DOI
https://doi.org/10.1080/26395916.2020.1814417

Summary
In sustainability science, revising the paradigms that separate humans from nature is considered a powerful ‘leverage point’ in pursuit of transformations. The coupled social-ecological and human-environment systems perspectives at the heart of sustainability science have, in many ways, enhanced recognition across academic, civil, policy and business spheres that humans and nature are inextricably connected. However, in retaining substantialist assumptions where ‘social’ and ‘ecological’ refer to different classes of entity that interact, coupled systems perspectives insist on the inextricability of humans and nature in theory, while requiring researchers to extricate them in practice – thus inadvertently reproducing the separation they seek to repair. Consequently, sustainability researchers are increasingly drawing on scholarship from the ‘relational turn’ in the humanities and the social sciences to propose a paradigm shift for sustainability science: away from focusing on interactions between entities, towards emphasizing continually unfolding processes and relations. Yet there remains widespread uncertainty about the origins, promises and challenges of using relational approaches. In this paper, we identify four themes in relational thinking – continually unfolding processes; embodied experience; reconstructing language and concepts; and ethics/practices of care – and highlight the ways in which these are being drawn on in sustainability science. We conclude by critically discussing how relational approaches might contribute to (i) a paradigm shift in sustainability science, and (ii) transformations towards sustainability. Relational approaches foster more dynamic, holistic accounts of human-nature connectedness; more situated and diverse knowledges for decision-making; and new domains and methods of intervention that nurture relationships in place and practice.

Relevance for Complex Systems Knowledge
This article builds further on the leverage points idea in transforming complex systems by suggesting a paradigm shift towards a "relational" turn in sustainability science.  The target for critique is the idea of coupled complex systems used to look at interrelations between society and ecology. With a relational turn, the dichotomy between human and nature is supposed to collapse into a relational processes.

Th proposal is to look closer to empirical understandings of such relational process, to find that rather than processes and relations being derivative of entities, they are constitutive of entities.  Consequently, concepts such as ‘social’ and ‘ecological’ are understood not as referring to foundational types of substance, but as tools that we use to make sense of our experience and act in the world. Practically, relational approaches suggest that researchers carefully trace the empirical relations in their context of  study, and attempt to explain concepts such as ‘social’ and ‘ecological’ rather than assume them.

A  ‘paradigm shift’ in coupled systems thinking from substantialist to relational assumptions can help overcome dichotomies and dualisms between humans and nature, better conceptualize complexity, and generate novel governance, management and policy approaches towards sustainability.

The article identifies four key themes in the relational literature – continually
unfolding processes; embodied experience; reconstructing language and concepts; and ethics/practices of care – and trace how sustainability scientists are connecting
to these themes in different ways.

Point of Strength
The point of strength is that the article points towards a possible way of interpreting the paradigm shift needed to reach the highest leverage points in Donella Meadows model. Pointing both to theoretical and philosophical opportunities, and to practical conduct of research guided by the idea of relational processes, the argument gets through. Adding to this some points of implicit critique and difficulties in applying the concepts, the article is well balanced and inspiring to read. However, it would take more research and educational practice to develop ways of thinking beyond the inherent  dichotomies of coupled complex systems.