The Resistive Plate Chambers (RPC) of the Compact Muon Experiment (CMS) experiment at the Large Hadron Collider (LHC) operates with a gas mixture composed of 95.2$\%$ of C$_2$H$_2$F$_4$, a greenhouse gas with high Global-Warming Potential (GWP). In recent years, several eco-friendly alternatives, such as hydrofluoroolefins (HFOs), have been investigated to identify sustainable replacements that preserve the detector performance. Another promising approach is to partially replace C$_2$H$_2$F$_4$ with CO$_2$, reducing the mixture's GWP by 30–40$\%$. These studies are being performed at the CERN Gamma Irradiation Facility (GIF++), which replicates the radiation conditions expected during the High-Luminosity Phase-2 data taking at the Large Hadron Collider (HL-LHC), using an 11.5 TBq gamma source and a muon beam. Updated results are presented on the performance of two 1.4 mm double-gap RPC chambers operating with various alternative gas mixtures under high-rate gamma irradiation. Results are also presented on RPC aging studies with these alternative gas mixtures, providing a deeper insight into the long-term performance and stability for the future of the RPC muon system.