In recent years RIAG has developed a statistical model to assess severe wind hazard in the non-cyclonic regions of Australia ('Region A' as defined in the Australian/NZ Standards for Wind Loading of Structures (AS/NZS 1170.2, 2002)). The model has been tested using observational data from wind stations located in South Eastern Australia. The statistical model matched the results of the Australian/NZ standard for wind loading of structures utilising a more efficient, fully computational method (Sanabria & Cechet, 2007a). We present a methodology to assess severe wind hazard in Australia for regions where there are no observations. The methodology uses simulation data produced by a high resolution regional climate model in association with empirical gust factors. It compares wind speeds produced by the climate model with observations (mean wind speeds) and develops functions which allow wind engineers to correct the simulated data in order to match the observed mean wind speed data. The approach has been validated in a number of locations where observed records are available. In addition a Monte-Carlo modelling approach is utilised to relate extreme mean wind speeds to extreme peak gust wind speeds (Sanabria & Cechet, 2007b).

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.

An assessment of the potential impacts of climate change on coastal communities has been undertaken in collaboration with the Department of Climate Change and Energy Efficiency (DCCEE). This first-pass national assessment includes an evaluation of the exposure infrastructure (residential and commercial buildings, as well as roads and rail) to sea-level rise (SLR), storm surge and coastal recession. Some of the information contained in this report was included in the Department of Climate Change (now Department of Climate Change and Energy Efficiency) report "Climate Change Risks to Australia's Coast", published in 2009, and its supplement published in 2011.

There has been much debate on the influence climate change may have on global tropical cyclone activity (Webster et al. 2005, Landsea 2005, Emanuel 2005, Knutson et al. 2001), but the impacts on human settlements is even less clear. Regional differences in projected changes are also apparent, further clouding the issue of identifying changes in hazard and risk. As part of a contribution to the Garnaut Climate Change Review (Garnaut 2008), Geoscience Australia examined the changes in a number of indices of tropical cyclone activity as diagnosed from IPCC AR4 simulations. These results can be used to infer likely changes in tropical cyclone hazard. General circulation models (GCMs) are normally too coarse to accurately resolve peak winds associated with tropical cyclones (Walsh and Ryan 2000). Tropical cyclone-like vortices may be present in the finer resolution models, but these are a poor facsimile of observed tropical cyclones and thus are unsatisfactory predictors of changing tropical cyclone characteristics (Camargo et al. 2007). To gain some understanding of the potential changes in tropical cyclone behaviour under different future climate regimes, we use GCM outputs to examine environmental indices that have been linked to the intensity and frequency 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...

Island nations in the South Pacific region are expected to be particularly vulnerable to the impacts of climate change. Tropical cyclones are one event that could potentially devastate the region in a warming world. To assist in evaluating this threat, Geoscience Australia has developed a Tropical Cyclone Risk Model (TCRM) to provide detailed hazard information to help guide policy makers and infrastructure planners. TCRM is a statistical-parametric model that generates synthetic tropical cyclone tracks via a Monte-Carlo process that requires the climatology of tropical cyclones to create probability density functions. These synthetic tracks can then be translated into wind hazard maps, using idealized wind profiles, to show return periods for severe winds and to inform detailed risk assessments. As part of the Pacific Climate Change Science Program (PCCSP), Geoscience Australia has been asked to provide cyclonic wind hazard assessments for the region and also to provide projections of how this risk will be affected by climate change. The presentation will provide a brief overview of previous work on cyclonic wind hazards in the South Pacific region, followed by an outline of the research that Geoscience Australia will be performing for the PCCSP.

Climate change is a challenge facing nations worldwide. The Fifth IPCC Assessment Report (2007) indicated that climate change is inevitable and that nations need to quickly adapt to mitigate its effects on the risks associated with increased tropical cyclone intensity, storm surge inundation, floods and exacerbated spread of disease. Nationally consistent exposure information is required to understand the risks associated with climate change and thereby support decision making on adaptation options. Decision makers can draw on this evidence-base to develop more rational, representative and objective strategies for addressing emerging challenges. Exposure information requires the translation of fundamental data into information and knowledge before it can be put to use for policy, planning and implementation. Communities, businesses, essential services and infrastructure are all exposed to these increased natural hazards. A thorough understanding of exposed infrastructure, building stock and population under current and future climate projections is fundamental to the process of future capacity building. The National Exposure Information System (NEXIS) provides a broad range of information on the exposure profile of any given area at various administrative and disaster sensitive geographic resolutions with Australia-wide coverage. The information is collected, collated and maintained at building level that can subsequently be aggregated geographically. The information recorded in NEXIS covers a wide range of building attributes such as building type, construction type and year built together with information on population demographics and metrics on business activity such as business type, turnover, employee numbers and customer capacity.

This paper describes two studies modelling the potential impacts of extreme events under sea level rise scenarios in two potentially vulnerable coastal communities: Mandurah and Busselton in Western Australia. These studies aim to support local adaptation planning by high resolution modelling of the impacts from climate change.

A statistical downscaling approach is used to compare changes in environmental indicators of tropical cyclone characteristics between three greenhouse gas emissions scenarios in the Australian region, using results from models used for the IPCC 4th Assessment Report. Maximum potential intensity is shown to change linearly with global mean temperature, independent of emissions scenario, with a 2-3% increase per degree of global warming in Australia's tropical regions. Changes in vertical wind shear are more ambiguous, however the magnitude of changes in tropical cyclone genesis regions is small. The genesis potential index increases significantly in all scenarios, and appears to be driven by the increase in MPI. Results for Australia's tropical regions suggest that tropical cyclone intensity is highly likely to increase with global warming, while results for frequency are suggestive of a frequency increase, but less conclusive. Further work to assess frequency changes will allow quantification of changes in tropical cyclone hazard under climate change.

Keppel Bay is a large shallow coastal embayment adjacent to the mouth of the Fitzroy River, located on the central coast of Queensland. The geomorphology and distribution of sediment in Keppel Bay is complex due to the influence of Late Quaternary sea-level change, relict topography, a geologically diverse catchment, macrotidal hydrodynamic processes and flood events. Seabed morphology, sub-bottom profiles and sediment cores reveal the former path of the Fitzroy River across Keppel Bay and the continental shelf. The palaeo-Fitzroy River flowed west across the shelf to the north of Northwest Reef, a position on the shelf that is now under approximately 60 m of water. With the rise in sea level during the early Holocene, the mouth of the Fitzroy River retreated across the continental shelf and by the middle Holocene it was landwards of its present location, near Rockhampton. During the last few thousand years under a relatively stable sea level, much of the shallow inner region of Keppel Bay has been infilled and the coast has prograded several kilometres. Palaeochannels in the inner section of Keppel Bay have mostly been infilled with sediment, which mainly comprises muddy sand from the Fitzroy River. In the outer bay and on the shelf further west many relict channels have not been infilled with marine sediment indicating that the area is relatively starved of sediment. Sediments in outer Keppel Bay are dominantly relict fluvial deposits that are well sorted with only a minor mud component. Subaqueous dunes in the outer southeastern section of Keppel Bay and Centre Bank indicate that tidal currents and currents associated with the predominant southeasterly winds, appear to be transporting marine biogenic sediments and relict coarse terrigenous sediments into Keppel Bay.