ABSTRACT

The paper updates normalisation of the Insurance Council of Australia’s Disaster List in the light of debate about the contribution of global warming to the rising cost of natural disasters. Normalisation estimates losses from historical events in a common year, here ‘season’ 2017 defined as the 12-month period from 1 July 2017. The number and nominal cost of new residential dwellings are key normalising factors and post-1974 improvements in construction standards in tropical cyclone-prone parts of the country are explicitly allowed for. 94% of the normalised losses arise from weather-related perils – bushfires, tropical cyclones, floods and severe storms – with the 1999 Sydney hailstorm the most costly single event (AUD5.6 billion). When aggregated by season, there is no trend in normalised losses from weather-related perils; in other words, after we normalise for changes we know to have taken place, no residual signal remains to be explained by changes in the occurrence of extreme weather events, regardless of cause. In sum, the rising cost of natural disasters is being driven by where and how we chose to live and with more people living in vulnerable locations with more to lose, natural disasters remain an important problem irrespective of a warming climate.

摘要

根据有关全球变暖对自然灾害成本上升的贡献的辩论，本文更新了澳大利亚灾难保险委员会的规范化。归一化估计的是一个普通年份中历史事件的损失，这里的“季节” 2017年定义为自2017年7月1日起的12个月。新住宅的数量和名义成本是关键的归一化因素，1974年后建筑标准的提高明确允许该国发生热带气旋的地区。正常损失的94％来自与天气有关的危险-丛林大火，热带气旋，洪水和强烈风暴-1999年悉尼冰雹是最昂贵的单一事件（56亿澳元）。如果按季节进行汇总，则与天气相关的危险不会​​造成正常损失的趋势；换一种说法，在我们对已经发生的变化进行归一化之后，无论原因如何，都没有残留信号可以用极端天气事件发生的变化来解释。总而言之，自然灾害成本的上升是由我们选择居住的地点和方式以及居住在脆弱地区的更多人造成更多损失的驱动的，不管气候变暖，自然灾害仍然是一个重要问题。