Actuarial and Quantitative Risk
The Global Risks Alliance (GRA)
Insurance premiums have traditionally been based on long averages of past losses. When hazards change with the climate, past averages can understate current risk. Climate-adjusted pricing uses trends, catastrophe models conditioned on current climate and forward-looking scenarios. This page sets out how climate adjustment enters pricing, where it is uncertain, the data and standards involved, and who decides.
Fig.Reserving workbench. Design wireframe with placeholder names and illustrative values, not a record or a live system.
Climate-adjusted insurance pricing is the practice of reflecting changing hazards in premiums, through trends, catastrophe models conditioned on current climate and scenarios, rather than relying only on long past averages. Rate regulation and affordability shape its use. Pricing actuaries, rate regulators, boards and governments hold the decisions.
How a storm crossing a trigger zone would set a payment. Real geography; synthetic storm and design terms.
How non-stationary hazard changes pricing assumptions. The dossier below sets out how the risk develops, what is measured, where the data come from, how it is modelled and who decides.
Long experience periods average over a climate that has already changed. Shorter periods are more current but noisier.
Catastrophe catalogues can be adjusted to reflect current or near-term climate, shifting expected loss and tail estimates.
Rate approval rules may limit use of forward-looking models or require public review, affecting how quickly prices reflect changing risk.
Higher risk-reflective prices can make cover unaffordable for some households, raising questions about cross-subsidy and public schemes.
Each term as this page uses it. Where a standard-setting body defines the term, the wording follows that body.
| Term | Definition |
|---|---|
| Experience period | The span of past years whose losses are used to set rates. |
| Rate filing | A submission to a regulator of proposed insurance rates and the evidence supporting them. |
| Risk-reflective pricing | Setting premiums in line with each policyholder's expected cost of risk. |
Each indicator carries its unit, its cadence, the kind of source behind it and the evidence label a value would carry. No values are shown: a programme supplies them under its own authority.
| Indicator | Unit | Cadence | Source type | Label |
|---|---|---|---|---|
| Change in expected loss from climate conditioning | percent | per model update | Catastrophe models | MODELLED |
| Experience period used in pricing | years | per filing | Rate filings | DECLARED |
| Trend applied to weather-related losses | percent per year | per filing | Rate filings | DECLARED |
| Rate filings using forward-looking catastrophe models | count | annual | Regulator records | OFFICIAL |
| Premium change in high-hazard areas | percent | annual | Regulator and market data | REPORTED |
| Observed trend in weather-related claims | change per year | annual | Claims data | ESTIMATED |
The topic as a computational graph: named sources feed the methods, an evidence review gates the outputs, and the decisions stay with the authorities that hold them.
Fig. 02Nodes carry their type, two metric rows and a state; connectors show what feeds what; dashed frames name the owners; the timeline is the cadence. Design of the pipeline, not a record of a run.
Named public datasets and institutional records, each with its licence class. Sources by agreement are used only under their terms and never republished.
| Source | What it gives | Licence class |
|---|---|---|
| NAIC SERFF rate filings | Pricing assumptions and models in United States filings | Public records, terms per state |
| California Department of Insurance catastrophe modeling regulation documents | Rules on using forward-looking catastrophe models in rates | Public records |
| IPCC Sixth Assessment Report, Working Group I | Assessed changes in extremes | Free, IPCC terms |
| Institute and Faculty of Actuaries climate research | Actuarial approaches to climate in pricing and reserving | Free to read, terms to check |
| EIOPA work on climate in non-life underwriting and pricing | Supervisory views on climate in pricing | Free, EU reuse terms |
Actuarial and Quantitative Risk prepares evidence. The decisions below are taken by the authorities named, under their own rules, and never by the platform.
| Who decides | The question | Evidence this page serves |
|---|---|---|
| Pricing actuaries | How to reflect changing hazard in rates | Trends, conditioned models and professional standards |
| Rate regulators | Whether forward-looking models may support filings | Model reviews and filing evidence |
| Insurer boards | How to balance risk-reflective pricing and market position | Pricing analysis and affordability evidence |
| Governments | Whether to intervene where risk-reflective prices become unaffordable | Affordability and availability data |
Climate science indicates that some hazards are changing, for example more intense heavy rainfall and heat extremes in many regions, and rising sea levels that raise coastal flood baselines, while changes in other hazards are less certain or vary regionally. Historical loss records therefore mix events from different climate states, and simple averages may understate current risk.
Practitioners respond in several ways: trending historical data, giving more weight to recent experience, using catastrophe models that represent current climate conditions, or adjusting event frequencies using climate science. For annual contracts, the relevant question is current-year risk, while long-term questions, such as the future insurability of a region, need scenario analysis over decades.
Exposure growth, from more and more valuable assets in hazardous areas, and changes in vulnerability, from building codes or adaptation, often drive loss trends as much as hazard change. Separating these drivers matters for pricing and for public policy.
Adjusting past losses for exposure, inflation and hazard trends.
Models calibrated to current or future climate; calibration depends on climate science and data.
Exploring insurability and pricing under climate scenarios.
Limits: attribution of loss trends to hazard change is difficult, climate projections are uncertain at local scales, and short records make trends hard to detect statistically.
The current service level is R0: information and enquiries. An enquiry receives a reference and names the next step; applications, payments, compute allocations and registrations open only when their team, terms and review capacity exist.