The temporally variable positional change of the Earth's axis related to the Earth's body is called polar motion. Polar motion manifests as an oscillation with multiple periods and is influenced to a significant part by the atmosphere. Although the mass of the atmosphere is small compared to that of the solid Earth, it undergoes substantial angular momentum fluctuations due to air movements within it, which are largely transferred to the solid Earth.In this work, the atmospheric excitation of polar motion is modelled using angular momentum functions and predicted up to 2100. The angular momentum functions are evaluated using surface air pressure and wind speed data, provided by eleven different climate models from the Coupled Model Intercomparison Project (CMIP), each of which was run for five climate development scenarios.Particular consideration is given to the influence of anthropogenic greenhouse gas emissions on climate development, and the changing atmospheric behavior concerning polar motion excitation is investigated. In other words, the main goal is to forecast atmospheric excitation of polar motion throughout the 21st century and to examine whether the development of atmospheric excitation varies between the different climate development scenarios.For each climate scenario, a Multi-Model Mean (MMM) time series of atmospheric angular momentum functions is calculated from the output of the eleven models. The atmospheric excitation of polar motion is primarily driven by pressure changes. Because oceans compensate for differences in surface pressure by lifting and lowering the water surface, polar motion is significantly damped in one direction, leading to an elliptical shape of its oscillation. The major period of atmospheric excitation is an annual wobble. The amplitude ranges between 14 and 18 milliarcseconds, corresponding to approximately 50 cm projected onto the Earth's surface. The comparison of the MMM time series reveals that the amplitude of atmospheric excitation increases more intensely with increasing greenhouse gas emissions assumed for the scenarios. At the beginning of the time series, the amplitudes of the scenarios differ by only about one milliarcsecond, while at the end, the scenarios differ by up to three milliarcseconds. These findings imply that the atmosphere excites polar motion more intensely with ongoing climate change than within a low greenhouse gas emission development.