Translating Earth system boundaries for cities and businesses

10 principles and a protocol

A new study published by an international team of researchers from the Earth Commission, hosted by Future Earth, introduces strategic and transparent procedures to help cities and businesses align their sustainability efforts with Earth system boundaries (ESBs).

Earth system boundaries define safe and just limits – in relation to the climate, the terrestrial biosphere, freshwater, nutrients and air pollution – within which a functioning Earth system can be maintained without incurring significant harm to people. Yet before they can be operationalized by cities and businesses, the safe and just boundaries have to be ‘translated’.

Translation is a two-step process of converting these safe and just limits into global and sub-global budgets that can then be apportioned to different actors. Budgets must be expressed in units that are meaningful to actors so they can take appropriate action (e.g., in volume of freshwater use per year, or amount of nitrogen fertilizer applied per hectare per year).

“Respecting ESBs requires concerted actions from diverse actors – including states, cities, businesses – based on a clear and shared understanding of their fair share of resources and responsibilities,” lead author Professor Xuemei Bai explains, highlighting the importance of collaboration and shared commitment in this endeavor.

The study presents 10 principles for how cities and businesses can conduct this process of translation in an effective and fair manner. It argues that translation activities must be:

  1. scientifically rigorous – evidence based, with reproducible quantitative outcomes;
  2. transparent – the rationale for allocations is clearly explained and underlying assumptions and normative considerations are made explicit;
  3. just – intergenerational and intragenerational equity is sufficiently incorporated;
  4. systemic – potential consequences of the activity on other locations and parts of the Earth system are considered;
  5. sufficiently safe – appropriate buffers are in place;
  6. context sensitive – local conditions are taken into account;
  7. enabling – simple and universal enough to allow for alignment in different contexts;
  8. incentivizing – actors who are ‘pioneers’ are emboldened to set more ambitious targets, while ‘laggards’ have suitable pathways to catch up;
  9. dynamic and time bound – targets are able to be updated and adjusted;
  10. synergetic – synergies are maximized and negative impacts are minimized.

These principles are designed to support local actors – specifically, cities and businesses who are often overlooked in sustainability plans but whose decisions can have widespread environmental impacts – so that they are able to contribute meaningfully to global efforts to live within safe and just boundaries.

After outlining the principles for translation of ESBs, the study presents a clear protocol to guide translation efforts. The protocol first takes actors through the different decision points pertaining to specific physical characteristics of each Earth system boundary. For instance, the authors highlight considerations relating to the spatial construct of the boundary (e.g., regional, local, ecoregion, biome, basin, grid), the state of the boundary (whether or not the safe boundary has already been transgressed and, if so, by how much and by whom), and the regenerative nature of the boundary (whether and how quickly the Earth system domain regenerates). The protocol then offers guidance on temporal perspectives (whether a forward- or backward-looking approach should be applied) and the selection of appropriate sharing approaches that adequately consider equity and local contexts.

The 10 principles and the protocol together provide guidance to actors in their selection of suitable sharing approaches for allocating budgets and impact reduction responsibilities. But, as Professor Bai cautions, “Each allocation according to a sharing approach will inevitably come with its own trade-offs and inbuilt biases, where moving towards equity in one aspect can move away from attaining equity in another, and where choices in the sharing approaches might favor or disfavor certain actor types over others,” and she adds, “Multiple sharing approaches often need to be incorporated into translation approaches to better approximate Earth system justice.”

The field of research exploring how ESBs can be translated across actors operating at different scales and in different contexts is still in its infancy. This study provides the first comprehensive framework on translation, grounded in both science and justice, for cities and businesses to move towards reaching urgent global sustainability targets. By developing common principles and a clear protocol, the paper aims to ensure ESB translation is robust, transparent, fair and comparable across domains and geographies.

Read the full article in Nature Sustainability here.

The Earth Commission is the scientific cornerstone of the Global Commons Alliance.

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