In the United States, averaged over the past 55 years, weather-related events have been responsible for 93% of all catastrophe events, 83% of the economic damages of natural disasters, and 87% of the insured losses. ... The observed upward trend in losses is consistent with what would be expected under climate change and with demographic factors (7).

Technical Risks

• Shortening times between loss events, such as more hurricanes per season,
• Changing absolute and relative variability of losses,
• Changing structure of types of events,
• Shifting spatial distribution of events,
• Damages that increase exponentially or nonlinearly with weather intensity,
• Widespread geographical simultaneity of losses (e.g. from tidal surges arising from a broad die-off of protective coral reefs or disease outbreaks on multiple continents),
• Increased difficulty in anticipating "hot spots" (geographic and demographic) for particular hazards,
• More single events with multiple, correlated consequences. This was well evidenced in the pan-European heat catastrophe of 2003. Immediate or delayed impacts included extensive human morbidity and mortality, wildfire, massive crop losses, and the curtailment of electric power plants due to the temperature or lack of cooling water, and
• More hybrid events with multiple consequences (e.g. El Nino-related rain, ice storms, floods, mudslides, droughts, and wildfires).

Market-based Risks

• Historically-based premiums that lag behind actual losses,
• Failing to foresee and keep up with changing customer needs arising from the consequences of climate change,
• Unanticipated changes in patterns of claims, and associated difficulty in adjusting pricing and reserve practices to maintain profitability,
• Responses of insurance regulators,
• Reputation risks falling on insurers who do not, in the eyes of consumers, do enough to prevent losses arising from climate change, and
• Stresses unrelated to weather but conspiring with climate change impacts to amplify the net adverse impact. These include draw-downs of capital and surplus due to earthquakes or terrorist attacks and increased competition from self-insurance or other competing methods of risk-spreading.

Pressure on insurance affordability & availability under climate change

Extreme weather events have already precipitated contraction of insurance coverage in some markets, and the process can be expected to continue if the losses from such events increase in the future. Impacts vary, of course, depending on the specific circumstances, and can be relatively minor (gradual price increases) to more significant. For the United States, the following outlook has been presented for different types of issues (7):

• Flood - currently a mix of public/private insurance and risk sharing. Under climate change, insurability problems may extend from the present personal and small commercial lines into larger commercial lines.
• Windstorm—a largely insured risk at present. There are already considerable insurability problems and associated changes in terms and pricing, non-renewals, market withdrawl, etc. This could increase dramatically under climate change, resulting in shifting of losses to governments and consumers.
• Agriculture and livestock—currently a public/private insurance partnership. Climate change will stress this sector considerably, with potential for impacts due to drought, flood, pests, or other events on a scale with the Great Dust Bowl of the 1930s.
• Wildfire—currently largely privately insured. More retention of risk by purchasers of insurance and more involvement by state governments is anticipated, while insurers raise deductibles and reduce limits of liability and scope of coverage.
• Mold and moisture damage—largely commercially insured until the crisis emerged a few years ago. Now, many states have exclusions.
• Earth movement and coastal erosion—primarily insured by government, if at all. With permafrost melt, subsidence of dry soils, sinkholes will become more prevalent, as will mudslides and property losses from coastal erosion. Government programs covering storm-surge-driven losses on eroded property could be overwhelmed with losses under climate change, with the result of more retention by property owners.
• Health impacts—currently largely privately insured. An insurability crisis under climate change is not anticipated. Impacts will manifest in the form of elevated health insurance prices.

In Europe, 64% of all loss events since 1980 are directly attributable to weather and climate events (storms, floods and heat-waves) and 25% to wild fires, cold spells, landslides and avalanches, which are also linked to weather and climate. 95% of the overall losses and 78% of all deaths caused by disastrous events result from such weather and climate-related events. The annual average number of these weather- and climate-related events in Europe increased during the period 1998–2007 by about 65% compared with the 1980s (3).

Swiss Re has estimated that in Europe the costs of a 100-year storm event could double by the 2080s with climate change (to EUR 40 billion compared with EUR 20 billion today), while average storm losses are estimated to increase by 16–68% over the same period (3). Analyses of long-term records of flood losses indicate that societal and economic factors have played an important role in the observed upward trends (4).

According to an estimate by the Reinsurance Association of America (RAA), 50% of insured losses in the world within the last 40 years have been the consequence of natural catastrophes in the 1990s. Insurance experts have warned that large regions of the world may be recategorised as ineligible for insurance, because changes in weather caused by climate change (such as heat waves and hurricanes) continue at an accelerating pace (4).

Climate change is expected to lead to an increase in compensable damage, which will contribute to increased insurance premiums. This means that extreme events will result in an increased level of risk in the insurance sector. Climate change may lead to increased costs and maybe even the bankruptcy of insurance companies (5).