The EX-ACT tool computes the carbon balance with and without the project. The difference represents the potential impact of the project in terms of mitigation, indicating the net amount of carbon sequestered  (carbon sink) or emitted (carbon source) as a result of the project.

The carbon balance, for a specific project (or scenario of action) in comparison with a reference, should be considered as the net balance of all GHG expressed in CO₂ equivalent computing all emissions (sources and sinks) with the atmosphere interface and the net change in C stocks (biomass, soil…). It can be realized at different scales, locally for an investment, an institution, or globally for a region, a value chain, a country, the planet. Within a dynamic process, it is also possible to appraise the global carbon balance effect of a new action, a project / programme, a strategy or a policy.

It shows if the project is able to supply environmental services in the form of C sequestration, thus contributing to climate change (CC) mitigation. Outputs could be used in financial and economic analysis of the project, guiding the project design process and the decision-making on funding aspects.

EX-ACT could therefore help project designers to select the project activities which have higher benefits both in economic and CC mitigation terms (added value of the project).

The obtained results emphasizes on the multiple benefit of carbon as public good: value to the farmer, value to the community, value to the society.

EX-ACT has been tested more specifically on agricultural development projects and investment programmes. Ongoing tests on forestry projects are in progress, as well as value chains analysis.