2013 Heatwave: Personally Delivered to you by Climate Change
Australians like myself are accustomed to enduring scorching hot summers, but the heatwaves that Down Under has recently been experiencing are longer, more frequent and more intense than ever before. The whole country is feeling the burn—starting around Christmas on the west coast, the heat quickly spread across the continent to hit the densely-populated eastern coast. Temperature records are being broken everywhere and catastrophic bushfires are burning in three separate states. Some think it’s only a taste of what to come—and others are being forced to reassess their attitudes to climate change.
2013 plunged the country into heatwaves that lasted over a fortnight. Temperatures have regularly surpassed 48° Celsius in inland Australia, and metropolitan areas have not been much cooler—Sydney recently clocked its hottest temperature ever of 45.8°C. The country’s record average was set at 40.33°C on January 7, and on the same day, the maximum temperature record was broken in Leonora, WA, with 49°C temperatures—and this record was beaten again the very next day by half a degree.
While heatwaves are a normal part of summer, the recent extreme heat is disturbing because it is proving astonishingly persistent. 2013 has seen average temperatures above 38°C for 11 days straight and above 39°C for 7 days straight, and the first eight days of 2013 were among the twenty hottest on record.
But this extreme weather has equally extreme negative consequences. Potential fire conditions are highly sensitive to changes in weather—prolonged dry spells lead to arid soils and abundant fuel for bushfires, and high winds allow such fires to spread quicker and burn more intensely than normal. These severe conditions have already prompted three Australian states to raise their fire danger risks to catastrophic.
Intense, difficult-to-control fires have sprung up in New South Wales at more than 130 locations, annihilating 74,000 acres of land, and in southern Tasmania, more than 40 bushfires have been raging since the beginning of the year. The extreme weather has allowed these scorching fires to spread at frightening speeds and devour over 50,000 acres of dry land. More than 100 properties have been destroyed—and 100 people are still unaccounted for.
In light of so many smashed temperature records and their devastating implications, it is clear that Australia’s climate is shifting. Long-term data shows that Australia’s average temperature has increased by 0.9°C since 1910, and extrapolations predict that it will increase by at least another 3°C over the next 90 years. Seeing the destruction following a 0.9°C increase it is terrifying to imagine the future devastation that a 3°C increase may cause: native flora and fauna may suffer, large parts of the continent may become uninhabitable, and the agricultural land with which we pride ourselves may be under threat.
The increasing temperatures are largely due to climate change. The planet is warming up and Australia is warming with it, and this is strongly attributed to human activities causing an increased greenhouse gas concentration in the atmosphere, predominately carbon dioxide. These gases trap heat in the lower atmosphere, which has warmed the global climate system by 1°C in the past hundred years, which in turn influences weather conditions around the world. Extreme weather is therefore directly connected to the greenhouse gas emissions of human activities.
1°C may sound like a modest increase, but even a tiny change can have a significant impact on weather systems—an increased in average temperature shifts the entire distribution, including minimum and maximum temperatures. In Australia, this shift has increased the likelihood of extreme heat events and dangerously changed their nature—the country’s number of record hot days has doubled since 1960, and there has been a clear decline in extremely cold days and an increase of extremely hot days. Over the past decade alone, extreme heat records have outnumbered extreme cold records 3:1.
Australia’s experiences are consistent with the global trend of shifting weather—the world’s 10 hottest years on record have all occurred in the last 15 years.
Understanding this link between climate change and extreme weather is key to preventing a catastrophic future outcome. Australia’s recent devastating weather has highlighted the urgent need to take action against climate change, because efforts to reduce greenhouse gas emissions today will influence the severity of future weather—saving not only human lives, but perhaps the planet too.