The circular economy is entirely in line with the European Commission’s long-term strategy aimed at moving toward an economy without any climate impact by 2050 (European Commission, 2018). Yet, to our knowledge, there is little work that analyzes the impact of the circular economy on CO2 emissions in Europe. The objective of this study is to analyze, at the level of the European Union (EU-15), the impact of the circular economy on CO2 emissions using an Autoregressive-Distributed Lag model (ARDL). The results of the study over the period 2000-2015 show that, in the long term, circular economy practices tend to reduce CO2 emissions, while in the short term, the effect is the opposite. The short-term results also question the modalities of our economic growth and the need to find a consensus between “efficiency and sufficiency” in order to limit resource consumption and CO2 emissions.