The Amazon Dieback Threshold

Assembled from 27 blocks · 4 evidence · 30 related

1. Story
2. The hypothesis that the Amazon has a point beyond which its own rainfall generation fails and large areas convert irreversibly to a degraded, fire-maintained savanna-like state - and the long, unresolved argument about where that point is. The mechanism is not in dispute and follows directly from moisture recycling: less forest means less transpiration, which means less rainfall downwind, which kills more forest. The number is entirely in dispute. Coupled climate models produced Amazon dieback as an output as early as 2000, though later model generations mostly did not reproduce it. Nobre and colleagues proposed in 2016 a boundary around forty per cent deforestation combined with substantial warming; Lovejoy and Nobre revised that sharply downward in 2018 to twenty to twenty-five per cent, arguing that fire and climate change interact with clearance rather than adding to it. Flores and colleagues reframed the question in 2024 in terms of compounding disturbances and proposed safe boundaries well below the earlier figures. Observational work has reported declining resilience across most of the forest since the early 2000s - slower recovery from perturbation, which is the generic statistical signature that precedes a critical transition in many systems. What no one has is an observed threshold, because a threshold can only be observed by crossing it.
3. Knowledge
4. Moisture Recycling
5. The Amazon Dieback Threshold
6. Connections
7. Amazon Deforestation
8. Moisture Recycling
9. Carlos Nobre
10. The tipping point estimate is revised sharply downward
11. The threshold question is reframed as compounding disturbance
12. Critical transitions in the Amazon forest system
13. Pronounced loss of Amazon rainforest resilience since the early 2000s
14. Amazon Basin
15. Flying Rivers (Aerial Rivers)
16. Cascading Moisture Recycling
17. Amazon Tall Tower Observatory (ATTO)
18. Amazon Deforestation
19. The Amazon Dieback Threshold
20. Eneas Salati
21. Isotope study quantifies Amazonian moisture recycling
22. The Amazon Tall Tower Observatory begins operating
23. Evidence
24. Supports the revised, substantially lower deforestation threshold for Amazon dieback and the argument that fire, clearance and climate change interact rather than add. V55 verification basis: the article DOI page was probed in this session and returned EGRESS_BLOCKED; neither the article nor any summary of it was retrieved, and the quoted percentage range is stated from the producing model's knowledge.
25. Supports the reframing of the Amazon threshold question in terms of compounding disturbances and proposed safe boundaries expressed as rainfall, dry season length, cumulative water deficit and forest loss. V55 verification basis: not retrieved in this session; none of the proposed boundary values is quoted, because they could not be checked.
26. Supports the earlier, higher tipping-point boundary for Amazon dieback combining deforestation extent with warming. V55 verification basis: not retrieved in this session; the specific percentage attributed to this paper must be confirmed by a curator, since the disagreement between successive estimates is the substance of the record that cites it.
27. Supports the observation, from satellite vegetation indices, that recovery rates from perturbation across most of the Amazon forest have slowed since the early 2000s - the generic statistical early-warning signature of approach to a critical transition. V55 verification basis: not retrieved in this session; the proportion of forest affected is deliberately not quoted, and volume and page details should be confirmed.