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Climate change in a rural shire

Summary

This case study outlines a risk assessment that examined the effects of climate change on a rural shire in Australia. It demonstrates the use of climate scenarios, and risk assessment over short-term, medium-term and long-term time horizons.

It uses an extended risk analysis template as a continuing record of important supporting information for justifying treatment responses. Some of these may relate to risks with impacts only in the far distant future but that require action in the short term to avert problems or to build resilience.

Background

The Shire

The shire is located in regional Australia. It has an extended ocean coastline, with a fertile coastal plain rising to forested mountains along its inland border. There is a city on the coast, and many small communities and farms scattered throughout the shire. There is a growing population of retirees.

Agriculture and horticulture are important parts of the local economy, and the city supports a moderate industrial base. Tourism generates significant revenue. The shire’s coastal environments, communities and infrastructure are potentially vulnerable to the effects of climate change, as are the extensive bushland, native wildlife and wetland ecosystems outside the main city.

The requirement and scope

The activities described in this case study were conducted in 2009. The council needed assistance in developing a response strategy and plan for addressing the short-term, medium-term and long-term effects of climate change. The specific objectives were to:

  • Identify, describe, analyse and prioritise risks to council infrastructure, assets and services arising from current and predicted climate change
  • Develop a strategy and action plan for responses and adaptations to address these risks.

The assessment was to cover all council responsibilities that might be affected by climate change, including:

  • Infrastructure management and maintenance of assets
  • Community services
  • Operational works
  • Planning and management of development and land use
  • Land and water management.

The assessment covered the entire geographic area of the shire, down to the mean low water mark along the foreshore.

To facilitate more precise targeting of responses, the council also wanted to understand the spatial extent of risks associated with predicted climate change scenarios. As a coastal shire, there was a particular interest in the spatial extent of risks associated with sea level rise, severe storms, storm surge and flooding.

The risk assessment and associated analysis described here was to be used as an important part of a community engagement process that would precede the development and issue of a climate change adaptation plan for the council.

Risk assessment for climate change

Approach

The risk assessment followed the approach described by the Australian Greenhouse Office (2006) Climate Change Impacts and Risk Management: A Guide for Business and Government. (Broadleaf and Marsden Jacob Associates authored the Guide, which was based on then current Australian and New Zealand Standard AS/NZS 4360:2004 Risk management, since superseded by ISO 31000:2018 Risk management – Guidelines.)

Context material was examined, a desktop review of risks was conducted, and a detailed briefing note was prepared for two assessment workshops.

Time horizons

The time horizons in which the council was interested (Figure 1) were interpreted as:

  • Short-term, to the end of the current business planning period in 2010
  • Medium-term, to the end of the strategic planning ‘extended timeframe annex’ in 2030
  • Long-term, using a projection to 2070 as an indicator of long-term prospects.

Some risks would not be likely to become serious until beyond 2030, or even towards 2070. However, they might be affected substantially by council's actions and decisions in the next few years, particularly decisions about land use planning, infrastructure development and asset management. In other words, while the time scale of some risks might have appeared to be so long that they fell outside the scope of immediate planning processes, the shire’s future community would be affected by decisions made now.

Figure 1: Assessments through time

Climate scenarios

Climate change scenarios provide a plausible summary of the changes to climate variables that are likely to apply to a geographical region and timescale of interest. They provide a consistent and efficient basis for assessing climate-related risks.

The scenarios for this study were based on the then best available projections for the region (CSIRO, 2006). (More current information is now available here.) They were consistent with mid-range projections for 2030 and 2070, with impacts adjusted to take account of the local biophysical and socio-economic information that was collected prior to the workshops. They represented ‘best estimate’ changes in climate variables, assuming no substantial reductions in global greenhouse gas emissions below ‘business-as-usual’ in the coming decades. For most of the variables, the direction of change was clear, although in many cases there was uncertainty about the magnitude of the change.

Climate variables used in the scenarios are noted in Table 1.

Table 1: Climate variables

Variable

Details

Temperature

Average annual temperature, days over 35°C, annual potential evapotranspiration

Rainfall

Average annual and seasonal rainfall, annual stream flow, drought, 24-hour rainfall intensity, number of rainy days, flood return intervals

Sea level

Sea level rise, storm tide height, worst-case storm surge

Wind and storm

Average and extreme wind speeds

Other

Solar radiation, humidity, number of extreme and high bushfire danger days

Risk analysis criteria

The risk analysis was based on the council’s risk management framework. The criteria against which the consequences of risks were analysed were linked to the objectives in the council’s corporate plan, which can be summarised under the following headings:

  • Financial outcomes
  • Loss of life, injury or illness
  • Environmental outcomes
  • Building and assets
  • Governance.

Key elements

The risk assessment workshops were structured around a set of key elements in the five broad categories noted in Table 2. They covered the council’s assets, operations and services.

Table 2: Key elements

Category

Elements

Infrastructure

Buildings, roads, coastal infrastructure, transport, power, stormwater, asset management

Planning

Strategic planning, economic development, commercial and industrial planning, residential development, open spaces

Environmental management

Biodiversity, catchments, wetlands, coasts, parks and reserves, pests and weeds, bushfires, waste management

Community and social matters

Health, aged care, public health and safety, emergency services, recreation

Corporate services

Workplace health and safety, legal, financial

Risk assessment process

Two risk assessment workshops were conducted, using the key elements to drive the agenda. Risks were identified for each element, and then analysed using the template in Table 3. Consequences and likelihoods were analysed for each risk as it was expected to be in 2010, then adjusted to represent its anticipated characteristics in 2030 and 2070, taking the details of the evolving climate scenario into account. It was assumed the current controls would be in place for all three time horizons of interest.

As well as the specific detail required for the risk analysis, relevant workshop discussion was recorded on the template. This included the rationale for the analysis and any changes from period to period. It was augmented with information generated during post-workshop follow-up analyses.

Spatial and other analyses were also conducted after the workshop. Their outcomes, and the need for further investigations, where relevant, were recorded in the template to preserve a single information base that would support adaptation planning.

Table 3: Risk analysis template

Assessment outcomes

The workshops identified and analysed 48 risks, including risks with positive impacts, and an additional risk was identified but not analysed pending further investigation.

The risk profile generated in the workshops is shown in Figure 2. No risks were rated as Extreme, using the council’s risk management framework, in any time period; they appear as zeroes in Figure 2. A large amount of information was generated; an illustrative selection of other outcomes is shown in Figure 3, Table 4 and Table 5. The High and Medium risks are associated predominantly with the effects of climate change on infrastructure, although community and social risks, and environmental matters, become more important in the long term.

Figure 2: Risk profile

Figure 3: High and Medium risks

Table 4: Important impacts on infrastructure management

Focus

Storm

Drought

Flood

Coastal inundation

Buildings

High

Medium

Low

Roads, footpaths, cycle ways

High

Low

Marine infrastructure

High

High

Closed landfills

High

Power infrastructure

High

Stormwater drains

High

Low

High

Ferries

High

Table 5: Summary of High risks in 2070

Category

Risk

Infrastructure

Increased storm tide damage to pontoons, marinas, jetties, piles and sea walls (armouring)

Infrastructure

Barges and ferries inoperable in rough weather

Infrastructure

Low-lying public infrastructure and council buildings damaged by flooding

Infrastructure

Stormwater treatment systems overwhelmed

Environment

Significant harm to animal or plant populations, habitat or ecosystem health through storms and flooding

Environment

Significantly increased algal blooms

Community and social

Public safety threatened through altered incidence of mosquito-borne infectious diseases

Corporate

Council liability for approved developments threatened by flooding or sea level rise

Adaptation planning

Some preliminary spatial and other assessments were conducted to better understand key issues that arose during the process. The risks and priorities obtained from the risk assessment workshops, together with these additional assessments, were taken forward for adaptation planning. That component of the work is not addressed in this case study.

Lessons

Climate scenarios

‘Standard’ climate scenarios are available for geographic regions, but they are usually quite general and cover a wide area. In this case we tailored a regional scenario to the specific area, using local physical, environmental and socio-economic information.

This approach provided a sound and scientifically-justifiable basis for the analysis, made relevant for the circumstances.

Time horizons

Time horizons should be selected on the basis of their usefulness for the objectives of the work. In this case, they aligned broadly with the council’s extended planning periods, and also with the availability of scenario data.

The risk analysis followed a sequential process for each risk (Figure 1) that reduced the confusion and potential for disordered discussions that can arise when trying to think about multiple time periods.

  • The first part of the analysis focused on the short-term implications of the climate scenario. This should be familiar and reasonable well understood, and thus provide a firm base on which to build the subsequent analysis for the risk.
  • Moving gradually into the future, first to 2030 and then to 2070, allowed the participants to examine changes in the climate scenario as it evolved, and the effects of those changes on the council, making adjustments to their analysis of consequences and likelihoods as circumstances changed.

Risk analysis template

The risk analysis template in Table 3 is more than just an extended ‘risk register’. It provides a structure for the analysis that promotes an efficient workshop process as well as recording additional information, including:

  • Additional explanatory detail about the assumptions, thinking and rationale underlying the analysis
  • The wider implications of the risk across the shire
  • Spatial analysis that may support more precise targeting of adaptation responses (risk treatment actions).

While each template initially provides a snapshot of the risk and the analysis at the time of the workshop, it serves as a continuing record that can be updated as circumstances change. It provides important supporting information for justifying treatment responses, some of which may relate to risks with impacts only in the far distant future but nevertheless require action in the short term to avert problems or to build resilience.

References

AS/NZS 4360:2004 Risk management, Third edition, Standards Australia, Sydney, and Standards New Zealand, Wellington.

Australian Greenhouse Office (2006) Climate Change Impacts & Risk Management: A Guide for Business and Government, Department of Environment and Heritage, Commonwealth of Australia.

  • Note: Broadleaf Capital International and Marsden Jacob Associates wrote this guide for the Australian Greenhouse Office.

CSIRO (2006) Climate change scenarios for initial assessment of risk in accordance with risk management guidance, Commonwealth Scientific and Industrial Research Organisation, Canberra. (More recent projections are available at https://www.climatechangeinaustralia.gov.au/en/.) ISO 31000-2018 Risk management – Guidelines, International Organization for Standardization, Geneva.

Client:
Rural shire council
Date:
2009
Sector:
Public sector and government business
Climate change