To the extent that resources available for climate science in Australia at the national level can be clearly identified, they have been broadly stable over the past 5 years. The 2 largest programs – the National Environmental Science Program (NESP) Climate Systems Hub and the Australian Research Council (ARC) Centre of Excellence for Climate Extremes – succeed predecessor programs that were in place in 2016; the NESP Climate Systems Hub is of somewhat larger scale than its predecessor. Significant climate science activity takes place within the core funding of larger organisations, such as the Bureau of Meteorology, or benefits from broader community infrastructure, such as the National Computational Infrastructure and the Bureau of Meteorology’s supercomputing capability. Many climate science activities in Australia also draw on resources from outside Australia, including climate models produced by international institutions, observations from satellites operated by other countries, and global or semi-global datasets maintained by other institutions. Research, data and monitoring Australian climate science research infrastructure and programs Climate science research in Australia takes place across a broad range of institutions, including the Bureau of Meteorology, CSIRO, other state and national organisations, and universities. The NESP has provided long-term support to science in this field. The largest current single Australian program in the area is the Climate Systems Hub under the NESP, which succeeds the previous NESP Earth Systems and Climate Change (ESCC) Hub, although with annual funding approximately 50% greater than the ESCC Hub. The hub is hosted by CSIRO, with involvement from the Bureau of Meteorology and various universities and state government agencies. The main purposes of the hub are to: maintain Australia’s world-class capability in multidisciplinary Earth-system science and modelling advance understanding of Australia’s climate variability, extremes and associated drivers, including the fundamental drivers of bushfires, drought and rainfall in the Australian region develop applied decision-making tools and information to inform policy and programs to prepare Australia to manage emerging risks and opportunities. There is significant involvement from state and territory governments, particularly in the area of applications of climate science. Numerous other climate science programs are supported by the Australian Government, in conjunction with partners in government, academic and private sectors. A pilot project to expand and upgrade Australia’s Australian Community Climate and Earth System Simulator (ACCESS) was funded under the National Collaborative Research Infrastructure Strategy, to commence in 2021. Numerous programs in the academic sector relate to climate impacts. Significant climate science is also carried out by the Bureau of Meteorology and CSIRO as part of their normal operations. The Bureau of Meteorology is responsible for foundational observational datasets, and CSIRO established a Climate Science Centre in 2016, consolidating various climate programs that had largely taken place within CSIRO Marine and Atmospheric Research. The Bureau of Meteorology and CSIRO also produce a biennial report on the state of the climate, which was most recently published in late 2020 (BOM & CSIRO 2020). In the university sector, the ARC Centre of Excellence for Climate Extremes replaced the previous Centre of Excellence for Climate Systems Science in 2017. The centre of excellence carries out research programs across several universities, with a number of national and international partners. State and territory governments have supported numerous climate science projects during the past decade, either by carrying out research themselves or by commissioning research by other organisations, focusing on their specific regions and subjects of particular importance to their jurisdiction. Examples include: the NARCliM (NSW and ACT Regional Climate Modelling) project, led by the New South Wales Government, and involving the Australian Capital Territory and South Australian governments and other partners; this has delivered high (spatial)-resolution climate projections across south-eastern Australia Victoria’s climate science report 2019 (DELWP 2019), which reports on a range of climate science matters relevant to Victoria; delivery of regular climate science reports is a requirement of Victorian climate change legislation the Climate Futures for Tasmania project, which provided downscaled climate projections for Tasmania, and case studies relating to specific industries and other stakeholders; Queensland has also developed downscaled climate projections for the state. These state-level initiatives followed the success of projects such as the Indian Ocean Climate Initiative in Western Australia, which ran between 1997 and 2006. The outcomes of this project were influential in many subsequent policy decisions in Western Australia (Indian Ocean Climate Initiative 2012), particularly decisions around the augmentation of water supplies in Perth and surrounding regions. Data The available data are generally sufficient for monitoring changes in key climate variables at the national, and state and territory scales. There are some data-sparse regions in remote areas, particularly the interior of Western Australia, the north-west of South Australia and parts of the Northern Territory. There are also some areas with complex topography and steep local climatic gradients, such as western Tasmania and parts of the coastal ranges of New South Wales, where the observation network may not adequately resolve local climate variations, particularly for rainfall extremes. The conventional observation network for temperature and rainfall has been relatively stable in size over recent decades. Dependence on automated observations is increasing. This has allowed increased time resolution of data and more observations in unpopulated areas, but has also led to a loss of data for some variables that cannot be easily automated, such as cloud amount and type, and pan evaporation. Satellite remote sensing has become increasingly important, and has allowed comprehensive monitoring of tropical cyclones over the full Australian region (including over the open ocean far from the coast), as well as monitoring of sea level around all parts of the Australian coastline. Only very limited use has been made of remote-sensing data in regular national-level monitoring of temperature and rainfall in Australia, although it has potential to support improved information from remote areas. Ocean temperature observations, both on and below the surface, have also improved considerably in recent decades. Historically, sea surface temperature observations were made from ships, leading to limited availability of data away from major shipping routes. These measurements are now complemented by satellite observations, and an increasing network of drifting and moored buoys. A major initiative over the past 20 years has been establishment of a network of Argo drifting buoys, which provide regular temperature profiles from the surface to a depth of approximately 2,000 metres over most areas of the world’s oceans. In addition to improved monitoring of the Australian region itself, such observations provide important information about modes of climate variability remote from Australia (such as parts of the equatorial Pacific that form a major indicator of the El Niño–Southern Oscillation). A significant constraint on the assessment of climate change over time is the availability of historical data. For some variables, historical data before a certain date either do not exist, exist only in paper form, or require significant rehabilitation to be useful for scientific purposes. A project is currently in progress at the Bureau of Meteorology to rehabilitate tide gauge data to allow improved assessment of Australian sea level changes before the start of satellite observations in 1993, following previous work to develop consistent temperature datasets back to 1910. Most Australian rainfall data have been digitised (except for daily data before 1907 in Western Australia), but significant quantities of pre-1965 daily and subdaily temperature data remain undigitised, constraining the assessment of some types of extremes. Apart from projects targeting a few individual locations (see Citizen science), this situation has remained largely unchanged since 2016. Indigenous engagement and data in research projects related to climate are also minimal. It is often a secondary element in research methodologies, but improving the capacities of First Nations people to collect and interface their own observational data would enhance the overall outcome of research projects. Modelling and communication There have been significant developments in seasonal and subseasonal climate prediction in recent years, including the introduction of a new seasonal prediction model (ACCESS-S) by the Bureau of Meteorology. This has supported the extension of seasonal rainfall and temperature predictions (previously only issued for 3-month periods) on timescales ranging from 2 weeks to 3 months. Work is ongoing to extend seasonal predictions to various indicators of extremes. Improved seasonal prediction supports farmers and other stakeholders in managing climate risk and is viewed as an important part of supporting climate change adaptation, particularly in the agricultural sector. Climate change projections in Australia draw heavily on a range of global climate models, which are coordinated under the Coupled Model Intercomparison Project (CMIP). The CSIRO climate model is one of many models contributing to CMIP, which involves a large number of international research groups. Models from the most recent stage of CMIP (CMIP6), timed to support the Intergovernmental Panel on Climate Change (IPCC) Sixth Assessment Report, are progressively becoming available. However, at the time of writing, the bulk of Australian climate science applications still draw on the previous CMIP stage (CMIP5), pending full availability and assessment of CMIP6 model results. A major channel for delivering information on climate change projections for Australia to users is the Climate Change in Australia website. This website (and its predecessors) generally have major updates following each IPCC cycle. The most recent update of these projections was released in 2015, following the release of the IPCC Fifth Assessment Report in 2014. As such, the climate projections reported in the 2016 state of the environment report are still the most current for Australia as a whole, although projects using regional models or downscaling have provided additional information since then at a local level in some regions. Citizen science Community volunteers have been instrumental in climate observations in Australia since the earliest days of formalised weather recording. A large proportion of the Bureau of Meteorology’s rainfall observations have been made by volunteers, many of them on rural properties. Many of the observation sites have operated for 100 years or more, often spanning multiple generations of the same family. The longest-standing volunteer rainfall site in Australia, at Mount Buninyong near Ballarat in Victoria, has been making observations almost continuously since 1856. Although these observations are not often considered under the term ‘citizen science’, they are critical to our understanding of rainfall change and variability in Australia. A specific application of citizen science in the climate area has been the recovery of historical data. Significant quantities of historical data exist only on paper and are effectively inaccessible for further analysis. Numerous citizen science projects, both in Australia and internationally, have involved digitising such records to make them available for further assessment by the scientific community. One notable international example took place through the Weather Rescue project (Zooniverse 2021), based at the University of Reading in the United Kingdom, which focused on digitising pre-1960 British daily rainfall records. As part of this project, during the first British COVID-19 lockdown in 2020, more than 5 million individual observations were digitised, by more than 16,000 volunteers. The first major Australian citizen science project of this type was also completed in 2020, drawing on both volunteers working under the auspices of the Bureau of Meteorology and the broader community. In this project, daily observations from Adelaide from 1839 onwards were digitised, combining with existing Bureau of Meteorology data (starting in 1887) to produce the longest single dataset in Australia and one of the longest in the Southern Hemisphere (Gergis et al. 2020, Ashcroft et al. 2021). Case Study Talking in Arrernte about climate change During 2014–15, the Ltyentye Apurte Central Land Council Rangers and CSIRO scientists shared knowledge about climate change to improve understanding and regional records. Ltyentye Apurte Rangers started by assembling local data, including photographs and recollections, to construct their own weather and climate timeline (Figure 22). They compared this timeline with scientific weather and climate data (Figure 23), showing a strong alignment that allowed the rangers to see trends that had not been obvious before: Timeline of major events, like floods, fires, droughts and other things people could remember … showed the knowledge of local people and how the events aligned with and matched weather patterns with those recorded with scientists. We … observed notable changes in those graphs and records, showed more days over 40 °C, also bigger floods happening in later times. (Ltyentye Apurte Ranger Coordinator, 2015) Figure 22 Ltyentye Apurte Rangers and CSIRO scientists looking at the 2 timelines together Expand View Figure 22 Ltyentye Apurte Rangers and CSIRO scientists looking at the 2 timelines together Photo: Fiona Walsh Figure 23 Days above above 40 °C by year, 1942–2019; dark bars highlight years with more than 20 such days Expand View Figure 23 Days above above 40 °C by year, 1942–2019; dark bars highlight years with more than 20 such days Source: Bureau of Meteorology Arrernte Elders also provided information about changes on Country, summarised by the ranger coordinator as: Indigenous people of central Australia have been carers for Country for generations, passing on important cultural knowledge for land management practices. Over time, our people have noticed changes in the weather and seasons. Seasons seem more mixed up. Bush tucker is not fruiting or flowering at the right time of year. The rangers were very interested in helping Arrernte people understand more – one of the rangers said, ‘I’m going learn this, learn all this, and put it in Arrernte so my mob can understand it.’ The scientists and the rangers worked together to produce a book and a slideshow in English. The rangers then presented this to Arrernte community audiences, speaking in Arrernte. People were grateful to hear about it in their own language, commenting that they had seen a lot about climate change on television, but had not understood what it was about before. Many impacts and potential solutions were also identified, including changes to houses, increased shade, and greater access to the swimming pool and cool buildings. The main road to the Ltyentye Apurte community where the rangers live and work is being threatened by an erosion gully that is rapidly expanding as a result of large rainfall events. These events are increasing in intensity and frequency due to climate change. Rangers undertook activities and co-learning about erosion, in collaboration with scientists and practitioners, and established a trial of a new way of managing erosion. They built a set of control banks along the contour in 1 small catchment. However, the trial was compromised by inconsistent management of free-ranging horses, which trampled the control banks and led to bank breaching during heavy rains. Rebuilding of the control banks is currently impeded by loss of access to necessary resources. The problem of climate change for Aboriginal people in central Australia is enormous. In the words of Central Land Council Chair Sammy Wilson during the 2019 Global Climate Strike (Central Land Council 2019): I call on them to spare a thought for Aboriginal people out bush who may not be able to travel to the strikes but who are already suffering most during our hotter, longer and drier summers … I am dreading another summer like the last one because it is especially tough on our old and sick people who live in overcrowded, poor quality houses. Sammy Wilson, Central Land Council Chair Share on Twitter Share on Facebook Share on Linkedin Share this link New technologies A wide range of new technologies have been deployed, or are in development, to reduce greenhouse gas emissions. Among the most significant to date has been technological development in the generation of solar power. Combined with increased economies of scale as the solar industry has grown, this has led to a dramatic fall in the price of solar power generation. Globally, the cost of utility-scale solar decreased on average by 82% between 2010 and 2019 (IRENA 2020). Technological improvements, particularly in increasing the capacity factor, in wind power generation have also led to falls in costs (globally averaged, 30% for onshore wind between 2010 and 2019). These falls in costs, largely technology driven, have made wind and solar electricity generation increasingly competitive in Australian electricity markets (even in the absence of market intervention) and have contributed to the increasing proportion of Australian electricity that is generated from renewable sources. This has contributed significantly to the declining trend after 2007 in emissions from the electricity sector in Australia. Improvements in battery technology have also driven cost decreases, as well as increased capacity. The Hornsdale Power Reserve in South Australia was installed in 2017, providing the largest capacity to date in utility-scale electricity networks, and further installations are planned. To date, these developments have primarily provided grid stabilisation services and have had only a marginal direct impact on emissions, but the existence of cost-competitive storage will be important in the further penetration of renewable energy in the electricity market. Improved energy storage options also support household-level solar power generation, and will be important to the future competitiveness of electric vehicles. Development of new technologies will continue to be an important contributor to emissions reduction in Australia and worldwide. The Australian Government has established a Technology Investment Roadmap that outlines its strategies and policies for supporting investment in new technologies. Priorities in this roadmap include hydrogen production using emission-free power sources (already the subject of initiatives in most states and territories), reducing the cost of energy storage and soil carbon storage, low-carbon materials, and carbon capture and storage. In addition to supporting emissions reductions in Australia, some of these also have potential as the basis for export industries.