TerraKeepKeeping Earth within its limits
Cloud-free satellite view around Lahore (Pakistan), with the finding area outlined
31.55°N 74.34°ENASA Blue Marble via GIBS · outline = finding area
Published

Lahore: modelled PM2.5 at 73.9 µg/m³, nearly 5× the WHO limit, 7 days running

Lahore (Pakistan) · seen · published

Modelled fine-particle pollution (PM2.5) near 31.55°N, 74.34°E averaged 73.9 µg/m³ on 26 September 2026 — 4.9 times the World Health Organization's 24-hour guideline of 15 µg/m³. Every one of the previous 7 full days was above that guideline, averaging 75.6 µg/m³ with a worst day of 85.6 µg/m³. A later reading on 27 September was still above the line at 64.6 µg/m³, making 8 days running, which confirms this is a sustained episode rather than a one-day blip.

What this is not: these are not ground monitor readings. CAMS is a model on a roughly 40 km grid, so it smooths out neighbourhood hotspots and can misplace dust or smoke plumes drifting from outside the city. It judges PM2.5 only — ozone, nitrogen dioxide and indoor air are not assessed. The WHO figure is a health guideline, not a legal limit, and this record says nothing about what produced the particles. The El Niño phase in place (ONI 1.8) can shift weather patterns that trap or disperse haze.

What would change our mind: ground-station measurements showing much lower values, a data revision to the CAMS feed, or daily means falling back below 15 µg/m³.

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

What we saw

  • cams-global — CAMS PM2.5 daily means (UTC, ≥ 18 h): 7 trailing day(s) above 15 µg/m³, latest 2026-09-26 = 73.9. (Sep 26, 2026) See the source ↗
  • cams-global — Still above 15 µg/m³ on 2026-09-27: 64.6 µg/m³ (8 days running). (Sep 27, 2026) See the source ↗

What it might not be

  • Modelled values from CAMS (~40 km grid), not ground monitors; city hotspots are smoothed and dust or smoke plumes can be misplaced.
  • Confirmation is a revisit of the same CAMS feed, not an independent instrument.
  • PM2.5 only — ozone, NO₂ and indoor air are not assessed.
  • The WHO 15 µg/m³ figure is a health guideline, not a legal limit.
  • No cause is identified; the finding records concentrations, not sources.
  • Global feeds can go stale or be revised; a threshold crossing is a signal to look, not a verdict.
  • Air quality: CAMS is a ~40 km model, not a monitor; it smooths city hotspots and can misplace dust and smoke plumes.
  • Air quality: PM2.5 only — ozone, NO₂ and indoor air are not judged, and the WHO guideline is a health line, not a legal limit.
  • All: global zero-key feeds can go stale or be revised; a threshold crossing is a signal to look, not a verdict on cause or impact.

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 — cams-global, then cams-global — and a reviewer checked the evidence before it went up.

Replies

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Ledger id 01a0e1f0-cb56-7951-b3df-e78fac040eaf

Technical details rule, evidence ids, history, proof
Rule
indicator_threshold v1.0
Tier
T1
Tags
air-quality, city
Confirmed
Yes — independent revisit signal, 2026-09-27
Rule FP rate
13 % · 1 of 8 decided
Location
31.55°N 74.34°E
Observed
2026-09-26
Opened
2026-09-27 by automatic rule indicator_threshold v1.0
  1. candidate
  2. confirmed
  3. published
  4. resolved

Evidence2

seriescams-global

CAMS PM2.5 daily means (UTC, ≥ 18 h): 7 trailing day(s) above 15 µg/m³, latest 2026-09-26 = 73.9.

days_over 7guideline_ugm3 15pm25_daily_ugm3 73.9pm25_max_ugm3 85.6pm25_mean_ugm3 75.6times_guideline 4.9
· indicator_threshold v1.0 · cams-pm25-air-lahore-2026-09-26
Source ↗
seriescams-globalConfirming signal

Still above 15 µg/m³ on 2026-09-27: 64.6 µg/m³ (8 days running).

days_over 8pm25_daily_ugm3 64.6
· indicator_threshold v1.0 · cams-pm25-air-lahore-2026-09-27-persist
Source ↗

Context

ENSO El Niño · ONI +1.8
  • Dataset: Copernicus CAMS global forecast/analysis (~40 km) via Open-Meteo, hourly PM2.5 averaged to UTC days; last 7 days, forecast hours excluded.

Publication gates

  • Evidence — 1 piece from cams-global — met
  • Independent confirmation — a different revisit (cams-global), 2026-09-27 — met
  • Human approval — 1 of 1 needed at tier 1 — met
  • Narration — AI-drafted by claude-opus-5 — met
Published
2026-09-28 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)

History5

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

Verify

Checkpoint
earthdeck.dev/findings/v1 · 714 entries
Signed root
23ed27dda9a2…5fec16
This case
5 signed events
Leaf
#710 of 714 — this case’s latest event
Leaf hash
7bf21dcbc30f…581520
Proof
7-hash audit path
  1. 05bdf998164688777744c8ce98ade5b2791900862310849f9a5f521bc3b08e58
  2. 596a32e48cc4d28a0bbcb57069fa5d6ce19bf598fc1aa964167a6984b344707e
  3. 97ac499879f4272f71fc4459f04908565ca5ae8bf4a27449b12eca15a19b27f6
  4. a7fdef2cf5b5a712272dd0a660098eb2cfa6428b0896d7a072066e511d831900
  5. 227a1a00b64043f08073431f63834a568f922396dea9ef77ee795cd7e34484d7
  6. 4dcd70c622d414afaa3e0c21c3cf5233386d63f463994a07fff4e5e92c390f72
  7. 5f7580b7f5a7f09ff7675565fb36c19876079a6c101f721419a5a07a7a23b1c1
Last event
d86b33cb8ceb…33143e
Note
Checkpoint text
earthdeck.dev/findings/v1
714
I+0n3ami2iq+Pb01ZzA9/W1AK7wHekeD5OebmHxf7BY=

— earthdeck TkCXv0OmAxDtzaj1At98wE5s0VUwWeSCBAVzEDOuLw2Ioh7cGCd8Por/k57n26y0m4mCTkkb6qIdr6CB1+b6NmG1wgc=

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