1. Introduction

The report presents Absolute Environmental Sustainability Assessment (AESA) as a framework to evaluate whether activities operate within planetary boundaries. It addresses limitations of relative metrics by linking environmental impacts to absolute thresholds, supporting finance and policy decisions on sustainability performance.

2. AESA framework and definitions

AESA compares quantified environmental burdens with allocated shares of global carrying capacities. It draws on planetary boundaries and life cycle assessment (LCA). Outcomes depend on allocation principles (e.g. equal per capita or economic value), which significantly influence whether activities are deemed sustainable.

3. Phase A: Estimate environmental burdens

3.1. Step 1: Define goal of assessment

The assessment objective, scope, and decision context are established. This includes identifying intended users (e.g. investors or policymakers) and specifying whether the focus is products, sectors, or consumption systems.

3.2. Step 2: Describe activity

The activity is defined in terms of system boundaries, functional units, and lifecycle stages. Clear definition ensures comparability and determines which environmental flows are included.

3.3. Step 3: Plan environmental accounting

Relevant environmental indicators are selected, typically aligned with planetary boundaries (e.g. climate change, resource use). Data sources and modelling approaches are determined, often using LCA methodologies.

3.4. Step 4: Quantify environmental flows

Material and energy inputs, emissions, and resource uses are quantified across the lifecycle. This step relies on existing datasets and models, with data quality influencing reliability.

3.5. Step 5: Estimate resulting environmental burdens

Environmental flows are translated into impact indicators (e.g. greenhouse gas emissions). Results represent total burdens attributable to the activity and form the basis for comparison with limits.

4. Phase B: Allocate carrying capacities

4.1. Step 6: Develop a list of quantified carrying capacities

Global environmental limits are identified and quantified, often based on planetary boundary literature. These define maximum allowable pressures for indicators such as climate and resource extraction.

4.2. Step 7: Allocate carrying capacities to activity

Carrying capacities are distributed to the assessed activity using allocation principles. The report shows that different methods can lead to significantly different sustainability outcomes, introducing uncertainty and requiring transparency.

5. Phase C: Interpret results

Environmental burdens are compared with allocated capacities to determine whether thresholds are exceeded. Case studies show frequent overshoot, particularly for climate and materials. Results highlight trade-offs across impact categories and sensitivity to assumptions, limiting comparability.

6. Conclusion

AESA provides a structured approach to assess environmental performance against absolute limits, relevant for finance and policy. However, methodological challenges remain, including data gaps, allocation uncertainty, and lack of standardisation, which constrain consistent application and decision-usefulness.