Sydney was recently hit with its fourth major flood event in just two years. On the night of July 4 more than 100 rescues were made to save people from their inundated homes, while 50,000 people waited anxiously on evacuation alert.
Parts of the region copped eight months’ worth of rain in just four days, overwhelming soils already saturated from two years of La Niña-driven storms.
Severe floods are not unheard of in NSW, which has recorded destructive rains, especially around the Hawkesbury River, since records began. But a recent report by the Bureau of Meteorology (BOM) found that while climate change was not directly responsible for this latest spate of floods, it may have made these disasters worse – a warmer atmosphere can hold 7% more moisture per 1°C of warming, making storm clouds more destructive.
Extreme weather is expected to be part and parcel of a warming climate. And the weather impacts of climate change may be underestimated, due to a relative dearth of data in lower-income countries.
But what complicates the picture even more is the as-yet poorly understood relationship between these isolated weather events, Earth’s broader climate oscillations (such as La Niña), and climate change.