An updated Earth System Impact metric for bridging sub-global pressures and planetary boundaries

The planetary boundaries (PBs) represent key Earth system processes and their safe limits to maintain planetary resilience and stability. The 2023 assessment reflects that the Earth has transgressed six of nine boundaries while the 2025 Planetary Health Check indicates that a seventh has been breached. Given that human pressures are driving these transgressions, guidance is needed for translating planetary-scale limits into decision-relevant inputs for local actors. Sustainability reporting standards provide business organizations with guidelines for disclosing their impacts but often do not require benchmarking against the PBs. Interactions across disclosure categories are also not captured in target-setting. Tools are needed to help organizations assess their performance while bridging local pressures to planetary impacts.

To this end, Lade et al. (2021) formulated a prototype Earth System Impact (ESI) metric which enables evaluations of an organization’s systemic impacts on climate, land, and water in relation to the 2015 PBs translated into sub-global guardrails. Interaction strengths for climate, land and water at the sub-global scale were derived from 1901-2013 simulations from a dynamic global vegetation model, LPJmL4. Feedback modeling was applied to estimate the impacts of pressures given these interaction strengths and to determine the extent to which pressure in one component of the Earth system is amplified into impacts in other components. Final ESI scores were produced by weighting impacts on climate, land and water with current state as of 2013 to account for existing degradation.

We present an update to the ESI which uses LPJmL5 simulations from 1901-2023 to estimate interaction strengths. Sub-global clusters were updated to include dominantly barren land types in additions to forests and grasses. We then draw from both the 2023 PBs and the 2025 Earth Commission safe and just Earth-system boundaries to develop sub-global guardrails. For water, we set guardrails for both wet and dry deviations from a preindustrial baseline. Current conditions are updated to 2023.

Overall, amplification of impacts increased compared to the prototype, largely due to how all runoff deviations are considered adverse. Notably, the effects of deforestation on the earth system are doubled to tripled. Most barren land experienced no net amplification except in Australia and Africa (~39% and 65%, respectively) where surface water scarcity is aggravated.  The final ESI metrics were higher in smaller areas (e.g. C3 grass ecosystems in Africa), indicative of the sensitivity of smaller ecosystems to anthropogenic pressures compared to the relative resilience of larger intact land with greater surface water availability. Insights from the ESI metrics can aid businesses, investors, and potentially the public sector in planning future developments by providing a basis for comparing impacts of assets in different sites globally beyond just carbon emissions. The ESI can help with setting site-specific targets for environmental performance that are aligned with sub-global guardrails, and, in this way, facilitate a shift towards a “business within boundaries” paradigm that supports sustainability transformations.

Lade, S. J., Fetzer, I., Cornell, S. E., & Crona, B. (2021). A prototype Earth system impact metric that accounts for cross-scale interactions. Environmental Research Letters, 16(11), 115005.