Climate change and heritage

The Heritage Council of NSW and Heritage NSW are developing resources to help owners and managers of heritage places manage the impacts of climate change.

The NSW Government is committed to effective action on climate change to ensure a sustainable and fair future for the people, economy and environment of NSW, including achieving net zero emissions by 2050.

Heritage owners can make a strong contribution towards achieving net zero emissions, by: 

retaining and reusing heritage places to maintain existing embodied energy and avoiding the emissions associated with new buildings, such as energy, transport, materials and waste
upgrading heritage buildings to improve energy efficiency
installing clean energy systems, such as roof-top solar.

The adverse effects of climate change in New South Wales are becoming more common. Warmer temperatures, rising sea levels, changing rainfall patterns and more frequent extreme weather events have the potential to impact the built and natural environment, including heritage places.

Owners and managers need to prepare heritage places for the impacts of climate change, now and into the future.

Principles

In 2023, the Heritage Council of NSW adopted 6 principles to guide heritage policy development, decision making, adaptation and rapid response to the impacts of climate change on heritage places into the future.

Heritage NSW is implementing these principles through a climate change action plan. The actions in the plan are designed to:

build the capacity of Heritage NSW and heritage place owners and managers to prepare for and respond to the impacts of climate change
support and provide guidance on the sustainable ongoing use and adaptive reuse of heritage buildings.

These principles have been adapted from the Heritage Council of Victoria’s Principles on the protection of cultural heritage from climate change impacts.

	Principle	Description
	1. Taking a values-based approach: understanding the values of the place or object	The values-based approach to assess, manage and respond to the impacts of climate change on heritage places and objects should: understand that heritage values are dynamic and change over time include tangible and intangible heritage include natural, social and economic values understand how heritage values are reflected in the fabric of a place as a prerequisite.
	2. Engaging communities	Communities should be: provided with information about climate change risks to heritage places and objects able to share knowledge and inform assessment of risks and the management of climate change impacts to heritage values given access to results of risk assessments given opportunities to participate in decision making including the design and implementation of responses to climate change.
	3. Evidence-based decision making	Actions to manage the impacts of climate change must: be based on current climate science and climate change projections recognise the uncertainty of these climate change projections be aware of the heritage values and condition of the heritage place be aware of the implications of loss, including social and economic. It should be recognised that local conditions and circumstances will likely have the greatest bearing on the extent and nature of the impacts.
	4. Assessing risks and resilience	Assessment of the risks of climate change to heritage values, and the vulnerability of individual places and objects to those risks and their capacity for adaptation, is fundamental for risk preparedness and building resilience. Assessments must recognise that climate change threats to heritage values: are diverse may be short- or long-term and cumulative could include complete loss. Assessment of risk and resilience should guide actions taken.
	5. Responsive strategies	Strategies for adaptation to and mitigation of the impacts of climate change should: respond to the scale and severity of the impact recognise and plan for the inevitable loss of some heritage places and objects be flexible and innovative to deal with uncertainty in managing impacts. Possible approaches should be widely shared across government and communities. These approaches may include nature-based solutions that offer long-term protection against flooding, storms, and sea-level rise.
	6. Integrating management approaches	Climate change compounds existing threats to heritage values. Management of climate change impacts to heritage places, objects and values should be integrated into: existing and future heritage management plans, existing heritage management processes and methods may need to change climate change policies and actions across government agencies and all levels of government. Climate change should also be added to risk registers, including identified risks and mitigation measures. Embodied energy in heritage places and the potential contribution of adaptation measures to greenhouse emissions should be considered.

Impacts

Heritage NSW has also been looking at the potential impacts that climate change will have on heritage places in NSW.

This table includes information that builds on a range of potential impacts related to weather.

Weather	Impacts	Impacts on heritage
Warmer mean temperatures	Rise in sea levels	persistent inundation and flooding loss of historic structures destruction of Aboriginal sites, such as coastal middens and campsites through storm surge and erosion permanent inundation of intertidal Aboriginal sites, such as axe grinding grooves and fish trap sites more frequent exposure and loss of Aboriginal traditional burial sites decline in heritage-related coastal economy, e.g. heritage tourism loss and inundation of archaeology on foreshore and coastal edge, e.g. shipwrecks, port infrastructure, seawalls and jetties direct and indirect impacts on historic assets and areas, and their settings from increased or strengthened engineered/physical protections damage to or loss of heritage value of coastal cultural landscapes due to installation of boulder breakwaters, riprap stone walls and other beach front protections damage or modification due to actions such as emergency response, mitigation and managed retreat damage from clean-up operations.
Warmer mean temperatures	Ecosystem changes and associated migration and proliferation of pests, diseases and invasive species	increased incidence and severity of fungal and insect attack causing harm to the building fabric, occupants and collections/archives, e.g. increased habitat for termites will impact alpine huts proliferation and expansion in range of invasive and non-native species change in marine species in response to warmer seas and increased acidification; loss of Aboriginal traditional foods (fish and shellfish) and/or resource gathering locations loss of species at threshold of tolerance leading to changes in distinctive character of heritage places changing pest and insect regimes leading to damage and loss of heritage plants and gardens, in particular loss of cool climate heritage gardens in places like the Blue Mountains and the Southern Highlands.
Long-term drier climate	Drying out, desiccation, shrinkage and erosion	Subsidence subsidence caused by clay shrinkage to features and structures, e.g. buildings, breaches in flood defences, dams and reservoirs, shafts and underground workings, and blockages of river courses Erosion and destabilisation erosion of heritage places exposed by loss of vegetation and/or the lowering of lake, inland waterways and river levels destabilisation/erosion of earth structures, embankments and cuttings destabilisation of tips, historic mine spoil heaps and other industrial remains leading to landslides and increased potential for pollution increased erosion from impaired pasture growth caused by desiccation increased use of marginal pastures leading to erosion of archaeological remains and cultural landscapes wind-blown movement of marine sediments, e.g. dunes, exposing Aboriginal sites and objects. Drying out lowering of water table causing loss of paleoenvironmental evidence changing decay and survival of organic artefacts, e.g. trackways and exposure of riverine shipwrecks changing use and/or abandonment of agricultural land and buildings to cope with water shortages, lack of fodder and poor harvests drying and stress to old growth trees, historic trees and plants and their contribution to cultural landscapes discovery of new historic assets in desiccated grassland and crops visible as parch and crop marks improved humidity levels in buildings including impacts to interiors and collections.
Long-term drier climate	More fire danger days and more frequent bushfires	Built heritage increased risk of fire in buildings and structures from drier conditions damage to buried and above ground archaeology, structures and movable heritage from wildfires opening of timber joints and cracking of masonry in buildings from drier conditions increased damage from fire protection measures, such as the creation of fire trails and firebreaks. Iconic species potential loss of iconic species, food, totems, etc. due to repeated high intensity fires. Vegetation loss of historic plants due to fire or changes to plants in response to fire risk affecting historic landscape character increased risk of erosion after coastal fire damage to surface vegetation and its protective effect.
Warmer drier winters	Increased fire danger in spring and summer	more intense fire conditions in the summer months with fire season starting earlier and lasting longer due to drier winters reduced viability of agriculture (where dependent on winter rains) and heritage properties that are active farms increased tourism potential of some regional areas through autumn and winter.
More frequent extreme weather	Frequent high winds, storms and heat/cold events	Damage from increased precipitation/high wind events reduced ability to prepare for storm events increased storm damage to features, historic buildings, settlements and structures above ground lack of capacity in roof and stormwater drainage systems wind driven rain and increased humidity reduce indoor air quality and health of building fabric, occupants and collections/archives. Damage from increased high-energy flooding and storm events damage/scour to underwater, intertidal and coastal archaeology due to turbulent seas exposure or covering of historic assets due to increased sediment transport erosion of foundations and destabilisation of structures damage to mature trees and woodland cumulative impacts from multiple events damage from clean-up operations and modifications increased maintenance and repair costs. Physical and chemical changes increased lightning strikes starting fires persistent saturation resulting in chemical changes to buried archaeology.
	Extreme heat/drought and cold events	extremes and fluctuations in weather conditions affecting physical weathering, exacerbating building material and structural problems, e.g. freeze/thaw action and shrinkage overheating of buildings and potential for unsympathetic additions, e.g. poorly designed air conditioning changing land use to cope with the impacts of extreme and fluctuating weather conditions increased heat and drought impacting on mature trees and woodland loss of traditional food sources increased fire risk during heatwaves and following droughts.
	More flooding events, increased ground moisture and precipitation	Increased erosion, scour and other damage damage to historic buildings, settlements, infrastructure and designed features destabilisation and subsidence of archaeology on the coast edge erosion, damage or loss of buried and above ground archaeological remains increased pressure, scour and damage to water-related features, e.g. bridges, overtopping of dams potential adverse impact from clean-up operations and modifications, e.g. installation of property flood resilience measures. Physical and chemical changes persistent saturation resulting in chemical changes to buried archaeology and cultural landscapes. Destabilisation and pollution inadvertent pollution episodes from flooding and increased precipitation, e.g. dispersal of toxic/hazardous materials destabilisation and subsidence of archaeology on mine spoil and designed features, archaeological deposits and earth structures leading to slippage or collapse potential adverse impact from clean-up operations.