Extreme Weather and Natural Disasters

Australia is a vast land in which weather varies significantly in different parts of the continent. Recent extreme weather events in Australia, such as the Queensland floods and Victorian bushfires are brutal reminders of nature’s devastating power. This book examines the causes of severe and extreme weather, and explores the history of natural disasters in Australia and their impact on humans and the environment. Is global warming increasing the rate of natural disasters? What part does La Nina play in the current extreme weather cycle? Cyclones, floods, severe storms, bushfires, landslides, earthquakes, tsunami – what are the natural and man-made causes of these phenomena, how predictable are they, and how prepared are we for the impacts of natural disasters at a national and global level?

Chapter 1: Climate and extreme weather events

Chapter 2: Natural disasters in Australia

Worksheets and activities; Glossary; Fast facts; Web links; Index

Fast facts:

• Indigenous Australians have their own seasonal calendars e.g. the Jawoyn, from the Northern Territory, recognise six seasons.
• The temperature in Australia changes with the seasons, but in general it ranges between highs of 50°C to lows of sub-zero temperatures.
• The 1895-1903 drought lasted 8 years and caused the death of half of Australia’s sheep and 40% of its cattle.
• In 1967, a huge fire burnt over 250,000 hectares of land in southern Tasmania in 5 hours, reaching as far as the outskirts of Hobart.
• In February 1983, around 180 bushfires were burning in Victoria and South Australia burning out over 1 million hectares and resulted in the death of 76 people.
• About 6 cyclones happen in Australia every year. The most famous being Cyclone Tracy, which hit Darwin in the Northern Territory on Christmas Eve 1974.
• In 1899, Cyclone Mahina killed over 400 people when it destroyed an entire pearl-fishing fleet at Bathurst Bay in Queensland.
• Many thunderstorms are typically short-lived, lasting less than 1 hour and affect an area of around 10 km in diameter.
• There are 3 recognised types of thunderstorms: single cell thunderstorms, multicell thunderstorms and supercell thunderstorms.
• While hailstones are most commonly only a few millimetres in diameter they can grow to 15 cm and weigh more than half a kilogram.
• In Australia, the strongest measured wind gust during a thunderstorm was 196 km/h at Double Island Point in Queensland on 16 December 2006.
• Severe storms are estimated to cost A$284 million per annum.
• In terms of insured costs, severe storms are responsible for more damage than tropical cyclones, earthquakes, floods or bushfires.
• A bolt of lightning can travel at a speed of 45 km/s or 160,000 km/h and can reach temperatures approaching 28,000°C.
• There have been more than 40 tornado-related deaths in Australia in the past 100 years.
• El Niño or La Niña are known to occur once in 2-7 years, and last for typically 9-12 months and occasionally for 2 years.
• A 1-in-20 year hottest day is likely to become a 1-in-2 year event by the end of the 21st century in most regions.
• It is likely the frequency of heavy precipitation will increase in the 21st century over many areas.
• It is very likely that heatwaves will increase in length, frequency, and/or intensity over most land areas.
• Deaths from natural disasters occur much more in devel-oping countries.
• In 2010, heatwaves and wildfires not seen for 1,000 years swept through Russia and Eurasia, killing 56,000 people from heat and pollution.
• In the fortnight preceding the 2009 ‘Black Saturday’ fires, Victoria was hit by a record-breaking heatwave with the capital seeing 3 days in a row in excess of 43°C.
• In 2006, Cyclone Larry pushed the price of bananas up 300%.
• On 14 October 1968, the small town of Meckering, about 130 km east of Perth, was destroyed by an earthquake.
• The strongest wind gust recorded at Port Hedland during a cyclone is 208 km/h during Cyclone Joan (1975).
• On Thursday 28 December 1989, the city of Newcastle, New South Wales was devastated by a moderate earthquake of magnitude 5.6.
• Of the 115 yachts that set sail on 26 December 1998 in the Sydney to Hobart yacht race, only 44 reached their destination due to an intense low pressure system.
• In Australia, natural hazards are estimated to cost an average of $1.14 billion annually.
• Tropical cyclones have caused over 2,100 deaths in Australia since 1839.
• The average annual cost of tropical cyclones accounts for a quarter of the cost of natural disasters.
• Records of flood impacts extend back further than those for many other hazards, with the first recorded death in 1790.
• Bushfires pose an estimated annual average cost of about $77 m and have claimed nearly 700 lives since 1850.
• The estimated cost of the 2011 disasters to the Common-wealth Government alone is expected to exceed $5.6 billion.
• It is generally accepted in the emergency management community that 1 dollar spent on mitigation can save at least 2 dollars in recovery costs.
• Non-government and community organisations are at the forefront of strengthening disaster resilience in Australia.
• Emotional reactions to a traumatic event are often more intense in the first weeks following the event.
• Approximately 65% of disasters from 1991-2005 occurred in developing countries, and over 95% of people killed by natural disasters are from developing countries.
• The number of people affected by climate-related disasters is predicted to increase by 54% to 375 million people by 2015.
• The second Wednesday in October is International Day for Natural Disaster Reduction.
• Few countries have all the resources necessary to meet the demands of a large-scale disaster.
• The most useful form of assistance during a humanitarian crisis is the donation of money to non-government overseas aid organisations.
• The Asia-Pacific region is the most disaster-prone region in the world, accounting for around 40% of disasters.