The "carbonization index" indicator is used to analyze the "uncoupling" between CO2 emission and energy consumption. This is a useful indicator to evaluate the evolution patterns of developing countries, such as Turkey, concerning climate change. Usually, the carbonization index is measured in tons of CO2 per tons of oil equivalent. In this study, employing data envelopment analysis and the Malmquist index, Turkey's carbonization index, compared to the European Union countries have been put in place. Since the data on Malta and Cyprus was inadequate, these two nations were excluded from the evaluation. In this performance, evaluation for the input gross domestic product, total production of primary energy, net imports of primary energy, total gross electricity generation, and carbonization index has been considered as the output value. Input-oriented constant returns to scale and variable returns to scale data envelopment analysis models are used in the analysis for efficiency and productivity growth computations. The relationships between efficiency scores and input/output factors are investigated.