Quantifying the financial impact of climate change on Australian local government roads

Published: 11 January 2017Australia’s 560 Councils are responsible for assets worth approximately $270 billion, many of which have a life span >50 years and so will be affected by climate change. Maintenance and replacement of Council infrastructure is guided by principles, models and tools in the International Infrastructure Management Manual that currently do not allow for climate change impacts or the likely flow-on effects to asset and financial management. This paper describes a financial simulation model developed to calculate the financial impacts of climate change on three major asset classes of importance to Australian Councils: hotmix sealed, spray sealed and unsealed roads. The research goes beyond previous studies of climate change impacts on roads in that it provides a location specific toolkit that is designed to assist councils in their asset management and planned maintenance programmes. Two categories of inputs are required for the model: climate inputs, relating specifically to baseline temperature and rainfall distributions and climate change parameters for temperature and rainfall; and engineering inputs, relating specifically to the three road types and the key parameters of their performance and useful lives over the scenario period. The baseline distributions are then shifted mathematically within the model by the mean change as projected by a selected Global Climate Model (GCM) scenario. Outputs of the model are the historical baseline climate variable distributions and the climate change (CC) impacts on road performance are in the form of changes to the useful life of the asset and associated changes in asset resurfacing and rehabilitation costs. Ten case study local councils in southern Australia are examined. Using IPCC AR4 scenarios, the results suggest that the incremental impact of climate change on all three types of road infrastructure modelled will be generally low. There are small cost reductions over the period for all road types as a result of the expected drying and warming trends in the climate.Jacqueline Balston, Steven Li, Ivan Iankov, Jon Kellett and Geoff Well

AI chatbots not yet ready for clinical use

As large language models (LLMs) expand and become more advanced, so do the natural language processing capabilities of conversational AI, or “chatbots”. OpenAI's recent release, ChatGPT, uses a transformer-based model to enable human-like text generation and question-answering on general domain knowledge, while a healthcare-specific Large Language Model (LLM) such as GatorTron has focused on the real-world healthcare domain knowledge. As LLMs advance to achieve near human-level performances on medical question and answering benchmarks, it is probable that Conversational AI will soon be developed for use in healthcare. In this article we discuss the potential and compare the performance of two different approaches to generative pretrained transformers—ChatGPT, the most widely used general conversational LLM, and Foresight, a GPT (generative pretrained transformer) based model focused on modelling patients and disorders. The comparison is conducted on the task of forecasting relevant diagnoses based on clinical vignettes. We also discuss important considerations and limitations of transformer-based chatbots for clinical use

Quantifying the effects of climate change and water abstraction on a population of barramundi (Lates calcarifer), a diadromous estuarine finfish

Many aquatic species are linked to environmental drivers such as temperature and salinity through processes such as spawning, recruitment and growth. Information is needed on how fished species may respond to altered environmental drivers under climate change so that adaptive management strategies can be developed. Barramundi (Lates calcarifer) is a highly prized species of the Indo-West Pacific, whose recruitment and growth is driven by river discharge. We developed a monthly age- and length-structured population model for barramundi. Monte Carlo Markov Chain simulations were used to explore the population's response to altered river discharges under modelled total licenced water abstraction and projected climate change, derived and downscaled from Global Climate Model A1FI. Mean values of exploitable biomass, annual catch, maximum sustainable yield and spawning stock size were significantly reduced under scenarios where river discharge was reduced; despite including uncertainty. These results suggest that the upstream use of water resources and climate change have potential to significantly reduce downstream barramundi stock sizes and harvests and may undermine the inherent resilience of estuarine-dependent fisheries. © 2012 CSIRO

Sea-level rise and planning: retrospect and prospect

Twenty-five years on from Graeme Pearman's review of coastal planning issues arising from climate change-induced sea-level rise, this article reviews the progress of our understanding of the scientific and geomorphological processes that are beginning to impact upon coastal communities. We outline legal and policy developments and specifically address perhaps the thorniest question facing governments – namely, how to address existing coastal developments threatened by rising sea levels. A Decision Mapping approach designed to assist local councils in analysing threats and developing policy initiatives is described.Jon Kellett, Jacqueline Balston and Mark Wester

Defining and predicting the 'break of the season' for north-east Queensland grazing areas

For pasture growth in the semi-arid tropics of north-east Australia, where up to 80% of annual rainfall occurs between December and March, the timing and distribution of rainfall events is often more important than the total amount. In particular, the timing of the 'green break of the season' (GBOS) at the end of the dry season, when new pasture growth becomes available as forage and a live-weight gain is measured in cattle, affects several important management decisions that prevent overgrazing and pasture degradation. Currently, beef producers in the region use a GBOS rule based on rainfall (e. g. 40mm of rain over three days by 1 December) to define the event and make their management decisions. A survey of 16 beef producers in north-east Queensland shows three quarters of respondents use a rainfall amount that occurs in only half or less than half of all years at their location. In addition, only half the producers expect the GBOS to occur within two weeks of the median date calculated by the CSIRO plant growth days model GRIM. This result suggests that in the producer rules, either the rainfall quantity or the period of time over which the rain is expected, is unrealistic. Despite only 37% of beef producers indicating that they use a southern oscillation index (SOI) forecast in their decisions, cross validated LEPS (linear error in probability space) analyses showed both the average 3 month July-September SOI and the 2 month August-September SOI have significant forecast skill in predicting the probability of both the amount of wet season rainfall and the timing of the GBOS. The communication and implementation of a rigorous and realistic definition of the GBOS, and the likely impacts of anthropogenic climate change on the region are discussed in the context of the sustainable management of northern Australian rangelands

Local council infrastructure and climate change

Jon Kellett, Ivan Iankov, Jacqueline Balston & Nikolas Vogiatzi

Responding to rising sea levels: the Australian experience

As sea levels rise over the next century many coastal settlements will face an increased threat from periodic flooding and permanent erosion. Planning policy in Australia and elsewhere is already starting to address this issue by defining coastal zones and placing specific controls on new development in these zones. But the question of how policy deals with existing development in threatened coastal areas remains problematic. Several locations in Australia have faced this problem in recent years and policy has begun to emerge as a result of experience. Much of this policy may be viewed as a reactive to specific circumstances. This paper reviews a range of issues and using three case studies from New South Wales and South Australia, seeks to outline the data requirements for proactive decision making. The discussion covers technical, legal and financial aspects. Using the results of a global literature review and interviews with Australian local councils facing coastal inundation and erosion problems, the paper proposes a decision mapping approach to analyse the threat of sea level rise to existing development and to generate robust policy. It suggests this methodology may also be appropriate to locations outside Australia.Jon Kellett, Jacqueline Balston, Steven Li, Geoff Wells and Mark Wester

Decision Making in the Face of the Rising Tide

The State of Australian Cities (SOAC) national conferences have been held biennially since 2003 to support interdisciplinary policy-related urban research. This paper was presented at SOAC 6, held in Sydney from 26-29 November 2013. SOAC 6was the largest conference to date, with over 180 papers published in collected proceedings. All papers presented at the SOAC 2013 have been subject to a double blind refereeing process and have been reviewed by at least two referees. In particular, the review process assessed each paper in terms of its policy relevance and the contribution to the conceptual or empirical understanding of Australian cities