia, particularly larger-bodied bird species that nest in tree cavities and are poor dispersers

| ( [[#Walker--2019|Walker et al., 2019]] )

|-
| Coastal ecosystems

| More severe storms and rising sea levels

| Erosion of coastal habitats, including dunes and cliffs, is reducing habitat

| ( [[#Rouse--2017|Rouse et al., 2017]] )

|-
| Beech forest ecosystems

| Increasing mean temperatures and indirectly through effects of events like ENSO

| Increased beech mast seeding events that stimulate population irruptions for invasive rodents and mustelids, which then prey on native species

| ( [[#Schauber--2002|Schauber et al., 2002]] ; [[#Tompkins--2013|Tompkins et al., 2013]] )

|}

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==== 11.3.1.2 Projected Impacts ====

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In the near term (2030–2060), climate change is projected to become an increasingly dominant stress on the region’s biodiversity, with some ecosystems experiencing irreversible changes in composition and structure and some threatened species becoming extinct ( ''high confidence'' ). Climate change will interact with current ecological conditions, threats and pressures, with cascading ecological impacts, including population declines, heat-related mortalities, extinctions and disruptions for many species and ecosystems ( ''high confidence'' ) (Table 11.5) '''.''' These include inadequate allocation of environmental flows for freshwater fish ( [[#Vertessy--2019|Vertessy et al., 2019]] ), native forest logging for old-growth-forest-dependent fauna ( [[#Lindenmayer--2015|Lindenmayer et al., 2015]] ; [[#Lindenmayer--2020a|Lindenmayer and Taylor, 2020a]] ; [[#Lindenmayer--2020b|Lindenmayer and Taylor, 2020b]] ), and invasive species ( [[#Scott--2018|Scott et al., 2018]] ). Climate change has synergistic and compounding impacts, particularly in bioregions already experiencing ecosystem degradation, threatened endemics and collapse of keystone species, including those of value to Indigenous Peoples, and high extinction rates as a consequence of human activities (Table 11.4) ( [[#Gordon--2009|Gordon, 2009]] ; [[#Australia%20SoE--2016|Australia SoE, 2016]] ; [[#Weeks--2016|Weeks et al., 2016]] ; [[#Cresswell--2017|Cresswell and Murphy, 2017]] ; [[#Hare--2019|Hare et al., 2019]] ; [[#MfE--2019|MfE, 2019]] ; [[#Lindenmayer--2020a|Lindenmayer and Taylor, 2020a]] ; [[#Lindenmayer--2020b|Lindenmayer and Taylor, 2020b]] ; [[#Bergstrom--2021|Bergstrom et al., 2021]] ). Some native species are projected to have potentially greater geographic range if they can colonise new areas, while other species may be resilient to projected climate change impacts ( [[#Bulgarella--2014|Bulgarella et al., 2014]] ; K.E. Lawrence et al., 2017; [[#Conroy--2019|Conroy et al., 2019]] ; [[#Rizvanovic--2019|Rizvanovic et al., 2019]] ).

'''Table 11.5 |''' An indicative selection of projected climate-change impacts on terrestrial and freshwater ecosystems and species in Australia and New Zealand respectively.

{| class="wikitable"
|-
! Ecosystem, species

! Climate-related pressure

! Projected Impact

! Source

|-
| Australia

|
|-
| Floristic composition of vegetation communities

| Increases in temperature and reductions in annual precipitation by 2070. Many plant species based on median projection from five global climate models (ACCESS1.0, CNRM-CM5, HADGEM2-CC, MIROC5, NorESM1-M) centred on the decade 2070 under RCP8.5

| 47% of vegetation types have characteristic plant species at risk of their climatic tolerances being exceeded from increasing mean annual temperature by 2070 with only 2% at risk from reductions in annual precipitation by 2070

| ( [[#Gallagher--2019|Gallagher et al., 2019]] )

|-
| Some south east Australian temperate forests

| Reduction in winter rainfall and rising spring temperatures resulting in an increase in the frequency of very high fire weather conditions and increased risk of catastrophic wildfires; based on output from 15 CMIP5 GCMs using RCP8.5 for years for 2060–2079 as compared to 1990–2009

| Increase in fire frequency prevents recruitment of obligate seeder resulting in changing dominant species and vegetation structure including long lasting or irreversible shift in formation from tall wet temperate eucalypt forests dominated by obligate seeder trees (e.g., alpine ash) to open forest or in worst case to shrubland

Declining rainfall and regolith drying, more unplanned, intense fires and declining productivity place stress on tree growth and compromise biodiversity in northern jarrah forest

| ( [[#Doherty--2017|Doherty et al., 2017]] ; [[#Zylstra--2018|Zylstra, 2018]] ; [[#Bowman--2019|Bowman et al., 2019]] ; [[#Dowdy--2019|Dowdy et al., 2019]] ; [[#Naccarella--2020|Naccarella et al., 2020]] )

( [[#Wardell-Johnson--2015|Wardell-Johnson et al., 2015]] )

|-
|
| Tree line stasis or regression (snow gum)

| ( [[#Doherty--2017|Doherty et al., 2017]] ); ( [[#Bowman--2019|Bowman et al., 2019]] ; [[#Naccarella--2020|Naccarella et al., 2020]] )

|-
|
| Increase in lightning-ignited landscape fires along with contracting palaeo-endemic refugia due to warmer and drier climates

| Population collapse and severe range contraction of slow-growing, fire-sensitive palaeo-endemic temperate rainforest species (e.g., pencil pine)

| ( [[#Doherty--2017|Doherty et al., 2017]] ); ( [[#Bowman--2019|Bowman et al., 2019]] )

|-
|
| Rhizosphere responses or accelerated rates of soil organic matter decomposition

| Plant nutrient availability may be enhanced

| ( [[#Hasegawa--2015|Hasegawa et al., 2015]] ; [[#Ochoa-Hueso--2017|Ochoa-Hueso et al., 2017]] )

|-
| Alpine ecosystems

| Increasing global warming and rising temperatures, ongoing reduction in snow cover and winter rain and increasing frequency and magnitude of wildfires

| Loss of alpine vegetation communities (snow patch feldmark and short alpine herb fields) and increased stress on snow-dependent plant and animal species; changing suitability for invasive species

| ( [[#Slatyer--2010|Slatyer, 2010]] ; [[#Morrison--2013|Morrison and Pickering, 2013]] ; [[#Pepler--2015a|Pepler et al., 2015a]] ; [[#Williams--2015|Williams et al., 2015]] ; [[#Harris--2017|Harris et al., 2017]] )

|-
| Northern tropical savannahs

| Rainfall and CO 2 effects

| Potentially resulting in an increase in ecosystem carbon storage

| ( [[#Scheiter--2015|Scheiter et al., 2015]] )

|-
| Murray-Darling River Basin

| Drought

| Reduced river flow; mass fish kills

| ( [[#Grafton--2014|Grafton et al., 2014]] ; [[#AAS--2019|AAS, 2019]] )

|-
| Unimpaired river basins

| Elevated CO 2 levels

| Increase plant water use reduces stream flow

| ( [[#Ukkola--2016|Ukkola et al., 2016]] )

|-
| Bearded dragons (lizards), ''Pogona'' spp.

| Changes in precipitation

| ''P. henrylawsoni'' and ''P. microlepidota'' to gain suitable habitat, ''P. nullarbor'' and ''P. vitticeps'' showing the most potential loss

| ( [[#Wilson--2017|Wilson and Swan, 2017]] ; [[#Silva--2018|Silva et al., 2018]] )

|-
| Xeric bees

| Broad temperate tolerances, arid climate adapted

| Climate-resilient, only small response

| ( [[#Silva--2018|Silva et al., 2018]] )

|-
| ''Great desert skink Liopholis kintorei''

| Buffering capacity of underground microclimates, for nocturnal and crepuscular ectotherms

| Warming impacts projected to be indirect

| ( [[#Moore--2018|Moore et al., 2018]] )

|-
| 22 narrow-range fish species in imminent risk of extinction

| Projected changes in rainfall, run-off, air temperatures and the frequency of extreme events (drought, fire, flood) compound risk from other key threats especially invasive species

| Extinction projected within next 20 years

| ( [[#Lintermans--2020|Lintermans et al., 2020]] )

|-
| Freshwater taxa (freshwater fish, crayfish, turtles and frogs)

| Changed hydrological regimes

| Substantial changes to the composition of faunal assemblages in Australian rivers well before the end of this century, with gains/losses balanced for fish but suitable habitat area predicted to decrease for many crayfish and turtle species and nearly all frog species

| ( [[#James--2017|James et al., 2017]] )

|-
| '''New Zealand'''

|
|-
| Modified lowland wetlands

| Intersection of warming, drought and heavy rainfall (ex-tropical cyclones)

| Prolonged anoxic conditions in waterways (blackwater events) leading to mortality of fish (e.g., shortfin eels) and invertebrates, while botulism outbreaks can lead to impacts on waterfowl

| ( [[#Pingram--2021|Pingram et al., 2021]] )

|-
| Native forests and lands

| Elevated CO 2 levels, warming, increased precipitation.

| Short-term beneficial effects on carbon storage; droughts in eastern areas would decrease productivity and rates of carbon storage in the medium term

| ( [[#Ausseil--2019b|Ausseil et al., 2019b]] )

|-
|
| Increased fire intensity and frequency in hot and dry parts of New Zealand

| Much of the native vegetation has no fire adaptations, causing vulnerability to local extinction due to ‘interval squeeze’

| ( [[#Perry--2014|Perry et al., 2014]] )

|-
| Freshwater rivers

| Rainfall variation

| Cascading effects of warming, drought, floods and algal blooms compounded by water abstraction

| ( [[#Macinnis-Ng--2021|Macinnis-Ng et al., 2021]] )

|-
| Three species of naturalised woody weeds

| Warming and increased CO 2 levels

| Increased geographic range

| ( [[#Sheppard--2014|Sheppard and Stanley, 2014]] )

|-
| Kauri tree, ''Agathis australis''

| Lower than average rainfall stimulates a drought-deciduous response in this evergreen species

| Increased litter fall

| ( [[#Macinnis-Ng--2015|Macinnis-Ng and Schwendenmann, 2015]] )

|-
| Windmill palm

| Warming

| Increased geographic range

| ( [[#Aguilar--2017|Aguilar et al., 2017]] )

|-
| New Zealand tussock grasslands

| Warming

| Enhanced respiration

| ( [[#Graham--2014|Graham et al., 2014]] )

|-
| Invasive species

| Warming

| Increased invasive species abundance and increased predation on native species

| ( [[#Tompkins--2013|Tompkins et al., 2013]] ; [[#Macinnis-Ng--2021|Macinnis-Ng et al., 2021]] )

|-
|
| Warming

| Expanded ranges of invasive species in higher/cooler areas

| ( [[#Sheppard--2014|Sheppard and Stanley, 2014]] ; [[#Walker--2019|Walker et al., 2019]] )

|-
|
| Warming

| Change in flowering phenology and pollination competition

| ( [[#Giejsztowt--2020|Giejsztowt et al., 2020]] )

|-
|
| Warming

| Increase in invasive plants, insects and pathogens from sub-tropical/tropical climates

| ( [[#Macinnis-Ng--2021|Macinnis-Ng et al., 2021]] )

|-
| Tuatara (reptile), ''Sphenodon punctatus''

| Warming

| Temperature-dependent sex determination with more male hatches threatening small, isolated populations

| ( [[#Grayson--2014|Grayson et al., 2014]] )

|-
|
| Warming

| Increased geographic range

| ( [[#Carter--2018|Carter et al., 2018]] )

|-
| Cattle tick

| Warming

| Increased geographic range and risk of tick-spread anaemia in cattle

| (K.E. Lawrence et al., 2017)

|-
| Brown mudfish, ''Neochanna apoda''

| Drought

| Reduced flow regimes associated with drought interact with reduced habitat due to land use change, leading to population declines and potential local extinction

| ( [[#White--2016b|White et al., 2016b]] ; [[#White--2017|White et al., 2017]] )

|-
| Suter’s skink (lizard) ''Oligosoma suteri''

| Warming

| Increased suitable range but unclear if dispersal is possible because habitats are isolated

| ( [[#Stenhouse--2018|Stenhouse et al., 2018]] )

|-
| Threatened endemic passerine bird, ''Notiomystis cincta''

| Fluctuations in total precipitation, particularly increased and more variable rainfall

| Heavy rainfall can flood nests and kill fledglings while droughts can cause population-wide reproductive failure

| ( [[#Correia--2015|Correia et al., 2015]] )

|-
| Feral cats

| Warming

| Increased geographic range

| ( [[#Aguilar--2015b|Aguilar et al., 2015b]] )

|}

In southern Australia, some forest ecosystems (alpine ash, snow gum woodland, pencil pine, northern jarrah) are projected to transition to a new state or collapse due to hotter and drier conditions with more fires ( ''high confidence'' ) (Table 11.5). In Australia, most native eucalyptus forest plants have a range of traits that enable them to persist with recurrent fire through recovery buds (sprouters) or regenerate through seeding ( [[#Collins--2020|Collins, 2020]] ), affording them a high level of resilience. For high-end projected 2060–2080 fire weather conditions in southeast Australia ( [[#Clarke--2019|Clarke and Evans, 2019]] ), stand-killing wildfires could occur at a severity and frequency greater than the regenerative capacity of seeders ( [[#Enright--2015|Enright et al., 2015]] ; [[#Clarke--2019|Clarke and Evans, 2019]] ). Most New Zealand native plants are not fire resistant and are projected to be replaced by fire-resistant introduced species following climate-change-related fires ( [[#Perry--2014|Perry et al., 2014]] ).

A loss of alpine biodiversity in the southeast Australian Alps bioregion is projected in the near-term as a result of less snow on snow patch feldmark and short alpine herb fields as well as increased stress on snow-dependent plant and animal species ( ''high confidence'' ) (Table 11.3, Table 11.5). In Australia, invasive plants’ and weeds’ response rates are expected to be faster than for native species, and climate change could foster the appearance of a new set of weed species, with many bioregions facing increased impacts from non-native plants ( ''medium confidence'' ) ( [[#Gallagher--2013|Gallagher et al., 2013]] ; [[#Scott--2014|Scott et al., 2014]] ; [[#March-Salas--2020|March-Salas and Pertierra, 2020]] ) (Table 11.5), along with declines in some listed weeds ( [[#Duursma--2013|Duursma et al., 2013]] ; [[#Gallagher--2013|Gallagher et al., 2013]] ). In New Zealand, climate change is projected to enable invasive species to expand to higher elevations and southwards ( ''medium confidence'' ) (Table 11.5) ( [[#Giejsztowt--2020|Giejsztowt et al., 2020]] ; [[#MfE--2020a|MfE, 2020a]] ).

Projected responses of ecosystem processes are uncertain in part due to complex interactions of climate change with soil respiration, plant nutrient availability ( [[#Hasegawa--2015|Hasegawa et al., 2015]] ; [[#Orwin--2015|Orwin et al., 2015]] ; [[#Ochoa-Hueso--2017|Ochoa-Hueso et al., 2017]] ) and changing fire regimes (Table 11.5) ( [[#Scheiter--2015|Scheiter et al., 2015]] ; [[#Dowdy--2019|Dowdy et al., 2019]] ). For aquatic biota, responses will reflect seasonal differences in water temperature ( [[#Wallace--2015|Wallace et al., 2015]] ) and changes in rainfall intensity, productivity and biodiversity ( [[#Jardine--2015|Jardine et al., 2015]] ). Extreme floods may have negative impacts on New Zealand river biota, by mobilising nutrients, sediments and toxic chemicals and aiding the dispersal of invasive species. These effects are compounded by homogenisation of rivers through channelisation ( [[#Death--2015|Death et al., 2015]] ).

Improved coastal modelling, experiments and ''in situ'' studies are reducing uncertainties at a local scale about the impact of future sea level rise (SLR) on coastal freshwater terrestrial wetlands ( ''medium confidence'' ) ( [[#Shoo--2014|Shoo et al., 2014]] ; [[#Bayliss--2018|Bayliss et al., 2018]] ; [[#Grieger--2019|Grieger et al., 2019]] ). Low-lying coastal wetlands are susceptible to saltwater intrusion from sea level rise (SLR) ( [[#Shoo--2014|Shoo et al., 2014]] ; [[#Kettles--2015|Kettles and Bell, 2015]] ; [[#Finlayson--2017|Finlayson et al., 2017]] ) with consequences for species dependent on freshwater habitats ( [[#Houston--2020|Houston et al., 2020]] ). Saline habitat conditions will move inland and new coastal ecosystem states may emerge, including the World Heritage listed Kakadu’s freshwater wetland ( [[#Bayliss--2018|Bayliss et al., 2018]] ) (Table 11.5). Increasingly, sea level rise (SLR) will shrink the intertidal zone, having implications for wading birds which use this zone ( [[#Tait--2019|Tait and Pearce, 2019]] ) (Box 11.6). The ecology of freshwater wetlands in New Zealand are projected to be impacted by the intersection of warming, drought and heavy rainfall ( [[#Pingram--2021|Pingram et al., 2021]] ) (Table 11.5).

The impacts on species from projected global warming depend on their physiological and ecological responses for which knowledge is limited (Table 11.5) ( [[#Bulgarella--2014|Bulgarella et al., 2014]] ; [[#Carter--2018|Carter et al., 2018]] ; [[#Green--2021|Green et al., 2021]] ). Knowledge of projected impacts is constrained by uncertainties about the influence of physiological limits, barriers to dispersal, competition, the availability of habitat resources ( [[#Worth--2014|Worth et al., 2014]] ) and disruptions to ecological interactions ( [[#Lakeman-Fraser--2013|Lakeman-Fraser and Ewers, 2013]] ; [[#Parida--2015|Parida et al., 2015]] ; [[#Porfirio--2016|Porfirio et al., 2016]] ). Gaps in ecological modelling of future climate impacts include consideration of long-term rainfall and temperature changes ( [[#Grimm-Seyfarth--2017|Grimm-Seyfarth et al., 2017]] ; [[#Grimm-Seyfarth--2018|Grimm-Seyfarth et al., 2018]] ), species dispersal rates, evolutionary capacity and phenotypic plasticity and the thresholds at which they are considered adequate to counter the impacts of climate change ( [[#Ofori--2017b|Ofori et al., 2017b]] ), as well as indirect effects including sea level rise (SLR) and altered fire regimes ( [[#Shoo--2014|Shoo et al., 2014]] ; [[#Cadenhead--2016|Cadenhead et al., 2016]] ; [[#He--2016|He et al., 2016]] ).

<div id="11.3.1.3" class="h3-container"></div>

<span id="adaptation"></span>
==== 11.3.1.3 Adaptation ====

<div id="h3-3-siblings" class="h3-siblings"></div>

Managing climate change risks to ecosystems is primarily based on reducing the impact of other anthropogenic pressures, including invasive species, and facilitating natural adaptation ( ''high confidence'' ). This approach is most feasible within protected areas on public, private and Indigenous land and sea ( [[#Bellard--2014|Bellard et al., 2014]] ; [[#Liu--2020|Liu et al., 2020]] ) but is also applicable elsewhere ( [[#Barnes--2015|Barnes et al., 2015]] ). Effective strategies promote ecosystem resilience by changing unsustainable land uses and management practices, increasing habitat connectivity, controlling introduced species, restoring habitats, implementing appropriate fire management, integrated risk assessment and adaptation planning (B. Frame et al., 2018; [[#Lindenmayer--2020|Lindenmayer et al., 2020]] ; [[#Macinnis-Ng--2021|Macinnis-Ng et al., 2021]] ). Complementary approaches include ''ex situ'' seed banks ( [[#Morrison--2013|Morrison and Pickering, 2013]] ; [[#Christie--2020|Christie et al., 2020]] ).

Best practice conservation adaptation planning is informed by data on key habitats, including refugia, and restoration that facilitates species movements and employs adaptive pathways ( ''very high confidence'' ) ( [[#Guerin--2013|Guerin and Lowe, 2013]] ; [[#Reside--2014|Reside et al., 2014]] ; [[#Shoo--2014|Shoo et al., 2014]] ; [[#Keppel--2015|Keppel et al., 2015]] ; [[#Andrew--2017|Andrew and Warrener, 2017]] ; [[#Baumgartner--2018|Baumgartner et al., 2018]] ; [[#Harris--2018|Harris et al., 2018]] ; [[#Jacobs--2018a|Jacobs et al., 2018a]] ; [[#Das--2019|Das et al., 2019]] ; [[#Walker--2019|Walker et al., 2019]] ; [[#Molloy--2020|Molloy et al., 2020]] ). Landscape planning ( [[#Bond--2014|Bond et al., 2014]] ; [[#McCormack--2018|McCormack, 2018]] ) helps reduce habitat loss, facilitates species dispersal and gene flow ( [[#McLean--2014|McLean et al., 2014]] ; [[#Shoo--2014|Shoo et al., 2014]] ; [[#Lowe--2015|Lowe et al., 2015]] ; [[#Harris--2018|Harris et al., 2018]] ; [[#McCormack--2018|McCormack, 2018]] ) and allows for new ecological opportunities ( [[#Norman--2016|Norman and Christidis, 2016]] ). Coastal squeeze is a threat to freshwater wetlands and requires planning for the potential inland shift ( [[#Grieger--2019|Grieger et al., 2019]] ). Adaptations that maintain critical volumes and periodicity of environmental flows will help protect freshwater biodiversity (Box 11.3) ( [[#Yen--2013|Yen et al., 2013]] ; [[#Barnett--2015|Barnett et al., 2015]] ; [[#Wang--2018b|Wang et al., 2018b]] ).

Adaptation planning for ecosystems and species requires monitoring and evaluation to identify trigger points and thresholds for new actions to be implemented ( ''high confidence'' ) ( [[#Tanner-McAllister--2017|Tanner-McAllister et al., 2017]] ; [[#Williams--2020|Williams et al., 2020]] ). Best planning practice includes keeping options open ( [[#Barnett--2015|Barnett et al., 2015]] ; [[#Dunlop--2016|Dunlop et al., 2016]] ; [[#Finlayson--2017|Finlayson et al., 2017]] ) and updating management plans in light of new information. New insights are emerging into how species’ natural adaptive capacities can inform adaptation planning ( [[#Llewelyn--2016|Llewelyn et al., 2016]] ; [[#Steane--2017|Steane et al., 2017]] ; [[#Hoeppner--2019|Hoeppner and Hughes, 2019]] ). Physiological limits to adaptation in some species are being identified ( [[#Barnett--2015|Barnett et al., 2015]] ; [[#Sorensen--2016|Sorensen et al., 2016]] ), and where natural responses are not feasible, human-assisted translocations may be warranted ( [[#Becker--2013|Becker et al., 2013]] ; [[#Chauvenet--2013|Chauvenet et al., 2013]] ; [[#Innes--2019|Innes et al., 2019]] ) for some species ( [[#Ofori--2017a|Ofori et al., 2017a]] ; [[#Ofori--2017b|Ofori et al., 2017b]] ). Legal reform may be needed to better enable climate adaptation for biodiversity conservation that recognises species’ natural adjustments to their distributions and the difficulties encountered in predicting the consequences for ecological interactions and ecosystem services ( [[#McCormack--2018|McCormack, 2018]] ; [[#McDonald--2019|McDonald et al., 2019]] ).

Adaptation research priorities include understanding of the interactions and cumulative impacts of existing stressors and climate change and the implications for managing ecosystems and natural resources ( [[#Williams--2020|Williams et al., 2020]] ). For Australia, research on implementation strategies for conservation and managing threats, stress and natural assets is a priority ( [[#Williams--2020|Williams et al., 2020]] ). For New Zealand, understanding how terrestrial ecosystems and species respond to climate change is a priority, and where existing stressors are affecting freshwater quantity and quality, ''in situ'' monitoring to detect and evaluate projections of climate change impacts on biodiversity and a national data repository are lacking ( [[#MfE--2020a|MfE, 2020a]] ). The projected increase in invasive species indicates the importance of a step-up in pest management efforts to ensure native species persistence as invasive species spread from climate change ( [[#Firn--2015|Firn et al., 2015]] ). There remains a gap between the knowledge generated, potential adaptation strategies and their incorporation into conservation instruments ( ''medium confidence'' ) ( [[#Graham--2019|Graham et al., 2019]] ; [[#Hoeppner--2019|Hoeppner and Hughes, 2019]] ), though there is increasing recognition of the need to improve governance and management structures for their implementation ( [[#Christie--2020|Christie et al., 2020]] ).

<div id="box-11.1" class="h2-container box-container"></div>

'''Box 11.1 | Escalating Impacts and Risks of Wildfire'''
<div id="h2-25-siblings" class="h2-siblings"></div>

Fire activity depends on weather, ignition sources, land management practices and fuel flammability, availability and continuity ( [[#Bradstock--2014|Bradstock et al., 2014]] ). Increased fire activity in southeast Australia associated with climate change has been observed since 1950 ( [[#Abram--2021|Abram et al., 2021]] ), though trends vary regionally ( ''medium confidence'' ) ( [[#Bradstock--2014|Bradstock et al., 2014]] ). In New Zealand, there has been an increased frequency of major wildfires in plantations ( [[#FENZ--2018|FENZ, 2018]] ) and at the rural–urban interface ( ''medium confidence'' ) ( [[#Pearce--2018|Pearce, 2018]] ). In northern Australia, increased wet season rainfall ( [[#Gallego--2017|Gallego et al., 2017]] ) has increased dry season fuel loads ( [[#Harris--2008|Harris et al., 2008]] ).

In Australia, the frequency and severity of dangerous fire weather conditions is increasing, with partial attribution to climate change ( ''very high confidence'' ) ( [[#Dowdy--2018|Dowdy and Pepler, 2018]] ; [[#Abram--2021|Abram et al., 2021]] ) (11.2.1, Figure Box 11.1.1), especially in southern and eastern Australia during spring and summer ( [[#Harris--2019|Harris and Lucas, 2019]] ). Although Australia’s eucalyptus forests and woodlands are fire adapted ( [[#Collins--2020|Collins, 2020]] ), increasing intensity and frequency of fires may exceed their resilience because of the shorter intervals between high-severity fires ( [[#Bowman--2014|Bowman et al., 2014]] ; [[#Etchells--2020|Etchells et al., 2020]] ; [[#Lindenmayer--2020a|Lindenmayer and Taylor, 2020a]] ). Recent fires have severely impacted eastern rainforests, including significant Gondwana refugia ( [[#Abram--2021|Abram et al., 2021]] ). In New Zealand, the trends in very high and extreme fire weather (1997–2019) have not yet been attributed to climate change ( [[#MfE--2020a|MfE, 2020a]] ).

[[File:0ce67cb007e6b46897955e449b6950ab IPCC_AR6_WGII_Figure_11_Box_11_1_1.png]]

'''Figure Box 11.1.1 |''' '''Change in the annual (July to June) number of days that the Forest Fire Danger Index (FFDI) exceeds its 90''' '''th''' '''percentile from July 1985 to June 2020 relative to July 1950 to June 1985 ( [[#BoM%20and%20CSIRO--2020|BoM]] and [[#CSIRO--2020|CSIRO, 2020]] ; Abram et al''' '''.''' ''', 2021).'''

Fire weather is projected to increase in frequency, severity and duration for southern and eastern Australia ( ''high confidence'' ) and most of New Zealand ( ''medium confidence'' ) (11.2.2), with projected increases in pyro-convection risk for parts of southern Australia ( [[#Dowdy--2019|Dowdy et al., 2019]] ) and increased dry-lightning and fire ignition for southeast Australia ( [[#Mariani--2019|Mariani et al., 2019]] ; [[#Dowdy--2020|Dowdy, 2020]] ). Increased fire risk in spring may reduce opportunities for prescribed fuel-reduction burning in some regions ( [[#Harris--2019|Harris and Lucas, 2019]] ; [[#Di%20Virgilio--2020|Di Virgilio et al., 2020]] ). Fuel dryness is a key constraint on wildfire occurrence ( [[#Ruthrof--2016|Ruthrof et al., 2016]] ). Vegetation change will affect fuel load and fire risk in different areas in complex ways ( [[#Watt--2019|Watt et al., 2019]] ; [[#Alexandra--2020|Alexandra and Max Finlayson, 2020]] ; [[#Clarke--2020|Clarke et al., 2020]] ; [[#Sanderson--2020|Sanderson and Fisher, 2020]] ).

Direct effects of wildfire include death and injury to people and animals and damage to ecosystems, property, agriculture, water supplies and other infrastructure ( [[#Brodison--2013|Brodison, 2013]] ; [[#Pearce--2018|Pearce, 2018]] ; [[#de%20Jesus--2020|de Jesus et al., 2020]] ; [[#Johnston--2020|Johnston et al., 2020]] ; [[#Maybery--2020|Maybery et al., 2020]] ). Indirect effects include electricity and communication blackouts leading to cascading impacts on services, infrastructure and communities (Bowman, 2012; [[#Schavemaker--2017|Schavemaker and van der Sluis, 2017]] ).

For New Zealand, there has been recent increased frequency and magnitude of property losses due to wildfire ( [[#Pearce--2018|Pearce, 2018]] ). The 1660-hectare Port Hills fire in 2017 resulted in the greatest house losses (9) in almost 100 years ( [[#Langer--2018|Langer et al., 2018]] ), but the subsequent 5540-hectare Lake Ohau fire destroyed 53 houses in 2020 (Waitaki District Council, 2020).

In Australia, between 1987 and 2016, there were 218 deaths, 1000 injuries, 2600 people left homeless and 69,000 people affected by wildfire ( [[#Deloitte--2017b|Deloitte, 2017b]] ). Wildfires cost about AUD$1.1 billion per year on average (11.5.2).

The Australian wildfires of 2019–2020 resulted in 33 deaths, over 3000 houses destroyed, AUD$2.3 billion in insured losses and AUD$3.6 billion in losses for tourism, hospitality, agriculture and forestry ( [[#CoA--2020e|CoA, 2020e]] ; [[#Filkov--2020|Filkov et al., 2020]] ) (Figure Box 11.1.2). Smoke caused a further 429 deaths and 3230 hospitalisations as a result of respiratory distress and illness, with health costs totalling AUD$1.95 billion ( [[#Johnston--2020|Johnston et al., 2020]] ). These fires burnt about 5.8 to 8.1 million hectares of forest in eastern Australia ( [[#Ward--2020|Ward et al., 2020]] ; [[#Godfree--2021|Godfree et al., 2021]] ), resulting in the loss or displacement of nearly 3 billion vertebrate animals ( [[#CoA--2020e|CoA, 2020e]] ; [[#Wintle--2020|Wintle et al., 2020]] ). Further, 114 listed threatened species lost at least 50% of their habitat, and 49 lost 80% ( [[#Wintle--2020|Wintle et al., 2020]] ), among other severe ecological impacts ( [[#Hyman--2020|Hyman et al., 2020]] ). Smoke carried over 4000 km to New Zealand, where it increased snow/glacier melt through darkening surfaces and produced a detectable odour (Pu et al. 2021;( [[#Filkov--2020|Filkov et al., 2020]] ). The fire season of 2019–2020 was at least 30% more likely than a century ago due to the influence of climate change ( [[#van%20Oldenborgh--2021|van Oldenborgh et al., 2021]] ). Following the fires, a Royal Commission into National Natural Disaster Arrangements made 80 recommendations, most of which were accepted by government, including establishing a disaster advisory body and a resilience and recovery agency (11.5.2.3) ( [[#CoA--2020e|CoA, 2020e]] ).

In the face of climate change and the increased cost of fire damage and suppression, there has been considerable investment in fire risk reduction (Table Box 11.1.1). Recent analysis of 8800 fires in Australia shows resource constraints in response capacity are a barrier to effectively containing fires ( [[#Collins--2018b|Collins et al., 2018b]] ), compounded by lengthened and more extreme fire seasons.

'''Table Box 11.1.1 |''' '''Examples of adaptation options and enablers to reduce wildfire risk''' '''( [[#Hart--2011|Hart and Langer, 2011]] ; [[#Mitchell--2013|Mitchell, 2013]] ; Price et al.''' , 2015; [[#Tolhurst--2016|Tolhurst and McCarthy, 2016]] ; [[#Deloitte--2017b|Deloitte, 2017b]] ; [[#Miller--2017|Miller et al., 2017]] ; [[#Steffen--2017|Steffen et al., 2017]] ; [[#Kornakova--2018|Kornakova and Glavovic, 2018]] ; [[#Newton--2018|Newton et al., 2018]] ; [[#Pearce--2018|Pearce, 2018]] ; [[#CoA--2020e|CoA, 2020e]] ; [[#McKemey--2020|McKemey et al., 2020]] ).

{| class="wikitable"
|-
! Land management

! Communications

! Infrastructure

|-
| Prescribed burning to reduce fuel load close to built assets.

| Clearer communication of existing exposure and vulnerability to enable informed decisions about risk tolerance and management, including sites of key biodiversity that are sensitive or susceptible to fire.

| Enhanced training and support for firefighters and aerial firefighting assets, including sharing of resources nationally and internationally to address the increasing overlap of fire seasons, which are lengthening across the world.

|-
| Engagement with Australia’s Aboriginal and Torres Strait Islander Peoples to utilise and learn from their fire management knowledge and skills to assist in landscape management and greenhouse gas mitigation.

| Increased research to understand interactions between fire, fuel, weather, climate and human factors to enhance projections of fire occurrence and behaviour.

| Nationally consistent response to exceedance of air quality standards.

|-
| Locating power lines appropriately or underground and decentralising power supply to reduce ignitions.

| Community education and engagement, encouraging house and property maintenance, improving early-warning systems, more targeted messaging and increased emergency evacuation planning and sheltering options.

| Improved governance arrangements to ensure greater accountability and coordination between agencies, sharing of data and resources for emergency planning and greater understanding of risks to critical infrastructure and supply chains.

|-
| Preventive, community-based interventions to reduce ignitions from arson and accidental fires.

|
| Development of new systems to augment capability of fire services and technological advances to detect and respond to fires.

|-
| Reduced exposure of new assets through statutory spatial planning and land use regulations, building codes and building design standards.

|
|}

[[File:03cc03ac3c2838b6f47e4a76aea631b5 IPCC_AR6_WGII_Figure_11_Box_11_1_2.png]]

'''Figure Box 11.1.2 |''' '''Cascading impacts on people, economic activity, built assets, ecosystems and species arising from the Black Summer fires of 2019–2020 in eastern and southern Australia''' ( [[#Boer--2020|Boer et al. , 2020]] ; [[#CoA--2020e|CoA, 2020e]] ; [[#CoA--2020b|CoA, 2020b]] ; [[#CoA--2020a|CoA, 2020a]] ; [[#CSIRO--2020|CSIRO, 2020]] ; [[#Filkov--2020|Filkov et al., 2020]] ; [[#Johnston--2020|Johnston et al., 2020]] ; [[#Ward--2020|Ward et al., 2020]] ; [[#Wintle--2020|Wintle et al., 2020]] ; [[#Abram--2021|Abram et al., 2021]] ; [[#Godfree--2021|Godfree et al., 2021]] ).

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