The increasing frequency and severity of natural catastrophes due to climate change is expected to cause higher natural disaster losses in the future. Reinsurance companies bear a large share of this risk in the form of excess-of-loss coverage, where they underwrite the most extreme portion of insurers’ risk portfolios. Past experience has shown that after a very large natural disaster, or multiple disasters in close succession, the recapitalization need of reinsurers could trigger a “hard” reinsurance capital market, where a high demand for capital increases the price charged by investors, which is opposed to a “soft” market, where there is a high availability of capital for reinsurers. Consequently, the rising costs of underwriting are transferred to insurers, which ultimately could trigger higher premiums for natural catastrophe (NatCat) insurance worldwide. Here, we study the vulnerability of riverine flood insurance systems in the EU to global reinsurance market conditions and climate change. To do so, we apply the “Dynamic Integrated Flood Insurance” (DIFI) model, and compare insurance premiums, unaffordability, and the uptake for soft and hard reinsurance market conditions under an average and extreme scenario of climate change. We find that a rising average and higher variance of flood risk towards the end of the century can increase flood insurance premiums and cause higher premium volatility resulting from global reinsurance market conditions. Under a “mild” scenario of climate change, the projected yearly premiums for EU countries, combined, are €1380 higher under a hard compared to a soft reinsurance capital market in 2080. For a high-end climate change scenario, this difference becomes €3220. The rise in premiums causes problems with the unaffordability of flood coverage and results in a declining demand for flood insurance, which increases the financial vulnerability of households to flooding. A proposed solution is to introduce government reinsurance for flood risk, as governments can often provide cheaper reinsurance coverage and are less subject to the volatility of the capital markets.

Flood insurance coverage can enhance financial resilience of households to changing flood risk caused by climate change. However, income inequalities imply that not all households can afford flood insurance. The uptake of flood insurance in voluntary markets may decline when flood risk increases as a result of climate change. This increase in flood risk may cause substantially higher risk-based insurance premiums, reduce the willingness to purchase flood insurance, and worsen problems with the unaffordability of coverage for low-income households. A socio-economic tipping-point can occur when the functioning of a formal flood insurance system is hampered by diminishing demand for coverage. In this study, we examine whether such a tipping-point can occur in Europe for current flood insurance systems under different trends in future flood risk caused by climate and socio-economic change. This analysis gives insights into regional inequalities concerning the ability to continue to use flood insurance as an instrument to adapt to changing flood risk. For this study, we adapt the “Dynamic Integrated Flood and Insurance” (DIFI) model by integrating new flood risk simulations in the model that enable examining impacts from various scenarios of climate and socio-economic change on flood insurance premiums and consumer demand. Our results show rising unaffordability and declining demand for flood insurance across scenarios towards 2080. Under a high climate change scenario, simulations show the occurrence of a socio-economic tipping-point in several regions, where insurance uptake almost disappears. A tipping-point and related inequalities in the ability to use flood insurance as an adaptation instrument can be mitigated by introducing reforms of flood insurance arrangements.

Future flood risk assessments typically focus on changing hazard conditions as a result of climate change, where flood exposure is assumed to remain static or develop according to exogenous scenarios. However, this study presents a method to project future riverine flood risk in Europe by simulating population growth in floodplains, where households’ settlement location decisions endogenously depend on environmental and institutional factors, including amenities associated with river proximity, riverine flood risk, and insurance against this risk. Our results show that population growth in European floodplains and, consequently, rising riverine flood risk are considerably higher when the dis-amenity caused by flood risk is offset by insurance. This outcome is particularly evident in countries where flood risk is covered collectively and notably less where premiums reflect the risk of individual households.

Flood insurance coverage can enhance financial resilience of households to changing flood risk caused by climate change. However, due to increasing risk in many areas, premiums are likely to rise, which may cause insurance to become unaffordable for low-income households. This issue can become especially prominent in high-risk areas, when premiums are risk-reflective. Consequently, increasing premiums can reduce the demand for insurance coverage when this is optional, as individuals often underestimate the flood risk they face. After a flood, uninsured households then have to rely on private savings or ex-post government disaster relief. This situation is suboptimal as households may not save sufficiently to cover the damage, and government compensation can be uncertain. Using a modeling approach we simulate unaffordability and uptake of various forms of flood insurance systems in EU countries. To do this, we build upon and advance the “Dynamic Integrated Flood Insurance” (DIFI) model, which integrates flood risk simulations, with an insurance sector and a consumer behavior model. We compute the results using various climatic- and socio-economic scenarios in order to assess the impact of climate- and socio-economic change for flood insurance in the EU. Furthermore, we assess the impact of remote natural disasters on flood insurance premiums in EU countries, which occurs through the global reinsurance market. More specifically, after large natural disasters or compound events occurring outside the EU, which are likely to occur more often due to climate change, reinsurance premiums can temporarily rise as a result of a global “hard” capital market for reinsurers. The higher cost of capital for reinsurers is then transferred to households in the EU through higher flood insurance premiums. We find that rising average, and higher variance, of flood risk towards the end of the century can increase flood insurance premiums, and cause higher premium volatility resulting from global reinsurance market conditions. The rise in premiums increases unaffordability of insurance coverage and results in declining demand for flood insurance. A proposed policy improvement is to introduce a public reinsurance system for flood risk, as governments can often provide cheaper reinsurance coverage and are less subject to volatility on capital markets. Besides this, we recommend a limited degree of premium cross-subsidization to limit the growth of premiums in high-risk areas, and insurance purchase requirements to increase the level of financial protection against flooding.