Winter is now in full swing in Sydney, which means lots of dry, sunny days and cool, crisp winds. If that sounds anomalous to your idea of winter, then it’s worth considering Sydney’s location climatically – nestled in the stretching neck of a temperate zone, just below and often influenced by the tropical zone to its north.
The benevolent influence of the warm Pacific ocean counters the chill winds coming off the Snowy Mountains and Southern Highlands, resulting in daily temperatures which, on average, range between 8 and 16 degrees.
In the strong, bright sunlight, the cold night air often warms rapidly and daytime temperatures regularly approach 18-20 degrees. This, combined with the low winter rainfall and lack of humidity, results in many beautifully crisp days with impossibly blue skies and mild temperatures.
Rainfall in Sydney has declined in recent decades, though for now it appears to have plateaued. This decline has been mirrored in other Australian capitals in the south and west – Mebourne, Adelaide and Perth. This is due to increasing amounts of rain falling at sea, rather than on land. How this will all track in future is uncertain, though the trajectory is clearly towards a considerably hotter climate. Indeed, between April 2012 and April 2014, Australia experienced the hottest 24-month period ever recorded, on the back of a decade of increasingly above average temperatures. In May this year – mid autumn – Sydney experienced 19 consecutive days of 22 degrees or hotter – one of a whole sequence of “warm-waves” across Australia through autumn.
Politicians and industry might be in denial about global warming’s very real effects in Australia, but the climate doesn’t care a rat’s flap for their opinions. It might seem deceptively calm and beautiful just now, and we might enjoy the warmer weather in Autumn, but Australia’s climate is in rapid transition, becoming more dangerous and less predictable every year. The feedbacks driving this mechanism are now firmly in place, and turning things around will take decades – like changing course on a supertanker. While Australia can stop directly harming its environment, in truth our fate depends on the rest of the world curbing its emissions. We could certainly set a better example than our present, shameful recalcitrance.