• Climate change is making extreme climate events more common, increasing the potential of hazard exposure highlighting the importance of proactive adaptation and risk-reduction measures to safeguard communities, infrastructure, and natural systems.
• The climate extremes data is based on the latest NARCliM2.0 climate projections providing new insights into the future of heatwaves, temperature extremes, precipitation extremes and bushfires in NSW.
• The data can support local and state government to conduct climate change risk assessments, policy development, and climate adaptation from a consistent evidence base across NSW.
• Data packs are available for every NSW local government area, NSW planning region, local health district and NSW Office of Local Government Joint Organisations.

Background

NARCliM2.0 climate projections provide the source data required to calculate climate indices, which are used to examine climate extremes such as heatwaves, consecutive dry days, and intense rainfall events. This information helps strengthen climate change resilience providing the information needed to support policy decision makers across a range of government and industry sectors.

Future projections

Under all climate change scenarios, average temperatures will increase, with extreme climate events such a heatwaves and extreme rainfall projected to change with the potential to be more impactful.

Compared to the 1990–2009 baseline the data shows:

• Heatwaves are projected to become longer, more frequent and more intense throughout this century under a low-, medium- and high-emissions scenario.
• Across parts of NSW, the intensity of short-duration, high intensity rainfall is projected to increase. However, changes to the total annual amount of rainfall received from extremely wet days is less certain, as the frequency of these events is highly variable.
• Days with consistent rainfall – as seen in Consecutive Wet Days (CWD) and number of very heavy rain days (R10mm and R20mm) indices – are projected to decrease, on average, across much of the state.

Applications

The NARCliM2.0 climate extremes datasets help support risk-informed decisions about the location, design and timing of future development. The data can inform regional and local planning processes, infrastructure investment, environmental conservation and disaster resilience initiatives.

The availability of locally-focused and packaged data provides opportunities for climate resilience at a local government level and supports strategic adaptation planning to ensure that communities, infrastructure and economies remain resilient under a range of future climate scenarios, while also reducing long-term exposure to climate-related risks. 

For example, local government can use the projections to assess the long-term exposure of key assets, such as roads, to the impacts of high heat and extreme rainfall-induced erosion and inundation. It can also support decisions on maintenance schedules, resilience upgrades, or relocation planning. 

Planners may use the data to identify impacts of heatwaves on infrastructure, health and the environment, helping refine risk and adaptation measures.

Other examples could include using the projections to identify climate constrained growth areas, inform urban heat planning, flood and storm water planning, planning for long term critical infrastructure, changes to bushfire risk planning, water sourcing and regional plans and biodiversity and green infrastructure planning.

Users are encouraged to interpret the information in line with their local context, exposure profiles, and risk tolerance, ensuring that adaptation strategies remain both targeted and flexible over time.

What assets and information are available

Non-bias adjusted (22 indices) and bias-adjusted (2 indices) data has been modelled to identify future changes in 24 climate extreme indices.

The purpose-built content within the data packs include:

• GIS shapefiles containing historical, projected and change values, including minimum and maximum statistics, CSV files of annual, per-model and ensemble statistics.
• Maps showing absolute and projected change values by epoch.
• Visualisations including time series, climate stripes, ensemble ranges and key metrics summaries.
• User guide and technical documentation describing methodologies, file structures and data attributes and guidance as to interpret and use the information and contextual information.
• Multi-model annual and epoch statistics, ensemble summaries and supporting analytical visualisations.

Indices included in the data packs are under 4 themes. Heatwave, bushfire weather, temperature extremes and precipitation extremes.