Public actors need to monitor the state of the environment in order to assess the effectiveness of their actions, prioritize management policies and measures, and thus objectively establish their contribution to the conservation of natural capital. To do so, they must be able to rely on science-based standards to identify the thresholds at which environmental functions can be considered sustainable.

The ESGAP (Environmental Sustainability Gap) is an innovative tool for assessing the condition of a territory’s environmental functions and how sustainable they are. For all critical components of natural capital in the territory concerned (air or water quality, pollution, forest resources, fisheries, etc.), this indicator calculates the difference between their current state and a state that would be sustainable (i.e., a state compatible with the sustainable functioning of the processes necessary for the preservation of life, human activities and well-being). This allows for the calculation of the “environmental sustainability gap”, which highlights the path to environmental sustainability. This can then serve as a guide for public policies to estimate and preserve the critical functions of the natural capital of a given territory. ESGAP has already been tested in New Caledonia, Kenya and Vietnam.

Within the framework of the ECOPRONAT research programme, AFD aims to develop methodologies for assessing strong sustainability, that is, adopting demanding criteria concerning the non-substituability of natural capital by other forms of capital (physical among others) in a territory or country. AFD also wants to promote their use in international frameworks and contribute to emerging international standards on the good ecological state of ecosystems.

Find out more about ECOPRONAT

Building on the previous work of University College London (UCL) on the application of ESGAP in countries of the Global South, this research project led by UCL aims to implement the ESGAP framework in Colombia and South Africa. It will test its relevance in fostering public policy dialogue in these two countries that already have a regulatory framework and natural resources management, but where not all data on biodiversity is available. 

More specifically, this project has four objectives: 

1. Developing the ESGAP components related to biodiversity and the state of ecosystems that could be used by Colombian and South African governments, and promoting the use of science-based targets for ecosystem maintenance;
2. Promoting reflection on strong sustainability in Colombia and South Africa through the ESGAP framework, by assessing whether the activities carried out in these countries are within the safe operating space for humanity;
3. Clarifying how the ESGAP framework aligns, complements and adds value to other types of existing sustainability indicators that national governments are already using;
4. Strengthening the capacity of partner countries to implement the ESGAP framework beyond this research project. 

The ESGAP framework is based on a dashboard that provides information on changes in the functional state of 23 components of the environment, focusing on the gaps that exist between these changes and the objectives of maintaining or achieving a "good environmental state". These components cover the 4 main categories of critical and essential environmental functions: resource provision, pollution reprocessing, biodiversity and human health. The scores for each of the twenty-three components are then aggregated to form a synthetic indicator and a dynamic indicator.

The research activities in the two pilot countries is carried out by researchers from Stellenbosch University (South Africa) and the National University of Colombia (UNAL). Capacity building will include training four postgraduate students as well as awareness-raising activities targeting policymakers and other stakeholders, in order for them to take ownership of the ESGAP and use it during public policy formulation.

The research teams will produce scientific papers on the relationship between the ESGAP framework and other sustainability indicator initiatives, as well as on the work and calculations of the ESGAP indicators carried out in each country, comparing the cases of Colombia and South Africa. A specific report will be produced on indicators of the state of biodiversity and ecosystems as well as the identification of data sources for the two countries studied.

In addition, an international workshop will be organized to present the complementarities between the ESGAP framework and relevant initiatives of existing sustainability indicators.

Finally, the research team intends to produce several documents for decision-makers and public policy actors:

• A summary of the review of biodiversity indicators and the state of ecosystems, which may be useful for negotiations at the Conferences of the Parties (COPs) to the Convention on Biological Diversity and for the design of national biodiversity strategies and action plans (NBSAPs);
• A webinar with a webinar report on the relationship between the ESGAP framework and other international sustainability reporting initiatives;
• A summary for decision-makers in each partner country on the rationale of the strong sustainability development approach and the methodology and ESGAP indicators that enable it to be implemented.

Download the publications related to the project: 

• The SDGs Provide Limited Evidence That Environmental Policies Are Delivering Multiple Ecological and Social Benefits, Earth's Future vol.12 (May 2024)
• Enhancing Environmental Sustainability Through the Environmental Sustainability Gap (ESGAP) Framework in Colombia, Policy Dialogues n°67, Editions Agence française de développement (October 2024)
• Strong sustainability in the SEEA and the wider indicator landscape, One Ecosystem (May 2025)
• Assessing environmental sustainability in Colombia: Metrics and policy recommendations, Environmental and Sustainability Indicators n°27 (September 2025)

A "Research Conversations" webinar presented the results of the articles to the scientific community in November 2024:

Public actors need to monitor the state of the environment in order to assess the effectiveness of their actions, prioritize management policies and measures, and thus objectively establish their contribution to the conservation of natural capital. To do so, they must be able to rely on science-based standards to identify the thresholds at which environmental functions can be considered sustainable.

The ESGAP (Environmental Sustainability Gap) is an innovative tool for assessing the condition of a territory’s environmental functions and how sustainable they are. For all critical components of natural capital in the territory concerned (air or water quality, pollution, forest resources, fisheries, etc.), this indicator calculates the difference between their current state and a state that would be sustainable (i.e., a state compatible with the sustainable functioning of the processes necessary for the preservation of life, human activities and well-being). This allows for the calculation of the “environmental sustainability gap”, which highlights the path to environmental sustainability. This can then serve as a guide for public policies to estimate and preserve the critical functions of the natural capital of a given territory. ESGAP has already been tested in New Caledonia, Kenya and Vietnam.

Within the framework of the ECOPRONAT research programme, AFD aims to develop methodologies for assessing strong sustainability, that is, adopting demanding criteria concerning the non-substituability of natural capital by other forms of capital (physical among others) in a territory or country. AFD also wants to promote their use in international frameworks and contribute to emerging international standards on the good ecological state of ecosystems.

Find out more about ECOPRONAT

The ESGAP pilot project recently conducted in Vietnam made it possible to measure the state of the environmental functions of this country. It identified fisheries resources, soil erosion, air and water pollution as the most degraded dimensions. 

It appears that some economic activities can put pressure on these different environmental functions, while other activities depend on their proper functioning. Developing the ESGAP framework is necessary to go further, by integrating the linkages that exist between the economy and the environment and identifying which human activities are concerned. 

In order to do this, the research team will try to link ESGAP measures to socio-economic activities and build a monetary ESGAP. The aim will be to assess the physical risks associated with certain economic activities on the basis of scenarios of environmental pressures (such as the breakdown of supply of certain essential environmental services, for example in agriculture). The development of these new applications of the ESGAP framework aims to guide policy makers in designing more sustainable development paths. 

The research project will be conducted in two phases: 

• The first step will consist in building a “monetary” ESGAP that measures the cost (expressed in monetary units) needed to achieve a sustainable environmental state. This cost is considered an unpaid ecological debt: it corresponds to the cost of effective measures that society would have to spend to achieve a good ecological state. It will be calculated as an abatement cost, that is, the expenditure necessary for human activities (such as production and consumption) in Vietnam to reduce their environmental pressures to a level that does not result in degradation of natural capital (or to an acceptable level, considering the good condition standards considered by the ESGAP).
• The second phase will use the modeling framework developed in the first phase, and assess how different public policies can improve Vietnam’s environmental sustainability by 2035, as well as mitigate the economic risks associated with the loss of the country’s natural capital. First, the team will develop scenarios to determine which interventions can improve Vietnam’s ecological status. Secondly, it will assess the extent to which economic risks related to biodiversity (due to the dependence of the Vietnamese economy on ecosystem services) can be mitigated through these interventions.

Since this study is considered experimental research, the different elements outlined in the research proposal and intermediate results may be adjusted throughout the study based on different factors – such as access to data, data quality, difficulties in implementing certain aspects of the methodology, or unsustainable or misleading results.

The team will produce a synthesis of the study, that will be used as a working document for communication purposes. The final deliverable will outline the methodology, database used and main results of the monetary ESGAP applied in Vietnam and the physical risk assessment methodology for the Vietnamese economy. This final deliverable will explore the relevance of ESGAP for the implementation of public policies aimed at achieving a good state of environmental conditions and future research pathways to link ESGAP measures to socio-economic activities.