Danger from extreme storms and high seas to rise

June 08, 2016

Storms that battered Australia's east coast are a harbinger of things to come and a stark reminder of the need for a national effort to monitor the growing threat from climate change, UNSW coastal researchers warn.

"The damage we've seen is a harbinger of what's to come," said Ian Turner, Director of the Water Research Laboratory at the University of New South Wales. "Climate change is not only raising the oceans and threatening foreshores, but making our coastlines much more vulnerable to storm damage. What are king high tides today will be the norm within decades."

Turner's lab manages one of the world's longest-running beach erosion research programs, at Collaroy and Narrabeen in Sydney, using drones, real-time satellite positioning, fixed cameras, and airborne LiDAR and quadbikes. The variability, changes and trends in coastal erosion at the beaches have been tracked since 1976.

But the data collected by the UNSW team is only reliable for modelling when it comes to predicting effects in southeastern Australia. For the vast bulk of Australia's 25,760 km long coastline, researchers -- and the governments and coastal communities they advise -- are largely making guesses based on limited or non-existent data, say researchers.

"The wealth of data we've collected over decades makes our models of coastal variability increasingly more reliable -- but only for a 500 km stretch of southeastern Australia," Turner added. "But when it comes to modelling other parts of Australia, in many locations we are basically working blind.

"There are very different coasts across the country exposed to very different conditions, and we just don't have the observational data we need to make predictions with any great confidence," he said. "For that, we need a national approach."

The long-term data from the UNSW program has been crucial in understanding how climate change is changing Australia's coasts, recently showing that El Niño and La Niña cycles will intensify coastal hazards, leading to changes in behaviour of storms, extreme coastal flooding and erosion in populated regions across the Pacific.

As a result, estimates of coastal vulnerability - which once focussed on sea level rise -- now have to factor in changing patterns of storm erosion, more intense storms, and other coastal effects.

Dr Mitchell Harley, a Senior Research Associate at the Lab who manages the Narrabeen-Collaroy program, said that beach erosion and coastal variability has been found to be a lot more complex than had originally thought, partly thanks to insights from the UNSW data.

"It's now clear that sea level rise is not the only player in climate change: shifts in storm patterns and wave direction also have consequences, and distort or amplify the natural variability of coastal patterns," Harley said.

Turner added, "These are precisely the conditions we experienced in Sydney over the past weekend -- waves from the north-east, combined with unusually high sea levels brought on by king tides wreaked considerable damage. And, as sea levels rise, even ordinary tides will reach higher. What we consider king high tides today will be commonplace within decades."

In 2014, Australian coastal researchers called for the creation of a national coastline observatory, with basic data - such as sub-aerial profiles, bathymetry and inshore wave forcing measurements - collected routinely from a network of around 20 'representative' beaches across Australia.

This would provide valuable data that could be used to more accurately model how Australia's more than 11,000 beaches are changing, and predict how they will respond as climate change sets in.

The long experience gained by UNSW in Sydney's Northern Beaches "gives us a template of what can be achieved across Australia," said Turner. "But without consistent and national observational data -- from very different regions like the tropical north, or the highly energetic southwestern coastlines, or the Indian Ocean coastlines of Western Australia -- it's of little value. To say we have blindspots is an understatement."

Harley agreed, adding: "For the great majority of Australia's coastlines, we don't have observations for how they are behaving now -- let alone any clear idea how they might respond to increasing variability in the future. We see it happening at Narrabeen-Collaroy, and can therefore predict it for this part of Australia. But elsewhere, we're largely operating in the dark."
DOWNLOADS & LINKS AVAILABLE (Must credit: "UNSW Water Research Laboratory")



UNSW's Faculty of Engineering is the powerhouse of engineering research in Australia, comprising of nine schools, 21 research centres and participating or leading 10 Cooperative Research Centres. It is ranked in the world's top 50 engineering faculties, and home to Australia's largest cohort of engineering undergraduate, postgraduate, domestic and international students.

UNSW itself has 52,000 students from 120 nations, and is ranked #1 in Australian Research Council funding ($68.3 million in 2014), ranked #1 in Australia for producing millionaires (#33 globally); and ranked #1 in Australia for graduates who create technology start-ups.

University of New South Wales

Related Climate Change Articles from Brightsurf:

Are climate scientists being too cautious when linking extreme weather to climate change?
Climate science has focused on avoiding false alarms when linking extreme events to climate change.

Mysterious climate change
New research findings underline the crucial role that sea ice throughout the Southern Ocean played for atmospheric CO2 in times of rapid climate change in the past.

Mapping the path of climate change
Predicting a major transition, such as climate change, is extremely difficult, but the probabilistic framework developed by the authors is the first step in identifying the path between a shift in two environmental states.

Small change for climate change: Time to increase research funding to save the world
A new study shows that there is a huge disproportion in the level of funding for social science research into the greatest challenge in combating global warming -- how to get individuals and societies to overcome ingrained human habits to make the changes necessary to mitigate climate change.

Sub-national 'climate clubs' could offer key to combating climate change
'Climate clubs' offering membership for sub-national states, in addition to just countries, could speed up progress towards a globally harmonized climate change policy, which in turn offers a way to achieve stronger climate policies in all countries.

Review of Chinese atmospheric science research over the past 70 years: Climate and climate change
Over the past 70 years since the foundation of the People's Republic of China, Chinese scientists have made great contributions to various fields in the research of atmospheric sciences, which attracted worldwide attention.

A CERN for climate change
In a Perspective article appearing in this week's Proceedings of the National Academy of Sciences, Tim Palmer (Oxford University), and Bjorn Stevens (Max Planck Society), critically reflect on the present state of Earth system modelling.

Fairy-wrens change breeding habits to cope with climate change
Warmer temperatures linked to climate change are having a big impact on the breeding habits of one of Australia's most recognisable bird species, according to researchers at The Australian National University (ANU).

Believing in climate change doesn't mean you are preparing for climate change, study finds
Notre Dame researchers found that although coastal homeowners may perceive a worsening of climate change-related hazards, these attitudes are largely unrelated to a homeowner's expectations of actual home damage.

Older forests resist change -- climate change, that is
Older forests in eastern North America are less vulnerable to climate change than younger forests, particularly for carbon storage, timber production, and biodiversity, new research finds.

Read More: Climate Change News and Climate Change Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.