Title:
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Quantifying the impact of historical and future climate change on windstorm insured loss in Great Britain
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Windspeed receives relatively little attention in the literature compared with other
meteorological variables, despite affecting many industries. European
extratropical cyclones create 70-75% of all European insured losses, with an
annual average of £1.5-2bn. This project quantifies the impact of historic and
future climate change on wind-related insured loss in the UK, using an
observational windspeed dataset established here and RCM model data.
A continuous 26-year (1980-2005) record of daily mean 10-metre windspeeds
and daily maximum gust speeds (DMGS) at 43 UK Met Office stations is
established. Statistically significant decreases in damaging windspeeds, of up to
20%, are found at stations in southern England during that period. Supplemented
by dynamically downscaled reanalysis data, statistically significant increases of
up to 8% are seen at locations in northern England and in Scotland in the period
1959-2001.
An operational windstorm loss model for Great Britain is developed, incorporating
socio-economic data to account for the exposure and vulnerability of domestic
properties to the windstorm hazard. Damaging windspeeds are found to be those
DMGSs exceeding the local 98th percentile. The model captures the variability in
losses reasonably well, although losses are markedly underestimated.
Impacts of individual storm events dating back to 1959 are quantified using Loss
Potentials, which are indicative of insured losses. Annual Loss Potentials reveal
no statistically significant temporal trends in the period 1959-2005, although a
slight increase is suggested between 1959-1979.
Three RCM simulations reveal increases of 15-34% in future (2071-2100) Loss
Potentials relative to baseline values. Without adaptation of domestic
properties to the future wind regime, these estimates rise to 38-533%. Greatest
Loss Potential increases are projected in South East England with adaptation,
and in North West England without adaptation. Increases in frequency and
intensity of damaging windspeeds in winter, simulated by this three member
ensemble, drive the increases in Loss Potentials.
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