The 1610 CO₂ minimum ("Orbis spike")

Assembled from 18 blocks · 2 evidence · 14 related

1. Story
2. Antarctic ice cores record a dip in atmospheric carbon dioxide in the late sixteenth and early seventeenth centuries, reaching a minimum around 1610, of a magnitude usually given as several parts per million. Lewis and Maslin proposed in 2015 that this minimum be adopted as the formal marker of the start of the Anthropocene, on the argument that it is the atmospheric signature of the American population collapse: tens of millions of deaths meant tens of millions of hectares of managed farmland reverting to forest and scrub, and regrowing vegetation drawing down carbon. Koch and colleagues later quantified the abandoned area and concluded the effect was large enough to contribute materially to the observed dip. The proposal is contested on two fronts — whether the land-use signal is big enough relative to ocean and volcanic contributions and to Little Ice Age cooling, and whether 1610 is the right place to put a boundary at all. The stratigraphic body reviewing the question favoured a mid-twentieth-century marker instead, and in March 2024 the relevant IUGS subcommission voted against formalising an Anthropocene epoch. Whatever is eventually decided about the boundary, the underlying observation stands and is remarkable in itself: a demographic catastrophe in one hemisphere is legible in the air trapped in ice at the other pole.
3. Knowledge
4. The post-contact population collapse of the Americas
5. The 1610 CO₂ minimum ("Orbis spike")
6. Connections
7. The post-contact population collapse of the Americas
8. Atmospheric CO₂ reaches a minimum recorded in Antarctic ice
9. The Columbian Exchange
10. The transatlantic slave trade
11. The 1610 CO₂ minimum ("Orbis spike")
12. Smallpox reaches Tenochtitlan
13. Atmospheric CO₂ reaches a minimum recorded in Antarctic ice
14. Earth system impacts of the European arrival and Great Dying in the Americas after 1492
15. Historia general de las cosas de Nueva España (Florentine Codex), Book XII
16. Evidence
17. The proposal that the c. 1610 minimum in the Antarctic ice-core CO₂ record be adopted as the marker for the start of the Anthropocene, on the argument that it records vegetation regrowth following the American population collapse. V55 verification basis: NOT consulted in this session — no network access. The volume number is given from the author's knowledge; pagination is deliberately omitted.
18. Supports the reconstruction of pre-contact American population, the scale of post-contact decline, the area of farmland abandoned and the resulting drawdown of atmospheric CO₂. V55 verification basis: NOT consulted in this session — no network access was available. The Journey declaration itself cites this paper as "Quaternary Science Reviews 207, 13", which corroborates the volume but is not independent confirmation. Every figure this pack attributes to it is flagged in the citing object's `missing` list as requiring a check against the paper.