Publications
Environmental eXternalities ACcounting Tool (EX-ACT)
Environmental eXternalities ACcounting Tool (EX-ACT) handbook – Guiding sustainable investments
07/2026
This handbook provides technical guidance on using the greenhouse gas (GHG) accounting component of the Environmental eXternalities ACcounting Tool (EX-ACT) online app to assess environmental externalities in agrifood system interventions.
Integrating permanence into greenhouse gas accounting for agrifood systems – Application of the Environmental eXternalities ACcounting Tool (EX-ACT)
05/2026
Assessing permanence is a critical consideration in project-level greenhouse gas (GHG) accounting to ensure that reported mitigation outcomes are durable and continue to deliver climate benefits over time. In agrifood systems, permanence encompasses both the stability of carbon stocks and the sustained implementation of emission-reducing practices.
Environmental eXternalities ACcounting Tool (EX-ACT) – User guide
03/2026
This user guide provides practical guidance for operating the Environmental eXternalities ACcounting Tool (EX-ACT) online app for assessing environmental externalities in agrifood system interventions.
Additionality and ex ante greenhouse gas project level accounting – Application of the Environmental eXternalities ACcounting Tool (EX-ACT)
02/2026
This report reviews the concept of additionality and how it is treated in major climate finance frameworks, to identify relevant practices for project-level greenhouse gas (GHG) accounting in agriculture. It proposes a practical approach to integrating ex ante additionality assessment into the Environmental eXternalities ACcounting Tool (EX-ACT), including guidance on credible baselines, realistic adoption rates of climate-smart practices and uncertainty management.
Environmental eXternalities ACcounting Tool (EX-ACT) – Checklist for EX-ACT implementation
10/2025
The Environmental eXternalities ACcounting Tool (EX-ACT) checklist guides the collection of essential data for the greenhouse gas (GHG) assessments of projects. It covers project-level details, land-based activities, livestock, fisheries, wetlands, downstream energy use, and inputs to ensure a comprehensive climate mitigation evaluation.
Expanding greenhouse gas accounting in the fisheries sector using the Environmental eXternalities ACcounting Tool (EX-ACT) – Review of the "Coastal and Marine Fisheries Management" module of EX‐ACT
08/2025
This methodological note presents the updated approach for estimating greenhouse gas (GHG) emissions from fisheries using the Environmental eXternalities ACcounting Tool (EX-ACT). It reviews the limitations of previous versions of EX-ACT and outlines the improvements implemented in the online EX-ACT application, in-cluding the introduction of dedicated modules for small-scale and large-scale fisheries.
Greenhouse gas accounting in the forestry sector – Refining the approach for forest management activities in EX-ACT
03/2025
This report aims to illustrate the methodological improvements for estimating greenhouse gas (GHG) emissions and removals from forest management practices and disturbances implemented in the FAO's Environmental eXternalities ACcounting Tool (EX-ACT), an online accounting app that estimates and tracks the outcomes of agricultural interventions on environmental externalities, including GHG emissions.
Making public investments Paris Agreement-aligned in a cost-effective way – Calculating marginal abatement cost curves for agricultural investments
05/2024
This paper proposes a novel methodology for calculating marginal abatement cost curves (MACCs) for public finance in agriculture using granular data on specific activities from investment projects. The proposed MACCs target public investment decision makers from the international and national financing institutions, as well as governments.
EX-Ante Carbon-balance Tool for Value Chains (EX-ACT VC) Guidelines. Third edition
10/2023
The Ex-Ante Carbon-balance Tool for value chains (EX-ACT VC) is a quantitative multi-appraisal tool that evaluates the sustainability of agrifood value chains simultaneously along several environmental, economic, and social dimensions.
EX-Ante Carbon-balance Tool for Value Chains (EX-ACT VC) Guidelines. Second edition
05/2022
The Ex-Ante Carbon-balance Tool for Value Chains (EX-ACT VC) is a quantitative multi-appraisal tool that evaluates the sustainability of agrifood value chains simultaneously along several environmental, economic, and social dimensions.
