Our City Our Future Workshop #1 8 February 2018
AGENDA Timing Item 08:00 ARRIVAL 08:25 – 08:30 Welcome Introductions and overview of the workshop purpose and structure 08:30 – 08:45 Climate Change in Dunedin: the science we need to understand 08:45 – 09:30 09:30 – 10:00 Presentation of causal maps from questionnaire 10:00 – 10:15 BREAK Working session #1: Mapping the issues 10:15 – 10:45 Feedback from session #1: Key Issues that will need to be addressed 10:45 – 11:00 Working Session #2 (Using the maps to explore potential actions) 11:00 – 11:30 11:30 – 11:45 Feedback from session #2: Key themes to guide next steps 11:45 – 12:15 Next Steps 12:15 – 12:30 CLOSING REMARKS
OUR CITY OUR FUTURE: WORKSHOP PURPOSE The prime purpose of this workshop is to develop an understanding and commitment to a city focus on collective action. To achieve this we will explore and discuss: i. the climate challenges facing Dunedin, ii. the issues these raise and the consequences for Dunedin of addressing them successfully or not, iii. why collective action is needed to address them successfully, iv. the benefits that can come from collective action, and v. what would be required to sustain collective action over time.
Presentations: Climate Science and its Implications for Dunedin 1. Change Ahead – Adaptive Planning Judy Lawrence 2. Global & NZ Climate Change Projections Andrew Tait 3. Natural Hazards in Dunedin City Mike Goldsmith 4. The Importance & Challenge of Downsizing Simon Cox 5. Possible Futures for Dunedin Chris Cameron
1. Framing the day Judy Lawrence Senior Research Fellow NZ Climate Change Research Institute Victoria University of Wellington
Response after events + Predict and act The shift Robust across many scenarios Anticipate Adapt Sea level rise is happening now It will accelerate It will continue for centuries Source picture: It is foreseeable http://www.ideachampions.com Source: PCE 2015
Different types of impacts Climate changes Systems affected • Slowly emerging impacts Planning • • Sea level rise ‒ Regional/district/asset • Widening climate variability Coastal and flood risk • Drought, increased flood and • Storm water, waste • coastal storm frequency water and water supply • Extremes Coastal storm surge, intense Transport and utilities • • rainfall, wind Finance and insurance • • Surprises Governance • • Accelerated sea level rise • Combined impacts
The ‘Goldilocks’ dilemma What to do? Not too much or too little When to do it? Not too early or too late
Challenges of long-term planning We need to do both • Tyranny of the present • Beyond imagining • Plays out a many levels • Others should solve it • Long-term commitment • Agency and community • Who pays? Changing risk over time ongoing-social and political variability outside experienced range. The future will not be like the past
Adaptive Planning From reactive adaptation to anticipatory adaptation
Adaptive Pathways Planning Asks the following questions Haasnoot et al 2013; Hermans et al • Will the option meet the long term objective? • Will it increase or decrease exposure to the changing risk? • What combination of options will give the greatest flexibility? 2017 • What are their side effects? • Considers lifetime of actions • What other measures will assist meeting the objectives? (e.g. • Short-term investment decisions can be made if they warning signals and decision don’t close off options for the future triggers, planning controls, information) • Explores different pathways for robustness and flexibility as the climate changes • Defines use-by date of options for change of path decisions • Monitors triggers to identify change for timely actions
Communities in a time of change What is important for a functioning liveable community? How will climate change affect these goals and expectations?
2. Global & NZ Climate Change Projections Dr Andrew Tait Principal Scientist – Climate National Institute of Water & Atmospheric Research Ltd (NIWA)
Global climate changes
NZ climate changes
NZ climate change impacts Floods and droughts • Heavy rainfall events are likely to become more intense, by around 8% per °C of warming, meaning future heavy rainfall events are more likely to result in localised flooding. • Extreme flood peaks for rivers in many parts of the country will increase by 10-20% by 2050, meaning present-day flood protection may be insufficient in the future. • Present-day droughts are expected to occur two to four times more frequently by the end of the century, particularly for eastern and northern regions.
NZ climate change impacts Urban Areas • Impacts are mostly associated with the exacerbation of extreme events – e.g. flooding (river), heavy rainfall (wastewater and sewerage), drought (water supply), heatwaves (health). • Sea-level rise is a crucial issue for most NZ urban areas, associated with coastal inundation, river flooding, drainage and salt-water intrusion into groundwater.
NZ climate change impacts Energy supply and demand • Inflows to the main hydro lakes are projected to increase by 5-10% over the next few decades. • Increasing winter precipitation and snow melt and a shift from snowfall to rainfall will affect the timing of winter/spring hydro lake inflows. • Climate warming is likely to reduce annual average peak electricity demands by 1-2% per °C across New Zealand, but increased summer peak demand in warmer areas (e.g. from Auckland) will place additional stress on networks at this time of year.
NZ climate change impacts Natural ecosystems • Climate change will almost certainly reduce biodiversity. • On-going impacts of invasive species and habitat loss will dominate climate change signals in the short- to medium-term, but climatic change has the potential to exacerbate these existing stresses. • The rich biota of the alpine zone is at risk through increasing shrubby growth and loss of herbs, especially if combined with increased establishment of invasive species.
NZ climate change impacts Coastal environment • Erosion and accretion rates of sandy coasts are likely to be affected by sea-level rise. • Coastal inundation risk during high tides and storm surge events will increase with sea-level rise. • For example, with 0.8m sea-level rise, the present-day 1-in-100 year tide level will be exceeded during more than 90% of all high tides.
Thanks for your attention Dr Andrew Tait Principal Scientist – Climate National Institute of Water & Atmospheric Research Ltd (NIWA)
3. Natural Hazards in Dunedin City Michael Goldsmith, RiskSEERS Ltd
Dunedin’s physical e e g g n n environment a a R R r r a a l l l l i i P P d d n n a a k k Geology • c c o o R R Geomorphology • Climate • Silver Peaks Hydrology • Lammerlaw Range Coastal processes • + Human life and property = hazard
Main channel Flood hazard
Coastal hazards: • Shoreline erosion • Storm surge • Tsunami • Groundwater • Changes in sea / ground level
Taieri Ridge Fault Billy’s Ridge Fault e Land-based hazards: g n a R r a l l • Seismic (fault i P d n a k rupture, shaking, c o R liquefaction, lateral Hyde Fault spread…) Silver Peaks Lammerlaw Range t u l a F i r e a i T h r t o N Maungatua Fault Titri Fault Akatore Fault
Land-based hazards: • Landslide / rockfall 2015
Climatic hazards: • Snow • Wind • Drought • Fire
Important natural hazard considerations… 1. Consequences of the hazard critical (as well as the likelihood) Abbotsford, August 1979
Considerations for managing natural hazards 2. Disruption and economic impact at many levels (individual, organisation, community) Fisher & Paykel, April 2006
Considerations for managing natural hazards 3. Consider likelihood of being affected over longer term Dunedin airport, June 1980
Considerations for managing natural hazards 4. Consider likelihood of being affected by any hazard
Considerations for managing natural hazards 5. Consider cumulative effects (repetitive nature of hazards…) Henley, May 2012 Henley, July 2007
Summary • Natural hazards: combination of physical environment, and the social or ‘built’ environment. • Wide range of natural hazards experienced in Dunedin. • Some important considerations for managing hazards. • Additional hazards due to climate change unlikely, but frequency and effects of existing hazards may change.
The importance and challenge of downscaling Thinking about differences between global and local natural processes in planning for and mitigating effects of climate change Dr Simon Cox Principal Scientist, GNS Science, Dunedin
Downscaling From probabilistic to deterministic. Problem from a technical perspective – local processes not always clearly enough understood to provide certainty needed for mitigation or zonation. Risk involves multiple hazards; there are both temporal (frequency) and spatial uncertainties
System overview South Dunedin Analogy Contribution runoff Infrastructure Leaky paper cup from hill suburbs Pu mp s Storm water
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