Reducing Greenhouse Gases (GHG) emissions from agriculture is a major challenge in order to reach national GHG emissions reduction goals. Landscape scale approach is an interesting scale to raise awareness and promote mitigation projects gathering different stakeholders (public, private etc.). ClimAgri® computer tool, developed by the French Environment and Energy Management Agency (ADEME), enables to perform energy and GHG assessments for agriculture and forestry, at a landscape scale and considering the “feeding potential” of the study area. This assessment must help local partners to understand better these environmental issues and to identify the best improvement options for their area. The implementation of ClimAgri® is performed through a participative approach, sharing and discussing the results of the energy and GHG balance with a large number of local stakeholders before defining together a mitigation program for the area. In more technical steps, such as data collection or computer simulations as well as when insuring the success of the participatory approach, the project coordinator is in charge of the consistency of the ClimAgri® assessment regarding environmental issues and with its link to existing programs in the study area. Thus, ClimAgri® is a tool to promote sustainable farming practices suitable to the local conditions of each area