We’ve all heard about the impacts of climate change to our oceans and coasts – from increasing ocean heat content to sea level rise to coastal erosion and inundation.
Here at the Earth Systems and Climate Change Hub we’ve contributed significantly to increasing scientific understanding of what these impacts might look like, where they might occur and by when. Research conducted into how our oceans and coasts are changing now and into the future is helping coastal managers to better understand their current and future climate risks and to develop effective and long-lasting solutions.
Here are some key areas the Hub has focused on in order to better understand our changing oceans and coasts.
Tracking ocean change
Observing and measuring the ocean is vital for managing and mitigating human impacts on our environment, understanding weather patterns and making climate and weather predictions. But the ocean extends far beyond any national boundary, making international collaboration and coordination vital.
The Hub has supported Australian participation and leadership in international ocean observing systems and initiatives helping to better understand our changing oceans and track climate change. We’ve also helped to support many of Australia’s operational data management and quality control activities of important global networks, including Ships of Opportunity, Argo, XBT and GO-SHIP.
Projecting future trends in marine heatwaves off the coast of WA and Tasmania
The Tasman Sea is a global hotspot for ocean warming, with sea temperatures rising much faster than the global average rate. The two most intense marine heatwaves in this region have occurred in recent years (2015/16 and 2017/18). In addition, the Western Australian coast experienced its most devastating marine heatwave event in 2011. Each of these marine heatwave events caused widespread impacts to the local environment, ecology and ocean-dependant industries.
Were these one-off events? Will we see more of these events into the future as the climate continues to warm? To answer these questions, Hub researchers investigated the likelihood of marine heatwaves with a similar intensity and duration to these events occurring in the future for both WA and the Tasman Sea.
Read about what they found in these two new factsheets:
Updating sea level rise projections
A business-as-usual climate scenario, whereby sea-level increases by 1.1 metre by 2100, would put more than A$226 billion (2008$) of Australian commercial, industrial, transport and residential assets at risk from erosion and flooding hazards. Up-to-date and relevant sea-level rise projections are therefore required to help identify and mitigate the risks for coastal communities and infrastructure into the future.
The Hub contributed to international research and collaboration to better understand and estimate future sea-level rise, which included revised contributions from melting Antarctic ice sheets. We found that a potentially higher Antarctic contribution (under a high-emissions scenario) raises the sea-level projections for Melbourne from around 1 m (as reported on the CoastAdapt website) to around 1.1 m by 2100.
Understanding future extreme sea level events: a Sydney case study
Extreme sea-level events impact our waterways and coastlines, causing coastal inundation and erosion. Coastal inundation events in Australia are projected to occur more frequently due to climate change and the resulting sea level rise. In coastal communities such as Sydney, there is evidence that inundation events once considered to be rare are now occurring much more frequently.
The Hub investigated how extreme sea level events may change for Sydney’s beaches and harbour under a warmer climate. We also updated an online sea level rise calculator (Canute3.0) to help coastal practitioners understand the risks of extreme sea level events inundating coastal structures and ecosystems. The tool can be used for various locations around the Australian coastline.
Changing wind-wave conditions along Australia’s coastline
Climate change is driving changes to surface ocean winds and to the characteristics of the resulting wind-waves. Changes to the height, length or direction of wind-waves are expected to impact Australia’s coastline, potentially contributing to future coastal flooding and erosion.
The Hub has led the international coordination of a new community-driven wind-wave climate model ensemble, which has been used to assess how wind-waves may change under future warmer climate scenarios globally, and around Australia. The resulting information will assist coastal managers in understanding which areas around our coastline will be most prone to changes in wind-wave conditions.
Climate change services for Australia’s blue economy
The blue economy refers to the sustainable use of ocean resources for economic growth, improved livelihoods and jobs and ocean ecosystem health. Australia’s blue economy industry sectors include tourism, ports, oil and gas, fishing and aquaculture, shipping and renewable energy. These blue economy sectors are responsible for significant infrastructure projects, deploy a wide range of offshore and coastal assets, and undergo a broad range of offshore operations. Increasingly, these sectors will be required to identify, assess and mitigate their exposure to climate change-related risks associated with their offshore infrastructure and operations.
The Hub has established a set of climate change projection products to support development of offshore climate change management and adaptation strategies for the blue economy.
The research which underpins these products was supported under ESCC Hub projects 5.7: Tracking ocean change – ocean observations and models and 5.8: Marine and coastal climate services for extremes information