This work examined the information efficiency of the European CO2 trading market for the period 2008-2021. The analysis is based on the singular value decomposition (SVD) approach and the task is to test whether the dynamics of logarithmic price differences are consistent with a random process. The results showed that the information efficiency changes over time and scales, which is in line with adaptive market hypothesis notions. High market efficiency was exhibited in Phase II (2008-2012), but large deviations from efficiency, especially for quarterly scale, were exhibited in Phase III. However, Phase IV has shown a behavior that is consistent with the information efficiency. The findings in the present study suggest that the European carbon market is gradually attaining a state of financial maturity.