The Climate Biennial Exploratory Scenario was, by design, a one-off. The methodology it forced — physical-risk and transition-risk shocks projected over a multi-decade horizon, mapped onto an insurer's asset and liability portfolios — has not been one-off. It has become the working scaffolding for how the PRA, EIOPA and the wider supervisor community now expect climate to be handled.
By 2026 the question is no longer whether the firm has a climate scenario capability. It is whether the capability is embedded in capital, underwriting and reserving — or whether it is still running as a parallel exercise that the actuarial team produces once a year, the board notes, and the day job moves past.
The three structural shifts insurers are working through
- Liability side: catastrophe-linked re-calibration. Climate-correlated mortality, morbidity and catastrophe shocks are no longer extreme tails — they reshape the central reserving view. Cat models calibrated against a 1995–2020 vintage of weather data are now structurally below the loss experience, and re-baselining is non-trivial.
- Asset side: transition risk in long-duration fixed income. For life and BPA portfolios with multi-decade asset horizons, sectoral transition pathways translate directly into credit-spread, default and re-rating risk inside the matched-asset book. This is a matching adjustment question, not a sustainability-reporting question.
- Underwriting: climate-aware pricing in commercial lines. The insurance leaders are pricing climate exposure granularly — not at portfolio level — using geospatial signal and forward-looking peril modelling. The trailers are still selling renewal-vintage policies that no longer reflect the loss distribution.
Embedded versus parallel
The distinction matters. An embedded climate capability changes the central case reserving view, feeds the ORSA, sits inside the matching-adjustment ALM monitor and influences live underwriting decisions. A parallel capability produces a glossy annex to the year-end report and is referred to in board updates but does not move a single capital or pricing decision.
The PRA and EIOPA are increasingly able to tell the difference, and 2026 supervisory dialogue is starting to ask the question directly: where in your operating model does the climate scenario actually bite?
What good looks like
An embedded climate capability has three artefacts on the shelf. A documented re-calibration of central-case reserving assumptions against the climate-adjusted loss distribution, owned by the chief actuary and reconciled to the year-end disclosures. A matching-adjustment ALM monitor that surfaces transition-risk-correlated downgrades in the matched book as a defined operational trigger. And an underwriting governance package that demonstrates which commercial-lines decisions have moved as a result of forward-looking climate signal, not just retrospective loss experience.
None of this is exotic. It is the discipline of treating climate as a risk to be priced, reserved and capitalised — rather than a topic to be reported on. The firms that internalise that distinction now will not be the ones explaining themselves to supervisors when the next physical-risk year arrives.