Towards Absolute Sustainability: Reflections on Ecological and Social Sustainability Frameworks—A Review

Abstract

The interconnectedness of Earth’s ecological and social systems means that changes in one area invariably affect others. Human activities continue to push the planet beyond safe thresholds, threatening both environmental stability and human well-being. Despite decades of discourse, a universally recognized and operational definition of sustainability remains elusive. While frameworks such as the Sustainable Development Goals, Planetary Boundaries, and Decent Living Standards have advanced the conversation, none fully captures the complexities of socio-ecological interdependencies or provides actionable guidance. This paper outlines the historical and conceptual context of sustainability, including the shift from the Holocene to the Anthropocene, and critically reviews key frameworks such as the Millennium Development Goals, Sustainable Development Goals, Planetary Boundaries, Doughnut Economy, and Decent Living Standards. It identifies key gaps, including the misalignment between biophysical thresholds and social goals, lack of regional specificity, and missing mechanisms for translating global objectives into just and implementable policies. Building on this analysis, this paper proposes a more precise definition of sustainability: any action that accelerates planetary overshoot or impedes the achievement of a decent life must be considered unsustainable. By advancing this integrative definition, this paper seeks to inform academic discourse and support the development of more equitable and operational sustainability strategies, particularly in the context of the Sustainable Development Goals. In doing so, it offers conceptual guidance to address persistent gaps in the SDG framework, with specific relevance to targets such as SDG 8 (Decent Work and Economic Growth).

1. Introduction

A future in which all Decent Living Standards (DLS) (defined as the essential material conditions for human well-being) are achieved and humanity lives within Planetary Boundaries (PBs) (defined as scientifically established ecological thresholds that must not be exceeded to preserve Earth system stability) would represent a milestone of global sustainability. In this world, everyone has access to safe and dignified living conditions, quality health care, and clean air. Information and communication technologies are universally available. Education is inclusive, and the freedom to gather is respected everywhere. What appears to be a shared global vision still remains out of reach (even by 2050). Moreover, the gap between this vision and actual developments continues to widen in both social and ecological terms [1,2].

By now, ample evidence suggests that the Earth system is approaching a state of significant change. The planet is experiencing escalating environmental stress and undergoing profound shifts driven by anthropogenic impacts. These changes pose substantial challenges to the sustainability of human civilization as it currently exists [3]. This accelerating crisis calls into question the adequacy of existing sustainability frameworks to effectively respond to the scale and urgency of the problem.

It also reveals the limitations of current approaches, particularly regarding the Sustainable Development Goals (SDGs), which were ratified by all United Nations member states and set to be achieved by 2030. According to recent forecasts, many countries face substantial obstacles in meeting the Agenda 2030, with significant gaps projected to remain. These include shortfalls in poverty reduction, education access, climate action, and institutional capacity [2,4]. This shortfall stems from a combination of systemic barriers and structural inefficiencies within societal and economic systems. For example, fossil fuel subsidies continue to incentivize environmentally harmful practices, while unequal access to education and health care limits opportunities for large parts of the global population to participate in sustainable development [5]. This tension is also reflected in the growing academic debate on the structure and implementation of the SDG framework itself. While the SDGs provide a broad and politically endorsed agenda for sustainable development, several scholars have raised concerns about their conceptual clarity, internal coherence, and enforceability [6]. Critiques point to the lack of binding obligations, the vagueness of many targets, and the dominance of economic growth narratives within goals such as SDG 8 [7]. Moreover, the framework has been criticized for insufficient integration of systemic interdependencies between goals, which can result in trade-offs and unintended side effects during implementation. These critiques underline the limitations of the SDG framework in guiding transformative change and emphasize the need for assessment models that are both conceptually robust and responsive to socio-ecological complexity [8].

These structural limitations are further reflected in the continued reliance on traditional economic indicators, which remain central to how progress towards sustainability is measured and evaluated. Traditional economic indicators, particularly those centered on growth, have limitations when it comes to adequately addressing the multidimensional goals of sustainability and human well-being [9]. Despite their recognized shortcomings in adequately reflecting environmental and social complexities, these indicators continue to dominate policy and decision-making processes. This persistence can be attributed not only to their historical embeddedness but also to their methodological simplicity. Their ease of quantification, standardization, and cross-national comparability makes them particularly attractive within technocratic governance structures that favor clear and measurable outputs [10,11,12].

This urgent socio-environmental crisis underscores the need for actionable and evidence-based solutions. Yet, even today, sustainability remains a deliberately broad and often poorly defined term, which impedes efforts to develop effective frameworks and policies. As a result, sustainability concepts often struggle to gain traction, while growth-centred development models continue to dominate, prioritizing technological solutions and efficiency improvements instead of addressing deeper systemic causes of socio-ecological crises [13]. This paper underscores the necessity for a paradigm shift that integrates sustainable development with robust and qualitative indicators [14,15]. The prospects for achieving a genuine transformation towards sustainability are becoming increasingly challenging, as some stakeholders prioritize short-term benefits, delaying the implementation of systemic changes needed for long-term sustainability [16]. The pursuit of individual wealth, particularly monetary wealth, frequently conflicts with the principles of sustainability, and therefore hindering their operationalization and enforcement [17,18,19]. At the industry and political levels, concerns persist regarding the intentional misrepresentation of emissions and sustainability metrics, contributing to widespread issues of greenwashing [16,20].

The objective of this paper is to contribute to the ongoing refinement of sustainability concepts by identifying key conceptual and methodological gaps in current frameworks. Despite the widespread use of approaches such as the Sustainable Development Goals (SDGs) and Life Cycle Assessment (LCA), many of these models fall short in capturing the complex and interdependent nature of socio-ecological systems [20]. Specifically, they often lack integration between environmental thresholds and social needs, offer limited regional applicability, and rely heavily on quantitative indicators that obscure underlying structural dynamics [19,21]. Addressing these shortcomings requires a conceptual foundation that is both integrative and operational. In response, this paper proposes the framework of Absolute Sustainability Assessment (ASA), which explicitly links environmental boundaries and socially defined thresholds through the use of qualitative indicators [22,23,24]. To develop this foundation, this paper conducts a structured review of selected sustainability frameworks, including the SDGs, Millennium Development Goals, Planetary Boundaries, Doughnut Economy, Decent Living Standards, Absolute Environmental Sustainability Assessment, and synthesizes their insights to outline a more context-sensitive and just approach to sustainability assessment.

2. Materials and Methods

The methodology of this paper is based on a systematic and structured literature review of key principles of sustainability and sustainable development. The review process employed snowball sampling via the Connected Papers platform [25]. The sampling strategy was informed by foundational publications and widely recognized frameworks in sustainability research. Key concepts such as the Anthropocene [26], Brundtland Report [27], Sustainable Development Goals [28], Three Pillars of Sustainability [29], Absolute Sustainability Assessment [30], Planetary Boundaries [22], and Decent Living Standards [23] were deliberately selected to ensure a comprehensive coverage of both historical and contemporary perspectives in the field (Supplementary Materials). The selection of frameworks in this review reflects an explicit focus on the importance of simultaneous applications of environmental and social dimensions within possible sustainability assessments. In contrast, approaches based primarily on quantitative, technocratic, or narrowly sectoral indicators, such as conventional LCA models or static sustainability reporting schemes, were deliberately excluded.

Within this selection, particular emphasis was placed on the Brundtland Report and the SDGs due to their pivotal role in institutionalizing sustainability at the international level. The Brundtland Report and the SDGs were selected for their role in shaping global sustainability and sustainable development discourse, particularly through their influence on multilateral policy agendas, institutional frameworks, and international cooperation mechanisms within the United Nations system. These frameworks incorporate fundamental principles, such as the three pillars of sustainability, and the distinction between strong and weak sustainability, which reflects different assumptions about the role and substitutability of natural capital [29,31].

Additionally, the concepts of the Anthropocene and Planetary Boundaries were integrated, as they provide an ecological systems perspective and emphasize the biophysical thresholds that define a safe operating space for humanity. For the assessment of sustainability’s measurability, the Absolute Sustainability Assessment framework was deliberately utilized due to its alignment with Planetary Boundaries. To address the gap in Absolute Social Assessments, the work “Decent Living Standards: Material Prerequisites for Human Wellbeing” [23] was selected for its focus on sufficiency and resilience, and its proposal for a sustainable living corridor akin to Planetary Boundaries.

While the concept of Absolute Environmental Sustainability Assessment (AESA) has gained visibility in recent years, it remains focused primarily on biophysical thresholds. In contrast, this paper introduces Absolute Sustainability Assessment (ASA) as an integrative framework that explicitly links environmental and social dimensions. ASA is not merely an environmental evaluation tool, but a response to the conceptual shortcomings of approaches that treat environmental and social sustainability as separate domains. The assumption here is that sustainability can only be meaningfully assessed when Planetary Boundaries and decent living standards are jointly considered. Isolated assessments, whether environmental or social, lack the capacity to guide systemic transformation. ASA, as proposed in this paper, addresses this gap and forms the conceptual core of the ongoing empirical application.

During the initial research phase, the literature was categorized along an internal analytical structure to ensure consistency and depth of review. This working structure included the following components: (1) Theoretical Foundation, (2) Key Frameworks and Models, (3) Case Studies and Practical Implications, (4) Challenges and Critique, and (5) Future Directions and Implications. While this framework guided the selection and categorization of sources, the final structure of Section 3 (“Results”) was organized thematically to reflect the logical development of sustainability concepts. The annex provides a comprehensive table detailing the full literature base and its classification according to these categories. Through this systematic approach, this paper establishes a broad and layered foundation encompassing both the historical evolution of sustainability concepts and current challenges and solutions.

3. Results

3.1. Challenges and Opportunities in Sustainability and Sustainable Development

This section presents two parallel developments: the long-term socio-ecological shift from the Holocene to the “Anthropocene”, and the evolution of international sustainability discourse through major conferences and initiatives. While the term “Anthropocene” is widely used to describe the current phase of human-driven planetary change, it remains controversial in both definition and classification. This applies in particular to its status as a formal geological epoch as well as to its normative and political implications. In this paper, the term is used as a conceptual reference to the period in which human activity has become the dominant force influencing Earth system processes.

3.1.1. Holocene

The complex social development of modern Homo sapiens occurred largely during the Holocene epoch. This development was facilitated by the relatively stable climatic conditions of the Holocene, which experienced only minor fluctuations compared to other geological periods [32]. Under natural conditions, absent of anthropogenic interventions, it is estimated that the Holocene’s stability could have persisted for over 50,000 years [20].

Prior to the Holocene, ecosystems had thousands to millions of years to adapt to prevailing conditions, gradually evolving to fit the environmental contexts of their time [33,34,35]. However, as human societies evolved and their influence on Earth’s systems grew, humans have emerged as a dominant force within the Earth system [36]. In less than 10,000 years since the onset of the Holocene, anthropogenic activities have triggered significant environmental changes, raising questions about whether these impacts have initiated a new geological epoch. This ongoing debate centers on whether the human-induced transformations of the Earth’s systems are substantial enough to signify a transition from the Holocene to the Anthropocene [26,33].

3.1.2. Anthropocene

There are three prevailing theories regarding the exact dating of the Anthropocene: (1) the settlement of humans, (2) the invention of the steam engine, and (3) the great acceleration. The latter refers to the sharp increase in human activity, energy use, and resource consumption since the 1950s, which has led to unprecedented impacts on Earth system processes. The significance of explicitly defining the Holocene and Anthropocene lies in the attribution of historical responsibility for environmental change.

This definition has implications for determining whether states or countries may justifiably continue emitting greenhouse gases in the future, based on their proportional contribution to historical emissions [33,34,35]. Historical responsibility is a central element in discussions of trans- and intragenerational justice concerning climate change. Within the context of the Anthropocene, this responsibility gains particular relevance, as the epoch is defined by the unprecedented scale and speed of human-induced transformations, largely driven by fossil fuel use. The availability and exploitation of these energy sources have enabled a profound expansion of human activity, marking a key turning point in the human-Earth system relationship. Before this energy source became widely available, energy constraints acted as a bottleneck, limiting the scale and pace of human expansion [26]. The large-scale use of fossil fuels did not resolve these constraints in a structural sense, but rather allowed them to be bypassed temporarily through unprecedented access to concentrated energy. This dynamic is one reason why the great acceleration is considered a potential starting point for the Anthropocene. This period marked a profound shift in the interaction between human societies and the Earth system [36,37].

The second half of the 20th century is characterized by a unique and unprecedented interaction between humans and the planet. If various growth indicators are examined, a significant increase can be observed across nearly all metrics since 1950. Following the aftermath of World War II, economic reconstruction efforts led to the rapid rebuilding of Western civilization [38]. However, this period of intense economic activity was accompanied by the extensive exploitation and modification of natural ecosystems, pushing Earth’s systems to their stress limits. Of the 24 ecosystems assessed in the Millennium Ecosystem Assessment, 15 were found to be degraded or used unsustainably. Particularly concerning is the Earth’s self-regulatory capacity, which is essential for maintaining planetary stability. Without supranational cooperation and coordinated action, a collapse of the Earth system appears increasingly likely [39].

Although the formal recognition of the Anthropocene was recently rejected, the concept has played a pivotal role in fostering diverse perspectives on the interaction between humans and nature [40,41]. Establishing qualitative definitions and principles to guide human activities is essential. They serve as foundational frameworks for decision making and help ensure coherence and alignment across different sectors and domains. Without adherence to such principles and without a precise identification of cause–effect relationships, efforts towards sustainability risk becoming fragmented and ultimately ineffective [42].

3.2. Principles of Sustainability and Sustainable Development

The origins of the modern sustainability debate can be traced back to the 18th century and the work of Saxon mining official Hans Carl von Carlowitz. Responding to the high demand for wood needed to stabilize mine tunnels, von Carlowitz proposed principles aimed at ensuring a permanent and sufficient supply of timber. In his book Sylvicultura oeconomica, he outlined what was considered at the time to be a sustainable approach to tree cultivation [43,44]. However, this early definition of sustainability must be adapted to align with the complex realities of the present day. In von Carlowitz’s era, the economic and environmental challenges we now face, particularly concerning growth and development limits, were not yet evident [43].

As sustainability concepts evolved, several milestones in the 20th century significantly shaped the modern debate. Rachel Carson’s Silent Spring (1962) brought attention to the detrimental effects of pesticides on ecosystems, serving as a critical turning point for environmental awareness. A decade later, The Limits of Growth by [45] introduced the paradigm that, if current trends in population growth, industrialization, and pollution continued unchecked, the Earth’s finite resources would be exhausted within 100 years. The same year, the United Nations Environment Programme (UNEP) was established during the Conference on the Human Environment, underscoring the growing recognition of global environmental challenges [20,45,46]. In 1987, the concept of sustainable development was formally defined in the landmark report “Our Common Future”, published by the World Commission on Environment and Development (WCED) under the leadership of Gro Harlem Brundtland. This report remains a foundational reference in sustainability discourse [27,47]:

“1. Sustainable development is development that meets the needs of the present without compromising the ability of future generations to meet their own needs.

But physical sustainability cannot be secured unless development policies pay attention to such considerations as changes in access to resources and in the distribution of costs and benefits.”

([27], p. 41)

The definition of sustainable development introduced in Our Common Future was not a paradigm shift intended to transition from the capitalistic system to one that holistically fosters human and environmental well-being. Instead, it emphasized the continued exploitation of human and natural resources as a means to eradicate poverty [48]. The United Nations adhered to the paradigm that poverty was the primary driver of environmental degradation and that economic growth was essential to mitigate this damage. However, perpetual economic growth is fundamentally incompatible with the finite limits of the Earth system [26]. To adapt the Brundtland definition of sustainable development to the 21st century, the concept of circular economy (CE) was introduced and has been significantly shaped by the Ellen MacArthur Foundation. The CE framework primarily focuses on closing production-consumption cycles, emphasizing resource efficiency and waste minimization. However, it remains limited by the lack of a clear and comprehensive scientific perspective, which restricts its ability to address sustainability in its entirety [49].

3.3. Millennium Development Goals and Sustainable Development Goals

3.3.1. Millennium Developement Goals

The introduction of the Millennium Development Goals (MDGs) in 2000 aimed to eradicate global poverty and ensure a decent life for all by 2015. As part of the preparations for the United Nations Millennium Declaration, an additional goal, “a global partnership for development”, was added to the existing seven global development goals [50] (pp. 16, 17, 26). This eighth goal, determined by the Development Assistance Committee (DAC), sought to secure the agreement of developing countries to the MDG framework. Prior to the inclusion of Goal 8, the MDGs solely targeted developing nations. By emphasizing international collaboration, the addition of Goal 8 elevated the MDGs to a higher level of global partnership, fostering broader acceptance and alignment [50]. The MDGs were described by the United Nations as having “produced the most successful anti-poverty movement in history” [51] (p. 5). However, by the end of the implementation period (2000–2015), it became evident that additional international action and cooperation were required to protect vulnerable groups and address remaining gaps. Building on the foundations of the MDGs, the Sustainable Development Goals (SDGs) were established to tackle a broader range of economic, social, and environmental dimensions, reflecting an expanded and more integrated approach to global development [51,52].

3.3.2. Sustainable Development Goals

“Equitable access to sustainable development” was emphasized as a key principle in the Cancun Agreement of the United Nations in 2010. This approach was further incorporated into the development of the Sustainable Development Goals (SDGs) [53,54] (p. 3). The establishment of the SDGs was first discussed at the United Nations Conference on Sustainable Development, held in Rio de Janeiro in 2012. The primary aim was to develop a set of goals addressing the pressing social, environmental, political, and economic challenges of the time. The Millennium Development Goals (MDGs) provided an initial framework for addressing critical global issues such as poverty, hunger, gender inequality, health care, and educational equity. Building on this foundation, the SDGs were designed with a broader thematic scope to ensure that no one is left behind globally [55]. A key innovation of the SDGs lies in their unified, globally applicable target system, which integrates global and national sustainable development objectives across all UN member states [28,55,56]. The indicators and objectives established by the SDGs were also intended to enhance communication between science, politics, and society. By providing concrete and measurable targets, the SDGs aim to facilitate effective collaboration and accountability in achieving sustainability objectives. This approach follows the principle of “what gets measured gets done,” underscoring the importance of measuring progress to achieve defined goals [57,58,59,60].

The interconnection and irreplaceability of the individual Sustainable Development Goals suggest a link to the concept of strong sustainability [56,61,62,63,64]. Although the SDGs were designed without an inherent hierarchy, many stakeholders view SDG 1 (No Poverty) and SDG 16 (Peace, Justice, and Strong Institutions) as central pillars. This prioritization reflects the belief that achieving these goals is a fundamental prerequisite for progress in all other areas of sustainable development [11,65]. Despite initial successes in reducing global poverty, recent trends indicate regression, with an estimated additional 75–95 million people living in extreme poverty in 2023. This underscores the need for significantly increased efforts to fulfill the Agenda 2030 [2,4,60,62,66,67]. Furthermore, the interdependencies between goals and the absence of a roadmap for their implementation highlight a persistent challenge.

Political decision makers often lack effective tools to measure progress towards achieving the SDGs, while the scientific community continues to advocate for evidence-based decision making [55,56,60,62,64,68,69].

Similar to the definition of sustainable development in “Our Common Future”, the SDGs were formulated using “weak” language, leaving room for potential loopholes [70,71]. Since the SDGs are not legally binding for nation-states, this flexibility has allowed for selective prioritization or “cherry-picking” of goals and indicators, with countries often showcasing data that present them in a more favorable light [56,60,62,63,65,67,72,73,74,75,76,77].

During the drafting and later ratification of the SDGs, the International Science Council (ISC) rated only 49 out of 169 targets as “well-developed” [10,21,78]. The same applies to a certain extent also to the SDG indicators. Out of the 244 SDG indicators, only 29 address environmental issues, with just 2 offering absolute measures [10,11]. Preventing negative spillover effects during SDG implementation requires continuous review of all goals and indicators to assess their impact on one another [2,4,60,63,68,79,80,81]. Furthermore, recent analyses highlight that one of the most pressing limitations of the SDG framework lies in its weak governance architecture, particularly regarding coherence, mandate, and coordination between implementing institutions [77].

This review process has been discussed in connection with broader sustainability frameworks, and could potentially be aligned with a comprehensive Absolute Sustainability Assessment framework to promote a more integrated approach [30,59,82]. At the midpoint of the Agenda 2030, the world is experiencing rising societal polarization and populism, which are often accompanied by increased racism and the erosion of welfare mechanisms [83]. These dynamics hinder the achievement of a decent life for all and risk eroding a decade of progress [2,21]. The current trend of declining access to social capital and basic infrastructure further exacerbates inequality, creating a fertile breeding ground for the escalation of hostile conflicts [4,11,12,84,85,86].

3.4. Three Pillars of Sustainability

The three pillars diagram of sustainability is arguably one of the most well-known graphic representations of sustainability concepts from the 20th and 21st centuries. Despite its widespread recognition, the exact origin of this concept remains uncertain. The diagram highlights three main pillars: social, environmental, and economic (Figure 1). Although the concept is not explicitly referenced in the Sustainable Development Goals (SDGs), it played a significant role during the elaboration phase of the SDGs [29]. The three pillars framework emphasizes the need to move beyond one-dimensional approaches to sustainability that focus primarily on environmental aspects, advocating instead for interdisciplinary and transdisciplinary perspectives. This approach has become a cornerstone of sustainability research, emphasizing the interconnectedness of social, environmental, and economic dimensions in achieving long-term sustainability [29,31].

Due to the unknown origin of the three-pillar model, it is challenging to draw definitive conclusions about the interactions between the pillars. In recent years, adaptations of the model have incorporated additional dimensions, including “institutional,” “cultural,” “technical,” and “governance” layers. Yet, these additions do not fully resolve the underlying tensions between the three original pillars. In practice, trade-offs between environmental protection, economic growth, and social justice frequently emerge, posing challenges for coherent sustainability strategies. Addressing such conflicts is essential to move from abstract models to actionable, context-sensitive solutions [87,88]. Some scholars have also proposed embedding language as a distinct level within the framework, recognizing its critical role in shaping sustainability concepts and policies [89]. Despite these developments, the thematic and conceptual evolution of the three-pillar model appears to remain incomplete, with its full potential yet to be realized since its inception [14,90,91].

3.5. Weak and Strong Sustainability

The concepts of strong and weak sustainability provide a useful framework for distinguishing between different understandings of how natural and human-made capital interact. These approaches originate from economic theory and reflect fundamentally different assumptions about the substitutability of natural resources. Weak sustainability operates under the assumption that natural capital can be altered or transformed as long as other forms of capital (e.g., social, manufactured and monetary) remain constant or can be increased. It posits that monetary value can restore the baseline state of natural capital, suggesting that human development can be decoupled from environmental degradation [91,92,93].

In contrast, strong sustainability adheres to the paradigm that natural capital represents an interplay of complex natural and societal factors. The non-linear relationships between these factors introduce significant uncertainties into monetary valuations of natural capital [92]. Following the precautionary principle, strong sustainability emphasizes that natural capital should not be altered to a point where it cannot return to its original state. Furthermore, it recognizes that certain natural life support functions are non-substitutable. Proponents of strong sustainability highlight three primary arguments for its consideration in all actions: (1) irreversibility: while manufactured capital is largely reproducible and reversible, changes to natural capital are often irreversible; (2) dependency: manufactured capital relies on natural capital for its production and therefore cannot entirely replace it; (3) intergenerational fairness: present generations cannot seek the consent of future generations to trade a degraded environment (e.g., polluted air or habitats) for increased goods and services. Such actions would significantly limit the freedom of choice for future generations [31,91]. Both concepts focus on the trans-, inter-, and intragenerational valuation of the environment. However, a critical question remains: What is the potential worth of an environmental system to future generations [91,94]?

In general, and in favor of strong sustainability, it is essential to recognize that human life requires an interdependent system: the economy must be embedded within a functioning society, and society, in turn, must operate within a functioning environment. The environment remains the ultimate foundation, as it is irreplaceable (Figure 2) [29,94].

The sustainability schools of Hedonism and Eudaimonic share some conceptual similarities but diverge significantly in their foundational approaches. Hedonism relies on monetary indicators to describe well-being, directly supporting the capitalistic economic system and aligning with the principles of weak sustainability [95]. In contrast, the Eudaimonic approach focuses on maximizing human life potential and achieving “the good life for all”.

Hedonism exhibits several notable limitations: (1) instability of preferences: societies do not maintain stable consumption preferences over time; (2) lack of intergenerational justice: hedonism is grounded in static assumptions of subjective personal preferences, making it ill-suited to address long-term sustainability challenges; (3) the Easterlin Paradox: an increase in national or personal monetary income does not necessarily correspond to an increase in overall well-being [70,96]. Given the urgency of the global sustainability transformation and the recognition that the hedonistic approach has contributed little to a dignified life for all in recent decades, the Eudaimonic school of sustainability is increasingly favored in sustainability science and among scholars advocating for well-being-centered and justice-based approaches [96]. From this perspective, the concept of sustainable consumption and production corridors has been developed. These corridors align with the principles of strong sustainability and reflect the frameworks of Planetary Boundaries and Decent Living Standards [95,97,98].

3.6. Planetary Boundaries

The concept of Planetary Boundaries (PBs) provides a critical foundation for defining these corridors. PBs outline clear and measurable biophysical limits within which humanity can operate safely within the Earth system. These limits are determined using biophysical indicators, encompassing various dimensions of ecological health and resilience [22,24,99,100]. The connection between strong sustainability and the Planetary Boundaries highlights the profound interdependence between human well-being and planetary health. This perspective necessitates a paradigm shift in how societies economize, consume, and manage natural resources [22]. Adherence to these limits is essential to maintaining and strengthening the resilience of the Earth system, which is a prerequisite for ensuring a livable future for humanity. A key challenge lies in integrating scientific findings into political, social, and economic decision-making processes [101]. Achieving this requires a deep understanding of the intricate connections between ecological systems and human activities. The fundamental principle of strong sustainability, which incorporates the Planetary Boundaries framework, extends beyond environmental preservation. It demands active engagement in restoring and enhancing the natural systems upon which human life depends [31,93].

Due to increasing anthropogenic pressures on the Earth system, abrupt fluctuations within natural environmental systems can no longer be excluded. Such changes introduce the possibility of unforeseen impacts on human life, making adequate adaptation to future events increasingly complex. In response to these challenges, the concept of nine Planetary Boundaries was introduced in 2009 to define a safe operating space for humanity [22]. These boundaries encompass the following critical Earth system processes: climate change, ocean acidification, stratospheric ozone depletion, biogeochemical flows of nitrogen and phosphorus, freshwater use, land system change, biosphere integrity, novel entities, and aerosol loading. By 2023, thresholds for all nine Planetary Boundaries have been established to provide clear indicators for maintaining the Earth’s stability. These thresholds were determined using environmental indicator values from the beginning of the Holocene, a period characterized by relatively stable conditions that supported the development of human civilization [3,22,100].

The Planetary Boundaries (PBs) framework is grounded in the precautionary principle and incorporates concepts such as tolerable windows and the safe minimum standard [22,101,102,103]. According to the latest assessment of the Planetary Boundaries, six out of nine boundaries have already been transgressed, triggering feedback mechanisms that further complicate efforts to return to a safe operating space (Figure 3) [3,22]. A recent addition to the framework, introduced in 2022, is the “green water” boundary, which accounts for the amount of water stored in the biosphere [104]. This enhancement reflects an evolving understanding of hydrological processes and their role in maintaining biosphere integrity. One of the strengths of the Planetary Boundaries framework lies in its graphical clarity, which makes the concept accessible to diverse audiences.

The framework has already influenced actions at both national and international levels. However, the lack of regional specifications for boundaries remains a critical limitation [105,106,107,108]. To enable regional calculations of Planetary Boundaries, data on diverse ecosystem values must first be collected and scaled according to regional distributions [38,109,110]. Only once usage budgets for each boundary are clearly defined and distributed, intersections with social factors can be effectively addressed. This integration of environmental and social dimensions is crucial for ensuring targeted sustainability transformation actions. A deeper understanding of these intersections is required to guide decision-making processes that align environmental protection with social well-being [23,111].

3.7. Doughnut Economy—“A Safe and Just Space”

Max-Neef postulated nine basic human needs: subsistence, protection, affection, understanding, participation, leisure, creation, identity, and freedom. According to Max-Neef, these principles are universal, applying to all cultures and human epochs [112]. He emphasized that these needs do not follow a strict hierarchy but interact dynamically. If Max-Neef’s theory is accepted, human needs are finite and classifiable [113,114]. Kate Raworth’s 2012 concept of the “Safe and Just Space for Humanity” (SJS) adopts a similar perspective, combining the social foundation of the Sustainable Development Goals (SDGs) with the environmental ceiling of the Planetary Boundaries [83]. The SJS builds directly on the Planetary Boundaries framework, expanding its scope by including social well-being as a central element. Since the indicators for social well-being in the SJS derived from the SDGs, making them uniform across all United Nations member states, regional results can be globally compared [114]. The SJS framework distinguishes twelve dimensions of social well-being, visually emphasizing the direct dependence of human well-being on Earth system processes [84]. Despite its innovative approach, the reliance on SDG-based indicators poses significant limitations for the SJS. Additionally, since 2012, there has been little advancement in refining the SJS framework to address these shortcomings, leaving it insufficient as a comprehensive tool for measuring social sustainability [115,116]. This underscores the urgent need for more refined methodologies that go beyond generic SDG-based metrics to effectively measure and support social sustainability. To address these challenges, the concept of Decent Living Standards (DLS) provides a more focused and actionable framework. By emphasizing the tangible elements required for a dignified and sustainable life, DLS offers an alternative to Doughnut Economics and its static SDG-based indicators, aiming to better capture the complexities of social sustainability in a changing world [9,23].

3.8. Decent Living Standards

“We do not aim to offer an exhaustive list of goods in this minimal basket, but instead to capture those components that matter most for a climate change regime” [53] (pp. 2, 3). The concept of Decent Living Standards (DLS) is founded on the premise that all individuals, across generations and geographic regions, share a specific and equivalent set of basic needs essential for a good life. For instance, while the need for quality nutrition is universal, its cultural, regional, or national expression may vary based on dietary preferences and traditions [70,117,118,119]. To qualify as a Decent Living Standard, these needs must be globally recognized, either as necessary and indispensable or as widely desired by the majority of the population. Any elements that negatively impact human well-being or significantly impair living comfort, such as alcohol and cigarettes, are excluded from the definition of DLS [23,120,121]. [23] categorize DLS at two primary levels: physical well-being and social well-being. Based on these dimensions, they identify ten key components of Decent Living Standards:

• Nutrition,
• Shelter,
• Living Conditions,
• Clothing,
• Health Care,
• Air Quality,
• Education,
• Information and Communication,
• Mobility, and
• Freedom to Gather.

Similar to the Sustainable Development Goals (SDGs) and Planetary Boundaries (PBs), the concept of Decent Living Standards (DLS) assumes that various human basic needs are neither comparable, hierarchically ordered, nor replaceable. The promotion of general well-being, extending beyond one’s own circumstances, represents an implicit responsibility for individuals within society [122]. This notion is grounded in the understanding that the more unequal a society becomes, the more unstable and vulnerable it is to extreme events [95,117]. Guaranteeing basic needs and well-being for all not only enhances individual quality of life but also contributes to societal stability and resilience [123,124,125,126,127]. Achieving this within the limits of the Planetary Boundaries requires a realignment of economic priorities and targeted degrowth in certain sectors and lifestyles. Importantly, this process of degrowth does not entail regressing to primitive living standards [128,129]. Instead, it involves reducing overconsumption, improving resource efficiency, and fostering equitable distribution of both material and immaterial goods. This approach seeks to balance ecological sustainability with social justice. It aims to ensure that modern comforts and technological advancements continue to support human well-being, while maintaining the integrity of natural systems [11,12,124,130,131]. As [129], (p. 8) humorously observe, “Decent living is of course a subjective concept in public discourse. However, the current work offers a response to the clichéd populist objection that environmentalists are proposing that we return to living in caves. With tongue firmly in cheek, the response roughly goes “Yes, perhaps, but these caves have highly efficient facilities for cooking, storing food and washing clothes; low-energy lighting throughout; 50 L of clean water supplied per day per person, with 15 L heated to a comfortable bathing temperature; they maintain an air temperature of around 20 °C throughout the year, irrespective of geography; have a computer with access to global ICT networks; are linked to extensive transport networks providing ~5.000–15.000 km of mobility per person each year via various modes; and are also served by substantially larger caves where universal health care is available and others that provide education for everyone between 5 and 19 years old.” This satirical commentary underscores a critical point: degrowth and sustainable living do not mean sacrificing modern achievements. Rather, they involve reimagining consumption and production systems to ensure a dignified life for all within planetary limits [129] (p. 8). This understanding is closely linked to current debates in ecological economics around the distinction between sufficiency and satiation. While sufficiency focuses on meeting essential human needs within biophysical constraints, satiation addresses the question of when additional consumption no longer contributes to well-being. As discussed by Gough (2020) and Brand-Correa & Steinberger (2017), establishing normative floors and ceilings is essential to avoid both deprivation and excess, thereby supporting socially just and ecologically viable living standards [95,97].

3.9. Absolute Sustainability

To achieve a meaningful coupling of societal and environmental systems, it is essential to develop qualitative indicators that reflect their interconnections. This is where the theoretical framework of Absolute Sustainability Assessment (ASA) becomes relevant [132,133,134]. While the Absolute Environmental Sustainability Assessment (AESA) framework has been advanced, the Absolute Social Sustainability Assessment remains in its infancy. Within the AESA framework, either ecosystem quality must be qualitatively described, or Planetary Boundaries (PBs) must be applied as a benchmark [30,135]. The description of ecosystem services within AESA faces inherent limitations similar to those of the Life Cycle Assessment (LCA) framework, including difficulties in extrapolating results to broader sustainability contexts, such as achieving life within Planetary Boundaries [136,137,138]. For this reason, indicators derived from the PBs offer a more suitable foundation for an AESA [139].

Regional Applicability and Challenges in Data Collection

To be effective, an AESA must partly allow for near-real-time evaluations while being globally applicable. Theoretically, global consistency paired with regional adaptability and sensitivity is achievable. A hybrid assessment with Satellite systems and the integration of LCA methods could serve as entry points for a comprehensive assessment [30,104,140]. Since 2015, four of the nine Planetary Boundaries can already be monitored regionally using satellite data [141,142]. The remaining boundaries could be simplified by utilizing material inventories, which are then matched against established threshold budgets on both consumption and production sides. Nonetheless, ensuring that boundaries are distributed and allocated to individual persons, companies, and states (usage rights) is indispensable [134]. This would prevent reliance solely on global-level assessments, which are subject to significant uncertainties for possible regional pathways. As a first step, an adequate regionalization of Planetary Boundaries depends on the ability to scale biophysical thresholds in a sufficiently granular way, so that they can be meaningfully allocated to the people who live and produce within a defined geographic area. In principle, this is already technically feasible: publicly available data sources such as ISIMIP2b provide high-resolution climate and environmental datasets, which could enable a preliminary regional distribution of Planetary Boundary thresholds. A second step would involve, downscaling boundaries to the individual level, followed by a possible upscaling to groups, companies, or nations for further analysis [136,138,141,142,143]. Ensuring regional adherence to boundaries inherently guarantees global compliance. A critical challenge in this regard lies in determining the allocation method for boundary budgets, as it significantly influences the magnitude of allocated resources. To guarantee a dignified life for all, a pure per capita allocation is insufficient. Instead, the allocation process must consider regional living realities, potentially requiring industrialized nations to implement faster and deeper reductions than previously anticipated or communicated by governments [78,134,135]. Combining environmental assessments with a social perspective allows for identifying which population groups have the capacity to contribute what share towards a life within biophysical limits. This makes the shift from AESA to ASA indispensable. ASA enables the integration of social dimensions that are both qualitative and regionally grounded. Given that SDG indicators do not enable a qualitative validation or measurement of societal development, Decent Living Standards (DLS) are proposed as an initial set of social/economic indicators [10,23]. Like the PBs, DLS can be quantified at both regional and global levels. However, a qualitative DLS assessments still relies on surveys conducted within specific study regions, as needed data strands are not yet available [144]. When designing these surveys, it is critical to reflect regional living realities and avoid redundant questions. Preventing biases in results should be a primary focus. A method akin to the Gallup World Happiness Report surveys, conducted via telephone, could theoretically be applied. However, such methods risk excluding marginalized or peripheral groups from the outset [144,145]. To ensure accurate representation of future developments, DLS surveys should ideally be designed as longitudinal panel studies, allowing for the consistent tracking of changes in living standards over time within the same populations. If regular intervals are not feasible, efforts should be made to conduct the survey during periods of significant change, such as regime shifts or major policy transitions [146].

3.10. Towards a Normative and Measurable Definition of Sustainability

Derived from the frameworks of Planetary Boundaries and Decent Living Standards, sustainability can be defined as any action that does not contribute to further crossing of the boundaries or impede the achievement of social well-being. While this conceptualization shares structural similarities with the Doughnut model proposed by Raworth, namely the coupling of ecological ceilings with social foundations, it differs in several critical aspects. The present approach is embedded in the operational logic of Absolute Sustainability Assessment (ASA), which is explicitly designed to be both normative and measurable. The use of Decent Living Standards introduces concrete, service-based social thresholds that can be assessed at the level of individuals or households, thereby enabling granular evaluations that go beyond the Doughnut’s more abstract framing. PBs offer clear environmental thresholds, while DLS represent the minimum requirements for social well-being. Without such quantifiability, sustainability risks being reduced to a vague, theoretical concept, limiting its practical implementation (like the SDGs) [78]. Since several Planetary Boundaries have already been exceeded, and Decent Living Standards remain unmet for much of the global population, any additional emissions or actions contributing to these overshoots must be considered unsustainable. For instance, the climate change threshold has already been breached. Therefore, no product, service, supply chain, or action that results in a net increase in atmospheric CO₂ concentration or radiative forcing can be deemed sustainable. Sustainability for humanity means living within Planetary Boundaries while ensuring a decent life for all. Unless these limits are respected, processes and behaviors that disregard these boundaries must be excluded from claims of sustainability.

To ensure the effectiveness of measures aimed at achieving sustainable development and sustainability, evidence-based decision making is essential. This requires the collection and evaluation of diverse indicators that address both environmental sustainability and human well-being [146,147]. These indicators must be comprehensive enough to provide a holistic understanding of the impacts of interventions, enabling a complete assessment of their outcomes. By utilizing such indicators, decision makers can rely on real data to inform their strategies, thereby maximizing the effectiveness of efforts to promote sustainable and equitable development [3,23,30].

The Eudaimonic principle, which focuses on the pursuit of a meaningful and fulfilling life, serves as a philosophical foundation for frameworks such as Planetary Boundaries (PBs), Sustainable Development Goals (SDGs), and Decent Living Standards (DLS) [96]. This principle underscores the importance of aligning sustainability efforts with the goal of enhancing human well-being, fostering an integrated approach to environmental and social progress. The current crises of Planetary Boundaries transgression and growing social inequities did not arise suddenly but are the culmination of long-term negative developments since the beginning of the Holocene [2,3,24,26,120,131]. Stable climatic and ecological conditions have historically been a prerequisite for the flourishing of humanity. However, if sustainability continues to be used as a tool to perpetuate capitalistic growth, achieving the necessary transformative changes for future sustainable development, will remain unattainable [148,149,150].

4. Discussion

The transition from the stable Holocene epoch to the Anthropocene highlights the profound impact of human activity on the Earth system [24,26,34]. The Holocene provided the stable climatic and ecological conditions necessary for human civilization to flourish. In contrast, the Anthropocene is characterized by unprecedented anthropogenic pressures, which challenge the stability and requires urgent rethinking of global development frameworks.

Concepts such as Planetary Boundaries (PBs) and Decent Living Standards (DLS) offer initial steps towards addressing these challenges by identifying critical thresholds and essential social needs [3,23,38]. However, these frameworks alone are insufficient to prevent recurring pitfalls, as they primarily describe historical unsustainable behaviors rather than prescribing actionable preventive measures [37]. A deeper understanding of the interactions between environmental and societal systems within this new epoch is imperative [38].

The Brundtland definition of sustainable development and the Three Pillars model (economic, environmental, and social) have been foundational in the sustainability discourse [27,28]. However, modernization approaches continue to dominate, emphasizing economic growth at the expense of critical sustainability efforts [12,17,71,111]. This tendency aligns with weak sustainability, which assumes natural capital can be substituted with manufactured or monetary capital, potentially undermining ecological integrity [91]. Strong sustainability, which recognizes the irreplaceability of natural systems, offers a more robust framework but remains marginalized due to its perceived incompatibility with prevailing economic paradigms [11,70,83].

Overcoming the dominance of weak sustainability requires adopting qualitative metrics that prioritize well-being and ecological integrity, such as those rooted in the Eudaimonic principle, which emphasizes meaningful and fulfilling lives for all [129].

Despite its promise, the implementation of Absolute Sustainability Assessment (ASA) faces notable challenges: (1) While Absolute Environmental Sustainability Assessment (AESA) offers a conceptual framework, its regional applicability is hindered by insufficient localized data [30,134]. (2) The development of Absolute Social Sustainability Assessment remains nascent, with limited clarity on which qualitative social indicators are most relevant [134,135,138]. (3) The selection of appropriate indicators is an ongoing challenge, particularly in ensuring they reflect cause–effect relationships across ecological and social thresholds [9,77,104,140]. While frameworks like PBs, SDGs, and DLS possibly provide a first direction, AESA and ASA require further significant refinement, in order to create a holistic, standardized, repeatable and actionable framework [30]. By explicitly linking biophysical limits with socially defined thresholds, the proposed ASA framework highlights both current inequalities and the normative challenge of ensuring just sustainability transitions. While this paper does not aim to develop a full political theory of global responsibility, it acknowledges that any fair sustainability assessment must confront disparities rooted in historical emissions and uneven development trajectories. In this sense, ASA offers not only a technical model but a conceptual tool for addressing systemic asymmetries between and within countries, particularly when used to inform regional adaptation, redistribution, and differentiated mitigation strategies.

The MDGs and SDGs have played a pivotal role in shaping global sustainability agendas. However, their effectiveness in addressing Planetary Boundaries and sustainable development remains limited [2,10]. For instance, qualitative deficiencies in SDG indicators hinder their capacity to measure sustainability in absolute terms [2,9,10]. Furthermore, their emphasis on economic growth often conflicts with the transformative changes required for sustainability [12,79,85,86]. While the SDGs have increased global awareness, their non-binding nature and selective implementation often result in greenwashing rather than substantive progress [2,62,66,72,76]. Even if all SDG indicators were fully achieved, there is no guarantee that these outcomes would align with PB thresholds or DLS targets, making alternative frameworks indispensable [7,11].

The PB framework has advanced understanding of critical Earth system thresholds, but several challenges remain. Notably, the interactions between boundaries are poorly understood, particularly at regional scales [3,104,106,108]. Additionally, mechanisms for distributing responsibilities among individuals, companies, and nations are underdeveloped, complicating equitable implementation [103,135,136,139]. Indicators used within the PB framework continue to evolve, reflecting ongoing challenges in ensuring they measure relevant cause–effect relationships [3,103]. The lack of reliable global data, particularly for qualitative indicators in underrepresented regions, further limits the universal applicability of PBs [100,139].

Kate Raworth’s Doughnut Economy offers a holistic visualization of sustainability, yet its practical utility is constrained by its reliance on SDG-linked indicators that lack granularity for regional or local applications. Used indicators are primarily designed for high-level international comparisons and lack the granularity required to measure well-being at regional or local levels [85,86,116]. This deficiency makes the concept less practical for guiding policies tailored to specific cultural and socio-economic contexts. Additionally, the framework inherits many of the SDGs’ shortcomings, including the absence of qualitative indicators and concrete operational pathways. Without more precise and actionable metrics, the Doughnut Economy risks remaining an abstract concept with limited transformative potential [16,116].

The DLS framework provides a promising approach to defining essential needs while emphasizing equity and sustainability. However, its weak integration with PBs limit its utility [23,53]. Achieving DLS globally requires affluent nations to reduce resource consumption significantly, highlighting a central tension between social standards and ecological sustainability [131]. This reveals a central dilemma: achieving social standards often comes at the expense of ecological sustainability, and prioritizing environmental goals can neglect basic social needs [111]. However, in order to ensure a dignified life for all, the focus should not be on achieving infinite economic growth, but rather on pursuing qualitative degrowth processes that prioritize well-being [11,12,16,79,86]. Additionally, the framework lacks sufficient exploration of interactions between its components, which is critical for ensuring compatibility with both ecological and social goals [119]. Future development should focus on establishing region-specific, culturally sensitive thresholds and qualitative indicators to enhance its applicability while maintaining global comparability [144]. Like PBs, DLS remains a work in progress, requiring iterative refinement to address its limitations and align with sustainability objectives [23,53].

5. Conclusions

The crossing of multiple Planetary Boundaries (PBs) and the rise in inequality signal an urgent need for transformative action. Humanity is knowingly steering towards a precipice, and the resulting consequences will likely disadvantage large segments of both present and future populations. These crises are predominantly human-made and thus require human solutions. This paper has shown that current sustainability definitions and monitoring systems remain inadequate to address socio-natural realities or guide equitable development. Addressing these challenges requires not only a clear definition of sustainability, but also appropriate indicators and actionable strategies.

Building on this understanding, the proposed Absolute Sustainability Assessment (ASA) framework addresses key shortcomings in current sustainability approaches. While it emphasizes Planetary Boundaries (PBs) and Decent Living Standards (DLS) for their measurability and conceptual clarity, ASA does not treat economic performance as a standalone pillar. Instead, it considers economic activity in terms of its ability to support ecological stability and social well-being. In contrast to many existing indicators, including those within SDG 8, ASA prioritizes qualitative and context-sensitive benchmarks that better reflect lived realities and societal needs. Although selected elements of SDG 8 may complement such assessments in the future, this will require a shift away from narrowly growth-focused indicators towards measures that genuinely capture sustainable and inclusive economic structures.

ASA enables a more differentiated view of inequality, both between and within countries, by linking social thresholds with ecological limits. Nevertheless, limitations remain. The framework must still be translated into regionally and culturally sensitive indicators to ensure fair implementation.

The implications of this work reach beyond conceptual debate. ASA provides a structured foundation for assessing sustainability in absolute terms and offers guidance for aligning policy and practice with global thresholds and social needs. Ultimately, the scenario introduced at the beginning, a world in which humanity flourishes collectively, remains within reach. Achieving it will require qualitative tools, institutional will, and a collective break from unsustainable patterns. The current trajectory can only be reversed through decisive, evidence-based and globally coordinated action.