Dr Tadhg O'Mahony

We have a new paper out in the Tier one journal Sustainable Development: considering the incompleteness of the common weak sustainability metrics in representing the urgency of environmental breakdown, which becomes obscured and deprioritised. The paper coauthored by with Arkaitz Usubiaga of BC3 Research (Spain), Miroslav Syrovatka of Palacky University (Czech Republic), Tadhg O’Mahony (UCD/FFRC) and Paul Ekins (UCL) points to how these weak sustainability metrics can contribute economic and social insights to the strong sustainability metrics, that better represent the crises of environmental degradation, but that better representation of the urgency of environmental crises is now necessary, which monetary aggregates do not convey.

Arkaitz summarised the article published on the 8th of March by Wiley as the following:

💡 Conflicting Messages From Weak and Strong Sustainability Metrics
In this paper, we examine how different sustainability metrics can lead to very different conclusions about whether development is sustainable.
While weak sustainability metrics often suggest that many countries — and even the world as a whole — are on a sustainable or near-sustainable path, strong sustainability metrics paint a much more alarming picture, showing that environmental limits are being exceeded in most cases.

Using a comparative review of widely used sustainability frameworks, we explore how these different approaches assess sustainability at both the global and national levels, including:
✅ Comprehensive Wealth (World Bank)
✅ Inclusive Wealth Index (UNEP)
✅ Planetary Boundaries
✅ Doughnut Economics
✅ ESGAP framework – Strong Environmental Sustainability Index (SESI)

From this analysis, we draw three main conclusions:

1️⃣ DIFFERENT METRICS TELL VERY DIFFERENT STORIES
Weak sustainability metrics, based largely on monetary aggregates of produced, human, and natural capital, often suggest that development is sustainable or only slightly unsustainable. In contrast, strong sustainability metrics, grounded in biophysical thresholds and environmental limits, indicate that the world — and most nations — are far from sustainable.

2️⃣ ENVIRONMENTAL DEGRADATION CAN BE DOWNPLAYED IN WEAK SUSTAINABILITY APPROACHES
Metrics based on non-declining wealth may classify development as sustainable even when natural capital is being depleted. This risks obscuring the severity of climate change, biodiversity loss, pollution, and other forms of environmental degradation.

3️⃣ STRONGER SUSTAINABILITY NARRATIVES ARE NEEDED
Our findings suggest that sustainability assessments should give greater weight to the biophysical reality rather than to the monetary perspective. At the same time, there is room to build more meaningful shared narratives by combining the biophysical insights of strong sustainability metrics with selected contributions from weak sustainability approaches.

✅ Overall, the paper highlights the importance of how sustainability is being measured and how this reflects the available scientific evidence, as this shapes policymakers’ perception on the urgency to act.

This is work done led by myself (BC3 – Basque Centre for Climate Change) with Miroslav Syrovátka (Palacký University Olomouc), Tadhg O’Mahony (UCD Environmental Policy) and Paul Ekins (The Bartlett School of Environment, Energy and Resources, UCL).

The article citation and doi link are: Usubiaga-Liaño, A., Syrovátka, M., O’Mahony, T., Ekins, P., (2026) Conflicting Messages From Weak and Strong Sustainability Metrics, Sustainable Development, early view online version 08 March 2026, https://doi.org/10.1002/sd.70908.

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