Global preview · Lagos, Nigeria · reference data: weak · read with care

Which climate models can you trust in Lagos?

This page is a real Arasense run, not a brochure: climate models scored against observed climate near Lagos, the skilful ones trust-weighted into a mid-century signal for the city’s worst rain day, with model agreement reported, because a projection without it is just a guess with confidence.

Max 1-day precipitation · SSP2-4.5 · 1995–2014 → 2040–2059
reference data · weak
+43.0%
50.43 mm → 72.14 mm (+21.71 mm)
trusted-model agreement on increase100%

The trust-weighted screening signal for Lagos is +43.0% change in maximum 1-day precipitation by 2040–2059 under SSP2-4.5: 50.43 mm → 72.14 mm on the baseline worst rain day. 100% of trusted-model weight points the same way: an unusually consistent screening signal: the worst rain day gets heavier.

Lagos is part of the atlas's global preview tier: the same pipeline as the ranked European cities, published unranked while coverage grows. One thing changes outside Europe: Sparse ground observations only weakly constrain the ERA5-Land baseline here; the trust scores inherit that uncertainty and should be read with the care the flag implies.


How the number was earned

Trust first. Then project.

Score model trust at Lagos

Each climate model is compared against observed climate behaviour near Lagos and decomposed with the Aras Diagram: bias, variability, and phase alignment, not one opaque score. Models that fail screening are rejected, and you see why.

Project with the models that earned it

Skill-weighted models estimate the mid-century change in Lagos’s maximum 1-day rainfall, with the spread and the 100% directional agreement reported, never hidden.

Escalate where it matters

Atlas signals are screening-level evidence. Where a decision depends on Lagos, the same pipeline runs the full CMIP6 ensemble: every trusted and rejected model named, weighted, and auditable.

Run settings · identical for every atlas city

What was computed

  • Metricrx1day (max 1-day precipitation)
  • ScenarioSSP2-4.5
  • Baseline window1995–2014
  • Future window2040–2059
  • Spatial footprint50 km radius
  • Ensemble5-model trust screening
  • ObservationsERA5-Land
  • Skill methodAras Diagram (peer-reviewed)
Scope note. This is screening-level evidence for prioritisation and planning conversations, not a substitute for site-specific engineering studies. The screening ensemble is small by design; a full-ensemble deep dive is how this number becomes decision evidence.

Next step

Get the full Lagos trust brief

The brief behind this page: the screening run in full, what a 34-model deep dive would add for Lagos, and how the evidence holds up in front of a technical reviewer. Prepared per request from the same pipeline; tell us where to send it.


Questions reviewers ask

Reading this number responsibly

What does “trust-weighted” mean?

Every climate model in the screening ensemble is scored against roughly 20 years of observed climate behaviour near Lagos (ERA5-Land) using the Aras Diagram, a peer-reviewed skill-decomposition method (Izzaddin et al. 2024). Models that track local reality earn weight in the projection; models that fail screening are rejected. The weights and rejections are reported, never hidden.

What does the reference-data confidence flag mean?

Trust scores are only as good as the observations behind them. The flag is a qualitative tier for how densely long-record ground observations constrain the ERA5-Land baseline in each region. For Lagos it reads “weak · read with care”. Sparse ground observations only weakly constrain the ERA5-Land baseline here; the trust scores inherit that uncertainty and should be read with the care the flag implies. Publishing the flag, instead of pretending every baseline is equally solid, is part of the method.

Can I use the +43.0% figure in a report?

As screening-level evidence, yes, always alongside its 100% model-agreement figure. It is built for prioritisation and planning conversations. For site-specific or engineering-grade decisions, the next step is a full-ensemble deep dive for Lagos, which names every trusted and rejected model with its weight.

Why not just average all climate models?

Averaging treats a model that mistracks Lagos’s observed climate the same as one that nails it, and it buries how much credible models disagree. Trust-weighting measures each model’s local skill first, then lets the skilful ones carry the projection, and reports the remaining disagreement as part of the answer.

What exactly was computed?

Maximum 1-day precipitation (rx1day) within a 50 km radius of the city, baseline 1995–2014 versus future 2040–2059, scenario SSP2-4.5, using the 5-model trust-screening ensemble shared by every Trust Atlas city. Bologna additionally has a 34-model deep dive, which is why its two published numbers differ, on purpose.

Machine-readable

This evidence is also an API

Every trust profile publishes its signal as JSON, so risk platforms, notebooks, and reviewers can pull the number with its uncertainty attached:

curl https://www.arasense.com/trust/lagos.json