The degree to which palaeoclimatic changes in the Southern Hemisphere co-varied with events in the high latitude Northern Hemisphere during the Last Termination is a contentious issue, with conflicting evidence for the degree of `teleconnection' between different regions of the Southern Hemisphere. The available hypotheses are difficult to test robustly, however, because there are few detailed palaeoclimatic records in the Southern Hemisphere. Here we present climatic reconstructions from the southwestern Pacific, a key region in the Southern Hemisphere because of the potentially important role it plays in global climate change. The reconstructions for the period 20-10 kyr BP were obtained from five sites along a transect from southern New Zealand, through Australia to Indonesia, supported by 125 calibrated 14C ages. Two periods of significant climatic change can be identified across the region at around 17 and 14.2 cal kyr BP, most probably associated with the onset of warming in the West Pacific Warm Pool and the collapse of Antarctic ice during Meltwater Pulse-1A, respectively. The severe geochronological constraints that inherently afflict age models based on radiocarbon dating and the lack of quantified climatic parameters make more detailed interpretations problematic, however. There is an urgent need to address the geochronological limitations, and to develop more precise and quantified estimates of the pronounced climate variations that clearly affected this region during the Last Termination.

The aim of this project is to equip ANUGA with a storm surge capability in partnership with the Department of Planning Western Australia (DoP), take steps to validate the methodology and provide a case study to DoP in the form of a storm surge scenario for Bunbury. The developed capability will provide a mechanism whereby DoP can investigate mitigation options for a range of hydrodynamic hazards.

We highlight the importance of developing and integrating fundamental information at a range of scales (regional to national to local) to develop consistency, gain ownership, and meet the needs of a range of users and decision makers. We demonstrate this with a couple of case studies where we have leveraged national databases and computational tools to work locally to gain ownership of risks and to develop adaptation options. In this sense we endorse the notion of combining top down and bottom up approaches to get the best outcome.

The development of climate change adaptation policies must be underpinned by a sound understanding of climate change risk. As part of the Hyogo Framework for Action, governments have agreed to incorporate climate change adaptation into the risk reduction process. This paper explores the nature of climate change risk assessment in the context of human assets and the built environment. More specifically, the paper's focus is on the role of spatial data which is fundamental to the analysis. The fundamental link in all of these examples is the National Exposure Information System (NEXIS) which has been developed as a national database of Australia's built infrastructure and associated demographic information. The first illustrations of the use of NEXIS are through post-disaster impact assessments of a recent flood and bushfire. While these specific events can not be said to be the result of climate change, flood and bushfire risks will certainly increase if rainfall or drought become more prevalent, as most climate change models indicate. The second example is from Australia's National Coastal Vulnerability Assessment which is addressing the impact of sea-level rise and increased storms on coastal communities on a national scale. This study required access to or the development of several other spatial databases covering coastal landforms, digital elevation models and tidal/storm surge. Together, these examples serve to illustrate the importance of spatial data to the assessment of climate change risk and, ultimately, to making informed, cost-effective decisions to adapt to climate change.

The short historical record of tropical cyclone activity in the Australian region is insufficient for estimating return period wind speeds at long return periods (greater than 100 years). Utilising the auto-correlated nature of tropical cyclone behaviour (forward speed and direction, intensity and size), Geoscience Australia has developed a statistical-parametric model of tropical cyclone behaviour to generate synthetic event sets that are statistically similar to the historical record. The track model is auto-regressive, with lag-1 auto-regression used for forward speed and bearing, and lag-2 auto-regression applied to the intensity and size characteristics. Applying a parametric wind field and a linear boundary layer model to the synthetic tropical cyclone tracks allows users to generate synthetic wind swaths, and in turn fit extreme value distributions to evaluate return period wind speeds spatially. The model has been applied to evaluate severe wind hazard across Australia and neighbouring regions. In conjunction with statistical models of synoptic (mid-latitude storms) and thunderstorm wind hazard, we have been able to generate a national assessment of severe wind hazard, which is comparable to existing wind loading design standards. Using tropical cyclone-like vortex tracks directly detected from regional climate models, it is also possible to project cyclonic wind hazard into future climate conditions, accounting for both changes in frequency and intensity of tropical cyclones.

The National Wind Risk Assessment (NWRA), a collaboration between Geoscience Australia and the Dept. Climate Change and Energy Efficiency, has developed a computational framework to evaluate both the wind hazard and risk due to severe wind gusts (based on modelling techniques and application of the National Exposure Information System; NEXIS). A combination of tropical cyclone, synoptic and thunderstorm wind hazard estimates is used to provide a revised estimate of the severe wind hazard across Australia. The hazard modelling utilises both 'current-climate' information and also simulations forced by IPCC SRES climate change scenarios, employed to determine how the wind hazard will be influenced by climate change. The results from the current climate regional wind hazard assessment are compared with the hazard based on the existing understanding as specified in the Australian/New Zealand Wind Loading Standard (AS/NZS 1170.2, 2011). Regions were mapped where the design wind speed depicted in AS/NZS 1170.2 is significantly lower than the hazard analysis provided by this study. Regions requiring more immediate attention regarding the development of adaptation options are discussed in the context of the minimum design standards in the building code regulations. A national assessment of localised wind speed modifiers including topography, terrain and the built environment (shielding), has also been undertaken to inform the local wind speed hazard that causes damage to structures. The effects of the wind speed modifiers are incorporated through a statistical modification of the regional wind speed. We report on an assessment of severe impact and wind risk to residential houses across the Australian continent (quantified in terms of annualised loss). Considering future climate scenarios of regional severe wind hazard, we consider the changing nature of severe wind risk focusing on the Southeast Queensland and Tasmanian regions, and illustrate where the wind loading stan...

Tropical cyclones present a significant hazard to countries situated in the warm tropical waters of the western Pacific. These severe storms are the most costly and the most common natural disaster to affect this region (World Bank, 2006). The hazards posed by these severe storms include the extreme winds, storm surge inundation, salt water intrusion into ground water supplies, and flooding and landslides caused by the intense rainfall. Despite the high vulnerability of the islands in this region, there have been relatively few previous studies attempting to quantify the hazard from tropical cyclones in this region (i.e. Shorten et al. 2003, Shorten et al. 2005, Terry 2007). Understanding this hazard is also vital for informing climate change adaptation options. This study aims to address the limited understanding of the extreme wind hazard in this region. The wind hazard from tropical cyclones is evaluated for the current climate and projections were made to assess how this hazard may change in the future. The analysis is performed using a combination of historical tracks and downscaled climate models with Geoscience Australia's Tropical Cyclone Risk Model. The work was funded as part of the Pacific Climate Change Science Program (PCCSP), which forms the science component of the International Climate Change Adaptation Initiative (ICCAI), an Australian government initiative designed to meet high priority climate change adaptation needs of vulnerable countries in our region. This study assesses the wind hazard for the fifteen PCCSP partner countries which include 14 islands located in the West Pacific as well as East Timor.

The cyclonic wind hazard over the Australian region is determined using synthetic tropical cyclone event sets derived from general circulation models (GCMs) to provide guidance on the potential impacts of climate change. Cyclonic wind hazard is influenced by the frequency, intensity and spatial distribution of tropical cyclones, all of which may change under future climate regimes due to influences such as warmer sea surface temperatures and changes in the global circulation. We evaluate the tropical cyclonic wind hazard using a statistical parametric model of tropical cyclones - the Tropical Cyclone Risk Model (TCRM) - which can be used to simulate many thousands of years of tropical cyclone activity. TCRM is used to generate synthetic tracks which are statistically similar to the input event set, which can be either an historical record of tropical cyclone activity or a record of tropical cyclone-like vortices identified in general circulation models. A parametric wind field is used to estimate the swath of winds associated with the simulated tracks. The resulting wind fields are then used to evaluate the average recurrence interval wind speeds using extreme value statistics. We present the average recurrence interval wind speeds based on three IPCC AR4 scenarios and draw comparisons with current climate simulations and the historical record.

Tropical cyclones pose a significant threat to islanders in the tropical western Pacific. The extreme winds from these severe storms can cause extensive damage to housing, infrastructure and food production, whilst low lying areas can be adversely affected by storm surge inundation. As part of the Pacific Climate Change Science Program (PCCSP), Geoscience Australia is assessing the wind hazard posed by tropical cyclones for 14 islands in the western Pacific and Timor Leste. The assessment will cover both the current climate as well as projections for future climate scenarios. Wind hazard maps are being generated using Geoscience Australia's open-source Tropical Cyclone Risk Model (TCRM) that applies a statistical-parametric process to estimate return period wind speeds. The climate projections are produced by applying this model to downscaled storm tracks from global climate models. Two types of downscaled tracks are used for the projections: tracks of tropical-cyclone-like vortices directly detected in dynamically downscaled climate simulations and tracks derived from GCM's using a statistical/deterministic model (Emanuel 2006). The presentation will provide an outline of the method applied.

Tropical cyclones, thunderstorms and sub-tropical storms can generate extreme winds that can cause significant economic loss. Severe wind is one of the major natural hazards in Australia. The Geoscience Australia's Risk and Impact Analysis Group (RIAG) is developing mathematical models to study a number of natural hazards including wind hazard. In this study, RIAG's severe wind hazard model for non-cyclonic regions of Australia (Region A in the Australian-New Zealand Wind Loading Standard; AS/NZS 1170.2(2010)) for both current and a range of projected future climate scenarios are discussed. Wind hazard in the cyclonic regions of Australia (mainly the northern states) is studied by using a cyclone model. The methodology to study non-cyclonic wind hazard involves a combination of three models: - A statistical model (i.e. a model based on observed data) to quantify wind hazard using extreme value distributions. - A technique to extract and process wind speeds from a high-resolution regional climate model (RCM), which produces gridded hourly 'maximum time-step mean' wind speed and direction fields, and a - A Monte Carlo method to generate gust wind speeds from the RCM mean winds. Gust wind speeds are generated by a numerical convolution of the mean wind speed distribution and a 'regional' observed gust factor. To illustrate the methodology wind hazard calculations under current and future climate for the Australian state of Tasmania will be presented.