11.2.2 Human systems: sensitivity/vulnerability to climate and weather
Extreme events have severe impacts in both countries (Box 11.1). In Australia, around 87% of economic damage due to natural disasters (storms, floods, cyclones, earthquakes, fires and landslides) is caused by weather-related events (BTE, 2001). From 1967 to 1999, these costs averaged US$719 million/yr, mostly due to floods, severe storms and tropical cyclones. In New Zealand, floods are the most costly natural disasters apart from earthquakes and droughts, and total flood damage costs averaged about US$85 million/yr from 1968 to 1998 (NZIER, 2004).
Box 11.1. Examples of extreme weather events in Australia and New Zealand*
Droughts: In Australia, the droughts of 1982-1983, 1991-1995 and 2002-2003 cost US$2.3 billion, US$3.8 billion and US$7.6 billion, respectively (Adams et al., 2002; BoM, 2006a). In New Zealand, the 1997-1998 and 1998-1999 droughts had agricultural losses of US$800 million (MAF, 1999).
Sydney hailstorm, 14 April 1999: With the exception of the droughts listed above, this is the most expensive natural disaster in Australian history, costing US$1.7 billion, of which US$1.3 billion was insured (Schuster et al., 2005).
Eastern Australian heatwave, 1 to 22 February 2004: About two-thirds of continental Australia recorded maximum temperatures over 39°C. Temperatures reached 48.5°C in western New South Wales. The Queensland ambulance service recorded a 53% increase in ambulance call-outs (Steffen et al., 2006).
Canberra fire, 19 January 2003: Wildfires caused US$261 million damage (Lavorel and Steffen, 2004; ICA, 2007). About 500 houses were destroyed, four people were killed and hundreds injured. Three of the city’s four dams were contaminated for several months by sediment-laden runoff.
South-east Australian storm, 2 February 2005: Strong winds and heavy rain led to insurance claims of almost US$152 million (ICA, 2007). Transport was severely disrupted and beaches were eroded.
Tropical cyclone Larry, 20 March 2006: Significant damage or disruption to houses, businesses, industry, utilities, infrastructure (including road, rail and air transport systems, schools, hospitals and communications), crops and state forests, costing US$263 million. Fortunately, the 1.75 m storm surge occurred at low tide (BoM, 2006b; Queensland Government, 2006).
New Zealand floods: The 10 April 1968 Wahine storm cost US$188 million, the 26 January 1984 Southland floods cost US$80 million, and the February 2004 North Island floods cost US$78 million (Insurance Council of New Zealand, 2005).