In line with its climate change commitments, Morocco has decided to introduce a carbon tax. This decision involves setting the value of the tax in dirhams per ton of CO2. According to several studies, the negative impact on the economy and household welfare of introducing this tax without accompanying measures makes it crucial to choose an optimal value. Achieving this optimality requires the use of a quantitative model and the definition of criteria. The use of a computable general equilibrium model is appropriate to assess the impact of the tax, according to different scenarios, on the main macroeconomic aggregates that form part of these criteria. Four scenarios are candidates, two of which propose a fixed annual value between 2024 and 2030, a minimum of $10/t CO2 (minimum tax) and a maximum of $30/tCO2 (maximum tax). The other two scenarios are progressive, starting with a value of $5/t CO2 in 2024 and increasing by $2.5/t CO2 per year for the first (slow-rhythm) and $5/t CO2 for the second (fast-rhythm). Examination of the impact results through the model with the criteria taken into account shows that the best scenario is the progressive one, increasing by $2.5/t CO2 per year.