La Nina is the large-scale cooling of surface temperatures in the central and eastern equatorial Pacific Ocean, normally occurring every two to seven years.
The effect has widespread impacts on weather around the world – typically the opposite impacts to the El Nino phenomenon, which has a warming influence on global temperatures.
A triple La Nina – in which the phenomenon spans three consecutive northern hemisphere winters, or southern hemisphere summers – has only occurred three times since the Bureau of Meteorology first started collecting records in 1900, most recently in 1998 to 2001.
Disaster responders in Australia’s east have been stretched thin by this year’s flooding, with New South Wales emergency services reporting its busiest ever year to Jun 30.
This even outstripped the need during the Black Summer bushfires, which burned through more than 24 million hectares of the country’s east and engulfed major cities in smoke.
Australia is at the forefront of climate change, with scientists warning floods, bushfires, cyclones and droughts are becoming more frequent and more intense as the planet warms.
