In 2007, the French government organized a series of meetings dealing with environment and sustainable development problematics under the title " Grenelle de l'Environnement ". The conclusions of these meetings were introduced in a new law published in August 2009 (Law N° 2009-967) known as 'Grenelle 1'. Article 1 requires that the State designs a so-called Sustainable Development National Strategy (SDNS) structured around 9 targets. Target 1 consists in fighting against climate change. The SDNS is used as a basis for the involvement of public and private agencies in this perspective. The struggle against climate change and implementation of sustainable development principles within the agency framework raises a number of practical questions: how are adaptive methods and tools to be developed to help the agency reach a new balance given the environmental, economic and social risks induced by these broad targets? Are there any standards of reference and if not can an innovative approach be developed to support decision-making in situations of uncertainty? How can a management dashboard be developed for a proportional allocation of resources adapted to the various stakeholders and decision levels within the agency? How does one compare actions that can have different impacts in different sub-systems and with different time frameworks ? Following a brief historical review of the origin of the challenges of sustainable development and climate change in the introduction part of the paper, we discuss the methodological approach selected and the investigator's intervention program in the first part of the paper. In the second part, we address practical issues for an agency facing the challenges of sustainable development and climate change. To this end we relate the experience of designing a sustainable development framework within a public agency using an organizational approach and a multiple criteria decision aid methodology. Finally, we discuss the decision-makers' choices and the lessons learned by implementing an innovative approach which we set up to face these new challenges.