Scientific evidence clearly demonstrates that we have reached a critical moment where sustainability is vital. Thus, there is a need for holistic and transdisciplinary approaches that integrate environmental, social and economic considerations for current and future generations. However, meeting this need is a complex and challenging undertaking. The UN Intergovernmental Panel on Climate Change (abbr. IPCC) has reported that a drastic rate of lifestyle change would be necessary to meet climate change challenges, and cautioned that failing to implement them would have potentially catastrophic consequences.1 Likewise, the concept of “planetary boundaries” highlights the existence of ecological limits and warns that crossing these thresholds would have devastating consequences for humanity.2 Where environmental self-regulation and moderately autonomous social and economic regulation is paramount, state intervention and eventually normative regulation has been favoured. The role of law in sustainable development can be that of a powerful ally in establishing sustainable behaviours and inhibiting environmental degradation; nevertheless, for law to participate in and promote sustainable behaviours, the law-sustainability dialectic, as well as questions regarding design and practical implementation, must be universally (?) understood. The 2015 Paris Agreement builds an international framework for countries (175 signatories) to initiate the reduction of greenhouse gas emissions, while having one objective: to keep the increase in temperature below 2°C above pre-industrial levels and pursue efforts to limit such increase to 1.5°C above pre-industrial levels. However, in recent years, world leaders have emphasised the need to limit global warming to 1.5°C by the end of the century.3

Another good example is the debate surrounding the Rights of Nature movement, which advocates for the legal recognition of ecosystems and natural entities as rights holders and legal subjects.4 This approach raises critical questions about legal frameworks and the ethical principles that can guide them in achieving environmental justice. By understanding the methodologies and research methods used in these and similar cases, we can gain valuable insights into how law can effectively promote sustainable development. In the fields of administrative substantive law (relevant specialised administrations) and administrative procedural law, a stronger connection between sustainability and legal research methods may have numerous benefits.

Empirical methods allow for the measurement of the efficiency and effectiveness of public administration practices, while qualitative methods provide deeper insight into the challenges and opportunities that arise during public administration procedures. The economic analysis of law can help understand how decision-making in public administration can be shaped in an economically sustainable way. Applying the community decision theory and the game theory can contribute to exploring conflicts and cooperation opportunities between the different interest groups. Integrating legal issues of sustainability into administrative procedural law can, therefore, be useful on several levels. Firstly, it helps to incorporate sustainability goals into decision-making and law-enforcement in public administration, and secondly, it contributes to increasing the efficiency and transparency of public administration.5 In addition, taking into account sustainability aspects can improve community well-being and the state of the environment in the long term.

For sustainability and law, three major methodological approaches can be identified, which complement each other. (1) Systems thinking seeks to understand the complexity of the world, examining things as wholes and in terms of their relationships. Beyond the traditional quantitative and qualitative social science methods, interdisciplinarity includes life cycle thinking (abbr. LCT), and life cycle assessment (abbr. LCA), with life cycle costing (abbr. LCC) and social life cycle assessment (abbr. S-LCA). Cost-benefit analysis (abbr. CBA) measures the economic costs and benefits of proposed legal interventions for sustainability. (2) The ethical principles of justice, equity, intra- and intergenerational equity play an important role in legal decision-making aimed at sustainable development. These include, for example, fundamental environmental rights (rights to a healthy environment, rights to information and participation, rights of future generations and sustainability, rights to technology and innovation) and the “polluter pays” principle. (3) Finally, in legal analysis, doctrinal research refers to taking a structured view of legal sources such as statutes, regulations and case law to learn how legal systems address sustainability dimensions. It refers to grammatical, logical, systemic and historical interpretations, as well as teleological and constitutional interpretations. In comparative law, we examine the legal systems of different jurisdictions to see systematic similarities and differences that might suggest best practices and draw attention to potential weaknesses faced when tackling sustainability-related challenges. Critical legal studies and critical environmental law critiques traditional legal paradigms, and they remind us that traditional legal paradigms often buttress existing unsustainable practices associated with power imbalances that result when indeterminate legality, law indeterminacy or non-legality remains unchallenged.

Obviously, the task is far from finished, as multiple pieces of recent evidence highlight the challenges in sustainability as well as the governance of sustainability. Blockchain can be employed for input and emissions tracking, trading emissions, or facilitating aspects of supply chains, but legal systems and frameworks must be capable of addressing issues like data security and governing environmental issues such as sustainability. More process-oriented legal systems must be capable of rendering flexibility to permit responses to challenges associated with the intangible forces of climate change, its intensifying related impacts, or top-down government design. By applying robust methodologies and research methods, legal scholars and policymakers can ensure that legal frameworks effectively address these and other emerging challenges on the path to a more sustainable future.