Temporal evolution of mechanisms controlling ocean carbon uptake during the last glacial cycle

- Atmospheric carbon dioxide decreases in three main steps during the last 130,000 yrs.
- We compile sea-surface temperatures and assess timing of carbon uptake mechanisms.
- Southern Hemisphere sea ice expansion is responsible for the first CO2 drop.
- Deep-ocean re-organization and marine biology responses dominate the second CO2 drop.
- Lowest glacial CO2 reached by combined contribution from all mechanisms.