The paper discusses the role of equatorial insolation in climate variability, focusing on the 100- and 5.5-kyr periods. It shows that the double maximum of solar irradiance in tropical latitudes leads to these cycles, which are related to eccentricity and precession. The study highlights that the tropics, often overlooked, play a significant role in climate change, influencing glacial-interglacial cycles and recent warming. The research demonstrates that the seasonal contrast in equatorial insolation, driven by astronomical factors, contributes to long-term climate variations. The paper also shows that the 100-kyr cycle is not solely due to eccentricity but is influenced by precession and other factors. The analysis of insolation data reveals that the 100- and 5.5-kyr cycles are significant in equatorial insolation spectra, indicating their importance in climate system responses. The study emphasizes the need to consider tropical regions in climate models and paleoclimatic research, as they may be as or more important than high latitudes in driving climate changes. The findings suggest that the tropics are crucial in modulating climate variability over long timescales, with implications for understanding past and future climate changes.The paper discusses the role of equatorial insolation in climate variability, focusing on the 100- and 5.5-kyr periods. It shows that the double maximum of solar irradiance in tropical latitudes leads to these cycles, which are related to eccentricity and precession. The study highlights that the tropics, often overlooked, play a significant role in climate change, influencing glacial-interglacial cycles and recent warming. The research demonstrates that the seasonal contrast in equatorial insolation, driven by astronomical factors, contributes to long-term climate variations. The paper also shows that the 100-kyr cycle is not solely due to eccentricity but is influenced by precession and other factors. The analysis of insolation data reveals that the 100- and 5.5-kyr cycles are significant in equatorial insolation spectra, indicating their importance in climate system responses. The study emphasizes the need to consider tropical regions in climate models and paleoclimatic research, as they may be as or more important than high latitudes in driving climate changes. The findings suggest that the tropics are crucial in modulating climate variability over long timescales, with implications for understanding past and future climate changes.