Weather change & weather resources will decide Australia’s future in a warming world

By Iain Strachan,
Senior Advisor – Engagement and Impact,
The ARC Centre of Excellence in the Weather of the 21st Century,

What will a typical Australian summer look like in 2060? How can we maximise the potential of our rapidly growing renewable energy infrastructure? And how will high-impact weather, like storms, floods, and droughts, change in a warming world?

While we know human-driven climate change is occurring, the picture of what exactly that will mean for Australia in the coming decades is unclear. Climate models created in the United States and Europe lack the local data and specificity to provide good insight into what we can expect here.¹

What is clear, though, is that we’re already experiencing climate change as a change in our weather. Shifting energy production from fossil fuels to clean, renewable sources of energy is an essential part of mitigating and adapting to the changing climate. The output of renewables like solar and wind are dependent on weather. As such, they constitute weather resources. How can we build new wind farms if we don’t know where strong, consistent winds will be in the future? How can we make informed decisions about new water catchment and storage infrastructure without more accurate and precise data about future rainfall frequency and intensity?

Currently, it’s hard to answer these questions, because translating ‘climate change’ into weather change remains a major challenge for Earth System sciences.²

A new research initiative

The ARC Centre of Excellence for 21st Century Weather was established in 2024 as a consortium of 24 organisations, led by Monash University in partnership with the University of Melbourne, the University of New South Wales, the Australian National University, and the University of Tasmania. Its goal is to answer these questions, and equip Australian governments, businesses, and communities with the information they need to make informed, evidence-based decisions about climate change, high-impact weather and the future of our weather resources.³

The Centre has partnered with government and industry organisations, including the Bureau of Meteorology, CSIRO, the federal Department of Climate, Energy, the Environment and Water (DCCEEW), and the state Department of Energy, Environment and Climate Action (DEECA).⁴ By co-designing our research with the end users, we will ensure that elected officials, policy-makers, civil servants, and businesses have the bespoke information and expertise they need to take meaningful action.

To enable Australia to navigate this century’s climate and weather challenges with confidence, two major problems must be overcome: we need better understanding of atmospheric circulation change, and to develop more accurate, high-resolution climate modelling.

Atmospheric circulation change

The weather we experience near the Earth’s surface – the wind, the heat, the rain – is created by the movement of air in our atmosphere. Clouds and rainfall occur in regions where air is laden with moisture, while clear skies are the result of calm, dry air.

Atmospheric circulation transports heat around the Earth’s surface, and it is affected by incoming solar radiation, the Earth’s rotation, and the distribution of continents. The atmosphere both shapes and is shaped by the circulation of the oceans.

Human-driven climate change is altering the way that atmospheric and oceanic circulations combine to create weather systems.

The traditional approach to climate science studies weather, climate variability, and global climate change separately. Yet it is the interactions between these parts that provide the greatest potential for scientific predictions of future weather change.

There are several gaps in our knowledge that must be closed to fully harness the advantages of a weather-systems approach to understanding the climate of Australia and how it is changing.

First, the weather systems of the ‘mid-latitudes’ – between the Antarctic Circle and the Tropic of Capricorn, and between the Arctic Circle and the Tropic of Cancer – are fundamentally different from those in tropics (around the equator). As the Australian continent covers both these climatic zones, we need new approaches to describe weather systems across them.

Second, existing algorithms to objectively detect and track weather systems are generally limited to a single weather feature, such as a heatwave or weather front, yet it is important to consider a more complete picture of the weather.^5,6,7

To address these challenges, among many other new approaches, researchers will:

• Develop innovative algorithms to detect and track weather systems in the Australian region.
• Develop a comprehensive understanding of the physical and dynamic processes that determine weather system behaviour.
• Develop the first-ever definition of continent-wide Australian weather regimes through a unified tropical/extratropical circulation framework.

Ultra-high-resolution climate modelling

Climate models are a key tool to understand the Earth’s climate and its future. These are computer programs that simulate climate or weather patterns over time, and can estimate the Earth’s climate under different conditions by running simulations.

The climate system is made up of varying factors such as rain, wind, temperature, humidity, and solar radiation. Climate models are similar to weather prediction models, using mathematical equations to describe each component of the climate and how they interact, like the movement of the air in the atmosphere, or the exchange of moisture between the ocean, land and atmosphere.

Using advanced supercomputing facilities, climate model simulations enable us to understand how the different components of the earth’s climate interact and are changing. They allow us to test ideas and measure how our actions or decisions will change the climate in the future. For example, what happens if we increase greenhouse gas emissions, or revegetate landscapes?⁸

The Australian Community Climate and Earth System Simulator (ACCESS) is one of the climate models used worldwide to collectively provide an understanding of weather change at continental and global scales, but improving the models we work with is fundamental to improving our ability to understand future weather change.⁹ One particular issue with existing climate models is they cannot faithfully represent the key interactions between weather and climate that are so important to determining the future of our weather.

In response, 21st Century Weather and its partners are developing new, ultra-high-resolution climate models based on the ACCESS modelling framework. With a more accurate and precise modelling system, we will be able to represent physical processes in the atmosphere, on the land, and in the ocean at very fine scales, over a wide area. This will allow us to explore the links between climate variability (like the oscillation between El Niño and La Niña) and the weather (such as thunderstorms).

To develop the modelling systems that will underpin the Centre’s research, scientists will need to better understand how the atmosphere, ocean, and land influence each other, as well as managing the computational and big data aspects of running such models. The size of the task is enormous. Australia’s oceans and climate variability, for example, are modulated by the Pacific, Indian, and parts of the Southern Oceans. The modelling systems must therefore focus on small scales, while also considering the influence of important processes that occur over larger regions or the entire globe.

Building ultra-high-resolution models will require us to combine scientific discovery with the large-software systems that are climate models, as well as the most advanced high-performance computing and big-data handling capabilities, and advances in artificial intelligence.

Weather resources

We often think about ‘bad’ weather such as destructive storms or heatwaves, but what about ‘good’ or ‘useful’ weather?

The Centre will have a strong focus on weather resources, such as the wind and sun that are used to generate renewable electricity. For example, we know that certain parts of Australia have some of the ‘best’ wind energy resources in the world, but how do weather systems influence the wind that we can harness?¹⁰ How will these weather systems change as our planet warms? Will there be more wind-droughts and/or cloudy days, and how might this affect our electricity production?

Scientists within the Centre will endeavour to understand how the wind resource varies in coastal areas, and the interplay between renewable resources and electricity demand.

Achieving future climate resilience requires us to transform our thinking of “climate change” to “weather change”. Australia’s adaptation to a changing climate needs to be informed by the highest quality data and models. How will our changing weather impact our economy and community? It is the day-to-day variations in local weather that constitute resources and hazards to our society.

Researchers at 21st Century Weather will help to protect the economy, to inform investment in effective adaptation and risk mitigation, and to establish a knowledge-based decision-making mechanism for a prosperous future.

High-impact weather

Floods and droughts are a challenging fact of life in Australia, but weather events don’t have to be extreme to have a big impact on us. For example, unexpected absence of wind over a long period of time or prolonged cloud cover won’t put lives at risk, but they will significantly impact Australia’s renewable energy generation capacity.

We define high-impact weather as those events that pose either a large risk or provide a large benefit to communities, businesses and governments, or the natural environment.

As the Earth’s climate is warming, high-impact weather events are undergoing fundamental changes at a time when our reliance on them is growing as we decarbonise our economy. Owing to the complexity of the climate system, weather changes do not relate to increases in global mean temperature in a straightforward way. Instead, they are the result of an intricate interplay of thermodynamic and dynamic changes in the climate system and are strongly coupled to circulation changes). Understanding the nature of high-impact weather events and how they change in a warmer world is a key focus of our research

For example, warmer than usual sea surface temperatures to the north of the Australian landmass can lead to more moisture being carried through the air, contributing to flooding events on the east coast. However, the current models used to analyse these dynamics aren’t advanced enough to include representations of some tropical processes, like warm air rising, which leads to thunderstorms.

More accurate climate models will help us identify and understand the high-impact weather that Australia is already seeing more of, and which is likely to escalate over time. By understanding the two-way interaction between local high-impact weather, with wider weather regimes and large-scale planetary circulation, we aim to get a better understanding of local and global weather systems.

Whether it’s a lack of wind or an abundance of low cloud and fog that inhibits renewable energy sector expansion, or the torrents of rain that cause flash flooding and infrastructure damage, our research will help prepare Australians for the future of extreme weather.

Future forecasting

Knowing the future of our weather in a changing climate matters. It provides the resources for the weather-fuelled, net-zero economy that we need to build to combat the worst effects of climate change. The teams at the ARC Centre of Excellence for the Weather of the 21st Century are providing the insights needed to better prepare our economy and communities for the changing weather ahead.

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This article was made possible with contributions from 21st Century Weather researchers Prof Christian Jakob, Prof Sarah Perkins-Kirkpatrick, Dr Andrew King, and Dr Claire Vincent.

References:

1. CSIRO, & Bureau of Meteorology. (2015). Climate Change in Australia Information for Australia’s Natural Resource Management Regions: Technical Report (pp. 53–76). CSIRO and Bureau of Meteorology. https://www.climatechangeinaustralia.gov.au/en/communication-resources/reports/
2. Marotzke, J., et al. (2017). Climate research must sharpen its view. Nature Climate Change, 7(2), 89–91. https://doi.org/10.1038/nclimate3206
3. ARC Centre of Excellence for 21st Century Weather. https://www.21centuryweather.org.au/
4. Partners – 21st Century Weather. https://www.21centuryweather.org.au/our-partners/
5. King, M. J., & Reeder, M. J. (2021). Extreme heat events from an object viewpoint with application to south‐east Australia. International Journal of Climatology, 41(4), 2693–2709. https://doi.org/10.1002/joc.6984
6. Catto, J. L., at al. (2014). Atmospheric fronts in current and future climates. Geophysical Research Letters, 41(21), 7642–7650. https://doi.org/10.1002/2014gl061943
7. Pepler, A. S., at al. (2020). The contributions of fronts, lows and thunderstorms to southern Australian rainfall. Climate Dynamics, 55(5-6), 1489–1505. https://doi.org/10.1007/s00382-020-05338-8
8. What is a climate model? (2023, July 18). The ARC Centre of Excellence for Climate Extremes. https://climateextremes.org.au/what-is-a-climate-model/
9. Australian Community Climate and Earth System Simulator (ACCESS). https://research.csiro.au/access/
10. Building an offshore wind industry. (2023, October 23). DCCEEW. https://www.dcceew.gov.au/energy/renewable/offshore-wind/building-offshore-wind-industry