Ozone abundances normalized to the amount produced at modern levels of CH₄ for both the high (left) and low (right) CH₄ models for all host stars at 0.1%, 1%, 10%, and 100% PAL O₂. The most striking result is that for the high CH₄ models there is less O₃ compared to modern CH₄, except for planets around the hottest hosts at 100% PAL O₂. This is due both to the indirect impact of CH₄ on the stratospheric temperature, as well as a boost in the smog mechanism due to a decreased NO_x/HO_x ratio. The rest of the cases for the CH₄ models show increased O₃ depletion due to a higher amount of CH₄ from the increased efficiency of the HO_x catalytic cycle’s ability to destroy O₃.