Planetary evolution of K2-18b. Left panel: Mass of K2-18b over time. The decrease is following the stellar evolutionary track (see Fig. 7) in the saturated regime, and assuming the system leaves this regime after 1 Gyr. Middle: Evolution of planetary radius. Right: Envelope loss rate. The dashed red line shows the evolution including the flare contribution (do Amaral et al. 2022), while the solid orange line followed the evolution predicted by the STELLAR model (Baraffe et al. 2015). Note that the planet radius shown here is limited by the Lehmer & Catling (2017) model.