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.
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.