A third La Niña weather event forecast by Australian meteorologists could have a devastating effect on communities along Australia’s east coast, a leading geographer warns.
University of Sunshine Coast coastal system researcher, Dr Javier Leon, said a “worst case” scenario could see erosion levels similar to 1974 – when three consecutive La Niña events occurred in Australia.
Settlements “highly valued for tourism” across Queensland’s Sunshine Coast including Noosa and Maroochydore are of particular concern.
Dr Javier explained beaches should be at their “widest and tallest” in the springtime. As part of a natural annual weather cycle, waves usually replace sand drawn out to sea by summer’s big easterly waves.
The previous two La Niña events over the past two years have already caused significant erosion and the sand has not returned as it usually would. Beaches along the eastern seaboard are vulnerable to future extreme weather events which are more likely if a third La Niña occurs.
“Chances are that we will be seeing significant erosion throughout the summer,” Dr Leon said.
Human settlements, not just beaches at risk: 'Big problem'
Beaches are expected to change their position but with the building of coastal settlements, human expectations have changed.
“I’m not concerned for sandy beaches themselves. I’m kind of humanising beaches when I say this, but if they are unobstructed they move,” Dr Javier said.
“That's a natural dynamic of a beach. The problem is when you have something behind a beach which you value.
Concern over Noosa's main beach
Dr Javier said he is particularly concerned about the “highly valuable infrastructure” which surrounds Noosa’s main beach, along with housing and roads close to Burgess Creek which has been affected by increase rainfall and wave activity.
“If the beach moves, if the infrastructure is damaged, then we have a big problem,” he said.
“There's a really nice quote which says that the issues between the ocean and the coast are just like a lover's quarrel.
“The real issue is when humans try to fix [in place] the [coast line] which is dynamic by nature.”
Cost warning for maintaining coastal communities
On top of erosion, there are a number of added climate change induced threats which include rising sea levels, changing wave patterns and an increased chance of larger cyclones.
Dr Javier said much of Australia’s coastal infrastructure should never have been built, and there is “no easy way” to fix issues of risk that now affect infrastructure.
For instance, the construction of sea walls usually results in the beach behind it being eroded away.
“You're protecting everything behind it, but everything in front of it which is actually what we value gets lost,” he said.
“Of course keeping that sea wall every year becomes very expensive. So, economically at some point someone has to make a call.
“But at what point do we just say: We shouldn't be doing this. Because in the long run it is going to be more expensive than just literally moving away.”
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