Understanding how Australia’s climate drivers influence extreme climate

December 1, 2023

Helen Bloustein from the Victorian Department of Energy, Environment and Climate Action is a hub knowledge broker. Together with hub scientists Dr Christine Chung and Dr Pandora Hope she has been working with the project to survey decision makers across Australia  to understand their needs for extreme weather and climate information.


Flooding: Greater Shepparton City Council (2022)

Flooding – Great Shepparton City Council (2022)

Over the last few years Australia has lived up to its name as a land of drought and flooding rains. That’s why a key focus for hub scientists is understanding how climate drivers such as El Niño and a positive Indian Ocean Dipole may lead to a warmer and drier climate this summer.

But it was not so long ago that extremely wet conditions affected large swathes of the nation. Australia was under the influence of 3 consecutive La Niña years. The 2022 La Niña was alongside a negative Indian Ocean Dipole and positive Southern Annular Mode phase exacerbating wet conditions.  

Thankfully, these wet conditions have not been in the headlines as much in 2023, but research to better understand the climatic conditions that contributed to the rainfall of the previous 3 years, and the influence of climate change on these factors, is ongoing.  

Maps of Australia showing spring rainfall totals in 2020, 2021 and 2022 (Australian Gridded Climate Dataset data). Darker green colours indicate higher rainfall totals.

Hub researchers are using multiple approaches to explain extreme events and understand the characteristics and dynamics of extremely wet conditions, droughts, and hot-and-dry events across the country. They’re investigating the science but also getting input from decision makers on what’s important to them so the science can be used by them to prepare for future events.

During 2023, the hub’s Extreme climate: dry, wet, hot-and-dry and Extreme events explained projects joined forces with hub knowledge brokers to enable state-based decision makers to contribute their perspectives and inform research design.

In particular, the team, led by hub scientists Dr Christine Chung and Dr Pandora Hope, wanted to know the types of questions different organisations had about the recent extremely wet years to:

  • directly inform the research including establishing which parameters to analyse in climate models
  • shape the research narrative
  • strengthen explanations about such events to help decision makers better understand the potential for extreme impacts if similar conditions were to re-occur.

A survey was sent to decision makers in Queensland, New South Wales, Victoria and South Australia – the states most affected by the wet conditions over recent years.

Survey participants came from multiple sectors, including water and catchments, emergency response, fire and forest management, education and training, and infrastructure. The majority affirmed that they needed to know more about which climate factors influence heavy rainfall events to make better decisions in their jobs.

Researchers reviewed and grouped all responses and identified common themes. Questions under 2 key themes are now being fed directly into a series of important research lines of inquiry.

Some common questions received include:

  1. Projections of modes of climate variability and associated climate drivers
  • How common have triple ENSO events been and how are these likely to change in the future? Is it possible to have, for example, more than 3 La Niñas, or 3 El Niños?
  • What regional changes to rainfall are projected for future ENSO events?
  • How does climate change impact the predictability of ENSO events?
  • What ocean conditions are associated with ENSO, and in particular triple La Ni ña events?
  • Can we provide clarity on uncertainty in these projections?
  1. Projections of extreme events
  • What are the projected changes to extreme rainfall (frequency, amplitude, spatial patterns) and likelihood of floods?
  • Can we improve spatial predictions of extreme events?
  • Can we find out more about the relative contribution of climate change and natural variability?
  • What is the link between the future scenarios and severity?

Where to next?

Research outputs are expected in 2024 with the synthesised results to be made available through the hub and other channels.

Understanding the behaviour and interaction of these drivers, especially under a warming climate, provides critical information to support evidence-based climate adaptation and decision-making, we’ll also provide further details about the co-design approach taken including insights from the decision-maker survey.

Stay informed

Contact us to ensure you receive updates about this important research when results are released in 2024.


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