TerraKeepKeeping Earth within its limits
Published

1,828 ha of forest loss flagged near Nova Maringá, Mato Grosso, over 90 days — greenness also dropped

Nova Maringá, Mato Grosso (Brazil) — tile 2/2 · seen · published

Between 28 June and 26 September 2026, the integrated Global Forest Watch alert system recorded 152,440 high-confidence deforestation alerts across this tile near Nova Maringá, Mato Grosso, covering 1,828.35 ha. An independent sensor check agrees: Sentinel-2 median-composite NDVI, a measure of live vegetation, fell by -0.207 between 14 May and 26 September, with 100% valid pixels in both composites — well past the rule's 0.1 threshold. What this is not: the alerts cannot tell apart legal clearing, fire, storm damage, selective logging or plantation harvest, and no protected-area or concession layer has been applied here. The AOI's alert density is only 1.082 times its 25 km neighbourhood, so this looks like part of a broader regional pattern rather than an isolated event. An El Niño phase (ONI 1.8) can deepen seasonal browning, and regrowth cycles can mimic loss. We would revise if higher-resolution imagery shows burn scars or standing canopy, if the cleared polygons fall inside a permitted or plantation boundary, or if NDVI recovers in the next composite.

Written by AI, then checked by a separate reviewer before publication. Every claim points at the evidence below.

Cloud-free satellite view around Nova Maringá, Mato Grosso (Brazil) — tile 2/2, with the finding area outlined
13.28°S 57.23°WNASA Blue Marble via GIBS · outline = finding area

What we saw

  • Area: 1,828 hectares — about 2,600 football fields
  • Nature’s work at stake: about $12M a year (a rough estimate of what this land does for people — clean water, carbon, food).
  • Global Forest Watch alerts — 152440 alerts (≥ high confidence), 1828.35 ha, 2026-06-28…2026-09-26. (Sep 26, 2026) See the source ↗
  • Global Forest Watch alerts — 152440 alerts (≥ high confidence), 1828.35 ha, 2026-06-29…2026-09-27. (Sep 27, 2026) See the source ↗
  • Sentinel-2 satellite images — Median-composite NDVI changed -0.207 (2026-05-14 → 2026-09-26); valid pixels 100% / 100%. Scenes: [object Object], [object Object], [object Object], [object Object], [object Object], [object Object] (Sep 26, 2026)

What it might not be

  • Alerts show change, not cause: fire, storm, logging or legal clearing look alike.
  • Alert density is just 1.082× the surrounding 25 km ring — close to the regional norm.
  • Alerts lag events by 1–2 weeks, so very recent clearing is undercounted.
  • El Niño (ONI 1.8) can amplify seasonal drying in NDVI composites.
  • Plantation harvest and regrowth cycles can register as loss.
  • Coverage is 30°N–30°S only — zero alerts outside the tropics means 'not monitored', not 'no loss'.
  • Cannot distinguish legal clearing, fire, storm damage and selective logging from illegal clearing; attribution needs concession/protected-area layers (M3).
  • Alerts lag reality by ~1–2 weeks; a burst just before the sweep is undercounted.
  • Regrowth and plantation harvest cycles look like loss; the baseline ring only partly compensates.
  • Persistent cloud can delay optical confirmation for months (SAR-only RADD alerts stay 'candidate').

What would change our mind

Newer satellite images that show no change, a correction from the data source, or a reply with evidence from the ground. If that happens, the case is marked “Turned out wrong” — in public — and it stays on this site.

Why this was published

Two separate sources agreed — Global Forest Watch alerts, then Sentinel-2 satellite images — and a reviewer checked the evidence before it went up.

Right of reply

If a case names or affects you, you can reply. A reply channel that keeps both sides on record is being set up; until then, every case page carries its ledger id so a reply can be attached to it.

Ledger id 01a0df83-6797-79ee-b0a9-76eb8d0c8c53

Technical details rule, evidence ids, history, proof
Rule
forest_loss v1.0
Tier
T1
Tags
forest-hotspot, discovered, bra, brazil, mato-grosso, nova-maringa
Confirmed
Yes — independent sensor signal, 2026-09-26
Rule FP rate
40 % · 4 of 10 decided
Location
13.28°S 57.23°W
Observed
2026-09-26
Opened
2026-09-26 by automatic rule forest_loss v1.0
  1. candidate
  2. confirmed
  3. published
  4. resolved

Evidence3

alertgfw-integrated-alerts

152440 alerts (≥ high confidence), 1828.35 ha, 2026-06-28…2026-09-26.

alerts 152440ha 1828.35high_alerts 151853high_ha 1821.3highest_alerts 587highest_ha 7.05living_value_100y_npv2_usd 529370804living_value_100y_usd 1228285500living_value_usd_yr 12282855
· forest_alerts v1.0 · gfw-integrated-bra-12-77-2-2026-06-28..2026-09-26
Source ↗
alertgfw-integrated-alerts

152440 alerts (≥ high confidence), 1828.35 ha, 2026-06-29…2026-09-27.

alerts 152440ha 1828.35high_alerts 151853high_ha 1821.3highest_alerts 587highest_ha 7.05living_value_100y_npv2_usd 529370804living_value_100y_usd 1228285500living_value_usd_yr 12282855
· forest_alerts v1.0 · gfw-integrated-bra-12-77-2-2026-06-29..2026-09-27
Source ↗
scenesentinel-2-l2aConfirming signal

Median-composite NDVI changed -0.207 (2026-05-14 → 2026-09-26); valid pixels 100% / 100%. Scenes: [object Object], [object Object], [object Object], [object Object], [object Object], [object Object]

deltaNdvi -0.20727817396837633validPctA 100validPctB 100
· eo_compare v1.0 · s2-ndvi-median-bra-12-77-2-2026-05-14..2026-09-26

Context

1.08×
AOI vs its 25 km neighbourhood
AOI
1715.874
Ring
1585.306
Metric
alert ha per deg²
ENSO El Niño · ONI +1.8
  • Living value (benefit transfer, order of magnitude): 1828.35 ha of tropical forest ≈ $12,282,855/yr alive (band $3,607,335–$47,586,465, 2020 USD), ≈ $1,228,285,500 over 100 yr ($529,370,804 NPV @ 2 %). Source: Costanza R. et al. et al. — a floor for one kind of value, not a price.

Publication gates

  • Evidence — 2 pieces from gfw-integrated-alerts — met
  • Independent confirmation — a different sensor (sentinel-2-l2a), 2026-09-26 — met
  • Human approval — 1 of 1 needed at tier 1 — met
  • Narration — AI-drafted by claude-opus-5 — met
Published
2026-09-27 by AI model
Narrated By
AI model
Reviewed By
AI model
Policy
2026-09-26-autonomous
Note
autonomous publish: narrated by model:claude-opus-5, reviewed by model:claude-sonnet-5 (policy 2026-09-26-autonomous)

History6

  1. status changed → publishedAI model
  2. reviewed → confirmedAI model
  3. narrated → confirmedAI model
  4. evidence added → confirmedautomatic rule forest_loss v1.0
  5. confirmed → confirmedautomatic rule forest_loss v1.0
  6. created → candidateautomatic rule forest_loss v1.0

Verify

Checkpoint
earthdeck.dev/findings/v1 · 474 entries
Signed root
3d5c0e5366ef…1a817d
This case
6 signed events
Leaf
#458 of 474 — this case’s latest event
Leaf hash
e7a4e2ea9ac4…88a531
Proof
8-hash audit path
  1. 92dbaded294ee925e5d4e511b37ff6231e6ed2ec7378f888a8c0f902040fa7da
  2. 53fa2a9321ef6f8f5cfaa4a43df0e178ebe7d8e7c28ae4c5f8b3aecacdf86b0f
  3. 37733ca994468dc5066917963b5f3ff01c3cce1040193daddc71f6672ca428da
  4. beb17f7f5093ab61c553878001efab997ada8fa41b6946b611d715a6e2c6944d
  5. d53da2d9a52c42afa1145e989e67defee70d1ab136a8450be836068243b2b4c4
  6. cfd8a9689a682dbadf13f73837442d7833d9a97eb16baacdedd92a148869879c
  7. 2ac34e8c0b554e5c34b3c90bfdddd542109474aaf07521b16dfe8be684c3edae
  8. 2334f041f7aa83a5ef6099e0c9511b6242e982238cdf9f30561e5bf0cb2526cc
Last event
1cb8563e7b10…2a9222
Note
Checkpoint text
earthdeck.dev/findings/v1
474
PVwOU2bv7a9jengu9r9j3dQn4kFgYu/+tvWa/eQagX0=

— earthdeck TkCXv/cvio9EAdvkzlL+Yd2YP4DpbJfAKLucFWpg9Lx0fsSq96qdwI14h8khEO0RbAZGTNPZZvO7btaXxroLJftBzwc=

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