University of Western Australia
Julian Partridge and Charitha Pattiaratchi show how climate change is affecting our oceans and the coasts we live on. While these expected changes are daunting, they can be tackled by bringing together experts from different fields to work on creative solutions.
If you are Australian, you probably live near the sea. Why? Because 85% of Australian’s live within 50km of the coastline. Are you concerned that your favourite bit of coast may be changed forever by a high tide and a big storm?
How climate change is changing our coasts
You might well be. Sea levels are rising all over the world due to climate change. As the oceans heat up, they increase in volume. As polar icecaps melt, more water spills into the sea. Sea levels are rising one or two millimetres per year. That doesn’t sound like much? By 2030 sea level will be 10-20 cm higher than now, and 15-40 cm by 2050.
Of course, sea level goes up and down every day with the tides. The greatest tide range occurs every 29.5 days at ‘spring tides’, when the moon is aligned with the sun. In the Kimberley in the North West of WA, spring tides can rise and fall over 11 meters in a single day; in Perth about a half a meter. But remember, these tides range around the average sea levels: you have to add them together to understand the level of the sea.
Then there are ‘high stands’ that happen every 18.6 years, due to the way the moon rotates around the earth, adding another 20 cm.
Also, the unpredictable swing between El Niño and La Niña (these are complex weather patterns resulting from variations in ocean temperatures in the Equatorial Pacific) changes weather and ocean currents across the Pacific every two to seven years. Here in WA, La Niña increases sea levels by up to 20cm.
As sea level rises, shorelines move further inland.
For every centimetre of sea level rise, a sandy coastline recedes a meter or more.
Unfortunately, climate change also brings frequent storms. Huge waves pound and reshape the coast, moving sand and sediments. Storms also bring pulses of higher sea level: ‘storm surges’ that push water inland.
“Imagine what might happen if a storm surge, La Niña, a lunar ‘high stand’, a spring tide and sea level rise were to combine sometime in the next 30 years. Coastal homes and industries could be flooded; battered coastlines changed forever. We need to prepare our lives for changes in the coastal zone.”
Who do we need to prepare for this change?
So, what can we do to prepare? To work out what is needed, imagine you live (as many Australians do) in a house built on low-lying land behind sand dunes and a sandy beach, close to the sea. Imagine you are part of a township that has lived there for decades, enjoying the convenience and closeness of the ocean. Perhaps you are noticing changes to your local shoreline or experiencing occasional flooding. How do you assess the threat from sea level rise or flooding? How do you, as an individual, family or town, decide what to do about it? What groups of people need to be involved in determining your options? It is likely that you will turn to experts. Fortunately, Australian universities train some of the best in their respective fields. These are some of the professions that, put together, will be able to help us prepare for the challenges of climate change:
- Oceanographers (they study waves and currents, ocean circulation, plate tectonics and the geology of the seafloor, and the chemical and physical properties of the ocean)
- Coastal ecologists (they study marine life and ecosystems: the animals, plants and other organisms inhabiting the coastal habitat)
- Cultural heritage experts and indigenous elders (they understand the ways of living developed by a community and passed on from generation to generation)
- Coastal, geotechnical, civil and environmental engineers (they create, design, invent and build structures, machines and systems that address the physical impacts of climate change)
- Biologists (they study the mechanisms that govern the functioning of living matter)
- Population health experts (they study patterns of health and disease in society)
- Economists (they know how people interact with value; in particular, the production, distribution, and consumption of goods and services)
- Lawyers (they apply abstract legal theories and knowledge to solve specific problems of individuals)
- Insurers (they create insurance schemes and provide financial compensation if needed)
- Social scientists (they provide insights into the different ways individuals, groups, and institutions make decisions, exercise power, and respond to change)
- Psychologists and psychiatrists (they assess, diagnose, and treat mental, emotional, and behavioural disorders)
- Communication experts (they know how to create effective and targeted messages)
Firstly, you will need oceanographers who can look at your local coast, map how it shelves into deep water and examine how currents and tides operate in your region to predict dangers where you live. You may also want to know the impacts on biodiversity and marine and coastal habitats – your local marine plants and animals - and whether impacts on wildlife will be long term or short term in their consequences: for that you need coastal ecologists.
You will probably have things in the town that you care about more than others. Things that matter to the culture or the heritage of your community, including those of particular significance to Indigenous Australians from your area, may need to be prioritised when making plans on how to safeguard your community from the effects of climate change. To fully work out the significance of such things you will need cultural and heritage experts and you will need to talk to Indigenous leaders.
You will probably quickly want to know ‘what can be done’ with structures that might provide a sea-defence. For that you will need coastal engineers to suggest hard structures such as groins, sea- walls, or barrages; as well as geotechnical engineers who can assess the best foundations for the engineers’ proposed structures. Well-versed engineers are also working with biologists to bring ‘biological engineers’, for instance marine plants such as sea grasses and mangroves that can provide natural sea defences, into the mix.
You should also be talking to civil and environmental engineers as flooding by the sea might be problematic for water supplies, drainage and sanitation. Population health experts are important too as they might look at the health impacts, diseases or injuries that are likely to occur if the sea invades.
Once the engineers have presented options, and you have different ideas before you, how will you decide which is the best? You will probably need economists who can work out the costs of different options and analyse the possible benefits, both in terms of money and in terms of other values – the things your specific community values highly, for instance.
At some point you will want to know how your local or State government intends to be involved; you will quickly find that the networks of responsibility overseeing decision-making in the coastal zone are complex and diverse. There are many different people who are interested in what happens in the coastal zone: house owners, industries, commercial and recreational fishers, aquaculture farms, tourists, and many others, all of whom have interests (sometimes competing) to be considered. Local councils and State government departments somehow have to represent all of them.
Inevitably, you will need the advice of lawyers to advise on the legal aspects of your community’s courses of action, as well as insurers who may be expected to compensate land or property owners if properties have to be abandoned or if proposed solutions might only be temporary fixes.
You may also have to face the reality that nothing can be done; and your neighbourhood has only one option – to retreat and relocate. Around the globe, this is what many communities are now doing. If options are limited in this way, you may be faced with huge changes to your way of life, such as having to move away from your home: for that you need social scientists who can liaise with your community to prepare for unwelcome options such as the abandonment of houses or other infrastructure.
You may well also need psychologists and psychiatrists to help people in dealing with negative reactions to change. As options are discussed, you might well need a communications team who can keep your community informed, who understands the best way to communicate with diverse groups of people, and who can translate sometimes complex advice from specialists into information that is easier to understand.
And given all this complexity, you are likely to benefit from educators who can empower your community with enough understanding of different sea-level rise scenarios, talk through the different probabilities of flooding or damage, clarify the different risks, explain how decisions are made, and how your community can drive that decision-making process.
Making expertise accessible for everyone affected is the very reason we are reframing our original chapter in the Preparedness Report for a younger audience. In order to address the challenges before us, everyone needs to understand the problem as well as the possible solutions – particularly young people like you, who will be bearing the brunt of climate change’s consequences.
Sounds complicated – but there is reason to be hopeful…
If this all seems daunting, it need not be. By preparation, society can be proactive, not reactive, as climate change impacts in coastal areas become frequent. The University of Western Australia recognises this need, and its Oceans Institute is well placed to put together teams with experts from different disciplines including oceanographers, marine engineers, ecologists, biologists, social scientists, economists, lawyers etc. To prepare further, the Oceans Institute is placing ‘Future Coasts’ as one of its key priorities for the next few years to ensure it is ready to provide leadership in coastal zone management and to identify coastal solutions for people in Western Australia, as well as across our wider region.
With so much of Australia’s population concentrated in coastal areas we all need to prepare now for inevitable challenges ahead. With that mindset, life will go on; different maybe, but hopefully more sustainable and, if we prepare well, it could be even better than before.
Julian Partridge is the Acting Director of The University of Western Australia’s Oceans Institute. He has a research background in marine biology and more than three decades experience developing research and teaching in world ranking Universities in the UK and Australia.
Charitha Pattiaratchi is Professor of Coastal Oceanography at The University of Western Australia. He uses field measurements, remote sensing, and computer modelling as the tools of his research to examine physical processes on coastal regions including impacts of climate change.