So many pressures that are progressively reducing biodiversity. All, or almost all, of the sectors of our economy, are concerned: industry, agriculture, drilling and quarrying activities, transport, tourism, housing, local recreational activities, etc. Although all have already undertaken significant efforts to reduce greenhouse gas emissions, initiatives with regard to the preservation of biodiversity continue to lag behind. It is the duty of the authorities to contribute to bridging this gap. Moreover, they have a field of investigation at their disposal that has still been little explored: with a view to both virtue and effectiveness, they are able to closely scrutinize all public subsidies which, due to their side-effects or pernicious impacts, may prove harmful to biodiversity. Such a change was established as a priority by the Convention on Biological Diversity held in Nagoya in 2010. In its communication of 20 September 2011, the European Commission also calls for the adoption of the “phasing-out”, by 2020, of “environmentally harmful subsidies”, “with due regard to the impact on people in need”. At the national level, this objective is included among the undertakings made at the time of the “Grenelle de l’environnement” (the French national consultation process on the environment) and in the National Strategy for Biodiversity presented by the Minister of Ecology on 19 May 2011.