Archaeology as Sustainability Science: Perspectives from Ancient Island Societies

Abstract

Humans and the diverse ecosystems we inhabit face numerous sustainability challenges due to climate change, rising seas, population growth, overfishing, natural habitat destruction, accelerating extinctions, and more. As an interdisciplinary paradigm that leverages both natural and social sciences to better understand linkages between humans and the environment, sustainability science focuses on how these connections shape understandings of and approaches to sustainability challenges. Here, we argue that archaeology and historical ecology are essential components of sustainability science. We view sustainability as a long-term process where historical sciences are critical to effectively measuring where we stand today and modeling future trajectories based on the baselines from the past that archaeology and historical ecology provide. We demonstrate that islands around the world are central to this endeavor because they serve as model systems that can capture the timing of human arrival, subsequent effects of cultural behaviors on pristine environments, and how humans adapted, survived, and often thrived for centuries or millennia. These cases provide important lessons about human responses in the past to similar challenges that we now currently face. In the uncertain futures of the Anthropocene, such historical baselines will contribute significantly to scientific approaches for building more resilient and sustainable societies.

1. Introduction

From an Anthropocene perspective, the Earth systems regulating planetary life are increasingly constituted through “joint human–biophysical processes” [1] (p. 7) (see also [2]), whereby human and non-human agents are inextricably linked in the co-creation of multi-scalar socioecological systems. Research from across the natural and social sciences indicates that socioecological systems worldwide are experiencing sustainability crises (e.g., [3,4]). As a result, the long-term continuation of human lifeways and society is no longer ensured due to the historically unprecedented, cumulative effects of anthropogenic impacts on climate regimes, biodiversity, and ecosystem functions. Recognizing and acknowledging the historical nature of the current crises is increasingly critical to how we define and document what may, or may not, constitute sustainability now and in the future.

1.1. “Sustainability”, Socioecological, and Political Systems

As employed in this paper, and most simply defined, sustainability is the ability of the present to endure into the future [5]. However, because the present is in a constant state of flux, the past is what provides needed baselines for recognizing and defining sustainability. As an inherently historical concept, therefore, what sustainability means for the Earth’s biosphere and humanity within any given ecosystem, or among any given group of people through time, is not simple. Nor are notions of who or what—including individuals, communities, and various “systems” (e.g., ecosystems, political systems, ideological systems)—benefits from it compared to who or what is disenfranchised/sacrificed (e.g., trade-offs [6]). Rather, sustainability is contingent on often extremely variable historical climatological, environmental, and cultural (e.g., politics, economy, religion, etc.) circumstances shaping socioecological systems and responses to change (e.g., [7,8]) (Figure 1).

In addition to “sustainability”, we draw on the concept of socioecological systems (SES). SES as a concept is commonly defined as an interconnected relationship between ecosystems and society [9]. SES is a key term that is readily recognized across a multitude of biological and social disciplines engaging sustainability issues (e.g., [10,11,12,13]). Its conceptual emphasis is on recognizing the interconnected relationships, processes, and feedbacks between ecosystems and human society [9,14], and acceptance that human–environmental relationships are “embedded parts of the biosphere and shape it” [15] (p. 41). Both points are fundamental to recognizing how powerful deep-time perspectives of sustainability in the past can be in the present (e.g., baselines; see below). We also note that a strength of the SES concept and its use as a scientific framework (e.g., social-ecological systems framework [16,17,18]) is its adaptability in modelling the complex interplay of both broader and more refined (e.g., local) social and ecological variables underlying societal relationships to nature [19,20].

We acknowledge that SES is not favored by all scholars engaging issues of sustainability. It has been critiqued for lacking a single, cohesive, and accepted definition, for instance, and for not being operationalized in a way that accounts for heterogenous social variables impacting engagements with the environment (i.e., individual or collective action), such as inequities in power, access to resources, and differences in free will within a society [21,22] (see Brumfiel [23] for broader perspective). It is absolutely the case that humans leverage cultural institutions and often economic disparities between different groups to wield power and influence inequitably over one another and the environments in which they live, resulting in different quality-of-life outcomes across groups and ecosystems. Indeed, despite popular campaigns heralding that we can all be winners in the race for sustainability, the reality is that not everyone or every ecosystem wins [24,25]. We assert, nonetheless, that SESs are just as much products of human power inequities, and differential outcomes, as they are of natural ecosystem functions and outcomes. We do not believe, for example, that using SES as a conceptual term is too simplistic or dismissive of political ecological approaches to sustainability giving primacy to political agendas as foundations for understanding the co-production of human-natural systems (e.g., [26]). SESs are just as much products of inequality in both personal and institutional power, and differential outcomes of those, as they are of natural ecosystem functions and outcomes. The tensions between the social, political, and ecological domains in SESs from a historical perspective of sustainability are a key component of why we call for the recognition of archaeology as a sustainability science.

1.2. Sustainability Science

Over the past two decades, sustainability science (SS) has emerged as an interdisciplinary paradigm focused on leveraging both natural and social science disciplines to better understand the links between biological and cultural systems and how these links shape understandings of, and approaches to, the sustainability crisis (e.g., [27,28]). Within the realm of SS, the concept of historical ecological baselines, and in particular shifting baselines championed by Pauly [29] and others (e.g., [30,31,32]), have been key to reconstructing historical reference points from which to measure ecological changes, identify so-called novel ecosystems, model sustainable natural resource use, and argue for conservation strategies likely to enhance sustainability in human societies intricately entangled with the ecosystems they live in and exploit.

The idea of novel ecosystems—ecosystems without known historical precedent—bears quick attention within the context of SS and Anthropocene socioecological systems. The majority of definitions for identifying a novel ecosystem focus on the role of direct or indirect human influence on shaping irreversible ecosystem changes (see [33], Table 1). However, as Truitt et al. [33] discuss, there is not one unified definition of what constitutes a novel ecosystem through time, nor is there uniform acceptance of the concept (e.g., [34]) This can be challenging from the perspective of sustainability goal setting, governance, and policy [35,36,37]. Nonetheless, much like recognizing and defining sustainability, historical baselines are essential to establishing standardized metrics from which to measure the timing and composition of novel ecosystem development within sustainability and management goals [33] (see also [38]). Although our focus here is primarily on ecological or environmental baselines, we note that archaeology can also contribute to reconstructions of the myriad sociopolitical baselines under which sustainable solutions have been developed, succeeded, or failed in various human societies in the past.

The temporal scales of ecological baseline reconstructions commonly cluster around three general chronological themes for assessing human impacts on socioecological sustainability [39]. The first is deep-time millennial scale reconstructions focused on documenting pre-human ecological baselines. These are generally paleontological or paleoecological in nature and, depending on the world area, may span tens or even hundreds of thousands of years. The second are century to millennial scale reconstructions focused on documenting human impacts on ecosystems prior to the ‘Columbian Exchange’ resulting from European colonialism after the late 15th century [40]. These are primarily archaeological in nature, with chronological resolution usually limited to the precision of radiocarbon or other dating techniques. The third spans the ‘Age of Exploration’ and subsequent eras of European colonialism, economic globalization, the Industrial Revolution, and the advent of the atomic bomb in the mid-20th century. Archaeology can contribute to understanding the dramatic changes of these centuries as well, but the primary sources for such reconstructions are high-resolution written records, architecture, photographs, and historical documents combined with recent biological, geochemical, and other scientific observations.

The pre-human and post-15th century baselines target the two extremes of temporal scale in examining human impacts on ecosystems, understanding the sociopolitical systems in which they occurred, and establishing baselines from which to assess historical contexts of sustainability. Yet, these two ends of the spectrum do not account for the multitude of Indigenous human-environmental relationships that have shaped socioecological systems around the world for most of our species’ history. This has left critical gaps in our ability to identify shifting ecological baselines, recognize and describe patterns of human-environmental sustainability through time, and learn how the past may better inform how we can approach and understand sustainability in the present and future.

Here we assert that as an interdisciplinary and historical science, archaeology is essential to SS. Archaeology is grounded in combining anthropological theories of human behavior and cultural practice with scientific methods of data collection and analysis to holistically document and interpret human–environment relationships (a.k.a., human eco-dynamics) through time. Within the context of SS and the sustainability crisis, archaeology provides critically needed deep-time “biocultural baselines”, where reference points for measuring the emergence of socioecological systems—as a system(s) composed of intricately linked social and ecological process or institutions, respectively—and their change are based on generating historical perspectives of how humans culturally interacted with, impacted, and were impacted by the ecosystems within which they lived (Figure 2).

In the past several decades, island and coastal archaeologists have compiled extensive data documenting that initial colonists and/or Indigenous people often had significant impacts on island ecosystems around the world [30,41,42,43,44,45,46,47,48,49,50]. Most have been careful to point out that Indigenous environmental impacts in places such as the Caribbean, Pacific, and the Americas paled in comparison to the rapid and devastating impacts that occurred after European conquest and colonization. Interdisciplinary archaeological studies of human impacts on islands worldwide have also contributed significantly to recent global syntheses that document an antiquity of human modification of Earth’s terrestrial and aquatic ecosystems that goes back millennia (e.g., [48,50,51,52,53,54]).

Acknowledging that humans are the ultimate niche constructing organism on Earth, we sense a tide turning among archaeologists in island and coastal settings, with the focus on human impacts shifting toward better understandings of mutually constitutive human–environment interactions and the interdisciplinary study of those cultures that managed to survive and even thrive on islands for many centuries or millennia without ‘collapse’ or devastating ecological disruption e.g., [55,56]. At the time of European contact, many of these island cultures had dense (and manageable) populations, sophisticated maritime and/or agricultural technologies, and intensive fisheries and land management practices. Many of them also survived major climate fluctuations, rising seas and shrinking land area, deforestation, natural disasters, animal extinctions, and cultural conflicts or reorganizations—problems island and coastal peoples around the world still face today. Rather than focus on the impacts past cultures had on their environments—though still an interesting and essential area of study today—our goal in this paper and volume is to explore the resiliency and sustainability of ancient island cultures and what we might learn from them in the present.

Focusing on archaeology in island settings, this special issue of Sustainability features exemplary case studies from a variety of island regions, time periods, and cultures. Individually and collectively, these papers demonstrate the relevance of archaeology and long-term anthropogenic perspectives to SS, including suggestions for how to more effectively mobilize knowledge about sustainability in the past for the sake of the present and future. The case studies often counter “impact” and “collapse” models that have become common in the scientific sustainability literature and popular media. They also explore and highlight the resilience of island cultures and ecosystems even in the face of the accelerating global changes associated with the Anthropocene [41,50,53,54,57,58,59,60].

Following a brief review of SS as a concept and archaeology’s inherent connection to sustainability, we summarize the special issue contributions within the context of contemporary SS research objectives and goals. We conclude with a call for more overt operationalization of archaeological data and deeper historical perspectives in SS to help facilitate engagement with these issues across the social and natural sciences.

2. Sustainability Science and Archaeology

For more than 50 years, scientists, educators, and policy makers around the world have debated how best to address the sustainability crisis (e.g., Intergovernmental Panel on Climate Change, National Research Council of the National Academies, United Nations General Assembly Sustainable Development Goals). Despite continued attention to an increasing number of climatic and anthropogenic predicaments, the fundamental notion of what constitutes socioecological sustainability and how to achieve it remain significant points of contention and promise within SS. Key to SS, and its role in elucidating sustainability, is the synergy within and between natural and social science disciplines [27,28,61]. In SS, the human (e.g., sociocultural) and biological (e.g., natural) components of socioecological systems are recognized as inherently linked in sustainability outcomes. While natural sciences have traditionally been privileged within SS [62], the social sciences have played increasingly pivotal roles in studies centering the “socio” in socioecological systems. These include the ways in which scientists can better define and produce more holistic understandings of what constitutes sustainability across different cultures and environments shaped by variable histories of local, regional, and global scale socioecological changes.

In a recent analysis of how to define what constitutes SS, Fang et al. [63] conducted a literature review of 832 scientific journal papers spanning the last 20 years. They examined papers that directly defined, discussed, or identified as contributing to “sustainability science”, “science of sustainability”, and “science for sustainability”. Overall, their analysis suggested that SS is best defined as a “use-based science focused on understanding human-environment interactions, as well as linking knowledge to action, and adopts inter- and transdisciplinary approaches” [63] (p. 11). The authors also identified 10 “Key Elements” that encapsulate SS research (see Table 1 in [63]). Fang et al. [63] ultimately argued that for SS to continue to grow and meaningfully contribute to elucidating and addressing the sustainability crisis, scholars and practitioners must learn how to leverage their particular disciplines and expertise to support SS as an overarching paradigm (e.g., [64]) with readily accessible pathways toward sustainability solutions.

We agree with Fang et al.’s [63] perspective on SS, furthering our assertion that archaeology has a pivotal role to play in the ongoing development of SS. This assertion is not new; archaeological engagement with sustainability has been at the forefront of interdisciplinary approaches to this concept for decades (e.g., [65,66,67,68]). Archaeologists have long endeavored to understand how human eco-dynamics and political ecology have shaped socioecological systems and their sustainability (or lack thereof) through time and across space [46,67,69,70]. Prominent topics within the archaeology of sustainability focus on the some of the most perennial challenges facing humanity today (

Table 1. Prominent topics in archaeology and sustainability research.

Sustainability Challenge	Archaeological Research Examples
1. Human responses to climate change (e.g., altered settlement patterns, human migrations, societal “collapse”)	[70,71,72,73,74]
2. Subsistence and natural resource security	[75,76,77]
3. Resource overexploitation and development of domestication	[78,79,80]
4. Biodiversity loss (e.g., species extinctions, extirpations, and bioinvasions)	[49,81,82,83,84]
5. Seafaring and climate change; climate migration	[85,86]
6. Indigenous perspectives, colonial legacies, and environmental injustice	[87,88,89]
7. Political ecology, social organization, sociopolitical power structures	[6,90,91,92,93,94]

) and include the development of methodological advancements in modeling long-term human-environment interactions and socioecological system changes.

As exemplified in this special issue, archaeology is an interdisciplinary, historical science with the theoretical and methodological ability to support the synergy of social and biological approaches to identifying sustainability in the past as a basis for recognizing sustainability in the present and planning for its future. Archaeology is, in fact, the only scientific discipline in which we can extract information about humans and their environments over hundreds to thousands of years through the recovery and analysis of material culture, faunal and floral remains, and other lines of evidence left behind in the past.

Sustainability and Island Archaeology

Island regions are ideal settings in which to study socioecological sustainability through time given that that the majority of the world’s human-occupied islands were settled well after the Pleistocene to Holocene Transition (PHT) and before European colonization. They are also model systems useful for examining the effects of humans on newly encountered and remote pristine ecologies [41,54,95,96,97,98]. The chronology of human settlement of oceanic and barrier islands after the PHT provides key opportunities to decouple major climate change and pre-human ecological baselines from later anthropogenic baselines, as well as to identify the origin(s) of socioecological systems and track their changes through time. This is especially important for gauging the effects of European colonialism on island socioecological sustainability where colonization events signaled the start of the current global sustainability crisis for many island groups and archipelagos. Those found in the California Channel Islands [30,99], Caribbean [87,100], Polynesia [101], and North Atlantic Islands [102] have proven especially fruitful but are only a small piece of a much larger and complex puzzle (see also [103,104]).

More specifically, the arrival of European settlers devastated both island ecosystems and Indigenous cultures, leading to widespread species extinctions and extirpations, the introduction of exotic species, habitat destruction, and massive ecological and cultural reorganizations. The magnitude of such historical changes has sometimes altered island ecosystems to such a degree that it can be difficult to envision the precolonial ecology and productivity of islands or the nature of human–environment interactions prior to Europeans (see [105]). The lack of pre-European historical baselines is problematic for sustainability planning and allied efforts such as biodiversity conservation aiming to restore island environments to a “pristine” condition or model more sustainable human-environment interactions. Archaeology and historical ecology can provide glimpses of the nature of island socioecological systems at various times prior to European contact, but they also tell us that truly pristine states are rarely static or fully knowable.

3. Case Studies from Caribbean, Pacific, and Mediterranean Islands

As noted earlier, a growing body of evidence suggests that Indigenous peoples measurably impacted many island ecosystems long before European arrival. Even as the evidence for such ancient impacts grows, however, it is becoming increasingly clear through archaeological research that many Indigenous cultures managed to live relatively sustainably on islands for centuries or millennia. In the remainder of this special issue, we highlight seven case studies of such sustainability and resiliency from islands around the world. The papers in this special issue focus on the Caribbean (e.g., islands at the intersections of the Gulf of Mexico, Caribbean Sea, and Atlantic Ocean), Pacific (e.g., Rapa Nui, Solomon Islands, Cook Islands), and Mediterranean (e.g., islands and seas included in the greater Mediterranean Sea). The papers exemplify archaeological contributions to SS, meeting research objectives, content, and characteristics outlined by Fang et al. [63] (

Table 2. Ten key elements of sustainability science (SS) as adapted by Fang et al. [63] Table 1 and archaeological examples from this special issue of Sustainability.

10 Key Elements of SS	Archaeology as SS
Research Objectives	Archaeological Topics Featured in Special Issue	Citation
1. What is to be sustained?	1. Fisheries; Vertebrate biodiversity 2. Terrestrial landscape and natural resource use 3. “Traditional” lifeways, including modes of social organization and maintenance or evolution of ecological knowledge	1. Giovas [106]; LeFebvre et al. [107] 2. Hofman et al. [108]; DiNapoli et al. [109]; Swift et al. [110]; Cramb and Thompson [111]; Plekhov et al. [112] 3. Hofman et al. [108]; Cramb and Thompson [111]
2. What is to be developed?	1. Rigorous zooarchaeological methods for identifying sustainable animal exploitation; historical baselines of taxonomic diversity 2. Models of pre-European settlement patterns and terrestrial landscape use and modifications	1. Giovas [106]; LeFebvre et al. [107] 2. Hofman et al. [108]; DiNapoli et al. 109]; Swift et al. [110]; Cramb and Thompson [111]; Plekhov et al. [112]
3. Sustainable for how long?	Focus on centennial to millennial scales of sustainability prior to European colonization	All papers
4. Strong or weak sustainability?	Focus on recognizing strength (i.e., success) or weakness (i.e., failure) of sustainability relative to the recent past (e.g., >1500) and present based on local to regional island settlement chronologies	All papers
Research Contents	Archaeological topics featured in special issue	Citation
5. Understanding human-environment interactions	Terrestrial and marine habitat animal diversity and exploitation; Terrestrial landscape modifications, subsistence regimes (e.g., hunting–gathering–fishing, horticulture, agriculture)	All papers
6. Linking knowledge to action	Define “sustainability” within the context of archaeological perspectives of human-environment relationships and how such perspectives are relevant to contemporary sustainability challenges	All papers
Research Characteristics	Archaeological topics featured in special issue	Citation
7. Cross disciplinarity (theories and methods beyond archaeology)	1. Contemporary ecological theory, animal biodiversity baselines, and sustainability initiatives 2. Contemporary design principles for sustainable community development 3. Isotopic ecology and geochemistry, paleoenvironmental data 4. Oral history, ethnography, traditional knowledge, contemporary disaster mitigation	1. Giovas [106]; Plekhov et al. [112]; LeFebvre et al. [107] 2. DiNapoli et al. [109] 3. Swift et al. [110]; Hofman et al. [108] 4. Hofman et al. [106]; Cramb and Thompson [111]
8. Use-inspired	Generation of precolonial perspectives and models of anthropogenic settlement, pressures, and adaptations on islands for use in local to regional-scale contemporary sustainability research and practice	All papers
9. Place-based	Focus on local (i.e., island) to regional (i.e., islands) scales of island precolonial history and conceptions of sustainability: 1. Caribbean 2. Pacific 3. Mediterranean	1. Giovas [106]; Hofman et al. [108]; LeFebvre et al. [107] 2. DiNapoli et al. [109]; Swift et al. [110]; Cramb and Thompson [111] 3. Plekhov et al. [112]
10. Scale-multiplicity	Century to millennia temporal scales of human–environment relationships	All papers

). As volume editors, we also asked the authors of each paper to specifically address some of the lessons modern peoples might learn from these ancient island societies.

In the first archaeological case study of this special issue, Christina Giovas [106] examines a millennium of fishing at the pre-Columbian Caribbean village of Sabazan on the small island of Carriacou in the southern Lesser Antilles. Her research applies foraging theory to investigate changes in subsistence practices over the course of a millennium (AD 400–1400). While zooarchaeological results suggest that there was a decline in fishing—possibly related to climate change—resources were not depressed; instead, the data point to the sustainable harvesting of fishes for at least 600 years. A region-wide comparison of other zooarchaeological assemblages also highlights disparities in the quality of datasets and a dire need for meta-level analyses of ancient fisheries in the Caribbean to examine nuances into whether (and why) subsistence behaviors may have changed.

A second example from the Caribbean region is by Corinne Hofman, Eloise Stancioff, Andrea Richards, Irvince Auguiste, Augustine Sutherland, and Menno Hoogland [108], which focuses on documenting long-term sociocultural and political adaptations and responses to climate change and weather event hazards (e.g., hurricanes, shoreline erosion) in the Lesser Antilles. The authors synthesize a combination of climate change, Indigenous archaeological, paleoenvironmental, historic, and ethnographic data as a baseline for identifying and modeling millennial-scale histories of resilience in the region. They contextualize the results of their analysis within contemporary community-based climate change mitigation efforts. Ultimately, Hofman and her colleagues argue that the most effective approaches to sustainability in the Lesser Antilles, and Small Island Developing States worldwide, must be rooted in acknowledging and understanding traditional knowledge and innovative adaptation practices spanning Indigenous, postcolonial, and more contemporary histories of human response.

The third paper by Michelle LeFebvre, Traci Ardren, Victor Thompson, Scott M. Fitzpatrick, and Sara Ayers-Rigsby [107] examines Native American vertebrate exploitation patterns in the Florida Keys. With a focus on the Clupper site (8MO17), a Native American village located on Upper Matecumbe Key and occupied between ca. AD 800–1250, the authors make the case for the relevance of archaeology in supporting regional biodiversity conservation and sustainability science. Their paper is the first published systematic zooarchaeological analysis of vertebrate exploitation for the Florida Keys and provides an initial 1st millennium baseline for assessing ancient Native American engagement with vertebrate fauna. In contrast to the unsustainable recreational and commercial fisheries characteristic of the region since the 1800s, their results suggest more generalized and sustainable fishing strategies for five centuries of Indigenous site occupation. Their data also provide initial evidence of possibly more taxonomic diversity and geographic distribution of terrestrial and non-marine aquatic animals in the past not documented in biological or historical records.

Moving into the Pacific, Robert DiNapoli, Carl Lipo, and Terry Hunt [109] harness a suite of archaeological data from Rapa Nui (Easter Island) and couch these within Elinor Ostrom’s eight design principles for sustainable community development (e.g., [18,113]). In their paper, they examine long-held scholarly and popular assertions that the Indigenous Polynesian inhabitants of this small island suffered a ‘tragedy of the commons’ that led to a self-inflicted ‘ecocide,’ catastrophic failure, and cultural collapse (e.g., [114,115]). Presenting a variety of archaeological data, DiNapoli and his colleagues argue against the traditional ecocide and collapse narratives, suggesting instead that the ‘collapse’ on Rapa Nui occurred only after European contact. They argue effectively that the people of Rapa Nui lived sustainably on this small, remote, and isolated island for centuries until European contact dramatically disrupted their culture and environment.

Next, Jillian Swift, Patrick Kirch, Jana Ilgner, Samantha Brown, Mary Lucas, Sara Marzo, and Patrick Roberts [110] use stable isotope analysis to trace nutrient flows and rejuvenation on Tikopia in the Solomon Islands. The remarkable history of this ‘Polynesian Outlier’ goes back 3000 years and has often been used by anthropologists and archaeologists as an exemplary case of long-term societal sustainability through self-imposed population control and arboricultural practices that mimic natural growth patterns using other plants. They discuss stable isotope analysis of rat and pig remains which show that after initial human arrival, forests were cleared, settlements expanded, and agricultural schemes were focused on slash-and-burn that negatively impacted the environment. However, Tikopians then switched to multistory agro-forestry that became a more sustainable strategy and offers a unique case of ingenuity and resiliency in the face of environmental degradation and impending destruction.

In a third Pacific case study, Justin Cramb and Victor Thompson [111] focus on the role of mass migration and collective action in supporting sustainable lifeways on two small atolls in the remote Cook Islands—Manihiki and Rakahanga. Combining oral histories with archaeological evidence of settlement shifts and radiocarbon dating, the authors provide a timeline and model of land-use from initial settlement of the atolls ca. AD 1200–1400 to European contact in the mid-19th century. They argue that the atoll inhabitants were able to sustainably structure natural resource use across the two diminutive island landscapes through the development of cyclical mass migrations managed across a dual-chiefdom political system not commonly found among Pacific Island cultures. Cramb and Thompson ultimately argue that the sustainability of human lifeways on atolls and other island environments today would benefit from lessons in the past showing that sustainability is more often than not dependent on cultural cohesion and cooperation.

Finally, Daniel Plekhov, Thomas Leppard, and John Cherry [112] conclude our special issue by investigating the nature of millennial-scale human settlement and sustainability on Mediterranean islands spanning hunter-gatherer and agropastoral lifeways. Analyzing multiple variables, including species richness, net primary productivity (NPP), isolation index, and area, they examine whether there were different colonization patterns in the region between hunter-gatherer and agropastoral populations. They conclude that for more mobile hunter-gatherer groups, area was the most significant variable for predicting sustainability, whereas for agropastoralists, both area and NPP were influential, which has implications for understanding how smaller islands were particularly limiting to colonization forays.

4. Discussion and Conclusion: Lessons from Island Archaeology and SS

At its core, SS is an “action imperative” science [116] (p. 146) (see also [117]) meant to inform and facilitate actionable sustainability research and practice. The temporal tensions of past, present, and future enmeshed within the concept of sustainability make it an interdisciplinary point of both great challenge and promise when formulating action. Given that sustainability is an inherently historical concept with historically contingent outcomes, how we recognize and manage sustainability practice in the present must be grounded in scientific historical context. To that end, sustainability in the present and future will always build on previous, and often predictive, biocultural baselines informing long-term socioecological systems change. Archaeology provides the theoretical, methodological, and technological means necessary to shift baselines documenting the biocultural diversity not represented in recent history, but that is nonetheless increasingly fundamental to Anthropocene SS. This assertion supports recent arguments highlighting the role of biocultural approaches to SS and action [118] (see also [119,120]).

As demonstrated in this special issue, the Indigenous archaeological histories of the Caribbean, Pacific, and Mediterranean islands provide baselines from which to understand past anthropogenic impacts on previously pristine ecosystems as well as ecosystems co-evolving through centuries to millennia of human inhabitation and niche construction. Perhaps more significantly, the contributors have demonstrated that a variety of cultural decision-making processes and actions supported relatively sustainable centennial-to-millennial-scale island occupations, cultural continuity, and socioecological systems. This is significant because the islands and people of the Caribbean, Pacific, and Mediterranean are exemplary cases of island societies and environments worldwide experiencing accelerated sustainability crises caused by climate change, ecosystem collapse, and biocultural diversity loss—all of which are directly related to rising food insecurity and new patterns of human migration and resettlement (e.g., [121,122]). Albeit on different scales of impact, there is precedent for these same variables and sustainability challenges in the deep past across each region. The archaeological and historical ecological perspectives offered here provide proof-positive case studies of how people have long been able to successfully act and adapt when living within ecologically vulnerable terrestrial or aquatic island environments.

For example, studies by Giovas [106], Hofman et al. [108], and LeFebvre et al. [107] all indicate more sustainable, local (i.e., island) histories of marine resource exploitation, terrestrial landscape use, and settlement patterns spanning the extent of the Caribbean prior to European colonization. The utility of these local perspectives is as baselines for local to regional-scale approaches to biodiversity, cultural heritage, and traditional knowledge conservation (e.g., [123,124,125,126])—each being essential to creating effective sustainability practice. The Pacific-focused case studies underscore how notions of socioecological “collapse” often misrepresent the lived reality of groups anticipating and/or overtly managing environmental variability and change due to either climatic or anthropogenic drivers. DiNapoli et al. [109], Swift et al. [110], and Cramb and Thompson [111] show that throughout Indigenous histories of their respective study islands and cultures, recognizing and responding to environmental change or resources depression was predicated on an ability to ostensibly accept and then adapt to change at societal levels. While various authors point out that such change was not simple, nor do their case studies provide direct analogs for potential human responses in the present and future, their historical findings nonetheless emphasize the need for contemporary societies to move beyond “sustainability or collapse” narratives (sensu [126]) when designing effective pathways toward sustainability practice and education. The Pacific studies provide concrete examples of how people can exercise great cultural flexibility and collective buy-in when facing sustainability crises, including resilience in economy and the organization of labor. Finally, Plekhov et al. [112] demonstrate that deep-time perspectives of the interplay between human colonization, subsistence, and landscape histories may be important to recognizing and managing contemporary outcomes of long-standing tensions between patterns of resilience and vulnerability within contexts of human migration, climate change, and food security (e.g., [127,128]).

While the authors of this paper and those of the special issue intentionally emphasize the “positive”, or sustainable, outcomes of long-term Indigenous island dwelling, our perspectives are not meant to down-play or necessarily ignore that the lived realities of the people and places studied and interpreted as sustainable were not without challenges and inequality. As contemporary SS demonstrates, sustainability within and between groups of people or cultures (however broadly or narrowly culture is defined) is rarely achieved through one-size fits all management of socioecological systems [19,129]. Archaeology has also demonstrated this to be the case throughout human history, where sustainability was sometimes achieved at the expense of others, privileged one ecosystem or societal sector over another, or sustained some lifeways and livelihoods over others (e.g., [23,130,131,132]. There were undoubtedly inequalities in power and control over decision making, as well as overt and concealed contestations and resistance to some of the practices revealed in the special issue case studies (e.g., Hofman et al. [108], DiNapoli et al. [109], Swift et al. [110], and Cramb and Thompson [111]). Similarly, suggested applications of some of the issue’s archaeological results to fisheries and biodiversity crises (e.g., LeFebvre et al. [107] and Giovas [106]) in the present may find support, objections, or manipulation across different communities with different resources and incentives when defining and practicing sustainability.

All of the case studies presented in this special issue of Sustainability provide much-needed perspectives and insights into how past human groups living on islands engaged with and overcame significant challenges—both natural and anthropogenic—that redirected their focus toward ensuring long-term survivability. While islands are useful model systems for examining cultural evolutionary processes and human impacts within these smaller, bounded landscapes [41,95,96,97,98], the fact remains that they can also serve as corollaries for examining what has (and might) occur in more expansive areas such as continents. These include the negative effects of non-native species introductions (e.g., extinctions, reduced habitats), landscape modifications (e.g., forest clearance for agriculture, construction of irrigation networks), and many other phenomena that can cause destructive and sometimes permanent ecological disruptions which are identifiable in archaeological and paleoenviromental records [35,50,51,81]. Expanding beyond terra firma, some scholars have also argued that islands are essentially microcosms for the human colonization of space in which new modes of travel (watercraft, aircraft, and spacecraft), advances in wayfinding/navigation, and other technological advances have allowed our species to reach new and often remote pristine environments [133]. The question here remains: are there lessons we can learn from the ancient settlement of islands that can help guide us in our desire to reach other celestial bodies?

In conclusion, we assert once again that archaeology is an essential component of SS, bridging natural and social sciences and effectively connecting the past, present, and future. To be as effective as possible in supporting local, regional, and global scale sustainability among islands and beyond, archaeologists must work to make the archaeological past and associated historical ecological data as widely accessible to a diversity of sustainability-focused disciplines, professionals, Indigenous peoples, local communities, and other stakeholders as possible for use in collaborative research, action, and policy [134] (e.g., [135]). Within the context of the Anthropocene, humans now inhabit one connected global socioecological system, and understanding the history of how this has become our collective present and future, based on a diversity of biocultural histories, is more essential than ever to SS and how we recognize and define sustainability both conceptually and through action. Archaeology has long been and will continue to be essential to this endeavor.