Preserving Australia's past in a changing climate: A call to action for climate-resilient heritage conservation

BUILT HERITAGE SERIES: PRESERVING AUSTRALIA'S PAST IN A CHALLENGING CLIMATE: A CALL TO ACTION FOR CLIMATE-RESILIENT HERITAGE CONSERVATION.

Mrs. Emilia Zambri, MSoc Sci Tangible Heritage Conservation.

PREFACE

Welcome to this series of techniques for managing change and assessing the condition of architectural heritage structures and historic heritage fabric. This newsletter aims to provide professionals, including Heritage Consultants, Architects, Archaeologists, and Conservators, with practical and effective methods to determine the most appropriate approaches to management, conservation, and restoration.

Inspired by the challenges encountered in safeguarding historic heritage, especially in under-resourced areas, particularly in Africa, this series has been developed to assist colleagues globally. The goal is to present simple and easy-to-use frameworks, case studies, and tests that can be employed to evaluate the preservation, conservation, and restoration needs of historic heritage, ensuring their safeguarding for future generations.

By utilising these techniques, the objective is to empower heritage professionals with the knowledge and tools necessary to make informed decisions about the preservation of our shared cultural heritage. Join us as we embark on a journey to protect and preserve the historical structures that define our shared identity.

ABSTRACT

Climate change presents a formidable threat to Australia's historic and natural heritage, impacting both tangible and intangible elements. This article evaluates the intersection of climate change and historic and natural heritage in Australia, current conditions, and vulnerabilities. Drawing on existing case studies, including the 2022 New South Wales Northern Rivers Project, the Shark Bay World Heritage Area, and the Lake Pedder – Opportunities for Restoration, this article aims to highlight the need for urgent and adaptive strategies. In addition, the article aims to provide opportunites for policymakers, heritage managers, and local communities, emphasising the need to enhance climate resilience in the conservation of Australia's diverse historic heritage.

1. INTRODUCTION

Australia's historic and natural heritage stands at the crossroads of an unprecedented challenge – climate change. The intensifying impacts of rising temperatures, extreme weather events, and sea-level rise demands immediate attention. This article aims to explore the intricate relationship between climate change and historic heritage in Australia, shedding light on unique vulnerabilities and opportunities for adaptive management.

2. DEFINITION AND TYPES OF AUSTRALIA'S HISTORIC AND NATURAL HERITAGE

Australia's historic heritage comprises tangible evidence and sites spanning from the arrival of the first European migrants in 1606. Recognised and protected under various legislative frameworks, historic heritage embodies the tangible remnants associated with Australia's rich history. This includes diverse sites, from iconic landmarks like the Sydney Opera House to more ordinary remains, all contributing to the nation's cultural identity. Historic heritage extends beyond structures to include underwater cultural heritage and sites of significance to Indigenous and non-Indigenous communities. Its multifaceted significance encompasses historical, scientific, aesthetic, social, and spiritual values, integral to the nation's identity and sense of place.

Natural heritage forms part of Australia's environment, intricately linked to this historical narrative. Encompassing the biological environment (flora, fauna, habitats, and ecosystems) and geological and geomorphological features (rocks, landforms, and landscapes), natural heritage adds another layer to the nation's story. Australia's natural heritage, ranging from expansive areas to small, localised sites of high conservation value, plays a defining role through iconic species and distinctive landscapes.

Within this spectrum, tangible elements include objects, buildings, landscapes, reflecting themes like exploration, economic development, and Indigenous heritage. Limited monitoring and evaluation efforts underscore the heightened susceptibility of these sites due to insufficient government resources, climate change-driven extreme weather events, and urban development pressures. As such a holistic management strategy is imperative.

3. CLIMATE CHANGE AND HERITAGE: AN OVERVIEW

Climate change significantly impacts World Heritage Sites globally, including the 20 Australian sites listed on the UNESCO World Heritage List. These range from convict sites like the Port Arthur Historic site in Tasmania to natural and cultural heritage sites like Kakadu National Park. The tangible effects of climate change on historical and cultural heritage are evident in rising temperatures, altered precipitation patterns, more frequent extreme events, and rising sea levels. A recent CSIRO-led paper,?Holistic Climate Change Adaptation for World Heritage,?published in Nature Sustainability, explores the implications of climate change on these iconic sites and proposes innovative management strategies.

Climate change, marked by increasing temperatures and more frequent extreme events, directly threatens the attributes that earned these sites their 'Outstanding Universal Value.'

The International Union for Conservation of Nature's (IUCN) World Heritage Outlook identifies climate change as the most significant threat to natural World Heritage Sites globally. Severe weather events linked to climate change are causing damage to the built fabric of these sites, including deterioration due to heat and humidity, water ingress from storms, and wind damage.

Lead-author Dr. Brenda Lin emphasises that climate change is not only altering the physical attributes of World Heritage Sites but is also reshaping societal and communal values attached to these sites. The paper advocates a threefold approach to site management:

1. considering diverse desires and values of stakeholders,
2. recognising the interconnectedness of natural and cultural values, and
3. ensuring Indigenous leadership in decision-making processes related to site management and adaptation.

The Tasmanian Wilderness World Heritage Area serves as a poignant example of the challenges posed by climate change, where threats such as bushfires require active intervention and adequate resourcing for effective adaptation. Long-term adaptation plans that integrate knowledge about future climate change threats are deemed essential for managing World Heritage values in a staged fashion.

4. CURRENT CONDITIONS AND HERITAGE VULNERABILITIES

Australia faces deteriorating heritage sites due to climate change, manifesting as rot, corrosion, and disintegration, as seen in recent events like the flooding of the Port Arthur Historic Site Penitentiary, ongoing coastal erosion at the Coal Mines Historic Site, and the general destruction caused by bushfires.Climate change impact is evident in Antarctica, affecting sites like the Mawson’s Huts Historic Site.

Changing fire regimes, becoming more common due to climate change, adversely affect natural terrestrial heritage, impacting significant plant communities and fauna habitats. While geoheritage's vulnerability to bushfires is comparatively lower, indirect effects like erosion from vegetation loss pose significant threats.

Cultural heritage, including structures, archaeological sites, landscapes, and traditional resources, is highly susceptible to bushfires. Indigenous communities, in particular, bear a disproportionate burden of extreme fire events, leading to lasting impacts on native species, Indigenous sites, stories, totems, and traditional resources.

The destructive consequences of climate change-induced bushfires extend to rock art sites, archaeological heritage, and accelerated erosion after fires. Additionally, major storms, strong winds, cyclones, and floods can damage both natural and cultural heritage, causing localised destruction of significant flora, habitats, geoheritage features, and cultural landscapes.

Coastal changes due to sea level rise, coastal erosion, and inundation pose severe and irreversible impacts on coastal built heritage, Indigenous and historic heritage, and underwater cultural heritage. The long-term, gradual-onset effects of climate change, such as increased temperatures, ocean acidification, and heightened drying, pose significant threats to Australia's natural heritage, particularly its biological values. While impacts on archaeological heritage are limited, built heritage and underwater cultural heritage face increased biodeterioration, corrosion, and structural damage due to changed foundation conditions.

Addressing these challenges requires urgent action to mitigate and manage their impacts. Although some regional heritage risk assessments are underway, substantial gaps in heritage resourcing hinder effective conservation efforts. Increased government support for research, training in historic trades skills, development of a national quality assurance framework, and assistance for private owners to fulfill their conservation obligations are crucial needs. A multidimensional approach integrating conservation, community engagement, and legislative enhancements is essential to safeguard Australia's invaluable historical legacy from the impacts of climate change.

5. CASE STUDIES

5.1 Case study: The NSW Rivers Project – Recording Underwater Cultural Heritage in Inland Rivers:

Rivers have played a pivotal role in Indigenous communities' lives for generations, serving as vital pathways for subsistence, transport, and cultural activities. The NSW Rivers Project, initiated by Heritage NSW, focuses on documenting archaeological remains and heritage sites along New South Wales rivers. This collaborative project involves citizen science, with over 60 volunteers and community groups contributing to the recording of underwater and terrestrial cultural heritage.?

Climate change opportunities:

Operating since 2010, the NSW Rivers Project has identified over 700 new sites in 30 waterways, shedding light on the diverse historical uses of riverine cultural landscapes. The project not only contributes to the protection of cultural heritage but also addresses gaps in underwater cultural heritage knowledge, enhancing the understanding of Australia's historical waterways.?

Challenges and lessons:

Community involvement: Engaging local communities through citizen science and collaboration with historical societies has proven instrumental in the success of the project. Community-driven initiatives and oral histories contribute significantly to the project's outcomes.?

Addressing thematic gaps: Systematic statewide projects, like the NSW Rivers Project, are crucial for improving the recognition and protection of cultural heritage. By addressing thematic gaps in underwater cultural heritage knowledge, the project sets a precedent for preserving historical identities associated with Australia's rivers.?

5.2 Case Study: Climate change and the Shark Bay World Heritage Area:

Shark Bay, located on the coast of Western Australia, spans 2.2 million hectares and is recognised for its marine and terrestrial biodiversity, ecological significance, and exceptional beauty. Designated as a World Heritage Area, Shark Bay boasts unique features such as extensive seagrass beds, hypersaline environments, stromatolites, and serves as a stronghold for the protection of dugong and various species. However, its Outstanding Universal Values face severe vulnerability due to climate change, particularly in the face of rising air temperatures, increased storm intensity and frequency, and extreme marine heat events.?

Climate change impacts:

The effects of climate change on Shark Bay are already evident, with tropical marine life shifting southward due to rising sea temperatures. A marine heatwave in 2011 resulted in a 25% loss of seagrass habitat, impacting dolphin birth rates and causing declines in crab, prawn, and scallop populations. The cyclone Seroja in 2021 exacerbated the situation, causing flooding and destroying vital infrastructure, including a viewing boardwalk over 1,300-year-old stromatolites.?

Challenges and lessons:

Complex interactions: The case illustrates the intricate and cascading effects of climate change, including interactions with existing climate-related events such as cyclones. This complexity emphasises the need for robust strategies for climate change adaptation and management planning.?

Strategic planning for balancing use: The example of recreational fishing closures following the 2011 heatwave showcases the importance of strategic planning to balance human use of the area with the imperative to protect its values. Reopening areas after recovery, coupled with adjusting catch limits, demonstrates the ongoing need for adaptive management.

Data-Driven Adaptation: Effective climate change adaptation requires accurate data and monitoring. The vulnerability of Shark Bay emphasises the necessity of developing adaptation measures based on good condition data to safeguard its Outstanding Universal Values.?

5.3 Case study: Lake Pedder – Opportunities for Restoration

Lake Pedder in south-western Tasmania, once a globally unique glacigenic lake with rare biological values, was flooded in 1972 as part of the Gordon River hydro-electricity scheme. The flooding, causing the loss of significant wilderness, led to unprecedented environmental controversy and laid the groundwork for increased Australian Government involvement in environmental matters. Today, within the Tasmanian Wilderness World Heritage Area, the potential for Lake Pedder's restoration is being explored.?

Restoration opportunities:

Scientific studies confirm that the original landforms beneath the reservoir remain intact, enabling the restoration of Lake Pedder. The removal of dams for environmental rehabilitation is increasingly common globally, presenting an opportunity to restore a key geomorphic attribute and demonstrate Australia's commitment to heritage restoration.?

Challenges and lessons:

Environmental controversy: The case highlights the historical environmental controversy surrounding the flooding of Lake Pedder, leading to legislative initiatives and increased government involvement in heritage conservation.?

Global restoration context: The current global focus on ecosystem restoration provides a conducive environment to examine the restoration of Lake Pedder. Such an action could restore the Outstanding Universal Value and wilderness value, showcasing Australia's dedication to heritage restoration.?

Technical feasibility: Scientific studies supporting the technical feasibility of restoration underscore the importance of evidence-based decision-making in heritage conservation. The case emphasises the need for comprehensive assessments and studies before undertaking restoration efforts.

6. RECOMMENDATIONS FOR CLIMATE-RESILIENT HERITAGE CONSERVATION:

1. Integrated risk assessments:?Conduct comprehensive risk assessments that integrate climate change considerations into heritage management plans. This involves evaluating the vulnerability of heritage sites to climate-induced events and developing mitigation strategies.
2. Community engagement:?Foster community engagement in heritage conservation. Local communities often hold valuable knowledge and can actively contribute to monitoring, protection, and adaptive management of heritage sites.
3. Capacity building:?Invest in training programs for heritage professionals and local communities, enhancing their capacity to implement climate-resilient conservation practices. This includes developing skills in adaptive management, climate monitoring, and sustainable conservation methods.
4. Legislative enhancements:?Advocate for legislative enhancements that explicitly address climate change impacts on heritage conservation. This includes incorporating climate resilience requirements into existing heritage protection frameworks.
5. Research and innovation:?Support research initiatives focused on developing innovative solutions for climate-resilient heritage conservation. This involves investing in technologies, materials, and methodologies that can enhance the durability of heritage sites in the face of climate-related challenges.
6. International collaboration:?Engage in international collaborations to share knowledge, best practices, and resources for climate-resilient heritage conservation. Learning from global experiences can provide valuable insights and strategies.

7. CONCLUSION

Australia's historic and natural heritage is at a critical juncture, facing unprecedented challenges from climate change. Urgent and adaptive strategies are imperative to ensure the preservation of the nation's diverse heritage. By implementing the recommended measures – from integrated risk assessments to international collaboration – Australia can embark on a path towards climate-resilient heritage conservation. Through collective efforts, policymakers, heritage managers, and local communities can safeguard Australia's invaluable historical legacy for generations to come.