This Professional Opinion reports the interim findings of a consultancy undertaken for the Secretariat for the Pacific Regional Environment Programme (SPREP) by Geoscience Australia in the period 15 December 2010 to 2 April 2011. Geoscience Australia was engaged by SPREP to assist in developing a business case for a Pacific Climate Change Portal. This portal will act as a focus for climate and climate change information relevant to the Pacific, provide up to date information for decision makers, and researchers, and improve communication and collaboration in adaptation initiatives by national, regional and international stakeholders. Geoscience Australia has consulted as much as possible in the time available with stakeholders for the portal identified by SPREP to be 'core'. These stakeholders include the Secretariat of the Pacific Community (SPC), United Nations organisations, notably the United Nations Development Programme (UNDP), and the National Oceanographic and Atmospheric Administration (NOAA), along with SPREP itself. The consultations allowed Geoscience Australia to identify key issues, recommend core functionalities of the portal and a preferred operational model and identify partnerships and resources required for sustainable, long term operation of the portal. As a part of this consultancy, Geoscience Australia constructed a 'demonstrator' Pacific Climate Change web portal to illustrate how users could operate the proposed key functionalities of the portal, and to give potential users an illustration of two 'look and feel' options. This demonstrator portal can be visited at http://www.pacificportal.com.au/ . It will be active until approximately the end of June 2011.

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.

This project aims to improve the estimation of tropical cyclone risk in the Australian region by employing a numerical simulation approach based on a climate model. Climate models are the main tools used for predicting the effects of climate change, but usually they have employed resolutions too coarse to simulate reliably smaller weather systems such as tropical cyclones. In this work, a regional climate model of unprecedented fine resolution (the CSIRO regional model CCAM) will be implemented over the Australian region and an improved estimate both of present-day and future tropical cyclone hazard will be made. When combined with the results of a tropical cyclone damage model, new estimates of the tropical cyclone risk to infrastructure in northern Australia will be obtained

The Australia/New Zealand wind actions standard (AS/NZS 1170.2 2011), rely to a significant extent on the peak gust wind speed observations collected over more than 70 years by the Australian Bureau of Meteorology (BoM). The Building Code of Australia (BCA) utilises AS/NZS 1170.2 to minimise natural hazard risk to people and buildings. The current wind loading code, and the performance of our infrastructure (residential, commercial, industrial and critical infrastructure) with regards to wind hazard, is based primarily on the Dines anemometer interpretation of the peak gust wind speed (commenced in the 1930's). In the mid-1980's, BoM began a program to replace the aging pressure tube Dines anemometer (paper record) with the Synchrotac and Almos digital cup anemometers. During the anemometer replacement process, many localities had more than one type of anemometer operating for significant periods. recording extreme events. Systematic differences in determining the magnitude of extreme events during this overlap period, raised serious concerns about the utility of the peak gust wind speed database. This study utilises statistical extreme value distribution analysis (Generalised Pareto Distribution; GPD) examining coincident maximum wind gusts over a fixed 30 minute time window. The analysis estimated of the 500-year return-period (RP) peak gust wind exceedance level derived from the coincident Dines and cup anemometer wind gust measurements. The extreme gust wind speeds for seven sites (coincident measurement period of 89 years) were considered, indicating a bias between the Dines and cup anemometers from +7% to +14% over the speed range from 45 to 60 m/s.

Australian present and past weather data as produced by the Bureau of Meteorology. Dataset contains: Present weather data as international code; Past weather data as international code; plus additional supporting information.

Some of the most visible consequences arising from climate change are sea level rise and more intense and frequent storms. On the open coast and low lying estuarine waterways these impacts will lead to the increased risks of inundation, storm surge and coastal erosion that can damage beaches, property and infrastructure and impact on a significant number of people. Understanding the potential risk of these coastal hazards is critical for coastal zone management and the formulation of adaptation responses, while early action is likely to be the most cost effective approach to managing the risk. Geoscience Australia (GA) is assisting the Australian Government's Department of Climate Change to develop a 'first pass' National Coastal Vulnerability Assessment. GA and the University of Tasmania (UTas) are developing fundamental spatial datasets and GIS modelling tools to identify which land areas of the Australian coast are likely to be physically sensitive to the effects of sea level rise, storms and storm surge. Of special interest is to identify sensitive areas where there is significant property and infrastructure that will be the focus of a more detailed study in a second pass assessment. A new national shoreline geomorphic and stability map or Smartline, developed for the project by UTas, is a key new spatial dataset. The Smartline is an interactive, nationally-consistent coastal GIS map in the form of a segmented line. Each line segment identifies distinct coastal landform types using multiple attribute fields to describe important aspects of the geology, geomorphology and topography of the coast. These data enable an assessment of the stability of the coast and its sensitivity to the potential impacts of shoreline erosion (soft coast) and inundation (low-lying coast), providing a useful indicative coastal risk assessment.

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.

This report, 'Pacific Climate Change Science Program: Evaluation of severe wind hazard from tropical cyclones', will be delivered to CSIRO to form a subsection of the 'Climate Change in the Pacific' report. The latter will be launched in November 2011 and will constitute one of the main deliverables for the Pacific Climate Change Science Program (PCCSP). The PCCSP is part of the Australian Government's commitment through the International Climate Change Adaptation Initiative (ICCAI) to meet high priority climate change adaptation needs in vulnerable countries in the Asia-Pacific region. This report provides an evaluation of cyclonic wind hazard for the fifteen PCCSP partner countries located in the western Pacific with the one exception of East Timor. The wind hazard is estimated for both the current climate and for the future climate under an A2 emissions scenario. The current climate wind hazard is estimated by applying GA's Tropical Cyclone Risk Model (TCRM) to the historical track record. TCRM is a statistical-parametric model of tropical cyclone behaviour, enabling users to generate synthetic records of tropical cyclones representing many thousands of years of activity. TCRM is then applied to tracks of tropical cyclone-like vortices (TCLVs) detected in downscaled global climate models to determine how the cyclonic wind hazard may change in the future. The results indicated that the wind loading design standard in this region may significantly underestimate the wind hazard for the current climate. For the future climate projections, the analysis suggests that the wind hazard may decrease for countries close to the equator and near the Australian coastline but could increase for countries greater than 20 degrees poleward from the equator.

A national review of existing literature on palaeovalley systems and their groundwater resources in the arid and semi-arid parts of Australia. The review has been compiled by John Magee as the Milestone 3 output for the Palaeovalley Groundwater Project.

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 (defined as the return period wind speed) 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. Cyclonic wind hazard is evaluated 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 cyclone activity. TCRM is used to generate synthetic tracks which are statistically similar to the input event set - either an historical record or other synthetic event set. After applying a parametric wind field to the simulated tracks, we use the aggregated wind fields to evaluate the return period wind speeds for three IPCC AR4 scenarios, and make comparisons to the corresponding average recurrence interval wind speed estimates for current climate simulations. Results from the analysis of two GCMs are presented and contrasted with hazard estimates based on the historical record of tropical cyclones in the Australian region.