Wildfires primarily occur after prolonged dry spells where the air temperature is high. Dry vegetation can then be easily ignited, starting a wildfire that quickly spreads out of control if the wind is strong. The majority of fires near populated areas are caused by human activity, while a smaller portion start naturally as a result of lightning, for example. Alongside accidental fires, a significant number are also started deliberately.
The hazard is especially high in climate zones where there is enough rainfall to allow vegetation to flourish some of the time but where there are also long periods of warm weather with little precipitation. Under these conditions, plants gradually dry out and become highly flammable. This type of climate is found in south-east Australia or in California, for example.
The worst-affected regions include the southwest United States and southeast Australia. Aside from the environmental aspects, urban sprawl is also playing a critical role in the changing loss potential. An increasing number of houses are being built in the transitional zones between the outskirts of cities and nearby forested areas.
In California, climate change is clearly a significant factor in the increasing risk of wildfires and related losses. The largest wildfires recorded in California since 1930 have predominantly occurred since the beginning of the new millennium. The same period has also seen the most years with exceptionally high temperatures and unusually dry conditions. However, the Mediterranean region and parts of Australia are also seeing the conditions for forest fires occurring more frequently.
Content retrieved from: https://www.munichre.com/en/risks/natural-disasters-losses-are-trending-upwards/wildfires-as-the-climate-changes-so-do-the-risks.html.
