Climate Change and Australasia

Regional Studies

Country-Level Studies

Australia

Evans, Jason and Sergei Schreider. 2002. "Hydrological Impacts of Climate Change on Inflows to Perth, Australia," Climatic Change, Vol. 55, No. 3, November, pp. 361-393.
ABSTRACT: The effects of climate change due to increasing atmospheric CO2 on the major tributaries to the Swan River (Perth, Western Australia) have been investigated. The climate scenarios are based on results from General Circulation Models (GCMs) and 1000 year time series are produced using a stochastic weather generator. The hydrological implications of these scenarios are then examined using a conceptual rainfall-runoff model, CMD-IHACRES, to model the response of six catchments, which combine to represent almost 90% of the total flow entering the upper Swan River, and hence the Perth city urban area. The changes in streamflow varies considerably between catchments, exhibiting a strong dependence on the physical attributes of the catchment in question. The increase in the magnitudes of rare flood events despite significant decreases in mean streamflow levels found in some catchments emphasizes the importance of estimating changes in the nature of the precipitation (variance, length of storm and interstorm periods), along with changes in the mean, in climate change scenarios.

Williams, Allyson A. J., David J. Karoly, and Nigel Tapper. 2001. "The Sensitivity of Australian Fire Danger to Climate Change," Climatic Change, Vol. 49, No. 1-2, April, pp. 171-191.
ABSTRACT: Global climate change, such as that due to the proposed enhanced greenhouse effect, is likely to have a significant effect on biosphere-atmosphere interactions, including bushfire regimes. This study quantifies the possible impact of climate change on fire regimes by estimating changes in fire weather and the McArthur Forest Fire Danger Index (FDI), an index that is used throughout Australia to estimate fire danger. The CSIRO 9-level general circulation model (CSIRO9 GCM) is used to simulate daily and seasonal fire danger for the present Australian climate and for a doubled-CO2 climate. The impact assessment includes validation of the GCMs daily control simulation and the derivation of `correction factors' which improve the accuracy of the fire danger simulation. In summary, the general impact of doubled-CO2 is to increase fire danger at all sites by increasing the number of days of very high and extreme fire danger. Seasonal fire danger responds most to the large CO2-induced changes in maximum temperature.

Guest, C.S., K. Willson, A.J. Woodward, et al. 1999. "Climate and mortality in Australia: retrospective study, 1979-1990, and synoptic predictions of the health impacts of climate change in 2030," Climate Research, Vol. 13, pp. 1-15.
ABSTRACT: Quantitative assessment of climatic and environmental health risks is necessary because changes in climate are expected. We therefore aimed to quantify the relationship between climatic extremes and mortality in the 5 largest Australian cities during the period 1979-1990. We then applied the relationship determined between recent climatic conditions and mortality to scenarios for climate and demographic change, to predict potential impacts on public health in the cities in the year 2030. Data on mortality, denominator population and climate were obtained. The expected numbers of deaths per day in each city were calculated. Observed daily deaths were compared with expected rates according to temperature thresholds. Mortality was also examined in association with temporal synoptic indices (TSI) of climate, developed by principal component and cluster analysis. According to observed-expected threshold analyses, for the 5 cities combined, the annual mean excess of deaths attributable to temperature over the period 1979-1990 was 175 for the 28°C threshold. This sum of statistically significant differences from the 5 cities was the greatest excess found in association with any threshold considered in the range of temperatures that occur. Excess mortality for the hottest days in summer was greater than for the coldest days in winter. Temperature-mortality relationships were little modified by socio-economic status. TSI analyses produced similar results: using this method, the climate-attributable mortality in the 5 cities was approximately 160 deaths yr-1, although this number was evenly distributed across summer and winter. Persons in the group aged 65 yr and older were the most vulnerable. After allowing for increases in population, and combining all age groups, the synoptic method showed a 10% reduction in mortality in the year 2030. We conclude that the 5 largest Australian cities exhibit climate-attributable mortality in both summer and winter. Given the scenarios of regional warming during the next 3 decades, the expected changes in mortality due to direct climatic effects in these major coastal Australian cities are minor.

John Walker. 1998. "Malaria in a changing world: an Australian perspective," International Journal for Parasitology, Vol. 28, No. 6, 1 June, pp. 947-953.
ABSTRACT: Three elements must be present for endemic malaria: infected humans, susceptible mosquitoes and a suitable climate. All three occur in parts of Australia and yet this country has always been a region of marginal malaria endemicity. With the exception of a large epidemic in Cairns during the Second World War, most outbreaks have occurred in small, isolated populations of the Northern Territory. The last epidemic was at the Roper River Mission in the Northern Territory in 1962. Since Australia was declared to be free of endemic malaria in 1983, only sporadic cases of local transmission have occurred. There have been suggestions that future climate change may increase the range of the major vector in Australia, Anopheles farauti, and consequently lead to the re-establishment of endemic malaria. This possibility is discussed in relation to experiences in this and other regions. It is stressed that climate change is only one component in a complex epidemiological setting, and that other aspects such as human activity are probably more important.

Russell, Richard C. 1998. "Mosquito-borne arboviruses in Australia: the current scene and implications of climate change for human health," International Journal for Parasitology, Vol. 28, No. 6, 1 June, pp. 955-969.
ABSTRACT: Of the mosquito-borne arboviruses, the encephalitic Murray Valley encephalitis and Kunjin viruses are a major public health concern, but the arthritides Ross River and Barmah Forest viruses are more important in a public health sense, being responsible for a far greater number of infections. Reported cases of Ross River totalled approximately 30 000 during 1991-1996; there have been several widely separated outbreaks of Barmah Forest in recent years and case reports are increasing annually. Surveillance programmes have increased our understanding of the geographic regions, climatic conditions and vector factors associated with viruses. Virus activity is widespread but is often localised, is driven primarily by mosquito abundance and various species are involved; host factors are involved also, but are not well understood. Typically, mosquito populations are governed by availability of habitat and environmental conditions. Models of climate change predict increases in rainfall, tides and temperature for parts of Australia, and such changes have the potential to increase the risk of arbovirus transmission by increasing the distribution and abundance of vectors, and duration of mosquito and arbovirus seasons. However, the amplitude of climate change is uncertain and the ecology of arbovirus transmission is complex. It is likely that some areas will have increases in arbovirus activity and human infection with predicted climate change, but risk of increased transmission will vary with locality, vector, host and human factors.

Meinke, H., R. C. Stone, G. L. Hammer. 1996. "SOI Phases and Climatic Risk to Peanut Production: A Case Study for Northern Australia," International Journal of Climatology, Vol. 16, No. 7, pp. 783-789.
ABSTRACT: Phases of the Southern Oscillation Index (SOI) in August/ September are used in conjunction with a dynamic peanut simulation model to quantify climatic risk to peanut production in northern Australia. Specifically, we demonstrate how a simulation model can assist to forward estimate production risk based on historic climate records and known atmospheric conditions prior to planting a crop. The SOI phase analysis provides skill in assessing future rainfall probability distributions during the growing season and thus allows an estimate of likely crop performance. Such knowledge can provide valuable information for producers and processors. For instance, the analysis shows that for negative SOI patterns prior to sowing the expected median yield potential for dryland peanut production in northern Australia is 1 25 t ha-1 or 27 per cent below the long- term median. Conversely, a positive SOI pattern shows a median potential yield of 2 11 t ha-1, an increase of 23 per cent over the long-term median. Other production variables, such as date and frequency of planting opportunities, also differ significantly depending on SOI patterns.

New Zealand

G. J. Kenny, R. A. Warrick, B. D. Campbell, et al. 2000. "Investigating Climate Change Impacts and Thresholds: An Application of the CLIMPACTS Integrated Assessment Model for New Zealand Agriculture," Climatic Change, Vol. 46, No. 1-2, July, pp. 91-113.
ABSTRACT: The determination of `critical thresholds' is an essential task for informed policy decisions on establishing greenhouse gas emission targets. This paper presents a framework for determining critical thresholds for New Zealand agriculture, focusing on three agricultural crops - kiwifruit, grain maize, and Paspalum dilatatum - as exemplars for the fruit production, arable cropping and dairy production industries in New Zealand. The approach is based on the application of a country-scale, integrated assessment model, called CLIMPACTS. The CLIMPACTS system contains a climate change scenario generator, climate and land data, and sectoral impact models. Importantly, CLIMPACTS allows time-dependent assessments of climate change and its effects, which facilitates the identification and examination of thresholds, which largely relate to spatial changes, over time, in regions of economic importance for these crops. However, whether such thresholds are `critical' for New Zealand cannot currently be addressed by the CLIMPACTS model. The determination of `criticality' requires a fully integrated assessment in which the social, economic, and environmental costs and risks associated with these thresholds are comprehensively evaluated.