Cenozoic sea-level and cryospheric evolution from deep-sea geochemical and continental margin records

Using Pacific benthic foraminiferal delta O-18 and Mg/Ca records, we derive a Cenozoic (66 Ma) global mean sea level (GMSL) estimate that records evolution from an ice-free Early Eocene to Quaternary bipolar ice sheets. These GMSL estimates are statistically similar to backstripped estimates from continental margins accounting for compaction, loading, and thermal subsidence. Peak warmth, elevated GMSL, high CO2, and ice-free Hothouse conditions (56 to 48 Ma) were followed by Cool Greenhouse (48 to 34 Ma) ice sheets (10 to 30 m changes). Continental-scale ice sheets (Icehouse) began similar to 34 Ma (>50 m changes), permanent East Antarctic ice sheets at 12.8 Ma, and bipolar glaciation at 2.5 Ma. The largest GMSL fall (27 to 20 ka; similar to 130 m) was followed by a >40 mm/yr rise (19 to 10 ka), a slowing (10 to 2 ka), and a stillstand until similar to 1900 CE, when rates began to rise. High long-term CO2 caused warm climates and high sea levels, with sea-level variability dominated by periodic Milankovitch cycles.