[en] A first report proposes an overview of environmental taxation in France, and notably shows and discusses that this taxation is a composite set of arrangements which differ by their base and by their objective, and that financial stakes of this taxation are representing between 2.2 and 3.3 per cent of the GDP, and are concentrated within the energy sector. It states that several scopes can be envisaged according to chosen taxation instruments. The second report addresses the legal framework of environmental taxation, and notices that there are few standards whereas many international principles and commitments encourage its implementation, that this taxation must comply with a specific legal framework which favours its consistency. It formulates recommendations for a readable and consistent ecological taxation. The third report discusses lessons learned from foreign experiments: instruments mainly based on carbon taxation, stake of maximisation the rate acceptance and of control of risks for companies and households, varying use of taxation incomes depending on countries, identification of some good practices for more transparency and credibility, difficult assessment of the impact of environmental taxation on the environment. The fourth report discusses macroeconomic and environmental impacts of carbon taxation (discussion of existing models and simulations, of usage modes, study of scenarios, discussion of simulation results). The last report addresses economic effects of environmental taxation of households and companies: discussion of the main economic equilibria of environmental taxation, economic effects on households and on companies, scenarios of increase of environmental taxation, effect of an evolution of environmental taxation (results of simulations on households)

[en] The fight against global warming requires us to limit quantities of greenhouse gases present in the atmosphere, carbon gas in particular. In order to honour its commitments in this regard, France must significantly step up its efforts. It is well behind schedule as regards the trajectory it needs to follow if it is to achieve the goal of climate neutrality, or net zero GHG emissions ('Net-Zero'), inscribed in the 2015 Paris Agreement and the 2017 Climate Plan. In order to de-carbonize, investments must be made to reduce emissions. The choice of what investments to carry out must be made according to a cost per metric ton of emissions avoided. This is what the State is doing for its own investments, making it a rule to take account of a value of the metric ton of CO₂ (or equivalent) avoided in the socioeconomic analyses it carries out. This is the 'shadow price' of carbon. The rule should be extended to all activities generating greenhouse gas emissions, in order to be able to provide a 'value for climate action' applicable to them. The Prime Minister requested Alain Quinet - who had already been responsible for an initial report on the subject in 2008 - to form a commission tasked with revising the shadow price, with support from France Strategie's teams and taking account of the many developments that have taken place over the last ten years. Alain Quinet's report provides a comprehensive overview of analyses enabling definition of a trajectory of values to be taken into account if we are to achieve the goal of net zero GHG emissions by 2050, given the current and foreseeable state of techniques available for reduction of emissions and carbon capture. The evolution of goals and techniques, together with the fact that we have fallen behind as regards the desirable emissions trajectory, requires significant upward revision of the target shadow price, which should be to the tune of Euros 250 per metric ton of CO₂ in 2030, whereas the target set for the same year in 2008 was Euros 100. The report requests the public authorities to adopt policies enabling this value to be taken into account as widely as possible. The 'Value for Climate Action' Commission recommends that tools be employed that go beyond simple price signals, combining all instruments - including regulations and measures facilitating access to credit and fostering green investments - that might have equivalent effects. This pragmatic approach is necessary to enable effective implementation that takes account of all the economic and social consequences of these essential developments, and provides appropriate responses to them