The thesis revisits the debates on the socio-economic impacts of a carbon tax reform and the controversies over the choice of a scheme. A diagnosis is primarily based on a review of a French failure (the carbon tax of Nicolas Sarkozy, 2009-2010). It distinguishes between problems of political acceptability and limits of economic analysis to define the scheme. The importance of the discussion about the use made off the tax proceeds is stressed. This point is indeed behind the political problems and determines the economic and legal consistency of the project with regard to the objectives (environment, equity, competitiveness). It shows that existing analytical tools can be improved to enable social dialogue and support collective bargaining on this point. A numerical simulation tool is then proposed and built. It can be used i) to compare the impacts of different schemes on various indicators (CO2, activity, employment, inequality, poverty, public debt), ii) to describe several views about how the economy works and will work in the future, and iii) to link the design of a climate policy with the other challenges of a tax reform (deficits reduction, funding of pensions). This tool is then used to revisit the controversy, clarify the tradeoffs and identify the best ways to find a compromise. It appears that the carbon taxation can provide co-benefits from a socio-economic viewpoint (for activity and employment, inequalities and deficits reduction). But this is not automatic: Some sensitive political choices must be made with regard to, not only the objective of climate action, but also the other challenges of a public finance and fiscal policy reform.
