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The tropics are expanding poleward at an alarming rate-with massive implications for societies, economies, and natural environments. This expansion appears to be determined largely by anthropogenic drivers-notably rises in greenhouse gases. Of greatest concern is the poleward shift of the dry sub-tropical zone into highly populated regions that have generally enjoyed a more temperate climate. While the effects of latitudinal shifts of climate zones will be most severe in temperate regions outside the tropics, there will also be significant changes in climate within the tropics-notably unprecedented thermal conditions for hundreds of millions of people, along with projections for more extreme weather events. Australia's geographical location makes it particularly vulnerable to an expanding tropics. As the tropics expand poleward, more of southern Australia will be influenced by the dry sub-tropical zone and associated reductions in winter rainfall. These drying trends are projected to continue over most southern parts of Australia this century, accompanied by rising temperatures and more hot days. Future rainfall trends for northern Australia remain uncertain, but there is an expected significant increase in the number of hot days, together with more extreme weather events. Future climate change in northern Australia has been ignored by the White Paper for the Development of Northern Australia (2015), bringing into serious question the feasibility and affordability of many of the development policies, plans, and projects promulgated in the White Paper. Even without climate change, the north faces many significant environmental and economic challenges for its future development. [ABSTRACT FROM AUTHOR]

Historical weather observations on the daily scale are vital for the improvement of reanalysis products and the analysis of long‐term variability of extreme events. While daily datasets extend for several centuries in parts of the Northern Hemisphere, the majority of historical data for the Southern Hemisphere are monthly averages or totals. In this paper, we describe a newly recovered dataset of ten daily meteorological variables for 1877 to 1922 from Eversleigh, a property in the New England region of New South Wales in Australia. Here, we present the full process of data rescue, from digitization to quality control and an assessment of homogeneity. We show that the majority of variables were recorded to a high standard and that the data are of general use for climate analysis. Forty years of daily temperature, cloud cover, wind, and pressure observations are now available for the New England Plateau, offering data that are more complete than any other records for the region in the Australian Bureau of Meteorology dataset. The Eversleigh dataset now provides an opportunity to gain more insight into the 19th century weather and climate of eastern Australia during a time of large interannual climate variability before the dominant impact of an anthropogenic warming signal. [ABSTRACT FROM AUTHOR]

Pride in Australia's extreme climate has long been a part of Australia's national identity. Today, climate continues to be enrolled in a range of nationalistic projects, including the (re)development of climate science and other responses to climate change. In this paper, we outline some of the contours of the 'Australian national climate', claims to know it, and four idealised responses to it: bounce back, dismissal, endurance, and migration. We argue that the deeply cultural framing of climate in Australia-in particular, Australians' emphasis on the climate's inherent variability and unknowability, and their own historical adaptability-is being exploited by the federal government and hampering climate change mitigation nationally. [ABSTRACT FROM AUTHOR]

As part of a special issue on natural hazards, this paper reviews the current state of scientific knowledge of Australian heatwaves. Over recent years, progress has been made in understanding both the causes of and changes to heatwaves. Relationships between atmospheric heatwaves and large-scale and synoptic variability have been identified, with increasing trends in heatwave intensity, frequency and duration projected to continue throughout the 21st century. However, more research is required to further our understanding of the dynamical interactions of atmospheric heatwaves, particularly with the land surface. Research into marine heatwaves is still in its infancy, with little known about driving mechanisms, and observed and future changes. In order to address these knowledge gaps, recommendations include: focusing on a comprehensive assessment of atmospheric heatwave dynamics; understanding links with droughts; working towards a unified measurement framework; and investigating observed and future trends in marine heatwaves. Such work requires comprehensive and long-term collaboration activities. However, benefits will extend to the international community, thus addressing global grand challenges surrounding these extreme events. [ABSTRACT FROM AUTHOR]

Droughts are a recurrent and natural part of the Australian hydroclimate, with evidence of drought dating back thousands of years. However, our ability to monitor, attribute, forecast and manage drought is exposed as insufficient whenever a drought occurs. This paper summarises what is known about drought hazard, as opposed to the impacts of drought, in Australia and finds that, unlike other hydroclimatic hazards, we currently have very limited ability to tell when a drought will begin or end. Understanding, defining, monitoring, forecasting and managing drought is also complex due to the variety of temporal and spatial scales at which drought occurs and the diverse direct and indirect causes and consequences of drought. We argue that to improve understanding and management of drought, three key research challenges should be targeted: (1) defining and monitoring drought characteristics (i.e. frequency, start, duration, magnitude, and spatial extent) to remove confusion between drought causes, impacts and risks and better distinguish between drought, aridity, and water scarcity due to over-extractions; (2) documenting historical (instrumental and pre-instrumental) variation in drought to better understand baseline drought characteristics, enable more rigorous identification and attribution of drought events or trends, inform/evaluate hydrological and climate modelling activities and give insights into possible future drought scenarios; (3) improving the prediction and projection of drought characteristics with seasonal to multidecadal lead times and including more realistic modelling of the multiple factors that cause (or contribute to) drought so that the impacts of natural variability and anthropogenic climate change are accounted for and the reliability of long-term drought projections increases. [ABSTRACT FROM AUTHOR]

Bushfires are one of the most frequent natural hazards experienced in Australia. Fires play an important role in shaping the landscape and its ecological dynamics, but may also have devastating effects that cause human injuries and fatalities, as well as broad-scale environmental damage. While there has been considerable effort to quantify changes in the occurrence of bushfire in Australia, a comprehensive assessment of the most extreme bushfire cases, which exact the greatest economic and environmental impacts, is lacking. In this paper we reflect upon recently developed understanding of bushfire dynamics to consider (i) historical changes in the occurrence of extreme bushfires, and (ii) the potential for increasing frequency in the future under climate change projections. The science of extreme bushfires is still a developing area, thus our conclusions about emerging patterns in their occurrence should be considered tentative. Nonetheless, historical information on noteworthy bushfire events suggests an increased occurrence in recent decades. Based on our best current understanding of how extreme bushfires develop, there is strong potential for them to increase in frequency in the future. As such there is a pressing need for a greater understanding of these powerful and often destructive phenomena. [ABSTRACT FROM AUTHOR]

Floods are caused by a number of interacting factors, making it remarkably difficult to explain changes in flood hazard. This paper reviews the current understanding of historical trends and variability in flood hazard across Australia. Links between flood and rainfall trends cannot be made due to the influence of climate processes over a number of spatial and temporal scales as well as landscape changes that affect the catchment response. There are also still considerable uncertainties in future rainfall projections, particularly for sub-daily extreme rainfall events. This is in addition to the inherent uncertainty in hydrological modelling such as antecedent conditions and feedback mechanisms. Research questions are posed based on the current state of knowledge. These include a need for high-resolution climate modelling studies and efforts in compiling and analysing databases of sub-daily rainfall and flood records. Finally there is a need to develop modelling frameworks that can deal with the interaction between climate processes at different spatio-temporal scales, so that historical flood trends can be better explained and future flood behaviour understood. [ABSTRACT FROM AUTHOR]

As part of part of a special issue on natural hazards, this paper explores recent changes in Australian minimum temperature extremes. Using minimum temperature data from the 112 observation locations making up the Australian Climate Observations Reference Network - Surface Air Temperature (ACORN-SAT) data set, as well as the Scientific Information for Land Owners (SILO) minimum temperature gridded data surface, we analyse and map trends in extreme minimum temperature indices across southern Australia at seasonal, annual and multi-decadal timeframes since 1960. Our analyses highlights that across southern Australia, despite a warming trend of 0.17 °C per decade since 1960 in the mean annual minimum temperature, there exist regions of localised cooling as well as a much broader spatially-coherent pattern of increasing 'frost season' length. Our analysis identifies that the 'frost season length' has, across the whole southern portion of Australia, increased on average by 26 days (at 2014) compared with the 1960 to 1990 long term mean. Some areas of south eastern Australia now experience their last frost an average four weeks later than in the 1960s (i.e. mean date of last frost for the period 1960 to 1970 was 19 September versus 23 October for the period 2000 to 2014). Over isolated portions of southern Australia (i.e. northern Victoria and southern New South Wales), the annual frequency of frost events occurring after August has increased by as much as 4 events per year over the last decade, with localised increases in the occurrence of consecutive frost days also observed. This analysis builds upon earlier more localised trend analyses work by these authors (Crimp et al. 2015), as well as a growing body of international research, highlighting a complex spatio-temporal pattern of temperature change despite a general pattern of annual warming in minimum temperatures. [ABSTRACT FROM AUTHOR]

A new climate modelling project has been developed for regional climate simulation and the attribution of weather and climate extremes over Australia and New Zealand. The project, known as weather@home Australia- New Zealand, uses public volunteers' home computers to run a moderate-resolution global atmospheric model with a nested regional model over the Australasian region. By harnessing the aggregated computing power of home computers, weather@home is able to generate an unprecedented number of simulations of possible weather under various climate scenarios. This combination of large ensemble sizes with high spatial resolution allows extreme events to be examined with well-constrained estimates of sampling uncertainty. This paper provides an overview of the weather@home Australia- New Zealand project, including initial evaluation of the regional model performance. The model is seen to be capable of resolving many climate features that are important for the Australian and New Zealand regions, including the influence of El Niño-Southern Oscillation on driving natural climate variability. To date, 75 model simulations of the historical climate have been successfully integrated over the period 1985-2014 in a time-slice manner. In addition, multithousand member ensembles have also been generated for the years 2013, 2014 and 2015 under climate scenarios with and without the effect of human influences. All data generated by the project are freely available to the broader research community. [ABSTRACT FROM AUTHOR]

This paper presents a comparative analysis of the use of climate science for adaptation policy in Queensland, Australia and the UK. We examine policy players’ perceptions of climate science alongside prevailing political influences on evidence-based policy making. In Queensland, the evidence-based mandate has been weakened by partisan politics so that the political acceptability of evidence is a foremost concern for policy makers. In the UK, the evidence-based mandate is enshrined in the Climate Change Act (2008), yet here too political forces have sought to limit the acceptable use of climate science for policy making. Both cases reveal normative and political tensions in the interpretation and use of climate science, suggesting that important political challenges must be overcome by the scientific community to ensure the ongoing utility of climate science for policy making. [ABSTRACT FROM AUTHOR]

The impacts on the Australian coast of a changing climate include environmental and property damage arising from increased frequency and severity of coastal weather events, storm surge, coastal erosion, and coastal flooding. Coastal management policies and planning laws are often relied upon to manage both the impacts and competing interests in the coast. The existence of these policies and laws, and their interpretation by the courts, bears a weight of expectation upon them to deliver in the face of climate change which merits further consideration. Indeed, a rich field is open from which to consider the constitution and construction of law in and across different places, in the context of climate change adaptation. The Australian coast is a unique and locally specific context from which to explore the relationship between law and place as performed in the Vaughan litigation, and this paper considers such important potential as it gains expression in the Vaughan litigation. © 2016 Institute of Australian Geographers [ABSTRACT FROM AUTHOR]

• Development of a new enthalpy-based Climatic Cooling Potential index. • Critical evaluation of using enthalpy to evaluate Climatic Cooling Potential. • Practical significance of the enthalpy-based Climatic Cooling Potential. • Critical discussion of climatic effects on applicability of Ventilative Cooling. • Spatiotemporal analysis of the Climatic Cooling Potential in Australia. Ventilative Cooling is a promising technique to improve the energy efficiency of buildings through reduced need for mechanical cooling to maintain thermal comfort. To assess the feasibility of Ventilative Cooling in a specific location, it is useful for designers to be able to evaluate the climate potential for cooling. This paper describes a new and enhanced version of the Climatic Cooling Potential (CCP) method, which is a simplified method to evaluate the climate potential for passive cooling that does not require detailed knowledge of the building characteristics. The proposed Enthalpy Climatic Cooling Potential (CCP h) integrates humidity into the climate evaluation, using the enthalpy difference between indoors and outdoors, instead of the temperature difference. It accounts for latent heat, providing a better estimate of locations where the use of outside air will be beneficial from an energy perspective. The methods were compared by mapping the Ventilative Cooling potential for the Australian climate, using weather data from 391 weather stations across Australia. Results showed that most of the highly populated cities in the south of Australia have a climate suitable for Ventilative Cooling. This is true even in the summer period, although the area where the climate is beneficial is significantly larger during the shoulder seasons and winter. The analysis showed that using the CCP index, rather than the new CCP h index, can lead to an under-estimation of the cooling potential during dry winters and an over-estimation during humid summers, due to the contribution of the latent heat. [ABSTRACT FROM AUTHOR]