Climate Change Risks in Auckland - Knowledge Auckland

 
Climate Change Risks in Auckland - Knowledge Auckland
Climate
Change
Risks in
Auckland

                                                    BC5983

                                                1
AUCKLAND COUNCIL TECHNICAL REPORT, TR2019/019
Climate Change Risks in Auckland - Knowledge Auckland
© 2019 Auckland Council

    Auckland Council technical report,
    TR2019/019

    ISSN 2230-4525 PRINT
    ISSN 2230-4533 ONLINE
    ISBN 978-1-98-858958-9 PRINT
    ISBN 978-1-98-858959-6 PDF
2   Prepared for Auckland Council by Arup.
Climate Change Risks in Auckland - Knowledge Auckland
Executive
Summary

Auckland is being      In response to the threat of         Climate change in Auckland
                       climate change, Auckland Council     The National Institute of Water
impacted by            has committed to facilitating        and Atmospheric Research climate
climate change and     the development of Auckland’s        projections (Pearce et al., 2018)
projections indicate   Climate Action Plan. It will steer   provide Auckland with the most
                       the region on a path toward          robust, localised information on
that impacts will      rapidly reducing greenhouse gas      the anticipated changes in climate
intensify over the     emissions and to prepare the city    for the region and is available
                       for the impacts of a changing
next century.          climate. This is in line with the
                                                            on Knowledge Auckland. The
                                                            anticipated changes in the climate
Action is required     2015 Paris Agreement to limit        in Auckland are changes in sea
to anticipate the      global warming to 1.5°C.             level rise, temperature, rainfall,
effects and adapt to   As part of developing the
                                                            storm events, wind and humidity.

a changing climate.    evidence-base for the action plan,   Climate Change Risk
                       Auckland Council’s Research and      Assessment
                       Evaluation Unit has produced a
                                                            The Climate Change Risk
                       Climate Change Risk Assessment
                                                            Assessment technical report
                       technical report series. This
                                                            series were undertaken using
                       assessment aims to provide
                                                            the Intergovernmental Panel on
                       information about the risks the
                                                            Climate Change methodology
                       Auckland Region may face and its
                                                            (IPCC, 2014) to assess impacts
                       impacts on people, society and
                                                            on people, the environment
                       the environment. This research
                                                            and infrastructure. The purpose
                       is underpinned by the Auckland
                                                            was to identify which parts of
                       Region climate change projections
                                                            Auckland are the most susceptible
                       and impacts research undertaken
                                                            to impacts of climate change and
                       by the National Institute of
                                                            also the social and environmental
                       Water and Atmospheric Research
                                                            vulnerability. This is understood
                       (Pearce et al., 2018).
                                                            by evaluating the adaptive
                       This document summarises             capacity of areas to impacts of
                       the research, key findings and       climate change.
                       considerations from the risk
                       assessment to contribute to
                       the development of Auckland’s
                       Climate Action Plan.
                                                                                                 3
Climate Change Risks in Auckland - Knowledge Auckland
E X EC U T I V E S U M M A RY

         Key findings                                The ability of people and households
                                                     to adapt and respond to the effects of
         Combining the impacts                       climate change is dependent on many factors.
         of climate change with                      • Where people live, their socio-economic
                                                       circumstance, their support networks, their
         relative vulnerability across                 occupations and their ability to have options can
         Auckland suggests that:                       impact their vulnerability.
                                                     • Children and older people will be more vulnerable
                                                       than others to some effects, especially related to
                                                       poor air quality.
                                                     • There is some evidence that Māori and Pacific
                                                       peoples may be more affected than others to some
                                                       effects, due to their generally younger age structures
                                                       as well as other factors.

                         Sea level rise could
         put infrastructure and ecosystems
         at risk while flooding poses
         direct and indirect risks to people,                   The changing climate will create
         infrastructure and services.                           an environment that allows water
                                                                and vector-borne diseases to thrive,
                                                                which will affect people
                                                                and ecosystems.

         Terrestrial, marine and freshwater ecosystems
         are at risk and face a combination of stressors.
         The most vulnerable species are those
         that have limited capacity to migrate                  Changes to these ecosystems are likely
         and those that will experience a                       to impact on human wellbeing and the
         ‘coastal squeeze’.                                     economy.

4
Climate Change Risks in Auckland - Knowledge Auckland
Informing Auckland’s                  It is worth remembering that          vary. Risks will continue to emerge
Climate Action Plan                   climate change is not happening in    due to the multiple stressors.
The Climate Change Risk               isolation and not just in Auckland.   Continual re-evaluation will need
Assessment identifies areas,          Rapid population growth, land         to be undertaken as more data
sectors and communities at            use changes, pollution and human      become available.
greatest risk from climate impacts.   induced stressors will compound
                                                                            Implementing precautionary and
This provides an evidence base        the effects of climate change for
                                                                            adaptive measures into decision-
to support the development of         people and the environment.
                                                                            making at every level will allow
Auckland’s Climate Action Plan.
                                      There is inherent uncertainty in      for better response to reduce risks
                                      the projections and the magnitude     and will help prepare Auckland for
                                      and extent of the effects could       climate change.

Contents                              01/ Introduction                                                        7
                                      02/ Auckland’s Changing Climate                                        11
                                      03/ Climate Change Risk Assessment                                    14
                                      04/ Technical Report Series                                           23
                                           4.1 Health effects of extreme heat                               23
                                           4.2 Connecting climate change to reduced air quality             26
                                           4.3 Creating conditions for disease vectors                      29
                                           4.4 Social vulnerability to climate change impacts               30
                                           4.5 Flooding risk in the built environment                       33
                                           4.6 Auckland’s exposure to sea level rise                        35
                                           4.7 Climate change impacts and risks for terrestrial ecosystems 38
                                           4.8 Climate change risks for marine and freshwater ecosystems 40
                                      05/ Additional and Emerging risks                                     44
                                      06/ Bibliography                                                      46    5
Climate Change Risks in Auckland - Knowledge Auckland
6

Wynyard Quarter © Auckland Council
Climate Change Risks in Auckland - Knowledge Auckland
01/   Introduction

      Auckland’s Climate                    Auckland’s Climate Action Plan       Specifically, the research covers:
                                            will set a path to rapidly reduce
      Action Plan will                      greenhouse gas emissions in line
                                                                                 • Health effects of extreme heat.
      set a path to                         with the 2015 Paris Agreement to     • Climate change, air quality
                                                                                   and health impacts.
      rapidly reduce                        keep warming within 1.5 degrees.
                                            It will ensure that Auckland is      • Creating conditions for
      greenhouse gas                        prepared for the impacts of            disease vectors.
      emissions to keep                     climate change. The plan is          • Social vulnerability.
                                            being developed in collaboration
      within 1.5 degrees                    with businesses, organisations,
                                                                                 • Flooding risk in the
      of warming while                      mana whenua, communities
                                                                                   built environment.
                                                                                 • Climate change impacts and
      ensuring Auckland                     and individuals as well as across
                                                                                   risks for terrestrial ecosystems.
                                            all levels of government.
      is prepared for                                                            • Climate change impacts
      the impacts of                        In developing the evidence             and risks for marine and
                                            base for Auckland’s Climate
      climate change.                       Action Plan, Auckland Council’s
                                                                                   freshwater ecosystems.
                                                                                 • Effects of sea level
                                            Research and Evaluation Unit
      Auckland Council is committed to                                             rise on Auckland.
                                            has developed a Climate Change
      reducing emissions and ensuring                                            Understanding the climate
                                            Risk Assessment technical report
      resilience for Auckland. In 2016,                                          change risks and impacts on
                                            series, using Auckland’s Climate
      Auckland Council joined the                                                vulnerability for Auckland is
                                            Change Projections (Pearce et al.,
      C40 Cities Climate Leadership                                              imperative to both mitigate and
                                            2018) as a basis. This research
      Group, a global network of over                                            adapt to climate change and to
                                            aims to provide information about
      90 cities committed to tackling                                            inform planning and decision
                                            the risks and vulnerabilities that
      climate change. In renewing C40                                            making. This research will help
                                            the Auckland region may face
      membership in November 2018,                                               Aucklanders to understand the
                                            under the changing climate.
      Auckland Council committed to                                              impacts of climate change on
      leading the development of a          This document summarises risks       their health, the health of our
      climate action plan for the region.   identified within the technical      ecosystems and the impact on the
                                            report series to understand          natural and built environment.
                                            how the Auckland region will be
                                                                                 The technical report series will be
                                            affected by climate change.
                                                                                 expanded and built on as data and
                                                                                 other resources become available.

                                                                                                                       7
Climate Change Risks in Auckland - Knowledge Auckland
01/ I N T RO D U C T I O N

    Collaborating with Māori
    Auckland Council             By working with the Mana              Future research aims to:
                                 Whenua Kaitiaki Forum, kaumatua
    is working to                and Māori experts, the plan seeks     Develop a more comprehensive
    interface Te Ao              to weave the mātauranga of those      understanding of the specific
                                                                       impacts of climate change
    Māori perspectives,          who have come before us and
                                                                       on Māori communities,
                                 the voices of mana whenua into
    values and ancient           solutions around specific climate     assets and economy across
    ancestral knowledge          challenges for Tāmaki Makaurau.       Tāmaki Makaurau.
                                 It is crucial that these meet the
    (Mātauranga Māori)           specific needs and interests of our
                                                                       Provide clarity around how
    into current and             Māori communities, give a voice
                                                                       Auckland Council and Council
                                                                       Controlled Organisations
    future decision              to our future generations through
                                                                       can enable and honour our
                                 the work we do today, and
    making around                give agency to the non-human
                                                                       commitment of active protection
    climate change.              elements around us who make up
                                                                       in relation to climate change
                                                                       under the Treaty of Waitangi.
                                 the world that we are a part of.

                                 Research across New Zealand
                                 highlights that Māori
                                 communities, assets and economy
                                 are vulnerable to the impacts of
                                 our changing climate.

8
Climate Change Risks in Auckland - Knowledge Auckland
Climate Change Risk Assessment document map

  Auckland Region Climate Change Projections and Impacts
                      NIWA, 2018

    RIMU Risks and Vulnerabilities Research Programme

        An assessment of                              Air quality and societal
     vulnerability to climate                         impacts from predicted
       change in Auckland                          climate change in Auckland

      Development of the
                                                         Creating conditions
        Auckland Heat
                                                         for disease vectors
      Vulnerability Index

          Sea Level Rise                                 Flooding risk in the
           in Auckland                                   built environment

     Climate change impacts                          Climate change impacts
     and risks for marine and                              and risks for
     freshwater ecosystems                            terrestrial ecosystems

               Climate Change Risks in Auckland
                      THIS DOCUMENT

                 Auckland’s Climate Action Plan
                    TO BE RELEASED 2019

                                                                                 9
                                Figure 2: Document map
10

Manurewa native forest remnants © Auckland Council
02/   Auckland’s
      Changing
      Climate

      The climate                          This research has been used to                           Future climate scenarios
                                           underpin the Climate Change                              were considered using four
      in Auckland is                       Risk Assessment.                                         Representative Concentration
      changing, with                                                                                Pathways, 2.6, 4.5, 6.0 and
                                           The report
      extreme weather                      The National Institute of Water
                                                                                                    8.5 for 2040, 2090 and 2110.
                                                                                                    These indicated the projected
      events becoming                      and Atmospheric Research                                 greenhouse gas concentrations
      more common and                      reviewed climate change                                  based on forecast emission
                                           projections in Auckland and                              trends and were used as inputs
      more severe.                         modelled expected changes for                            to the model to represent
                                           21 different climate variables                           different scenarios. The graph
      The National Institute of Water      out to 2120. The future changes                          below demonstrates the
      and Atmospheric Research has         were assessed by incorporating                           different pathways:
      undertaken an important research     knowledge of natural variations
      piece – Auckland region climate      in the climate and changes
      change projections and impacts       that may result from human
      (Pearce et al., 2018) – which        induced increases in greenhouse
      provides Auckland with the most      gas concentrations.
      robust information on the climate
      projections for the region.
                                                                                       historical
                                                                       12
                                                                                       RCP2.6
                                          Radiactive forcing (W m-2)

                                                                                       RCP4.5
                                                                       9
                                                                                       RCP6.0
                                                                                       RCP8.5
                                                                       6

                                                                       3

                                                                       0

                                           Year                            1850 1900   1950 2000 2050 2100   2150 2200 2250 2300

                                           Figure 3: Representative Concentration Pathways

                                                                                                                                     11
02/   AUCKL A N D’ S CH A NG I NG CLI M AT E

      Application to the Climate
      Change Risk Assessment            The future climate is uncertain
      The climate change projections
                                        Climate change projections are a snapshot in time and are
      have been used as the basis for
                                        projections based on current models. There is inherent
      assessing impact and risk in
                                        uncertainty in climate change projections and the future
      the Auckland Council Research
                                        changes that will occur as a result. Uncertainty is due to:
      and Evaluation Unit Climate
      Change Risk Assessment            • The cumulative impacts of climate change.
      technical report series for
      Auckland. The forecasts for       • Conflicting impacts of climate change and what this
      Representative Concentration        means for the natural and built environment.
      Pathway 8.5 have been
                                        Evidence demonstrates that the climate is changing
      used as these are most
                                        more rapidly than anticipated by climate scientists.
      representative of current
                                        Therefore, projections for the next century could very
      emission trends and allow a
                                        well be accelerated into the latter part of this century.
      precautionary approach.

12
Climate
projections

                 Increasing annual average
                 temperatures and extreme
 TEMPER ATURE    temperatures, and significantly
                 more hot days each year.
                 Plant growing days also increase.

                 Rising sea level puts coastal
                 communities and infrastructure at
   SEA LEVEL     risk from inundation and erosion.
                 Under RCP 8.5 1m sea level rise is
                 projected by the end of this century.

                 Uptake of atmospheric CO2 is leading
    OCEAN        to ocean acidification. Changes in the
 ACIDIFICATION   oceans will adversely impact health of
                 marine life and cause nutrient decline.

                 Annual relative humidity is projected
   HUMIDIT Y     to slightly decrease while absolute
                 humidity is expected to increase.

                 Seasonal distribution of rainfall is
                 projected to change with wetter
   R AINFALL     autumns and drier springs. More extreme
                 rainfall events are expected to increase
                 while the number of rain days and soil
                 moisture deficit are set to decline.

                 Average wind speed and number
     WIND        of windy days are decreasing and
                 this is projected to continue, while
                 intensity of tropical cyclones
                 is expected to increase.

                                                            13
14

Auckland skyline © Istock
03/   Climate
      Change Risk
      Assessment

      Purpose               Definitions

      This Climate Change   This research utilises the Intergovernmental Panel on Climate
                            Change definitions (IPCC, 2014):
      Risk Assessment
      technical report        RISK
      series provides a       The Intergovernmental Panel on Climate Change defines risk as
      technical,              the likelihood of an event occurring combined with the impacts.
                              Specifically, for climate change, risk is comprised of three
      evidence-driven         components (seen in Figure 4):
      foundation to           • The hazard.
      guide actions for       • Exposure of people, infrastructure, economy
      Auckland’s Climate        and natural environment to the hazards.
      Action Plan.            • Vulnerability to the hazards.

                              VULNERABILITY
                              The vulnerability of people, a species or habitat, infrastructure,
                              economy or the natural environment is a component of risk.
                              Vulnerability includes the following:
                              • Exposure to the hazard.
                              • Sensitivity.
                              • Adaptive capacity.
                              Vulnerability includes the physical, geographic and socio-economic
                              contexts that determine an individual’s or group’s ability to adapt
                              to change. For species, their ability to migrate would influence their
                              adaptive capacity.

                            Understanding the most vulnerable areas of Auckland is important to
                            understand how to build resilience and develop targeted actions to
                            prepare Auckland in response to a changing climate.

                                                                                                       15
03/   CLI M AT E CH A NG E RISK A SSESSM ENT

         Risk and vulnerabilities relationships

                                                                       IMPACTS

                                 PHYSICAL IMPACTS OF                               VULNERABILITY
                                                                                                      SOCIOECONOMIC
                                   CLIMATE CHANGE                                                       PROCESSES
       CLIMATE

        Natural                                                                  RISK                  Socioeconomic
       Variability                                                                                       Pathways
                                                HAZARDS                                    Emergent

     Anthropogenic                               Trends & Events                                        Adaptation &
                                                                                    Key
     Climate Change                                                                                   Mitigation Actions

                                                                                                         Governance

                                                                                          EXPOSURE

                                           EMISSIONS
                                       & Land-use Changes

         Figure 4: Relationship between vulnerability, risk, exposure and hazards (IPCC, 2014)

16
Methodology
   The Intergovernmental Panel on                3. Identification of quantifiable       4. Indices: indicators for each
   Climate Change methodology                       indicator variables that cover          spatial unit were scored
   was undertaken for the Climate                   exposure, sensitivity and               and weighted to develop
   Change Risk Assessment technical                 adaptive capacity:                      index values.
   report series. This methodology
                                                    Exposure indicators are variables    5. Identification of vulnerability
   was applied to people,
                                                    that measure the region’s               hotspots: these were identified
   ecosystems, societal systems,
                                                    exposure to climate change.             based on spatial units with high
   built infrastructure and green and
   blue infrastructure to understand                Sensitivity indicators illustrate       sensitivity, high exposure and
   risks and vulnerabilities.                       reactiveness to changes in              low adaptive capacity.
   The methodology included:                        the climate. For people this
                                                                                         6. Assessment and discussion:
                                                    includes employment status,
   1. Understanding stressors                                                               identifying the vulnerability
                                                    age, accessibility and underlying
      on the people, society and                                                            hotspots in Auckland enabled
                                                    health conditions. For species it
      environment as a result of                                                            an analysis of the most at
                                                    includes ability to migrate and
      climate change.                                                                       risk areas, groups, species,
                                                    distance from coastal regions.
                                                                                            habitats infrastructure.
   2. Definition of the spatial scale               Adaptive capacity covers the
      being assessed – in most                      ability to react to the changes.
      ‘people specific’ cases this was a            For people this includes factors
      census area unit – for habitats it            such as socio-economic standing
      was a specific species.                       and accessibility to greenspace.

   Climate Change risk assessment methodology

                                                       identify                                        map
                             define
understand                                           indicators:               develop              & identify              assessment
                             spatial
 stressors                                           exposure, sensitivity     indices             vulnerability            & discussion
                              scale                      & adaptive
                                                          capacity                                   hotspots

   Figure 5: Climate Change risk assessment methodology
                                                                                                                                      17
03/ CLI M AT E C H A NGE
     RISK A SSESSM ENT

     Key Messages
                                A few of the key findings from the Auckland’s climate change
     Climate change             research undertaken include:
     will impact people,        Climate change is happening, and effects can already be seen
     societal structures,       Climate change is linked to deteriorating air quality which
     the natural and            will further impact the health of the population.
     built environment,         Weather patterns will change. Spring rainfall is
     species and habitats.      projected to decline and autumn rainfall is projected
                                to increase across the Auckland Region.

                                Climate change will increase extreme heat events (hot days)
                                which will likely impact the health of Auckland’s communities
                                and environments. There may be further unknown consequences
                                that cannot be projected at this stage, such as the risks
                                associated with the establishment of new disease and disease
                                vector populations such as mosquitos and parasites.

                                Storm surge and sea level rise are already affecting
                                Auckland’s people and infrastructure.

                                Ocean acidification is already threatening Auckland’s
                                marine ecosystems, including culturally, economically
                                and ecologically significant species.

                                Terrestrial, marine and freshwater ecosystems will change due
                                to the compounding effects and multiple stressors of climate
                                change and other environmental stressors such as pollution.

                                The current projections may accelerate at an unknown rate,
                                so that effects projected for the next century – such as sea
                                level rise – may take place over a much shorter time frame.

18
The Climate Change Risk
   Assessment takes into consideration         The ability of people and households
   scientific projections, our current         to adapt and respond to the effects of
   understanding of climate change             climate change is dependent on many factors.
   effects and Auckland’s current              • Where people live, their socio-economic circumstance,
   environment, in order to better               their support networks, their occupations and their
                                                 ability to have options can impact their vulnerability.
   understand the key risks and
   vulnerabilities of Auckland.                • Children and older people will be more vulnerable than
                                                 others to some effects, especially related to poor air
   Some of the key findings include:
                                                 quality.
                                               • There is some evidence that Māori and Pacific peoples
                                                 may be more affected than others to some effects,
                                                 due to their generally younger age structures as well as
                                                 other factors.

                   Sea level rise will
   put infrastructure and ecosystems
   at risk while flooding poses
   direct and indirect risks to people,                    The changing climate will create
   infrastructure and services.                            an environment that allows water
                                                           and vector-borne diseases to
                                                           thrive, which will affect people and
                                                           ecosystems.

   Terrestrial, marine and freshwater ecosystems
   are at risk and face a combination of stressors.
   The most vulnerable species are those
                                                           Changes to these ecosystems are likely
   that have limited capacity to migrate
                                                           to impact on human wellbeing and the
   and those that will experience a
                                                           economy.
   ‘coastal squeeze’.

The Climate Change Risk Assessment technical report series identifies some evidence-based, targeted
considerations for those areas, sectors and communities at greatest risk from climate impacts.
These considerations will tie into Auckland’s Climate Change Action Plan. The considerations from these
risk assessments are not comprehensive and actions identified in Auckland’s Climate Change Action Plan
will encompass these considerations and more.

The following sections summarise the technical report series and further detail Auckland’s climate change
impacts and the risks for people, society and the environment.
                                                                                                            19
CLI M AT E CH A NGE I N AUCKL A N D
            Causes and effects

  INCREASED
FOREST FIRE RISK

                                  INCREASED
                                FOREST FIRE RISK

                                                                                                                COASTAL
                                                                                                              INUNDATION

                                                                                                                                   COASTAL
                                                                                                                                 INUNDATION

                                                                                WATER-BORNE
                                                                               DISEASE INCREASE

                                                                                                      WATER-BORNE
                                                                                                     DISEASE INCREASE
                     FLOOD

                                                       FLOOD

 INSECT BORNE
DISEASE INCREASE                 INSECT BORNE
                                DISEASE INCREASE

                              TERRESTRIAL                                                                               INCREASED     INCREASED
                                                             TERRESTRIAL                                                ALLERGENS
                           ECOSYSTEM DECLINE              ECOSYSTEM DECLINE                                                           ALLERGENS

            CLI M AT E
            CH A NGE I N
            AUCKL A N D
            Causes

                                    TEMPERATURE                             OCEAN                            ABSOLUTE HUMIDITY
                                      INCREASE                           ACIDIFICATION                           INCREASE
20

     TEMPERATURE                                 OCEAN                                   ABSOLUTE HUMIDITY
                                              ACIDIFICATION                                  INCREASE                               STORM INTEN
       INCREASE
SOIL & MOISTURE
                                                                                                                                 DECLINE

                                                                                                                SOIL & MOISTURE
                                                                                                                    DECLINE
                                                    MARINE ECOSYSTEM
                                                         DECLINE
                                                                                                    REDUCED FOOD
                                                    MARINE ECOSYSTEM
                                                         DECLINE
                                                                                                       SECURITY
                                                                                             REDUCED FOOD
                                                                                                SECURITY
         POLLUTION
       ACCUMULATION
                    POLLUTION
                  ACCUMULATION                                    FRESH WATER
                                                              ECOSYSTEM
                                                               FRESH WATER DECLINE
                                                            ECOSYSTEM DECLINE

D
S

                                     DECREASED                                                               VARIABLE
    STORM INTENSITY INCREASE                                           SEA LEVEL RISE
                                    RAINFALL DAYS                                                           WIND SPEED
                                                                                                                                       21

                                  DECREASED                                                                               VARIABLE
NSITY INCREASE                                                              SEA LEVEL RISE
                                 RAINFALL DAYS                                                                           WIND SPEED
The following section summarises the Technical
      Report series developed by Auckland Council’s
      Research and Evaluation Unit.

    22

Whangaparoa Peninsula © Istock
Technical
04/

  Report Series

      4.1 Health effects of extreme heat
  Based on: Joynt, J. L. R. and
  Golubiewski, N. E. (2019).
                                         and those with pre-existing mental      Increasing access
                                         and chronic health conditions.
  Development of the Auckland            According to the index the most         to social and green
  Heat Vulnerability Index.
  Auckland Council technical report,
                                         vulnerable populations are in           infrastructure,
  TR2019/013                             South and West Auckland. The
                                                                                 like community
                                         cause of the vulnerability in each
  The Auckland Heat Vulnerability        area varies but includes limited        cool spaces, can
  Index identifies the areas and         adaptive capacity because of            help reduce heat
  populations more sensitive to          high socio-economic deprivation,
  the effects of extreme heat.           tenure type and limited transport
                                                                                 stress for those
  Vulnerability to extreme heat is       access, as well as increased            most vulnerable.
  influenced by socio-economic,          sensitivity to extreme heat due to
  health and environmental               the prevalence in the population
  factors. Ten representative            of either old or young, underlying
  indicators derived from census         health conditions, single occupant
  and land cover data for Auckland       households as well as the
  are combined and mapped                effects of limited greenspace.
  (overleaf) to indicate areas of
  greater sensitivity and reduced        Social infrastructure, such
  adaptive capacity to hot days.         as community centres, can
                                         increase social cohesion
  Vulnerability to extreme heat is       and reduce isolation and
  not the same across Auckland           vulnerability to extreme heat.
  – heat related impacts are             Although not factored into the
  closely related to both social         Heat Vulnerability Index, the
  vulnerability and the local            considerable community cohesion
  environment. Evidence from             evident in many parts of South and
  the literature indicates that          West Auckland enabled through
  heat related mortality and             existing social infrastructure is
  morbidity is more common in            likely, in part, to mitigate the risk
  certain groups, including: female      for some communities. Measuring
  householders, the socially isolated,   and including social infrastructure
  the elderly and the young,             in the Heat Vulnerability Index
  those with language barriers,          represents a future research
  ethnic minorities, low income          development opportunity.                                      23
  households, renter households,
04/ T ECH N IC A L REPORT SERI ES

     People working in heat sensitive     Reducing the effects of extreme heat
     occupations including construction   Examples of effective heat mitigation actions include:
     and labour activities may be
     subject to negative outcomes.        • Heat management plans and warning systems.
     There is evidence to suggest
     this may affect some groups          • Inventories of social infrastructure.
     such as Māori and Pacific
                                          • Establishment of ‘buddy systems’ to check on isolated and high risk
     peoples more than others.
                                            community members.

                                          Natural and built environment investment and intervention can have a
                                          significant effect on reducing the severity of heat events, for example:

                                          • Cooling can be achieved through increasing green-infrastructure
       Social                               design, such as increased tree canopy and green space and green
       infrastructure can                   warrants of fitness on buildings. Many of the areas identified as
                                            high risk in the Heat Vulnerability Index have proportionally less
       increase social                      green space.
       cohesion and
                                          • Further, the provision of improved social infrastructure can create
       reduce isolation                     greater community cohesion, which reduces social isolation, as well
       and vulnerability                    as provide for community ‘cool spaces’, particularly in low socio-
       to extreme heat.                     economic communities for the population to evacuate to during
                                            extreme heat days.

                                          • The Heat Vulnerability Index highlights the importance of green
                                            space, and addressing underlying depreivation and health issues in the
                                            community.

24
Figure 6: Heat vulnerability
index for Auckland             25
04/ T EC H N IC A L REPORT SERI ES

     4.2 Connecting climate change to reduced air quality
     Based on: Talbot, N. (2019).        Increased air temperature results       Drought could also result in
     Air quality and societal impacts    in a longer growing season for          plant stress. Through a complex
     from predicted climate change       plants, increasing pollen in the        process, plant stress could result
     in Auckland. Auckland Council
                                         atmosphere. Once mixed with             in increased ozone and nitrogen
     technical report, TR2019/012
                                         airborne pollutants, the allergenic     dioxide with organic compounds
     The impact of climate change        properties can be enhanced – if         released by plants mixing with
     has strong implications on air      inhaled, it can trigger asthma          vehicle exhaust and sunlight.
     quality across Auckland.            attacks and other acute
                                                                                       WIND
                                         respiratory disease symptoms.
     Health implications from
                                                                                       Changes in wind speed
     climate forecasts                         HUMIDITY                          and direction will alter how
     Air quality is highly susceptible          Humidity can make pollen         pollutants are carried to and
     to other changes that result        more problematic by causing             dispersed around the city. The
     from climate change, such as        spores to split and allowing them       wind speed and direction regulate
     increased temperature, decreased    to infiltrate further into the lungs.   aerosol loading as well as brown
     humidity and rainfall and changes   Humidity levels also change the         haze events. Changing wind
     in wind speed and direction.        nature of particulate matter in         directions may also increase
                                         the atmosphere. Low and high            contribution of shipping emissions
           TEMPERATURE
                                         humidity favour transmission and        over Auckland from the Port.
            Heat stress makes people     survival of influenza virus and
     more susceptible to acute health                                            Impact on community
                                         increased humidity can impact
     problems. High temperatures         indoor air quality, potentially         There are poor health outcomes
     also tend to occur during periods   increasing mould growth.                from reduced air quality due
     of reduced airflow, resulting                                               to a number of factors. Health
     in a ‘pooling’ of air, increasing          RAINFALL                         conditions such as respiratory
     pollutant concentrations through            Fewer rainy days will lower     illness and asthma are exacerbated
     chemical processes. This is         the efficiency of the removal of        by worsened air quality.
     most likely to occur in densely     atmospheric pollutants and may
     populated urban street canyons                                              The built-up city centre could
                                         allow accumulation of pollutants
     surrounded by tall buildings and                                            be an area of high exposure due
                                         on road surfaces which could
     along heavily-trafficked roads.                                             to the condensed architecture
                                         remain suspended within road
                                                                                 of tall buildings and high
                                         dust. Drier conditions increase the
                                                                                 vehicle traffic volumes.
                                         chance of wildfires, for example, in
                                         the Waitakere Ranges, which
26                                       would reduce air quality.
Dispersion of particulate matter      • Communities with low income         Air quality will
is reduced at ground level which        and employment are less
affects those who live and work in      likely to have capacity to          be negatively
built-up urban centres.                 protect themselves against          impacted by climate
Research identified that
                                        air pollution impacts.
                                                                            change. We must
certain communities are                                                     focus efforts to
disproportionately vulnerable
to health impacts from
                                                                            increase resilience
air pollutants in Auckland.                                                 for those that are
Vulnerable populations are:                                                 most vulnerable
• Communities with elderly                                                  to the changes.
  or young populations as
  relatively small increases in air
  pollutants disproportionately       How Auckland can adapt
  impact them.                        Several considerations are recommended to improve air quality and limit
                                      the impact on populations:
• Māori and Pacific peoples
  may be disproportionately           Air quality can be improved by reducing the wood-burning emissions
  affected by adverse social          from domestic heating and industrial emissions across Auckland.
  and economic circumstances,         Green infrastructure can improve air quality as natural vegetation can act
  as well as higher rates of          as a filter to remove or divert air pollutants from the atmosphere.
  diseases and chronic illness,
  making them more vulnerable         Target areas of high density living near busy roads for air quality
  to reduced air quality.             improvement measures. This would build on the Fossil Fuel Free Streets
                                      initiative and include procuring zero-emission public transport.
                                      Technology can be developed to target specific vulnerable populations
                                      such as those with pre-existing health conditions to provide alerts and
                                      advice in real-time. This could include pollen or particulate matter
                                      warnings and encourage people to stay inside or limit exposure during
                                      periods of poor air quality.

                                      This research will enable Auckland Council to better mitigate and adapt
                                      to climate change and to focus efforts on specific key vulnerable groups.    27
04/ T EC H N IC A L REPORT SERI ES

              CLIMATE                             AIR QUALIT Y          POSSIBLE HEALTH           COMMUNIT Y
             FORECAST                               IMPACTS              IMPLICATIONS             LEVEL RISKS

          Lower wind speed                       Less dispersal of        Increases in urban       Old and young
                                                    pollutants                heat stress         most susceptible
        Increased temperature
                                                Photo-oxidation =        Increased hospital        Increased social
          Changes in rainfall                  Increase in O3 / NO2       admissions from             inequality
              patterns                                                  respiratory disorders
                                             Increase in an-allergens                             Increase in mental
         Increasing humidity                                            Increase susceptibility      health stress
                                                  Lower emissions          to flu / allergens
          Changes in rainfall                   from wood burning                                   Absence from
              pattern                                                    Increase in viruses        work / school
                                                  Longer lifetime        carried by airborne
              Changes in                           for pollutants              aerosol            Lower income less
            climatic cycles                                                                         able to adapt
                                             Increased plant stress =      Environmental
                                             Release of VOC’s = > O3        degradation

                                                 Increase runoff of
                                                pollutants (metals)

                                            More lightning, NO2 / O3

                                             Changes in atmospheric
                                                flow- cycle / SO2

     Figure 7: Connceting climate change, air quality and its
     impacts

28
4.3 Creating conditions for disease vectors
By: Joynt, J. L. R                     New Zealand. The Malarial parasite
                                       is carried by the anopheline
                                                                             The changing
Auckland is at risk of being
exposed to new diseases as
                                       mosquito which is endemic in          climate could create
a result of climate change.
                                       Australia and South East Asia and     an environment
                                       has been previously intercepted
Increased temperature, humidity        at New Zealand’s borders.             that allows water
and rainfall can all facilitate
                                       Other vector-borne diseases
                                                                             and vector borne
the spread of disease and
allow conditions for disease
                                       that could become established         diseases to thrive
to thrive and establish in the
                                       in New Zealand include Murray         as well as the
                                       Valley Encephalitis, Japanese
community. Water and vector-
                                       Encephalitis and dengue fever,        introduction of
borne diseases – those carried
by mosquitoes and parasites
                                       which has already had previous        new diseases to the
                                       outbreaks in New Zealand
– are of particular concern.
                                       with Pacific Island origin.
                                                                             Auckland Region.
As Auckland’s climate becomes
                                           Climate change and disease
more tropical, conditions
grow more favourable for the           Climate change will make              supply and waterways in flooding
establishment of mosquito and          conditions more favourable for a      events from sewage overflow.
other vector species populations.      population to become established      Parasites such as giardia and the
                                       and highlights a significant threat   Escherichia coli (E.coli) bacteria can
     Mosquito borne diseases           to public health. Flooding events     cause illness when contaminated
New Zealand has 16 species of          can create breeding grounds,          waterways are used for recreation
mosquito, and several others have      particularly in increasingly warm     such as swimming and fishing.
been intercepted at its borders.       conditions and lead to increased      Cyanobacteria and avian botulism
For disease to establish in the        vector establishment. Waterborne      in reservoirs also pose a risk as dry
community, both the vector and         disease outbreaks are closely         conditions with low water levels
the disease need to be present.        correlated with extreme weather       can result in their establishment
                                       events which are projected to         in drinking water reservoirs.
To date there has never been           increase in intensity and frequency
a confirmed case of a human            in Auckland with climate change.      How Auckland can adapt
acquiring a mosquito-borne                                                   Regular surveillance and
disease in New Zealand. However,                                             monitoring of disease outbreaks,
there are established species             Other health risks                 as well as disease vectors, will
already which are capable of                                                 help assess and forecast changes.
                                       Other health risks include
being vectors for diseases such as
                                       contamination of drinking water                                                29
West Nile Virus, if it were to enter
04/ T EC H N IC A L REPORT SERI ES

     4.4 Social vulnerability to climate change impacts
     Based on: Fernandez, M. A. and
     Golubiewski, N. E. (2019). An
                                           that characterise vulnerable          Exposure to climate
                                           hotspots are: a low share of
     assessment of vulnerability to        green space such as cropland,         change effects
     climate change in Auckland.
     Auckland Council technical report,
                                           grassland or tree cover, high rates   combined with
     TR2019/011                            of single-person households,
                                                                                 socio-economic
                                           low average household income,
     Vulnerability has been assessed       high housing stress, low levels       vulnerability
     across the census area units of       of house ownership and high           results improves
     Auckland based on the degree          deprivation levels. Some of
     to which geophysical, biological,     these stressors correspond to
                                                                                 our understanding
     and socio-economic systems are        the physical and geographical         of who climate
     susceptible to, and unable to cope
     with, adverse impacts of climate
                                           environment, while others are         change will impact
                                           characterised by socio-economic
     change. The assessment combines       context and social preferences.
                                                                                 the most severely.
     multiple factors in order to
     stress test areas of Auckland and     How Auckland can adapt
     identify which will be the most       This assessment improves the
     vulnerable to climate change.         understanding of what drives
                                           vulnerability in Auckland
     Vulnerability is characterised by
                                           and informs development
     the potential impact (comprising
                                           of adaptation options and
     exposure and sensitivity) and
                                           priorities for intervention.
     adaptive capacity of each census
     area unit. Indicators used for
     characterisation are shown in
     Table 1. Vulnerable areas are those
     that suffer potentially high impact
     (high exposure and sensitivity)
     and have a low adaptive capacity.

     Assessment results show the
     impact and adaptive capacity
     across the Auckland region, with
     hotspots located in southern and
     western areas of Auckland. Factors
30
Figure 8: Vulnerability assessment and hotspots:
Impact (sensitivity and exposure)

Figure 9: Vulnerability assessment and hotspots:
Adaptive capacity                                  31
04/ T EC H N IC A L REPORT SERI ES

     TABLE 1   INDICATORS USED TO MEASURE VULNERABILITY COMPONENTS

      INDEX                   INDIC ATORS                                        FUNCTIONAL REL ATIONSHIP

      Exposure                Coastal inundation                                 Vulnerability  as indicator 
                              – 50 years return 1 metre sea level rise
                              Dry days < 1 mm                                    Vulnerability  as indicator 
                              Total precipitation percentage change              Vulnerability  as indicator 
                              Heavy rainfall days > 25 mm                        Vulnerability  as indicator 
                              Hot days > 25                                      Vulnerability  as indicator 
                              Mean temperature                                   Vulnerability  as indicator 
                              Mean wind speed                                    Vulnerability  as indicator 
                              Relative humidity                                  Vulnerability  as indicator 
      Sensitivity             Deprivation Index                                  Vulnerability  as deprivation index 
                              Unemployment rate*                                 Vulnerability  as unemployment 
                              Ratio of population under                          Vulnerability  as rate of dependency 
                              15 and over 65 to 19 – 64 *
                              Percentage of populated area                       Vulnerability  as % populated area 
                              relative to CAU area
                              Percentage of single-headed households*            Vulnerability  as % of single-headed households 

                              Road density (ratio of km of road                  Vulnerability  as ratio 
                              per km2 of populated area)
      Adaptive Capacity       Average household income*                          Vulnerability  as income 
                              Housing stress (ratio of rent                      Vulnerability  as housing stress 
                              payments to household income)*
                              Percentage of population that are                  Vulnerability  as % owning house 
                              owner-occupiers of house*
                              Percentage of area in cropland**                   Vulnerability  as % on crops production 
                              Percentage of area in grassland**                  Vulnerability  as % on grass production 
                              Percentage of area in forest**                     Vulnerability  as % of forest cover 

     NOTE
     * Data at census area unit level, extracted from Census 2013.
32   ** Data extracted from LUCAS NZ land use map 2012. Climatic (exposure) data extracted from Pearce et al. (2017)
4.5 Flooding risk in the built environment
Based on: Joynt, J.L.R, Golubiewski,
N.E. and Balderston, K.
                                                Almost one quarter (23%) of
                                                                                                 Improving green
                                                Aucklands buildings are exposed
(Forthcoming). Flooding risk in the             to flood hazards. It is estimated                infrastructure and
built environment. Auckland Council
technical report, TR2019/016
                                                that that 16,000 buildings                       having less paved
                                                are at risk of floor flooding
Flooding is the most common                     in a 100 year flood event.
                                                                                                 surfaces can help
natural hazard in Auckland.                                                                      absorb some of
With its many harbours, inland                  Impacts
watercourses and tributaries,                   Flood events damage property
                                                                                                 the impacts of
there is no part of the region                  and endanger the population                      flooding and protect
that is not close to and                        directly through debris fields,                  infrastructure.
intimately related with water.                  high velocities and increased risk
                                                of drowning. Secondary effects
Auckland’s sub-tropical climate                 include but are not limited to
means that high humidity                        increased risks of vector and
and heavy rainfall events are                   water-borne diseases following
not uncommon year-round.                        flood events and contamination
Further, there is a risk of tropical            from wastewater overflows.
storms from the Pacific.
                                                Infrastructure failure,
Climate change will increase                    displacement, disruption and
the severity and frequency                      insurance costs all have further
of flooding across the city,                    impact on society and have long
particularly in winter and autumn.              lasting impacts. Increased risk of
Auckland's urban area has                       Post-Traumatic Stress Disorder
large amounts of impervious                     can result from extreme natural
surfaces. These surfaces can                    disasters such asHAZARDS
                                                TABLE 2 FLOOD     flooding.
alter the volume, speed and
                                                  FLOOD                         NUMBER OF                      PERCENTAGE OF
path of rainfall runoff.
                                                  HA Z ARD                      BUILDINGS*                     TOTAL BUILDINGS 6

                                                  Floodplain (FP)               64,064                         12%
                                                  Flood prone area (FPA)        22,798                         4%
                                                  Overland                      80,244                         15%
                                                  Total                         127,593                        23%
                                                                                                                                                33
NOTE
* Buildings are defined as structures greater than or equal to 60m2 in area, many small structures such as garden sheds would not be included
in this estimate.
04/ T EC H N IC A L REPORT SERI ES

     Vulnerability                                                                How Auckland can adapt
     Current and future flooding           Responding to climate change           Reduce the effect of impervious
     exposure and risk is core council     requires fundamental changes           surfaces in new developments,
     information. How exposure             in how we think about and plan         utilising green infrastructure
     translates into vulnerability is      for the future of our catchments,      to decrease runoff.
     necessary to understand the           coastlines and communities. Some
                                           hard decisions will be required        Locating new development
     impact of flood events on different
                                           about the acceptability and            appropriately, outside floodplains.
     communities.
                                           affordability of sustaining human      Work across Council to create
     As with all climate related risks,    habitation and infrastructure in       future focussed policy, planning,
     the effects of flooding will be       some areas. We need to change          development and asset
     influenced by a range of factors.     how we use land and waterways,         management that is informed
     These factors can include things      and design, construct, and manage      by the long-term consolidated
     such as household income,             buildings and infrastructure           risk to human life, property and
     housing tenure or personal            to reduce the risk. We need to         infrastructure from all natural
     mobility. More information is         consider the whole of life risks and   hazards and future climate change.
     needed to understand the level of     costs of future investments in land
     flood vulnerability that Auckland     and infrastructure development,
     communities in different locations    and engage the community in
     experience now and may in the         open and honest conversations.
     future.

                                                                                      Flooding is the
                                                                                      most common
                                                                                      natural hazard
                                                                                      in Auckland.

34
4.6 Auckland’s exposure to sea level rise
Based on: Golubiewski, N. E.,              Scenarios                      Coastal inundation
Balderston, K; Hu, C. and Boyle, J.        The following scenarios were
(2019) Auckland’s exposure to sea
                                           assessed for sea level rise,
                                                                          and sea level rise are
level rise: part 1 – regional inventory.
Auckland Council technical report,
                                           and for coastal inundation     already affecting
TR2019/017                                 to understand Auckland’s       Aucklanders.
                                           exposure impacts over time.
And Boyle, J. Golubiewski, N. E.,                                         We need to prepare
Balderston and K; Hu, C. (2019).
Auckland’s exposure to sea level
                                                SEA LEVEL RISE
                                                                          our infrastructure
                                           • 0.25 metre sea level rise
rise: part 2 – local inventory.
Auckland Council technical report,
                                                                          now and understand
TR2019/018 (forthcoming)
                                           • 0.5 metre sea level rise
                                                                          limitations to areas
Auckland will experience sea-              • 1 metre sea level rise       available for future
level rise and coastal inundation,
                                           • 2 metre sea level rise       infrastructure.
with significant impacts on
people, the environment, land,
                                                COASTAL INUNDATION
buildings and infrastructure.
                                           • 1 in 100-year average
Over this century approximately              return interval (ARI)
1.5-2.5% of Auckland’s land area
could be exposed to sea level              • 1 in 100-year ARI + 1
rise. This encompasses 0.3%                  metre sea level rise
of buildings, 80% of coastal
                                           • 1 in 100-year ARI + 2
ecosystems and 6% of dairy land.
                                             metre sea level rise
Outside of these potentially
exposed areas, there are
other areas across Auckland
that are predicted to become
exposed to coastal inundation
in extreme weather events.

                                                                                                   35
04/ T EC H N IC A L REPORT SERI ES

     Exposure                                                                                How Auckland can adapt
     • A substantial proportion of                  • Many parks lie along shores and        Understanding the specific
       coastal ecosystems would                       coastal margins, with between          areas that are exposed to sea
       be exposed with projected                      1% and 7.5% of Council-owned           level rise and coastal inundation
       sea level rise. Some coastal                   green space exposed to sea             will enable a targeted focus
       and scrub forests exposed                      level rise, including sports           to assist building capacity and
       to sea level rise and                          fields, parks and cemeteries.          preparation. These specific areas
       inundation, with mangroves                                                            identified will inform additional
                                                    • Utilities and transport have
       and saltwater wetlands                                                                actions for Auckland’s Climate
                                                      high proportional exposure
       being the most exposed*.                                                              Action Plan to build resilience,
                                                      as they are more likely to be
                                                                                             planning and regulations and to
     • Some unitary plan zones are                    below sea level and may be
                                                                                             mitigate the impacts of climate
       exposed in long-term sea level                 exposed to salt intrusion, as
                                                                                             change as much as possible.
       rise scenarios, particularly                   well as utility assets on the
       coastal zones, port zone and                   coast being more directly
       the central business district.                 exposed, due to their location.

     • Buildings have been                          • Livestock farms including sheep,
       constructed in zones that are                  beef and dairy comprise most
       now known to be exposed to                     of the agricultural production
       sea level rise, although planning              land in the Auckland region
       regulations require habitable                  and have the greatest area of
       floors to be above the 100                     land exposed to sea level rise.
       year storm inundation level
                                                    • Further industries that
       including 1 metre sea level rise.

     • Some residential land is
                                                      will be affected include:
                                                      fisheries, hatcheries and                 1.5-2.5%
       exposed (the most exposed                      other marine aquaculture.                 of Auckland's
       being Rural and Coastal                                                                  land area could
       Settlement zones), and less
       than 1% of the future urban
                                                                                                be exposed to
       zone is exposed across sea level                                                         sea level rise
       rise scenarios investigated here.                                                        this century.

     NOTE
36   * Vulnerability is not known e.g. there may be room for these to move/adapt with SLR.
Figure 10: Exposure of Auckland to possible sea level rise scenarios

Figure 11: Exposure of Auckland to coastal inundation
coupled with sea level rise                                            37
04/ T EC H N IC A L REPORT SERI ES

     4.7 Climate change impacts and risks for terrestrial ecosystems
     Based on: Bishop, C. D. and Landers,   Additionally many ecosystems           Most of Auckland’s indigenous
     T. J. (2019). Climate change risk      have restricted spatial distribution   ecosystems are already under
     assessment for terrestrial species     that make them more vulnerable         threat from introduced animal
     and ecosystems in the Auckland
                                            to regional extinction from            or plant pests, and clearance
     region. Auckland Council technical
     report, TR2019/015                     changed environmental conditions       and fragmentation as a result
                                            or extreme events.                     of development and agriculture.
     Auckland’s current climate is                                                 Climate change has the potential
     classified as sub-tropical with                                               to exacerbate these effects.
     warm humid summers, mild
     winters and plentiful rainfall.                Ecosystem assessment           There are several ecosystems
                                             Ten regional ecosystems are           that have highly localised or
     Climate change will result in                                                 restricted distributions and so
                                             classified as having severely
     changed weather patterns and                                                  are more vulnerable to regional
                                             restricted spatial distribution,
     conditions, with accumulating                                                 extinction or severe reduction
                                             six of which are critically
     impacts, as well as increased                                                 of their range from a random
                                             endangered. These are mostly
     risk of extreme events that                                                   physical disturbance event. With
                                             coastal and therefore are most
     damage ecosystems.                                                            the increasing frequency and
                                             vulnerable to severe weather
     Rainfall is projected to increase       events, flooding, erosion and         severity of extreme weather
     in intensity and decrease overall       changed weather patterns.             events due to climate change,
     which will have a direct effect                                               events such as landslides,
                                             Native ecosystem maps were            flooding or erosion can severely
     on ecosystems that will be
                                             overlain with projected sea           impact the health of ecosystems.
     subject to drought and flood
                                             level rise and inundation             In the worst-case scenarios,
     conditions more frequently.
                                             scenarios to understand the           ecosystems can be completely
     The varied ecosystems across            effects on these habitats.            inundated or destroyed.
     Auckland will be affected               Ten ecosystems were identified
     differently, for example taraire        as being at risk; where more          Coastal areas are particularly
     and rimu forests are more               than 10% of their area is             prone to the effects of climate
     susceptible to drought stress.          vulnerable to a storm surge           change due to their exposure
     Changes in the pattern of drought       event. Of those, nine are             to storm events, salt deposition
     conditions have the potential to        native ecosystems that are            and rising sea levels.
     alter Auckland’s ecosystems.            classified as endangered
                                             or critically endangered.

38
Species most at risk include         The compounding
bats, reptiles and amphibians,
invertebrates, birds and plants      cumulative effects
with restricted or exclusively       of climate change
coastal distributions. Many
                                     will affect our
already vulnerable or endangered
species will experience greater      native ecosystems.
stresses from climate change.

Seabirds are particularly at risk
as they are most affected by
sea level rise, storm events and
destruction of their habitats
and nesting colonies.

How Auckland can adapt                 Auckland is a
Further research is recommended        seabird hotspot
to understand different                with 24 species
ecosystems. Currently there is
                                       breeding in
a lack of detailed knowledge on
how different ecosystems and           the region.
their species components react
to climate change and so future
                                       Seabirds are at
predictions cannot be accurately       risk as they are
made, particularly as accumulating     most affected by
impacts of climate change will
                                       sea level rise.
impact species uniquely.

                                                          39
04/ T EC H N IC A L REPORT SERI ES

     4.8 Climate change risks for marine and freshwater ecosystems
     Based on: Foley, M.M. and Carbines,   Understanding the interplay           • Ocean acidification affects
     M. (2019). Climate change risk        between climate change                  the condition and survival of
     and vulnerability assessment for      impacts and other human-                marine species, particularly
     marine and freshwater ecosystems.
                                           induced stressors is paramount          those that have hard, carbonate
     Auckland Council technical report,
     TR2019/014                            to protecting culturally,               structures, such as shellfish,
                                           economically, and ecologically          urchins (kina), marine snails
     Aquatic ecosystems are highly         important species.                      and plankton, all of which are
     susceptible to the projected                                                  important components of
     effects of climate change.            Assessment undertaken
                                                                                   Auckland’s marine ecosystems,
     Increases in air temperature          The sensitivity of specific aquatic     and a food source for many as
     and water temperature, ocean          species and habitats in the             well as important aquaculture
     acidification, sea level rise and     Auckland region to potential            species like mussels.
     changes in circulation and storm      climate change stressors was
                                                                                 • Lower nutrient concentrations
     intensity can all affect marine and   assessed and results indicate:
                                                                                   could result in fewer
     freshwater ecosystems.
                                                   STRESSORS ON                    primary producers, such
     Whilst the National Institute of      MARINE ECOSYSTEMS                       as phytoplankton and
     Water and Atmospheric Research                                                macroalgae which form the
                                           • Increasing water and air
     projections illustrate individual                                             base of the marine food web
                                             temperatures in freshwater
     variables, it is difficult to model                                           and underpin the stability
                                             streams and marine habitats
     how changes in multiple variables                                             of marine ecosystems.
                                             affect reproduction and growth
     will cumulatively affect aquatic        rates. This can also result in a    • Increasing sea level rise reduces
     ecosystems. In addition, the            shift in species distributions        the viability of some marine
     projected climate-related changes       and create conditions that            habitats, particularly intertidal
     are occurring within the broader        allow for invasive species to         habitats and coastal vegetation
     context of environmental change         establish new populations             that are at the edge of the
     and human-induced stressors,            in New Zealand. Intertidal            coastal margin and those
     including sedimentation, pollution,     mud flats and rocky reefs             species that rely on exposure to
     disturbance, and harvesting.            are highly sensitive to both          air throughout the tidal cycle.
                                             water and air temperature.          • Changes to rainfall and
                                                                                   storm patterns may cause
                                                                                   declines in water quality due
                                                                                   to increased sediment and
                                                                                   other contaminant runoff.
40
Aquatic ecosystems                   • Reduced wind speed will affect
                                       mixing dynamics in the surface
are affected by                        of lakes, altering the physical
the accumulating                       and chemical conditions of
impacts of climate                     the water column. Less ability
                                       for freshwater species to           Rising
change. The health                     migrate also increases their        temperatures
of these aquatic                       vulnerability if their habitat
                                                                           will increasingly
                                       degrades or is damaged.
ecosystems is                                                              stress marine
fundamental to                       The results of the assessment         and freshwater
human wellbeing.                     can be seen in Table 3 overleaf.      ecoystems.
                                     These changes also need to be
      STRESSORS ON                   considered with natural variability
      FRESHWATER ECOSYSTEMS          including long term climate cycles.

• Increases in air temperature       Intact aquatic ecosystems provide
  may result in increased stream     a range of ecosystem services
  temperature, particularly in       that Auckland relies on every
  places where there is little       day, including oxygen production,
  riparian vegetation for shade      climate regulation, and food and
  and in shallow streams             clean water provision. Changing
  characteristic of Auckland         ecosystems will impact our
• Decreased rainfall will result     ability to adapt. The health of
  in decreased stream flow,          these aquatic ecosystems is
  reducing the amount of in-         fundamental to human wellbeing.
  water stream habitat available
  for fish and macroinvertebrates.
• Heavy rain events can result in
  increased sediment runoff from
  the land, stream bank erosion,
  and stream habitat scouring.

                                                                                               41
04/ T EC H N IC A L REPORT SERI ES

     TABLE 3   CLIMATE CHANGE SENSITIVITY MATRIX
               FOR KEY AQUATIC SPECIES AND HABITATS

      HABITAT/SPECIES            WATER         EXTREME     NUTRIENTS    OCEAN           SEA LEVEL   WATER
                                 TEMPERATURE   RAINFALL                 ACIDIFICATION   RISE        CIRCULATION

      Intertidal mud flats       High          High        Low          Moderate        High        Moderate

      Intertidal rocky reef      High          High        Moderate     High            High        Moderate

      Mangroves                  Low           Low         Low          Low             High        Low

      Kelp forests               High          Moderate    Moderate     Moderate        Moderate    High

      Seagrass                   Moderate      Moderate    Low          Low             Moderate    High

      Subtidal rocky reef        High          Moderate    Moderate     High            Low         Moderate

      Subtidal soft bottom       Moderate      High        Low          Low             Low         Low

      Freshwater hard bottom     Low           High        Moderate

      Freshwater soft bottom     Low           High        Moderate

      Marine shellfish           Moderate      High        Low          High            Moderate    Low

      Marine fish                Moderate      Low         Low          Moderate        Low         Low

      Freshwater fish            High          Low         Low

      Freshwater invertebrates   Moderate      High        Low

     How Auckland can adapt
     Understanding the impacts of climate change and interactions with other
     multiple stressors on the aquatic ecosystems is imperative to planning for
     a more resilient Auckland.

     Taking action to manage other ecosystem stresses such as habitat loss,
     sedimentation and pollution that will be exacerbated by climate change
     effects and reduce ecosystem resilience

     Restoration of natural ecosystems to increase resilience

     Undertaking ongoing New Zealand based studies to assess ecosystem risk.
42
43

Devonport © Istock
05/   Additional and
           emerging risks

           In addition to                       A rapidly growing population puts pressure on the environment
                                                through sprawl and urbanisation that inevitably encroaches
           the risks already                    on the environment. Climate migrants are likely to come to
           identified, there                    New Zealand from the Pacific Islands due to rising sea levels.
                                                This will place further pressure on the country’s resources.
           are other factors
           – known and                          Food security is a broader issue than merely considering
                                                available land allocated to agriculture. A changing climate will
           emerging – that                      alter crop production and increase the risk of drought or flood, as
                                                well as increasing the risk of new disease. New Zealand’s economy
           may compound                         is heavily dependent upon agriculture, which may be affected by
           with the effects                     the exacerbated effects of climate change on the land.

           of climate change                    The magnitude of health consequences from climate change is
           and potentially                      unknown. There is increased risk of extreme weather events that
                                                could cause injury or damage to key infrastructure. New diseases
           exacerbate them.                     and vectors may become established in New Zealand and events
                                                such as extreme heat may cause acute health problems and
           These could include land use         exacerbate chronic illness, particularly in vulnerable populations.
           change, increasing population
                                                Saltwater intrusion will increase with rising sea levels and affect
           and climate migrants, food and       a greater area surrounding Auckland. This can pose risks to buried
           energy security, pollution, global   infrastructure such as utilities and transport tunnels, as well as
           economy, and human induced           agricultural land. It can also pose risk to artesian water supplies.
           stressors. There is uncertainty as
           to how exactly these effects may
           compound or interact.
                                                The cumulative effect of multiple stressors will also
                                                pose emerging risks. While National Institute of Water
                                                and Atmospheric Research predictions provide an idea
                                                of the effects of individual variables, it is unclear what
                                                the effect of multiple variables will be on the ecosystem
                                                and Auckland. In the absence of this information, it
                                                is critical that precautionary and adaptive measures
                                                be taken in decision-making at every level.

                                                It is imperative to keep researching, monitoring and
                                                reviewing the impacts of climate change to continue filling
                                                in the gaps and prepare. Collaboration is the way forward
44                                              for Auckland to create resilience amongst our communities.
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