The article reviews the Phanerozoic record of global sea-level changes over various time scales, presenting a new sea-level record for the past 100 million years (My). Long-term sea levels peaked at 100 ± 50 meters during the Cretaceous, indicating lower ocean-crust production rates than previously thought. Sea levels are influenced by oxygen isotope variations, reflecting ice-volume changes on the 104- to 106-year scale, and temperature changes on the 107-year scale due to tectonically controlled carbon dioxide variations. Over the past 100 My, sea-level changes have been driven by global climate evolution, from ephemeral Antarctic ice sheets to large ice sheets in Antarctica and the Northern Hemisphere. The study uses satellite measurements, tide gauges, shoreline markers, reefs, atolls, and oxygen isotopes to estimate eustatic variations. The growth and decay of continental ice sheets cause eustatic changes, which are indirectly recorded in foraminifera δ18O values. The long-term flooding of continents is attributed to subsidence and uplift, with high Late Cretaceous sea levels due to high ocean-crust production rates. The study's new eustatic record for the past 100 My suggests lower amplitudes on the 107- to 108-year scale compared to previous estimates, indicating a modest decrease in ocean-crust production rates. The 108-year scale eustatic changes are dominated by ice-volume changes, with significant events occurring during the Oligocene-Miocene transition. The 104- to 105-year scale changes are influenced by astronomical variations in insolation. The study also discusses the impact of sea-level changes on phytoplankton evolution, ocean chemistry, and sediment burial. The article concludes that the existence of continental ice sheets in a Greenhouse world is controversial but supported by evidence from the Cenozoic. The study provides insights into the tempo of climate and ice-volume changes in both Icehouse and Greenhouse worlds, highlighting the role of sea-level variations in driving these processes.The article reviews the Phanerozoic record of global sea-level changes over various time scales, presenting a new sea-level record for the past 100 million years (My). Long-term sea levels peaked at 100 ± 50 meters during the Cretaceous, indicating lower ocean-crust production rates than previously thought. Sea levels are influenced by oxygen isotope variations, reflecting ice-volume changes on the 104- to 106-year scale, and temperature changes on the 107-year scale due to tectonically controlled carbon dioxide variations. Over the past 100 My, sea-level changes have been driven by global climate evolution, from ephemeral Antarctic ice sheets to large ice sheets in Antarctica and the Northern Hemisphere. The study uses satellite measurements, tide gauges, shoreline markers, reefs, atolls, and oxygen isotopes to estimate eustatic variations. The growth and decay of continental ice sheets cause eustatic changes, which are indirectly recorded in foraminifera δ18O values. The long-term flooding of continents is attributed to subsidence and uplift, with high Late Cretaceous sea levels due to high ocean-crust production rates. The study's new eustatic record for the past 100 My suggests lower amplitudes on the 107- to 108-year scale compared to previous estimates, indicating a modest decrease in ocean-crust production rates. The 108-year scale eustatic changes are dominated by ice-volume changes, with significant events occurring during the Oligocene-Miocene transition. The 104- to 105-year scale changes are influenced by astronomical variations in insolation. The study also discusses the impact of sea-level changes on phytoplankton evolution, ocean chemistry, and sediment burial. The article concludes that the existence of continental ice sheets in a Greenhouse world is controversial but supported by evidence from the Cenozoic. The study provides insights into the tempo of climate and ice-volume changes in both Icehouse and Greenhouse worlds, highlighting the role of sea-level variations in driving these processes.