The global warming issue arises from climate change, which draws scientists’ attention toward cleaner energy sources. Among clean sources, renewables and nuclear energy are getting immense attention among policymakers. However, the signifcance of nuclear energy in reducing CO2 emissions has remained ambiguous, necessitating further research. Therefore, the present study draws impetuous attention to the United Nations Sustainable Development Goals-7 (afordable clean energy) & 13 (climate change mitigation) by looking at the relationship between energy mix (fossil fuels, renewables, and nuclear), economic growth, technological innovation, and CO2 emissions in Mexico from 1980 to 2019 using the autoregressive distributed lag (ARDL) model. In addition, to assess the direction of causality, this study applied wavelet techniques and spectral causality. The fndings afrm that renewable and nuclear energy use and technological innovation tend to curb CO2 emissions, whereas fossil fuel consumption and economic expansion trigger CO2 emissions. The study lends support to the environmental Kuznets curve (EKC) phenomenon in Mexico. The FMOLS and DOLS tests show that our long-run estimates are reliable. In diferent time scales, the wavelet coherence result is also consistent. Finally, the results of the spectral causality approach demonstrate a signifcant causal association between the variables tested at various frequencies. As a result, in order to achieve SDGs 7 and 13 and support an environmentally friendly ecosystem, Mexico’s energy mix must be changed to renewables and nuclear.