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Proc Natl Acad Sci U S A
Proc Natl Acad Sci U S A
PNAS
Proceedings of the National Academy of Sciences of the United States of America
0027-8424
1091-6490
National Academy of Sciences

38527215
202317158
10.1073/pnas.2317158121
research-articleResearch Articlesustainability-socSustainability Science9
Social Sciences
Sustainability Science
Capacity of the U.S. federal system for cultural heritage to meet challenges of climate change
Rockman Marcy mrockman@umd.edu
a 1 https://orcid.org/0000-0003-3831-4788

aDepartment of Anthropology, University of Maryland, College Park, MD 20742
1Email: mrockman@umd.edu.
Edited by William Clark, Harvard University, Cambridge, MA; received October 3, 2023; accepted February 16, 2024

25 3 2024
9 4 2024
25 9 2024
121 15 e231715812103 10 2023
16 2 2024
Copyright © 2024 the Author(s). Published by PNAS.
2024
https://creativecommons.org/licenses/by-nc-nd/4.0/ This article is distributed under Creative Commons Attribution-NonCommercial-NoDerivatives License 4.0 (CC BY-NC-ND).

Significance

Cultural heritage holds centuries to millennia of human experience living in and with the natural world, while climate change presents a wide range of challenges to human and natural systems that extend into the future. But heritage and climate are not yet well linked in research or policy. With a case study of the U.S. federal government, this paper brings together legislative history, emerging theoretical understandings of heritage and climate, and developments in the U.S. National Park Service and other federal agencies to present a model of how heritage and climate came to be disconnected. It recommends research and policy steps that may more fully engage heritage as part of the U.S. climate change response, including its roles internationally.

The U.S. federal government is unbalanced in its capacity to recognize, manage, and engage cultural heritage as part of its response to climate change. Legislation from the 1906 Antiquities Act to Executive Order (EO) 13990 signed in 2021 has set an overarching approach in which heritage is understood to be primarily tangible places and things that should be conserved, foremost through monument and park boundaries and significance designations. Such conservation, however, does not protect heritage from impacts of climate change and how to manage these components of heritage is nearly invisible in recent climate-focused publications of the two agencies assigned by legislation to serve as leads for cultural heritage in the U.S. government. Yet further, the long-standing tangible approach to heritage does not incorporate emerging understandings of its intangible components and the diverse connections of all forms of heritage to place, meaning, identity, and global change goals of sustainability and equity. In contrast, analysis of 27 federal agency climate adaptation plans prepared in response to 2021 EO 14008 shows that multiple agencies not assigned lead roles for heritage recognize a range of responsibilities that include heritage as part of climate adaptation, mitigation, equity, and coordination with Indigenous communities. This paper explores U.S. heritage legislative history, the definition it helped create for heritage, more recent understandings of heritage, and relationships of these to climate change and how these are represented in climate work and plans across U.S. federal agencies. On these bases, recommendations are provided for research and policy steps.

climate change
cultural heritage
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pmcOn January 20, 2021, the first day of his administration, U.S. President Biden signed Executive Order (EO) 13990 (86 FR 7037), Protecting Public Health and the Environment and Restoring Science To Tackle the Climate Crisis, which begins with the following statement:

“By the authority vested in me as President by the Constitution and the laws of the United States of America, it is hereby ordered as follows: Section 1. Policy. Our Nation has an abiding commitment to empower our workers and communities; promote and protect our public health and the environment; and conserve our national treasures and monuments, places that secure our national memory. Where the Federal Government has failed to meet that commitment in the past, it must advance environmental justice” (emphasis added).

This appears to establish a high level of U.S. federal concern for cultural heritage and its connections to the environment, climate change, science, health, and justice. But such concern is not carried through in this or subsequent EOs and legislation. Section 3 of EO 13990 expands on the opening statement by directing attention to boundaries of three national monuments that were contested during the previous administration; “national treasures and monuments” or other forms of cultural heritage are not mentioned elsewhere in the EO. Subsequent Biden Administration EOs that directly address climate change (14008 [86 FR 7619], 14013 [86 FR 8839], 14027 [86 FR 25947], and 14030 [86 FR 27967]) do not mention aspects of cultural heritage at all. The 2022 Inflation Reduction Act, the largest piece of climate-change-focused legislation passed in the United States to date, does not specify that any of its approximately $1 billion in climate conservation funding be directed toward cultural heritage (43 USC §3006).

This suggests a disconnect between U.S. policy and emerging science and practice. Challenges and complexities of climate change are well established even while more research across many areas is needed. As set out in the recent 6th Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), average global temperatures are now exceeding 1.1 °C above the pre-Industrial era (1). This increase is due principally to emissions of greenhouse gasses from human-based activities such as burning of fossil fuels and changes in land use and related consumption patterns (1). Consequences of this warming are evident across all earth systems, including but not limited to increasing heat in oceans and melting of the cryosphere (2–4), and loss of biodiversity (5).

Reducing emissions and finding ways to adapt and live through this range of changes will reach across the wide range of human systems. These include technology of energy, water, food, and transportation systems (6). They also include where and how it is possible to live (7, 8) and whether and how people are able to move from where they no longer can (9, 10). These in turn engage multiple dimensions of security (11, 12), understanding and management of conflict (13, 14), expectations and values for growth and human economy (15, 16), and ultimately relationships between people, communities, societies, and environments (17).

As used here, cultural heritage is the outcome of centuries and millennia of human experience living in and with physical and social worlds. It incorporates material components such as archaeological sites, built environment, and landscapes alongside knowledge, practices, traditions, language, and values for them developed over time in relation to place (18–20). With this perspective, cultural heritage is part of or contributes to all of the human systems affected by or part of solutions to climate change. Further discussion of legal and emerging definitions of heritage is developed below.

Over recent decades, research and international conventions have expanded understanding of what cultural heritage is and all the forms in which it is held (21, 22). Academic and resource management studies are documenting the diversity of effects of climate change on cultural heritage (19, 23, 24) and a range of forums are weaving together multiple lines of evidence that describe the essential role of time-depth that heritage fields bring to issues of vulnerability (25), sustainability (26, 27), and the complexity of human connections to and care for place in the Anthropocene (18, 20, 28).

But these expansions have not been even and are not yet widely recognized or stable. Within academic research, there is ongoing concern as to how archaeology and other forms of heritage can be seen as relevant and more widely used for climate change research and action (29, 30). In academia and resource management, more heritage studies have been directed toward impacts of climate change than adaptation (19, 23, 31–33) and many more publications are from and about the Global North than Global South (24, 34). Most IPCC reports include some attention to archaeology and heritage of Indigenous communities, but discussion is variable between reports and in the nature of its representation (35). In 2021, the IPCC was a partner in an international co-sponsored meeting on culture, heritage, and climate change (ICSM CHC) in recognition of a need to assess the state of knowledge of connections between these. The ICSM CHC report lists 43 points for action, an indication of the scale of recommended work (28). Since 2013, cultural heritage has been listed as part of non-economic loss and damage by the Warsaw Mechanism of the U.N. Framework Convention on Climate Change (UNFCCC), but as of 2022, a workplan appears to remain in development (36).

The U.S. government established its role in protecting selected “national treasures and monuments” more than a century ago with passage of the 1906 Antiquities Act (AA). Federal structures for identifying and managing these places expanded over the course of the 20th century, including the 1916 Organic Act (OA) that established the U.S. National Park Service (NPS), the 1935 Historic Sites Act (HSA), and the 1966 National Historic Preservation Act (NHPA, plus amendments) (Table 1 lists all abbreviations).

Table 1. List of abbreviations used in this article

Abbreviation	Refers to	
AA	1906 Antiquities Act	
ACD	Authorized Climate Discourse	
ACHP	Advisory Council on Historic Preservation	
AHD	Authorized Heritage Discourse (Smith 2006, 2022)	
alt-CD	Alternative climate definition	
alt-HD	Alternative heritage definition	
CCRP	National Park Service Climate Change Response Program	
CRPS	National Park Service Cultural Resources Partnerships and Science Directorate	
EO	Executive Order	
HSA	1935 Historic Sites Act	
ICCROM	International Centre for the Study of the Preservation and Restoration of Cultural Property	
ICOMOS	International Council on Monuments and Sites	
ICSM CHC	International Co-Sponsored Meeting on Culture, Heritage, and Climate Change	
IPCC	Intergovernmental Panel on Climate Change	
NHA	National Heritage Area	
NHAA	2023 National Heritage Areas Act	
NHPA	1966 National Historic Preservation Act, plus amendments	
NPS	National Park Service	
SDGs	United Nations Sustainable Development Goals	
SHPO	State Historic Preservation Office	
THPO	Tribal Historic Preservation Office	
UNEP	United Nations Environment Program	
UNFCCC	United Nations Framework Convention on Climate Change	
USGCRA	1990 United States Global Change Research Act	
USGCRP	United States Global Change Research Program	
WMO	World Meteorological Organization	

But these pieces of legislation and the distribution of responsibilities they set up were established by and large by the later middle of the 20th century, before the scope and scale of climate change impacts and diversity of actions necessary for response were widely recognized (37) (Fig. 1). Therefore, this paper explores the capacity of the U.S. federal system to conserve its “national treasures and monuments” in a changing climate and to engage and support the diverse connections of cultural heritage to climate change response that heritage is increasingly understood to have.

Fig. 1. Timeline of U.S. legislation and Congressional events discussed in this article. Cultural heritage dates are above the timeline and those regarding climate change below. Legislation titled in bold established key definitions, organizational structures, and/or funding directives.

Methods and Materials

Four lines of evidence are developed with the following methods. Line 1.) builds a brief legislative history of the U.S. cultural heritage system using textual analysis of legislation and related histories. Line 2.) works with a combination of governmental documents and scholarly literature to outline developments in definitions of heritage and climate change and propose a model of relationships between them. Line 3.) reviews the scope of recent climate-focused reports (2019 to 2023) by U.S. agencies with primary responsibilities for cultural heritage. Line 4.) presents a heritage keyword analysis of 27 agency climate adaptation reports developed in response to EO 14008 (86 FR 7619). Raw data for Lines 2, 3, and 4 and details of its collection are included in SI Appendix. This paper concludes with a summary assessment of U.S. federal capacity for heritage and climate and recommendations for policy steps and further research.

Lines of Evidence.

Line 1. Brief legislative history of heritage in the United States.

In the United States, federal protection for cultural heritage broadly began in 1906 with passage of the AA. Prior to this, several Civil War battlefields had been made into federal property in recognition of the role they served in that war (38). Other places had been purchased for preservation by private groups, such as George Washington’s Mt. Vernon home by the Mt. Vernon Ladies’ Association of the Union in the late 1850s (39). The AA, however, was the first federal action to create a process for protecting heritage rather than doing so on a case-by-case basis.

Impetus to develop and pass the AA was an effort to stop looting of archaeological sites and pueblos in the American Southwest, such as Mesa Verde (38). The approach the AA took is to provide a means to declare “historic and prehistoric structures, and other objects of historic or scientific interest” as national monuments and “reserv[e] parcels of land” on which they are located [16 USC §431-433 (40)]. In so doing, the AA focused on tangible heritage and established the preservation method of drawing boundaries around this heritage and removing the areas so defined from other uses such as development and daily life.

The 1916 OA that established the NPS used a similar approach. The stated purpose of the NPS is “to conserve the scenery and the natural and historic objects and the wild life therein and to provide for the enjoyment of the same in such manner and by such means as will leave them unimpaired for the enjoyment of future generations” [16 USC §1 (41)].

While the OA refers to “historic objects” and Mesa Verde was one of the monuments created under the AA that was moved into the national park system, the NPS was not created foremost as a cultural heritage agency. The Civil War battlefields that had been acquired previously remained under management of what was then the War Department and the NPS directed primary attention and funding to large scenic parks popular with tourists (42).

It was the 1935 HSA that set the NPS as the lead U.S. federal agency for cultural heritage. The push for this Act came largely from President Franklin Roosevelt who sought to bring the U.S. in line with European countries, many of which by that time had named heritage ministries (43).

The HSA expanded the scope of historic preservation in the United States. It developed a process for identifying historic places that were not already federal property and bringing these into the federal system. It also established a program for documenting historic buildings (Historic American Buildings Survey), which has since been supplemented with documentation programs for engineering and for landscapes.

The HSA did not, however, change the name of the NPS to indicate its additional roles for cultural heritage. With its opening purpose statement of “a national policy to preserve for public use historic sites, buildings, and objects of national significance for the inspiration and benefit of the people of the United States” (16 USC §461), the HSA also maintained a definition of heritage as being tangible things and holding them in a fixed state as a priority.

The 1966 NHPA and its amendments [54 USC, Pub. L. No. 89-665, as amended by Pub. L. No. 96-515 (44–46)] is the largest piece of heritage legislation in the United States and established the structure of heritage management the United States uses today. Interest and energy to develop and pass the NHPA came together as recognition grew of the destruction of historic areas of many cities and towns due to urban renewal projects and construction of the interstate highway system in the late 1950s and early 1960s. In briefest terms, the NHPA was in part an effort to stop these bulldozers or at least slow them down (47).

Of the many provisions of the NHPA, key for consideration of climate change is its establishment of a system for considering impacts to heritage from development, commonly referred to as the Section 106 process. In this system, any federal undertaking, which includes any project on federal land, that uses federal money, or which otherwise must comply with other federal regulations, is required to consider impacts of the project on significant cultural heritage, although they are not required to avoid impacts (48). Significance in this context is determined in accordance with the National Register of Historic Places, which the NHPA established as a program managed by the NPS. Project proponents pay for the costs of evaluation of impacts and any mitigation, creating a “polluter pays” approach to heritage conservation.

Implementation of the Section 106 process and other heritage support is provided in part by a nation-wide set of State and Tribal Historic Preservation Offices (SHPOs/THPOs). Funding for SHPOs and THPOs is shared by the federal government, states, and Tribes, with federal funding directed to the Historic Preservation Fund (HPF) and distributed by the NPS. The fund source for the HPF is royalties from offshore oil and gas drilling (54 USC §3031).

While the NHPA reaffirmed the NPS role as a lead federal agency for cultural heritage with roles for national parks and provision of programs for heritage outside of park units, the NPS does not manage heritage for other agencies. Under the NHPA and EO 11593 (36 FR 8921), each U.S. federal agency is responsible for ensuring its own compliance with the NHPA and management of heritage on land or property held by that agency. The NHPA also established the Advisory Council for Historic Preservation (ACHP), a separate agency with overarching responsibilities for Section 106 and to advise the President and coordinate other activities regarding historic preservation.

The U.S. has not passed legislation since 1966 that substantially changes this structure and approach to heritage. The Native American Grave Protection and Repatriation Act (NAGPRA, Public Law 101-601), passed in 1990, provided long-needed rights to Tribes with regard to burials and associated objects, but did not otherwise change the previously established historic preservation system and premises (49). The National Heritage Areas Act (NHAA) was passed in 2023 (Public Law 117-339). National Heritage Areas (NHAs) are areas designated by Congress with programmatic oversight by the NPS but are managed locally in public–private partnerships with the goal of integrating cultural and natural resources in tourism, education, and resource management (50). NHAs have been established individually since 1984; the NHAA sets up a system of NHAs and updates authorization and funding levels for previously established NHAs. Broad impacts of this legislation are not yet evident, but it is relevant here for its introduction of the term heritage in a legislative title and its vision for local management.

Each of the major pieces of heritage legislation, the AA, HSA, and NHPA, as well as the OA, is an outcome of its time and efforts to solve recognized problems. Each can be seen as a means to do so broadly and establish processes for problem resolution. However, through their definitions of what comprises connection to the past and how these are to be managed, each piece of legislation also can be seen to have stayed within frameworks established by earlier laws. Collectively, these laws set out an understanding that tangible connections to the past that are deemed important by experts should be set aside from modern life, within a boundary (monument, park) or with a designation of significance. They emphasize preservation, which prioritizes holding components of the past as they are or were, and impacts to heritage are understood to be from planned development with consideration and mitigation paid for by developers or project proponents.

Climate change is presenting multiple challenges to this framework. Evidence from storms (51), wildfires (52), and other impacts (53) show that effects of climate change do not stop at park or monument boundaries. Preservation practices that prioritize holding heritage as unchanging or in the case of archaeology leaving sites in place (in situ) may increase risk of loss as environments that hold them change (23, 54). To date, no “polluter” has been tapped to pay for climate-related heritage care outside of federal management.

Further, developments in heritage research and management over recent decades recognize that heritage is more than its tangible components, that it is a web of knowledge, practice, place, and values that people ascribe to their connections from and with the past (21, 22). Concurrently, there is growing recognition of the diverse human systems that must be brought together to reach overarching goals of sustainability (55) and that responding to climate change well must include, as noted in EO 13990 (86 FR 7037), environmental justice. Therefore, it is important to consider these developments as part of the capacity of the U.S. federal system to manage its responsibilities for both heritage and climate.

Line 2. Authorized heritage, climate, and alternate discourses.

Priorities and approaches of the major pieces of U.S. heritage legislation also were used outside of the United States. Through the mid-later 20th century multiple Global North and international structures followed similar frameworks. These include the founding in 1946 of the International Centre for the Study of the Preservation and Restoration of Cultural Property (ICCROM) in Rome; in 1966 of the International Council on Monuments and Sites (ICOMOS); and in 1972 passage of the UNESCO World Heritage Convention and initiation of the World Heritage Site system. For ICCROM and ICOMOS, founding interest in tangible monuments, sites, and property is evident in their names. World Heritage Sites in turn follow the national park approach of setting an area designated to be of outstanding universal value within a boundary.

It is important to recognize here that two of the major pieces of U.S. heritage legislation, the AA and HSA, as well as the OA, do not use the term heritage at all. The terms that are defined and operationalized in these pieces of legislation are “ruin, or monument, or object of antiquity” (AA), “historic sites, buildings, and objects” (HSA), and foremost throughout the NHPA (all versions) “historic property.” The 1966 NHPA uses heritage once in its opening statement of purpose, noting that “the present governmental and nongovernmental historic preservation programs and activities are inadequate to insure future generations a genuine opportunity to appreciate and enjoy the rich heritage of our Nation” (Public Law 89-665). Amendments to the NHPA passed in 1980 and 2016, for example, use the term heritage more often, but primarily in reference to the World Heritage Convention rather than incorporation of new meaning (data in SI Appendix).

Heritage is used as the frame for analysis in this paper as it is a term and concept used widely in international legal contexts and academic research. For example, importance of heritage to all people is a rationale of the 1954 Hague Convention on the Protection of Cultural Property in the Event of Armed Conflict. While this Convention gives priority to built and tangible heritage, which is consistent with its mid-20th century time frame, it recognizes that such cultural property is a component of a larger whole, for which it uses the term cultural heritage (56, 57). By 2003 heritage is the operational term in the U.N. Convention on the Safeguarding of Intangible Heritage (21). Thus heritage is a term with wide and evolving use and as such is a relevant reference point for considering capacity of the U.S. federal system to address connections to and from the past as part of its climate change response.

Such developments in meanings and uses of heritage have been explored in the field of critical heritage studies from later decades of the 20th century onward (58, 59). One of the outcomes these studies have identified is that legislation in the United States and other countries of the Global North, 20th century international heritage conventions and organizations, and their structures of practice have collectively set up and reinforced a default definition of cultural heritage. Scholar Laurajane Smith has termed this definition the Authorized Heritage Discourse (AHD) (22, 59, 60).

As a default definition, the AHD is what heritage is most often understood to be if it is not otherwise defined and it incorporates how heritage should be approached and managed. Drawing on examples from the United States, Australia, Europe, and the UK (22), Smith has succinctly outlined heritage in the AHD as:“Grand,” “tangible,” “old” and “aesthetically pleasing” sites, monuments and buildings

All that is “good” and “great”

Value inherent

Conserve as found for future generations

Expertise has “duty” to act for and steward a universal past

“fragile, finite and non-renewable” (22, 61).

Though brief, use of “national treasures and monuments” by EO 13990 (86 FR 7037) as its call-out for heritage reflects components of the AHD.

With this history and content, the AHD also provides a lens through which to explore relationships between heritage and climate change. As described above, representation and incorporation of heritage in climate change response is uneven and low (28, 34), with ongoing discussions of how to convey and improve relevance of heritage with respect to climate change and sustainable development (35, 62). There is a history of thought from before the Enlightenment that has separated consideration of humans from that of their environments (63, 64). Noting this, Morel and oud Ammerveld (65) describe how words used for climate change have generated a fragmentary but powerful “authorised climate discourse.” Building on this, I propose here that legislation and related documents can be used to define such an Authorized Climate Discourse (ACD) and that gaps in use and representation of cultural heritage as part of climate change are due in part to limited visible overlap between the AHD and the ACD.

The ACD can be seen to have emerged and been reinforced through a range of legislative documents and governmental reports from the 1980s onward. For example, testimony by scientist James Hansen to the U.S. Senate Committee on Energy and Natural Resources in 1988 described the greenhouse effect, evidence of warming global temperatures due to greenhouse gas emissions, and pointed to implications of such warming (66).

Shortly after this, in 1990, the U.S. Global Change Research Act (USGCRA) that established the U.S. Global Change Research Program (USGCRP) and U.S. National Climate Assessment defined “global change” as “(3) …changes in the global environment (including alterations in climate, land productivity, oceans or other water resources, atmospheric chemistry, and ecological systems) that may alter the capacity of the Earth to sustain life;” (15 USC §2921). In turn, “global change research” is described foremost as “(A) the interactive physical, chemical, and biological processes that regulate the total Earth system;” (15 USC §2921).

The IPCC was established in 1988, the same year as Hansen’s Senate testimony. Set up under the auspices of the U.N. Environment Program (UNEP) and the World Meteorological Organization (WMO), the objectives of the IPCC are less prescriptive than that of the USGCRP but follow a similar format, namely:“(i) to make assessments of available scientific information on climate change;

(ii) to make assessments of environmental and socio-economic impacts of climate change;

(iii) to formulate response strategies to meet the challenge of climate change” (67).

The primary components of the ACD, therefore, are the physical global climate system and the human capacity to describe and study it, including atmospheric concentrations of greenhouse gasses and modeling of the atmospheric system across projected and potential future concentrations. Additional components include impacts of rising global temperatures, such as sea level rise, other effects on ice, oceans, and ecosystems, and technology and economic arrangements to address these. The ACD in the format of the AHD (22, 61) is shown alongside the AHD in Fig. 2.

Fig. 2. Venn diagram of major components of the Authorized Heritage Discourse (Left, AHD) and an Authorized Climate Discourse (Right, ACD). AHD follows Smith (22, 61) and the ACD is built from Morel and oud Ammerveld (65), testimony (66), establishment of the IPCC (67), U.S. legislation on global change (USGCRA), and ongoing trends in climate research and funding. Primary point of contact is between is “fragile, finite and non-renewable” component of the AHD and the impacts component of the ACD.

Issues in integrating cultural heritage and climate change are due at least in part to lack of overlap between concepts of the AHD and ACD (Fig. 2). A point of contact can be drawn between them that links “fragile, finite, and non-renewable” (heritage) with “measurement of impacts” (climate). Supporting this point of connection is publication evidence that, as described above, while studies of all forms of interconnection of climate and heritage are relatively limited (32, 33), climate impacts on cultural heritage have received the earliest and so far the most extensive research attention (23, 32, 33, 68). As well, Goal 11.4 of the U.N. Sustainable Development Goals (SDGs) is phrased “protect and safeguard the world’s cultural and natural heritage” (55), which speaks to countering a range of impacts.

Attention to impacts of climate change on cultural heritage as the meeting point of climate and heritage discourses is not wrong but it is incomplete. Even considering only impacts, both the AHD and ACD lack space and attention to many meanings and experiences of loss that come from impacts (69). They also obscure connections as diverse as use of archaeological data in climate models (7) and roles of historic buildings in holding carbon and improving energy efficiency (70, 71).

Further, over recent decades, developments in heritage research and practice have begun to challenge the AHD. These have built broader awareness and understanding of intangible heritage, such as adoption in 2003 of the U.N. Convention on the Safeguarding of Intangible Heritage. This Convention recognizes that heritage includes “practices, representations, expressions, knowledge” alongside tangible elements, and that heritage is held and continually recreated by individuals and communities in relation to their environments (21). Heritage can be seen as a dialogue between people and place (72) and that ways in which people act in relation to their connections to the past are part of identity and political power (22, 73). Memory has been shown to not be contingent on exact preservation of place (74) and the capacity of heritage to provide engagement with change and transformation as one of its essential roles in society (75). Concurrent proliferation of terms in scientific literature such as cultural ecosystems services (76, 77) and nature’s benefits to people (78) may be a reflection of efforts to convey this complexity and depth of human connections to environment and place that have been increasingly recognized to exist over recent decades but which the default definition of heritage (AHD) does not communicate.

Smith has gathered these approaches and proposed an alternate definition of heritage that describes it as:“A process in which people negotiate the meaning of the past to address contemporary social and political problems and navigate change;

Reformative and emotive process of meaning making and affirming or challenging social values, sense of place, identity and well-being” (61).

This approach, which I here term the alt-HD, avoids dividing lines of physicality and sets heritage as created by the ascription of value (22, 59). In the alt-HD, places set aside as parks and monuments can continue to be significant, but they are not important because they hold inherent qualities but rather because creation of parks and monuments is a negotiated cultural statement that gives them that importance. This approach also allows connections to and from the past that matter to a diversity of groups and places but which are not protected by law to be identified as heritage, which is a path for equity. As well, the alt-HD does not prescribe preservation in the state in which heritage is identified, which makes space for adaptive care and management as climate change and responses to it develop (79).

An alternate definition of climate change (alt-CD) requires some construction, but also can be seen to focus on capacity of human social and political systems to recognize and respond to change. For example, the opening key message of the IPCC 6th Assessment synthesis report begins by referencing “human activities” (1) and concludes by describing types and patterns of such activities. This emphasis on human action contrasts with the initial IPCC priorities in physical science with which it was established (67). In turn, IPCC Chair Jim Skea, in a statement announcing his election in July 2023, described priorities for his term as including “(1)…inclusive participation and collaboration; (2)…”use of best and most relevant science”; and (3)…engagement with policymakers and other stakeholders” (80). At the opening of the UNFCCC 24th Conference of the Parties (COP24) in Katowice, Poland in 2018, Chair Michal Kurtyka began by describing the 12th century origins of the city and, from this basis, said that what is most needed is a “vision and hope…of a different world;” support in the transition, and policies and means to make changes (81). Together, these describe primary challenges of climate change as being not physical science and models but rather people sharing ideas and information and building action on plans for change.

In brief summary, the alt-HD (61) sets heritage as a means by which people engage with meaning and change and the alt-CD describes climate as a complex situation requiring change in human vision, engagement, and action. When these alternate definitions of heritage and climate change are set next to each other, overlap and connections between them are more apparent (Fig. 3).

Fig. 3. Venn diagram of an alternate definition of cultural heritage (Left, alt-HD) and of climate change (Right, alt-CD). The alt-HD, framed by Smith (22, 61), describes heritage as a process created out of present-day human relationships in regard to social and political change. The alt-CD, developed from recent statements of global climate leaders, describes major climate issues as comprised of a need for vision and hope, justice and change, meaningful science, and engagement of policymakers and stakeholders. These alternate definitions share an overlapping area of support for adaptive social and political change not described by the AHD and ACD, illustrating a greater potential for integration between heritage and climate than has been developed to date.

U.S. legislation and the federal structures of practice and funding these established have contributed to both the AHD and ACD. Description of the alt-HD here is part of outcomes of multiple studies over years that have shown that what heritage is and does extends well beyond the outlines of the AHD (22, 60, 79). In turn, components of the alt-CD are drawn from recognitions that development of the physical sciences of climate change is necessary, but insufficient on its own, to meet the human challenges of social, economic, and environmental change. Capacity of the U.S. federal system for climate change therefore should consider the extent to which recent federal practice and publications follow outlines of the AHD and ACD and whether elements of the alt-HD and alt-CD have been identified or incorporated, as follows.

Line 3. Climate approaches of lead U.S. federal agencies for cultural heritage.

Lead U.S. federal agencies for cultural heritage include the NPS, as assigned by the 1935 HSA and 1966 NHPA, and the ACHP, as established by the 1966 NHPA. Climate approaches of both agencies were assessed through review of climate-focused reports and documents released over the past 5 y (2019-September 2023). While not an exhaustive assessment, the nature and scope of these documents are indicators of recent agency perspectives on cultural heritage and climate change and corresponding responsibilities.

NPS.

As described above, the NPS is responsible for cultural heritage in all national park units and provides guidance and programs for cultural heritage outside of national park units. Primary categories through which NPS manages cultural heritage, which the NPS terms cultural resources, are archaeology, historic structures, cultural landscapes, museum collections, and ethnographic resources (82). Cultural resources in parks and programs for heritage outside of parks, such as the National Register of Historic Places, historic documentation programs, Historic Preservation Tax Credit program, American Battlefield Protection Program, and coordination of the NHAs and other grant programs, are managed by the Cultural Resources Partnerships and Science Directorate (CRPS).

Climate change research and management at NPS is led by the Climate Change Response Program (CCRP) (83), which is headquartered in the NPS Natural Resources Stewardship and Science Directorate.

CRPS and CCRP have previously released two pieces of policy guidance for heritage and climate change, Director’s Policy Memorandum 14-02 in 2014 (84), and the Cultural Resources Climate Change Strategy (Strategy) in early 2017 (85). Both of these documents clearly state that there are two primary connections of cultural resources and climate change: cultural resources are being affected by climate change and they hold information and capacity to learn from them. While these phrasings do not fully capture the alt-HD and alt-CD developed above, guidance in both documents points to efforts to move beyond the AHD and work with meaning and community connections and build a larger overlap between cultural resources and climate change. The Strategy also states that “cultural resources in all park units are or will be affected by climate change in some way” (85).

Recent publications listed by CCRP for 2019 to 2023 (86), however, do not continue these directives and overarching guidance documents on this list are explicit in their lack of attention to culture resources. For example, Planning for a Changing Climate published in 2021 sets out an adaptation framework for use across all parks but states at several points that “although this framework (resist, accept, direct) is optional and may not work well for non-living resources or the visitor experience, examples are provided here if useful to ‘stretch thinking’ about adaptation options” (87). Non-living resources are noted in the report as including the majority of cultural resources managed by the NPS.

As well, a framework for assessing climate vulnerability across all parks of the national park system (88) includes no authors with cultural resources training and makes several assertions about cultural resources that are not tested with data. These include statements such as that cultural resources can be assessed either as natural resources or infrastructure without attention to cultural significance (88), that legislative rationales for parks (historical vs. natural environment focus) can be a basis for assessing vulnerability (88), and that smaller sizes of historical parks may make them less sensitive to climate change (88).

Publication counts also show prioritization of natural resources over cultural resources. An assessment of vulnerability assessments (89) published in 2022 lists 91 vulnerability reports for facilities and infrastructure, 71 for natural resources, and 14 for cultural resources. Overall, research publications listed by CCRP (86) for years 2019 to 2023 show nearly 20 times as many journal articles for natural resources topics as for cultural resources (data in SI Appendix).

ACHP.

Within the past 5 y, based on information available on its website (90), the ACHP has published one climate change document, its 2023 policy statement. The purpose of this policy statement is “to define more clearly connections between climate change and historic properties” (91). It uses the term “historic property” throughout and defines this in its glossary as “[a]ny prehistoric or historic district, site, building, structure, or object included in, or eligible for inclusion in the National Register.” While this policy statement describes issues of equity facing disadvantaged communities and recognizes Indigenous knowledge, which are developing areas of work that align with the alt-HD (28), its focus on tangible heritage with significance evaluated by experts continues major points of the AHD. This statement is also divided with respect to U.S. federal capacity for heritage and climate change. Major points of the document direct “all public-serving institutions” in what to do for historic properties in relation to climate change, which is consistent with the advisory role of the ACHP assigned by the NHPA, but the document does not describe how to do so or whether the ACHP will develop such guidance.

Together, recent climate-focused reports and documents of the NPS and ACHP align with and tend to reinforce separation of the AHD and ACD. NPS CCRP reports show a lack of data, analysis, and expertise with respect to cultural resources and climate vulnerability, which suggests there are substantial gaps in addressing even the limited contact point of climate impacts on heritage. The ACHP policy statement describes a range of equity, mitigation, and adaptation issues regarding cultural heritage and climate change, but limits its purview to historic properties and does not present itself as the agency to figure out how to address such issues. Its role in coordinating as other institutions develop their own methods is not yet clear.

Line 4. Cultural heritage in U.S. federal agency climate adaptation plans.

EO 14008, (86 FR 7619) Tackling the Climate Crisis at Home and Abroad, signed on January 27, 2021, required each federal agency to prepare a plan that outlines the agency’s climate vulnerabilities and steps the agency will take to bolster adaptation and increase resilience to climate change impacts (Sect. 211). While EO 13990 (86 FR 7037), signed a week earlier on the first day of the Biden Administration, mentions “national treasures and monuments” in its opening section, EO 14008 does not mention cultural heritage in any form. This raised the question, given the history of U.S. cultural heritage legislation and distribution of cultural heritage responsibilities across federal agencies set by the NHPA, of whether and how cultural heritage is incorporated into the set of agency climate plans submitted in response to EO 14008.

To address this, I conducted a cultural heritage keyword analysis of the 26 agency plans released by the White House on October 7, 2021 (92), plus the plan released for the Army on October 5, 2022 (93). Keywords searched included: culture, cultural, heritage, historic*, Indigenous, and traditional. Each use of each keyword was collected and assessed as to whether it referenced an aspect of cultural heritage or a contemporary situation (such as references to “agency culture” or use of historic flood records for risk modeling). Each climate heritage-relevant use was given a phrase description, which were then grouped into themes.

Indigenous was included as a keyword with interest in exploring how Indigenous knowledge and the concept of traditional ecological knowledge were incorporated into the agency plans. Uses of “Indigenous” that incorporated aspects of time-depth in descriptions of practice and knowledge were counted as cultural heritage-relevant uses. Uses that describe contemporary aspects of Indigenous communities were not. Details of methods and raw data are included in SI Appendix.

More than half of the agency plans, 16 (59%), included at least one climate heritage-relevant use of a keyword in their climate adaptation plans (Table 2). Department of the Interior (DOI) had the largest count, which aligns with heritage responsibilities assigned to the NPS, which is part of DOI, and land management responsibilities across other DOI agencies. The second highest count is from the Smithsonian, which aligns with its roles in cultural curation and education. Other agencies with multiple counts, however, range widely in their roles, including General Services Administration (GSA), Department of Agriculture (USDA) (which includes the U.S. Forest Service), Department of Homeland Security (DHS), and the Environmental Protection Agency (EPA).

Table 2. Summary counts of unique cultural heritage-relevant keywords used in 2021 to 2022 U.S. federal agency climate adaptation plans

Agency	Counts of unique heritage-relevant keyword uses	Total unique relevant keyword uses	
Culture	Cultural	Heritage	Historic*	Indigenous	Traditional	
Department of Agriculture (USDA)	0	2	0	0	0	3	5	
Department of Commerce (Commerce)	0	2	0	0	0	0	2	
Department of Defense (DOD)	0	1	0	0	0	0	1	
U.S. Army (Army)	0	2	0	0	0	0	2	
Department of Homeland Security (DHS)	0	1	0	3	0	0	4	
Department of Housing and Urban Development (HUD)	0	0	0	2	0	0	2	
Department of the Interior (DOI)	0	29	1	1	2	2	35	
Department of Transportation (DOT)	0	1	0	0	0	1	2	
Department of Veterans Affairs (VA)	0	0	0	1	0	0	1	
Environmental Protection Agency (EPA)	0	1	0	1	2	0	4	
General Services Administration (GSA)	0	4	0	3	0	0	7	
Millennium Challenge Corporation (MCC)	0	0	0	0	0	1	1	
National Capitol Planning Commission (NCPC)	0	0	0	1	0	0	1	
Office of Management and Budget (OMB)	0	0	0	1	0	0	1	
Smithsonian Institution (Smith.)	2	4	1	3	1	0	11	
Agency for International Development (USAID)	0	0	0	1	0	0	1	
Total	2	47	2	17	5	7	80	
Agencies with no cultural heritage-relevant uses of keywords in their climate plans include: Department of Education (ED), Department of Energy (DOE), Health and Human Services (HHS), Department of Justice (DOJ), Department of Labor (Labor), Department of State (State), Department of Treasury (Treasury), National Aeronautics and Space Administration (NASA), Social Security Administration (SSA), U.S. Army Corps of Engineers (USACE), and U.S. International Development Finance Corporation (USIDFC).

Analysis of keyword uses by theme shows that federal agencies are engaging with components of heritage in diverse ways (Table 3). A majority (48, 60%) of uses describe agency responsibilities in the management and research of impacts of climate change on cultural heritage – the touchpoint of the AHD and the ACD. These include nearly 75% of the keyword uses by DOI, approximately a third of the Smithsonian mentions, and all of the mentions by the GSA, which manages federal real estate. The single uses by the Veterans Administration (VA) and the National Capitol Planning Commission (NCPC), which also have real estate roles, also fall in this category. But other uses show a wider understanding and approach of connections between cultural heritage and climate change.

Table 3. Summary counts of cultural heritage-relevant keywords in 2021-2022 U.S. federal agency climate adaptation plans by theme

Agency	Total unique heritage keyword uses	Agency has a role in	No. of agency roles for climate and heritage	
Understanding and managing climate connections of cultural heritage	Recognizing time-depth as element of environmental justice	Supporting indigenous and traditional communities re: climate implications for their heritage	
Manage and research impacts	Incorporate in climate mitigation	Engage with intangible and social aspects	
USDA	5	2	0	0	0	3	2	
Commerce	2	2	0	0	0	0	1	
DOD	1	0	0	1	0	0	1	
Army	2	2	0	0	0	0	1	
DHS	4	2	0	0	2	0	2	
DOI	35	26	0	1	0	8	2	
DOT	2	0	0	0	2	0	1	
VA	1	1	0	0	0	0	1	
EPA	4	0	0	0	1	3	2	
GSA	7	7	0	0	0	0	1	
HUD	2	0	0	0	2	0	1	
MCC	1	0	0	0	0	1	1	
NCPC	1	1	0	0	0	0	1	
OMB	1	0	1	0	0	0	1	
Smith.	11	4.5	2	2.5	1	1	3	
USAID	1	0.5	0	0	0.5	0	2	
Total uses	80	48	3	4.5	8.5	16		
No. agency plans	16	10	2	3	6	5	
Themes include understanding and managing climate connections of cultural heritage, time-depth of environmental justice, and climate implications for heritage of Indigenous and traditional communities.

The Smithsonian and Office of Management and Budget (OMB) plans include heritage as part of climate mitigation and emission reduction planning. And Smithsonian, Department of Defense (DOD), as well as a single use of DOI, speak to intangible cultural heritage and its social dimensions.

Further, a fifth of the keyword mentions across five agencies [USDA, DOI, EPA, Millennium Challenge Corporation (MCC), and Smithsonian] speak to responsibilities for supporting Indigenous communities with respect to climate impacts on their heritage. Ten percent of keyword uses across six agencies [DHS, Department of Transportation (DOT), EPA, Department of Housing and Urban Development (HUD), Smithsonian, and U.S. Agency for International Development (USAID) speak to time-depth and history as an element of environmental justice.

For four agencies, DOT, EPA, HUD, and MCC, their only references to cultural heritage occur in the Indigenous and environmental justice categories.

These findings indicate that while major U.S. heritage legislation has helped to shape the AHD and the agencies assigned primary responsibility for heritage by that legislation have set up their approach to climate change in accordance with the AHD and ACD, there is an emerging recognition across ten agencies of intangible and community connections of heritage and that these are essential in addressing climate change.

As EO 14008 did not require description of roles and responsibilities for cultural heritage in agency climate plans, additional research is needed to confirm whether and how agencies that did not use keywords in heritage-related ways in their plans are working with heritage.*

As well, additional work is needed to explore the extent of interagency coordination for heritage-related work. Agency climate plans do not include bibliographies and generally do not reference work of other agencies. For this reason, the role of the NPS, for example, in shaping or guiding work of other federal agencies with respect to heritage and climate, particularly in the category of research and impacts where the majority of the DOI plan keyword use occurs, cannot be determined from this set of agency plans.

Discussion

Climate change encompasses a wide range of challenges. Historically, work on and with regard to climate change began with identifying and tracking atmospheric and environmental changes and projecting potential future consequences, such as captured in the 1988 U.S. testimony of James Hansen (66) and establishment of the IPCC (67). Subsequent legislation such as the U.S. 1990 USGCRA organized research around and from related physical sciences. Collectively, these helped shape a default definition in which the core of understanding and responding to climate change is a combination of atmospheric models, measurable environmental impacts, water, and energy-using systems, here termed the ACD (building on ref. 65).

Recognition is now growing that changes in climate due to human activities are a hub that connects essentially all human systems. These include use and expectations of energy, water, and food systems; knowledge of weather systems, other species, and oceans and capacity to track and adjust livelihoods in relation to these; and distribution of people in nations and governance and rights within and between them. As outlined in the SDGs, climate action is a component of sustainable development (55), but evidence is also showing that equity and sustainable development are essential to reaching climate goals (5, 94). Recent statements from persons in lead roles with the UNFCCC and IPCC have noted that the pressing challenges of climate change are vision and hope (81) and collaboration and engagement to carry them through (80). This collection of characteristics and challenges is the alt-CD.

Heritage is interwoven with all of these developments. While emissions have accelerated over the later 20th century and the start of the 21st, they began before then, as indicated by the Paris Agreement target of limiting warming to well below 2 °C above pre-industrial global temperatures. The IPCC defines the pre-industrial period as 1850 to 1900, but notes that this time frame is due in part to availability of data (95). Technological, economic, and social trends that came to characterize the industrial era and its emissions began earlier, in some estimates as early as 1720 to 1800 (96). Thus many of the places, people, dynamics, and perspectives that contributed to development of climate change over the course of the industrial era are now part of what many people and communities recognize as their cultural heritage (75); climate change is part of heritage.

The United States began its system for cultural heritage in 1906 with passage of the AA. The AA and subsequent legislation over the first two-thirds of the 20th century developed an approach to heritage that describes it foremost as property and tangible things, to be conserved as found under care of experts either within a boundary or by a designation, with an emphasis on impacts from planned human development (NHPA, while AA was an effort to address looting). This legislation and practices they set in motion contributed to and reinforced this approach as an overarching definition of cultural heritage which Smith (22, 60) describes with the term AHD. The AHD has little direct overlap with the topics outlined the ACD. Their primary point of contact is climate impacts, against which boundaries and significance designations do not, in and of themselves, provide protection.

Heritage work over recent decades has begun to challenge the AHD. This includes international recognition of intangible heritage (21) and development of critical studies and perspectives that set heritage as processes of engaging with and giving value to connections from and with the past. Such processes interweave with research on sustainability (26), security (97), and understandings and negotiations of identity, meaning, and power (22, 59). This approach to heritage (61), here termed the alt-HD, in providing avenues for envisioning and adjusting human relationships both in the present and into the future, overlaps with the alt-CD, the human systems challenges of climate change.

Recent publications and guidance from the two U.S. agencies designated as leads for cultural heritage, NPS and ACHP, show gaps in research and coordination regarding protection of cultural heritage from climate change impacts and engagement of many components of heritage for climate response. But evidence volunteered from other agencies in their climate plans prepared in response to EO 14008 indicates that cultural heritage is understood to be part of the mission of more than half the agencies that prepared plans and an integral part of adapting to climate change. Further, more than half of the agencies indicating responsibilities for heritage in relation to climate did so in ways that reflect components of the alt-HD.

On these bases, the following are recommended next steps for research and policy:

Recommendations

1) Conduct an in-depth study of federal capacity to integrate heritage as part of U.S. government work on climate change. As described above, agency climate plans do not provide information on coordination between agencies on climate and heritage issues, interagency collaboration, or staffing and training. A study is needed to develop this information. Further, as EO 14008 did not require agencies to include heritage in their agency plans, such a study should contact agencies that did not mention heritage topics in their plans to determine whether they are doing such work and its nature.

2) Establish a named U.S. climate heritage coordination office. A named federal climate heritage coordination office was proposed by Rockman and Hritz in their 2020 paper that describes the relative invisibility of heritage in the U.S. federal government and consequences of this for federal and non-federal work and funding for climate change (98). On the basis of the gaps outlined by recent climate products of the NPS CCRP and ACHP and the diversity of climate heritage approaches reported across other agencies developed above, this recommendation is reaffirmed here. Such an office would improve visibility of connections between climate change and cultural heritage and provide a central point for interagency and external collaboration. Such collaboration could include support for U.S. engagement with heritage in international climate and sustainability forums, including the UNFCCC and others. The study recommended in point 1) above would provide relevant information about potential locations for and organization of such an office.

3) Build climate support for and engagement with cultural heritage that is outside of direct federal management. While diversity of places and stories held in and designated as significant by the federal heritage system has expanded in recent years, representation remains skewed toward predominantly white history (99). Further, with histories of redlining and other processes of marginalization, communities now being recognized as environmental justice communities have knowledge of and connections to places and practices that may not be considered significant under frameworks such as the National Register of Historic Places. Due to these same histories, these places and connections often have high exposure to climate impacts and other forces of climate displacement (100). Therefore, building capacity for heritage as part of equity and climate includes supporting programs with roles outside of direct federal management. Relevant steps may include designing climate support for NHAs, SHPOs, and THPOs, dedicating heritage roles for Climate Adaptation Science Centers under the U.S. Geological Survey, and ensuring that funding for the HPF does not decline in response to decarbonization. In recognition of the tempo of passage ofprevious major U.S. heritage legislation, which has occurred at intervals of approximately 30 y (Fig. 1), such work may point toward future legislation.

EO 14008 states the goal of a whole-of-government approach in the U.S. federal response to climate change. Cultural heritage is interwoven with nearly every aspect of climate change. However, the primary structures and practices set up by U.S. federal legislation for cultural heritage over the past century are not yet well aligned to meet the needs and challenges of the U.S. program for climate change. At the same time, other federal agencies are recognizing need for and their own roles in human connections to place, knowledge, and equity in their climate change plans. Data and recommendations developed here outline the disconnects between federal goals and roles and directions for action that can strengthen the capacity of the U.S. federal government to engage all that cultural heritage is in its response to climate change.

Supplementary Material

Appendix 01 (PDF)

Inspiration for this article was a question from a U.S. Congressional office about agency climate plans. My appreciation to the reviewers for their helpful comments.

Author contributions

M.R. designed research; performed research; analyzed data; and wrote the paper.

Competing interests

The author declares no competing interest.

Data, Materials, and Software Availability

All study data are included in the article and/or SI Appendix.

Supporting Information

This article is a PNAS Direct Submission.

*The emerging recognition of heritage across federal agencies also can be seen in the 5th U.S. National Climate Assessment (NCA5). Primary data collection and analysis for this paper were completed before release of NCA5 in November 2023. A brief overview analysis of the use of the term heritage shows that it is used in more than half of the 37 chapters of the NCA5, but this use is uneven (data in SI Appendix). For example, heritage is one of the seven categories of impact listed in the Overview (“Livelihoods and heritage”) and appears 12 times in U.S. Caribbean chapter, but other chapters such as Economics, Sector Interactions, and Social Systems and Justice use it once or not at all. As with the agency climate plans, this pattern of usage suggests growing engagement with alt-HD forms of heritage. Further work is needed to track changes from earlier NCAs and identify steps needed at the federal level to follow up on the heritage issues included in the NCA5.
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