Extreme weather

In Australia today, we are seeing the effects of climate change in extreme weather. These include drought, higher temperatures, storms, floods and bushfires.

Read about recent extreme weather in Australia

Heating up the sunburned country

Australia is becoming hotter, with the average temperature expected to rise up to 2ºC by 2030 and 6 ºC by 2070. Canberra is predicted to average up to 30 days over 35ºC by 2070, compared to just four such days now. Sydney’s record heatwave of New Year’s Day, 2006, topped out at 44.2ºC, and led to power blackouts and train line shutdowns, while 44 fires burned across the state. Extreme summer heat can be lethal, especially for young, infirm and elderly people.

"Climate change has customarily been viewed as a gradual, creeping process ... That idea has been shaken by Hurricane Katrina, road-melting European summers, the drought and now cataclysmic wildfires sweeping down from the Victorian Alps."

Dr Peter Fisher, Central Queensland University

January, 2007

Extreme storms on the rise

Research shows that rising ocean temperatures are linked to increased tropical storm intensity. In Australia increasingly intense tropical cyclones are expected with climate change, and the cyclone region is also expected to move further south.

Heavy rainfall, winds and storm surges are intensifying, with impacts that include flooding, landslides, erosion and damage to buildings, not to mention the threat to human lives and livelihoods.

In March, 2006, Australia’s strongest recorded storm, the category five Cyclone Larry, focused its fury 100 kilometres south of Cairns. It left most buildings in the towns of Innisfail and Babinda without roofs and 120,000 people without power. Larry also flattened banana plantations in the region, destroying $300 million worth of fruit and leaving many without jobs.

Drought: The big dry

Australia is already the world’s driest inhabited continent. With hotter temperatures, evaporation rates are expected to rise in all parts of Australia, by as much as 32 per cent by 2070. Higher evaporation rates combined with decreased rainfall increases drought vulnerability in some areas, with the northeast and southeast most susceptible. According to some researchers, the 2002 drought (which continues) is Australia’s first to bear the fingerprint of climate change. Over 2002-03, the drought shaved about one per cent off Australia’s GDP in 2002-03 – or about $6.6 billion. Some researchers now say we have entered a 1000-year drought.

Rain and flood surges

Climate change is making rainfall more variable and extreme. This means more floods, as well as more drought.  Severe rainfall may become 30 per cent more intense and occur more frequently. At the same time, rainfall is expected to decline in the southern part of mainland Australia, where most people live. In the more sparsely populated north, rainfall is expected to increase. These shifts are of serious concern given that every major Australian city already faces water stress.

Sea level rise and extreme weather events are likely to combine to increase the number and severity of flood surges. Sea levels are expected to rise by 10-40 centimetres by 2040. Research shows that flood damage costs in southern Queensland and northern New South Wales will increase by 50 per cent if sea levels rise by 20 centimetres, and will double if sea levels rise by 40 centimetres.

Bushfires flare up

Climate change affects the number of bushfires through changes in temperature, humidity and precipitation. Higher temperatures combined with reduced rainfall and greater evaporation leave many southern forests and woodlands more bushfire prone. US research has found that a 1°C increase in average summer temperature translates into a forest fire frequency increase of up to 28 per cent. Most of Australia’s natural landscape is already vulnerable to fire, the country’s southeastern corner most vulnerable of all.

References

CSIRO (2002) Climate Change and Australia’s Coastal Communities
Australian Greenhouse Office (2005) Climate Change Risk and Vulnerability.
Climate Action Network Australia (2006) Climate Change and Water in Australia.