When climate turns the state into a reinsurer

Two storms hit France. Torn roofs open an ordinary insurance claim. Flooded homes may open a Cat Nat claim. The weather event is the same, but the law, funding and final risk bearer change. At the end of the second circuit stands an unlimited guarantee from the French state.

The title needs one immediate clarification. CCR is the reinsurer. The French state is its guarantor. The state does not write the household policy or pay each homeowner directly. It guarantees CCR when the scheme’s own resources are no longer sufficient. In legal terms, it is the guarantor. In economic terms, it carries the extreme tail risk.

That architecture helps France maintain broad coverage at a heavily pooled price. It also raises a public-finance question: what happens to a guarantee designed for exceptional losses when expensive disasters become more frequent?

One storm can open two insurance claims

Storms Nils and Pedro, on 12 and 19 February 2026, provide an unusually clear example despite the severity of the damage.

France Assureurs estimated storm damage at €900 million. CCR estimated flood damage covered by the French Cat Nat scheme at €290 million. The combined total was close to €1.2 billion, but the two amounts did not enter the same mechanism. The ordinary storm cover could be activated without an interministerial decree. Cat Nat cover required official recognition of a natural disaster. (France Assureurs and CCR, 2 March 2026)

The perimeter is less intuitive than the name suggests. France’s Cat Nat scheme covers certain floods, coastal flooding, drought-related clay shrinkage and swelling, landslides, earthquakes and cyclones above legal thresholds. Non-cyclonic storms, hail, snow and forest fires fall under other covers, which may be mandatory or optional depending on the policy. (French Economy Ministry, 29 July 2026, Cour des comptes, April 2026, pp. 10-11)

The word “climate” describes a physical cause. Cat Nat is a specific French legal regime.

A national surcharge pools local risk

The Cat Nat guarantee is a mandatory extension of French policies that cover the relevant property damage. It does not make home insurance universal: an owner occupying a detached house may remain uninsured. Once an eligible property-damage policy exists, however, the insurer must include the statutory guarantee.

Funding appears on the premium as an additional charge, commonly called the Cat Nat surcharge. Since 1 January 2025, its rate has been:

• 20% of the reference premium for household and business property-damage policies, up from 12%;
• 9% for the main motor-insurance base, up from 6%.

The French state sets these rates. They do not change according to whether a home stands on relatively safe high ground or in a repeatedly flooded area. Two policies with different base premiums pay different amounts in euros, but the Cat Nat percentage is national. (Decree of 22 December 2023, French Economy Ministry)

The surcharge is not a tax transferred in full to the French budget. It is part of the economics of the insurance contract. Insurers retain part of it and may cede a share of the premiums and risk to a reinsurer. For 2025, CCR reports €3.71 billion in Cat Nat premiums: €1.94 billion from households, €1.54 billion from businesses and €230 million from motor insurance. CCR puts the average contribution at about €41 a year per household policy. (CCR, Natural disasters in France, 1982-2025 review, pp. 3-4)

A uniform rate creates deliberate redistribution. Policyholders in less exposed areas help keep coverage affordable in riskier places. It prevents fully individualised Cat Nat pricing from quickly excluding some households or territories.

The trade-off is a weaker local price signal. A highly vulnerable home does not necessarily pay a Cat Nat surcharge that reflects its physical exposure. Prevention, land-use rules, deductibles and the policy’s general terms must then carry some of the incentive that the uniform price does not transmit.

Four balance sheets absorb the loss

Once the authorities recognise a natural disaster and the loss falls within the policy, the policyholder turns to the insurer. The insurer compensates its customer. The statutory deductible remains with the policyholder.

The insurer may retain the entire risk, use a private reinsurer or buy coverage from CCR. Buying CCR coverage is not legally compulsory, and the state-owned company has no monopoly. Its offer is dominant because it combines proportional loss-sharing with unlimited cover backed by the French state guarantee. (French Insurance Code, Article L. 431-9, Cour des comptes, pp. 57-59)

In the structure described by the Cour des comptes, CCR’s treaty has two layers:

1. a 50% quota share: the insurer cedes half the corresponding surcharges and CCR takes half the claims after deductibles;
2. an annual excess-of-loss layer, also called stop-loss: once the insurer’s retained share crosses a contractual threshold, CCR takes the excess.

Reinsurance therefore does not alter the household’s policy. Behind the scenes, it redistributes the liability already owed by the insurer.

The public guarantee remains conditional

France’s state guarantee is neither a certain annual expense nor debt immediately added to the public-debt stock. It is an off-balance-sheet commitment: a legal obligation whose cost depends on a future event. Once a call becomes probable, public accounting must recognise a provision. When the guarantee is called, it generates an expense and a budgetary cash payment. (Cour des comptes, Identifying and accounting for the state’s off-balance-sheet commitments, pp. 81-82)

The threshold depends on CCR’s reserves and treaty structure. CCR says the state intervenes when the loss borne by the reinsurer exceeds 90% of its reserves. Expressed as a total market loss, CCR estimated the threshold at €3.9 billion in 2025 and €5.3 billion in 2026, after the surcharge increase began rebuilding reserves. This is an estimate of the scheme’s capacity, not a statutory cap applied directly to every disaster. (CCR, 1982-2025 review, pp. 80-81)

Since 1982, the guarantee has been called once, in 2000 for the 1999 financial year. The French state paid €263 million after a year combining drought, floods and the consequences of storms Lothar and Martin. Wind damage fell under ordinary storm cover, while Cat Nat recognitions for floods and ground movements contributed to the year’s exceptional burden. (French Senate, report on the Cat Nat scheme, October 2024, p. 18, French National Assembly, 1999 budget execution)

The public guarantee is not provided to CCR for free. The Cour des comptes reports that the reinsurer pays the state a share of its premiums as remuneration for the guarantee, at 10.8% since 2017. The state receives revenue while the scheme operates without a call, then carries the extreme-loss exposure. (Cour des comptes, pp. 63-64)

The arrangement resembles insurance: regular remuneration is exchanged for a promise to absorb a rare loss. The state still is not the contractual reinsurer. It carries the public tail once the intervening private and public reserves have been consumed.

The 2025 surcharge increase buys time

The scheme needed financial breathing room. According to the Cour des comptes, average annual claims for all participants, expressed in 2024 euros, rose from roughly €800 million in 2004-2015 to nearly €2.7 billion in 2016-2024. CCR’s Cat Nat equalisation reserve was close to €1.5 billion at end-2021, fell below €300 million at end-2022 and was exhausted by end-2023. (Cour des comptes, pp. 65-66)

The higher surcharge reversed the flow. CCR estimates that France’s Cat Nat scheme collected €3.71 billion in premiums in 2025 and reports a claims-to-premiums ratio close to 50% for the year. That creates room to rebuild reserves. One benign year does not settle the problem of several bad years in succession.

Projections require their full uncertainty range. The Cour des comptes summarises CCR’s work as a 47% to 85% increase in costs by 2050, depending on climate assumptions, changes in exposed property and the perils included. These are modelled paths, not bills already incurred. (Cour des comptes, p. 18)

The court also tested paths more volatile than CCR’s central trajectory. Under an adverse combination of high-loss cycles, slower premium growth and a rare shock, it obtained guarantee calls reaching €300 million a year in 2026-2029, €1.3 billion in 2034 and €1 billion a year in 2039-2041, in constant 2024 euros. These amounts are stress-test outputs, not a budget forecast. (Cour des comptes, pp. 68-70)

In June 2026, the French government said it would review the surcharge rate at least every five years. The announcement follows a recommendation from the Cour des comptes, but says nothing about the next rate or the decision that will eventually be made. (French Treasury, 22 June 2026, ministerial answer to the Senate, 23 July 2026)

Access to insurance is holding up so far

CCR’s first insurability observatory examined 19 million detached-home policies, nearly half of French property-damage contracts, across three perils responsible for more than 90% of household Cat Nat compensation.

Its central result is reassuring: none of the municipalities examined lacked an insurance offer and none was classified as facing severe tension. CCR nevertheless identifies mild tension in 568 municipalities in metropolitan France and moderate tension in 335 municipalities, including 92 in overseas France. (CCR, 2025 Insurability Observatory, 15 June 2026)

The limitation matters. The first edition mainly uses 2022 data. It therefore predates the 2023 and 2024 floods in Nord and Pas-de-Calais. The Cour des comptes also notes that insurers participate in the observatory’s validation bodies and calls for a more detailed perimeter, including prices and post-loss behaviour. (Cour des comptes, pp. 55-56)

The diagnosis says that the market still held up in the observed data. It cannot ensure that every policyholder today finds the same price, the same deductible or the same number of competing insurers.

Solidarity reshapes incentives

National pooling performs a task that a purely private market struggles to deliver: keeping rare, correlated and geographically concentrated risks insurable. It can also create three tensions.

The first concerns land use. If the insurance price barely reflects local exposure and public help is expected after every disaster, building or rebuilding in a risky area appears cheaper than its cost to society. The IMF uses the term charity hazard when the expectation of public relief reduces demand for insurance or prevention. (IMF, Natural Disaster Insurance for Sovereigns, 2020)

The second concerns the scheme’s boundary. Cat Nat covers the abnormal intensity of a natural agent. If a phenomenon becomes very frequent, should it remain legally exceptional forever? Narrowing the perimeter protects the scheme’s finances but may leave households without an affordable solution. Expanding it without additional funding transfers the bill to premiums, CCR’s reserves or the state.

The third concerns prevention. Since 2021, France’s Barnier Fund has been part of the general budget. CCR notes that the direct link between surcharge proceeds and the money actually spent on prevention has weakened. Raising premiums repairs the balance sheet faster. Reducing exposure, adapting buildings and avoiding some new construction reduce future losses. (CCR, 1982-2025 review, pp. 19-20)

The scheme cannot be judged only by its capacity to pay after a shock. Its incentives before the shock also matter.

Europe considers another layer

France has relatively broad household coverage, but the European landscape is much more fragmented. A joint EIOPA and European Stability Mechanism paper estimates the uninsured share of natural-disaster losses at about 75% in historical data and 50% in its modelled approach. The difference mainly reflects scope: historical data include more rarely insured infrastructure, while the model focuses on real estate. (EIOPA-ESM, Sharing the risk, April 2026, pp. 5 and 12-13)

The authors examine a European layer made of:

• a pool funded by risk-based premiums from insurers, reinsurers or national schemes;
• a loan backstop for extreme events that exhaust the pool’s resources.

Their model estimates that diversification across countries and perils could reduce required capital by as much as 67% compared with isolated national solutions. The loan backstop would have a capacity of €10 billion to €65 billion depending on the assumptions. Members would have to repay the loans and their costs in full over time. The paper is a technical contribution to the debate and explicitly states that it is not an adopted policy. (EIOPA-ESM, pp. 5-9)

The proposal raises the same question at a higher level. European diversification can reduce locked-up capital, but pooling will remain politically fragile if premiums do not sufficiently reflect risk or if prevention becomes negotiable after a disaster.

Insurance Europe, the industry federation, disputes the premise that private capacity is necessarily insufficient. It argues that any European solution should preserve risk-based pricing, adaptation and existing national schemes. The disagreement is not about whether losses exist. It concerns the most effective institutional layer for absorbing them. (Insurance Europe, response to the EIOPA-ESM paper, June 2026)

The choices now facing France

France has built a robust machine. The policyholder retains a deductible. The insurer pays and keeps part of the risk. CCR pools portfolios, builds reserves and absorbs heavier losses. The state closes the chain with an explicit guarantee.

This system has protected almost the entire French territory and has required only one direct public payment since 1982. It does not make disasters free. It distributes their cost across current premiums, accumulated reserves, insurers, CCR and, in an extreme scenario, a future French budget.

The practical questions are now clear:

• how often should France raise the surcharge when models and observed losses diverge?
• which prevention spending avoids more damage than an additional euro placed in reserves?
• when should a frequent risk receive a different legal treatment?
• how far should national solidarity offset a decision to build or rebuild in a highly exposed area?
• would a European pool genuinely improve diversification without turning a last-resort loan into a permanent subsidy?

Calling the state the reinsurer is therefore legally imprecise, but it captures the economic shift. As climate change thickens the tail of losses, a long-invisible public promise moves closer to the centre of the budget debate.

For related analysis of public and private guarantees, see our work on climate risk in US mortgage finance, what France’s Livret A really finances and who pays in a sovereign default.

Main sources and limitations

• French Insurance Code, Articles L. 125-1 to L. 125-7 and Article L. 431-9: legal scope and the French state guarantee.
• CCR, Natural disasters in France, 1982-2025 review, 23 June 2026: premiums, claims, reserves and the estimated public-intervention threshold.
• Cour des comptes, Natural catastrophe insurance: a financial sustainability challenge, April 2026: financial mechanics, limitations, stress tests and recommendations.
• CCR, first Insurability Observatory, 15 June 2026: municipal coverage and observed tension in a 19-million-policy sample.
• EIOPA and ESM, Sharing the risk, April 2026: modelling of a European pool and loan backstop.
• IMF, How to Manage the Fiscal Costs of Natural Disasters, 2018, and Bova et al., The Fiscal Costs of Contingent Liabilities, 2016: budget treatment and the cost of contingent liabilities.
• Razmig Keucheyan, The Battle over Socialization, 2025: academic analysis of the politics of France’s reinsurance regime.

Initial loss estimates may be revised. The 2050 projections depend on climate scenarios, future property values, urbanisation, prevention and the perimeter of insurance cover. CCR’s 2025 data describe the national scheme, while the observatory published in 2026 mainly relies on 2022 policies. Finally, the EIOPA-ESM mechanism is a design paper. It has not been adopted by the European Union.