Methanol synthesis through CO2 hydrogenation under fluctuating conditions was investigated over a CuO/ZnO/Al2O3 catalyst in an integral reactor. The performance of the catalyst was examined under stable conditions at 563K and 80bar. For dynamic experiments, the H-2/CO2 ratio of the feed gas was changed sequentially. Although the activity and selectivity towards methanol of the catalyst was affected more under dynamic conditions, long-term stability of the synthesis process was not influenced. The results show that it is possible to operate methanol synthesis with a fluctuating feed gas composition, as it is the case when CO2 is captured from a power plant and H-2 from an electrolysis unit driven by a regenerative energy source, such as solar or wind power.