Thousands evacuated in Australia's worst flooding in almost half a century https://t.co/IMuH3ctNtm pic.twitter.com/InQuvXtCZB

— Reuters (@Reuters) March 23, 2021

by Amy Lupica, ODP Staff Writer

The Australian Government along with the state of New South Wales have signed 16 disaster declarations after heavy rains and flooding forced 18,000 residents to evacuate the region. 

• Some affected areas have seen more than the average March Monthly rainfall in just four days, and the Bureau of Meteorology expects an additional two to four inches to fall in the next 24-36 hours. 
• NSW officials are overwhelmed by the volatility of the region’s recent weather events. 

“Communities who were battered by the bushfires are now being battered by the floods and a deep drought prior to that,” said NSW Premier Gladys Berejiklian. “I don’t know any time in our state’s history where we’ve had these extreme weather conditions in such quick succession in the middle of a pandemic.”

Why This Matters: Australia has experienced extreme weather fluctuations in the past, but experts say they’re getting much worse as global temperatures warm. 2019 and 2020 were two of the country’s warmest years on record, and 2020 began with much of the country in a severe drought. The result was raging bushfires that consumed 44 million acres of land, destroyed 3,000 homes, and killed 28 people.

Nerilie Abram, professor at the Australia National University Research School of Earth Sciences in Melbourne explains, “what we’re seeing now is that natural variability is occurring on top of the long-term, human-induced climate changes and that we’re seeing the extremes becoming even more extreme.”

Although current flooding has yet to result in casualties, officials expect that there will be deaths before the rain stops and that recovery efforts will extend past Easter. The flooding is also expected to disrupt COVID-19 vaccine supply chains in NSW, which is home to more than 8 million people. 

Cause and Effect: The torrent of rainfall was caused by two weather systems coming together. A “slow-moving coastal trough” is pushing moisture into the region, which is then being agitated by easterly winds. This perfect storm has led to some regions receiving nearly a meter of rainfall, and 8,000 emergency calls from trapped residents. And while this storm is severe, combination climate events are hardly new for Australia. 

The Indian Ocean Dipole (IOD) is a phenomenon during which the waters off the east coast of Africa become warmer, while the waters around Indonesia and Malaysia become cooler, preventing storms from reaching Australia, causing droughts. Another climate system, the Southern Annular Mode (SAM), usually directs wind and rain to southern Australia, but due to climate change, it’s pushing those winds further south, missing Australia entirely.

For Now: Prime Minister Scott Morrison is warning residents to stay inside their homes and listen to officials and emergency workers. More than 130 schools will be closed on Monday, and some will need to be repaired after sustaining damage from the storm. Authorities don’t currently have an accurate estimate on the extent or cost of damages but believe that this flooding may be the worst since 1961. “This is different,” warned Berejiklian, “what we’re going through is different to what you’ve been through for the last 50 years. So please take it seriously.”