CLIMATE CHANGE IN THE SOUTHERN GULF REGION: A background paper to inform the Southern Gulf Natural Resource Management Plan SUGGESTED CITATION Crowley, G.M. (2016) Climate change in the Southern Gulf region: A background paper to inform the Southern Gulf Natural Resource Management Plan. Southern Gulf Natural Resource Management, Mount Isa, Queensland. ISBN 978-0-9808776-3-2 This report is licenced under a Creative Commons Attribution 3.0 Australia licence. You are free to copy, communicate and adapt this work, so long as you attribute Southern Gulf NRM Inc. DISCLAIMER While every effort is made to ensure the accuracy of this publication Southern Gulf NRM accepts no liability for any loss or damage that result from reliance on it. ACKNOWLEDGEMENTS This project was fund by the Australian Government’s Regional Natural Resource Management Planning for Climate Change Fund. My thanks go to Andrew Maclean (Southern Gulf NRM) for inviting me to undertake this project, and for providing guidance and feedback throughout. I also thank David Gillieson for his forbearance, proof-reading and GIS advice. Climate change in the Southern Gulf region: A background paper to inform the Southern Gulf Natural Resource Management Plan Gabriel Crowley April 2016 EXECUTIVE SUMMARY The region of Indigenous people is one third that of non- Indigenous people. The Southern Gulf region is situated in the far north-west of Queensland and covers all Only a small proportion of pastoralists across catchments that drain into the southern Gulf of northern Australia possess characteristics to Carpentaria between Karumba and just west of make them resilient to major stresses and the Northern Territory border. upheaval: strategic planning skills; sound business management principles; preparedness Land systems of the region are mostly extensive to experiment and try new ideas; and strong links plains and dissected uplands in the south-west, with industry and community networks. around Mount Isa. Mining, cattle grazing, fishing and tourism are Only around 5% of the native vegetation of the the region’s most important industries. Each of region has been cleared, mostly for urban and these industries is subject to global fluctuations in agricultural development. The remaining native commodity prices, leading to rapid changes in the vegetation, mostly comprising tropical savannahs, economic fortunes of the region with associated grasslands and extensive coastal wetlands social impacts. At a community level, the remains largely intact although disturbed by Southern Gulf has only moderate resilience. grazing and land degradation, in particular weed invasion. Climate Change The dominant land use in the region is cattle The climate of the Southern Gulf region ranges grazing undertaken on freehold land (chiefly in from semi-arid environment in the south to the south east of the region) or leasehold land semi-humid in the north. Most rain falls between (the remainder). The Boodjamulla National Park November and March. The region is hot and is a significant feature of the north west of the humid, with mean maximum temperatures at region. Land reserved for nature conservation has Mount Isa approaching 40°C in summer and mean increased in recent years with the addition of new minimum temperature exceeding 10°C in winter. nature refuges and Indigenous Protected Areas. Summer maximums frequently exceed 40°C. Communities and Industries Rainfall is highly variable. In about one-third of years, rainfall falls short of the average by more The population of the Southern Gulf region is than 100 mm, and exceeds the average by at least low and dispersed. Indigenous people make 100 mm in another third. up approximately 22% of the population of the 35,000 people living in region. There is less than The impact of climate change is becoming one person per square kilometre throughout the evident in the region. Average temperatures in region, with the lowest densities in the Burke Shire the Southern Gulf region have increased by more and McKinlay Shire, and highest densities in the than 1.5°C since 1910. At Camooweal, the number Doomadgee Aboriginal Shire and on Mornington of days hotter than 40°C have doubled from about Island. 20 per year to about 40 per year over the same period. Indigenous disadvantage in the region is high. The Indigenous unemployment rate in 2011 was High variability makes any trend in rainfall difficult approximately 23%, roughly 10 times that for non- to discern. However, despite recent droughts, Indigenous people. Private sector employment Southern Gulf’s wet season rainfall in the last 20 years was very much above the long-term average. Climate Change in the III Southern Gulf region SOUTHERN GULF NRM Predicted future change in the region’s climate is and mangroves, near-coastal wetlands and that: tropical savannas. Indeed, very little of the region • Average temperature will continue does not fall into one of these categories. to increase in all seasons • There will be more hot days and warm spells Refugia providing opportunities for plants and • Changes in rainfall are possible but unclear animals to minimise the adverse impacts of • Extreme daily rainfall events changing climate are very important priorities for will be more intense conservation effort in response to climate change. • Mean sea level will continue to In the Southern Gulf region, higher elevation (thus rise and the height of extreme sea cooler and free of flooding) areas and floodplain level events will also increase (thus generally wetter and more humid) areas are • There will be fewer, but more among the most important refugia. intense tropical cyclones The region’s vegetation communities are also Climate Change and Biodiversity expected to be influenced by climate change. Increased temperatures, intensity of wildfires, The Region supports diverse ecosystems, cyclones and flooding, and carbon-dioxide wetlands and threatened species. Species fertilisation (favouring shrubs and trees over considered a priority for climate change are tropical grasses), along with uncertain changes those which have been assessed as vulnerable to in rainfall, are expected to cause a reshuffling climate change and for which the Southern Gulf of plants and animals to create new ecological region provides significant habitat. Southern Gulf communities. These communities are still species considered a priority for climate change expected to have a recognisable savanna action are: character. However, weeds are expected be Marine: favoured by disturbance caused by increased Australian snub-fin Dolphin, Green Turtle, Green wildfire and cyclonic damage. Modelling based Sawfish on current vegetation extent and moderate and Riparian: extreme climate change scenarios indicates large Gulf Snapping Turtle, Freshwater Sawfish, Red shifts in vegetation will occur by 2070, however Goshawk, Star Finch. caution is required in the interpretation of the Terrestrial mammals: models because of the limited amount of baseline Julia Creek Dunnart, Carpentarian Antechinus data. Terrestrial birds: Kalkadoon Grasswren, Night Parrot, Gouldian Because climate change is likely to affect the Finch. nature and distribution of biodiversity in the Plants: region, it is necessary to take these changes into Pink Gidgee, Solanum sp. account in determining priority areas for future protection or investment. The Queensland Numerical modelling to predict climate change Department of Environment and Heritage impacts on biodiversity in the Southern Gulf Protection used a combination of biodiversity region tends to be less reliable than in other parts records and expert opinion to identify Strategic of Australia because of the relatively low density of Investment Areas (SIAs), which are either hubs, weather recording sites in and near the region and which are core areas of high biodiversity value, or because of relatively fewer biodiversity records corridors, which are interconnecting areas that that provide the basis for predictive modelling. In provide migration pathways between the hubs. this situation, expert assessment is necessary to supplement and validate numerical models. Environments that are in good condition are most able to survive climate stresses. Therefore, the The Southern Gulf region contains three of the ten best way to instil climate change resilience in Australian ecosystems that are considered most terrestrial environment in the Southern Gulf is to vulnerable to climate change, namely saltmarsh continue investing in best practice grazing, weeds, Climate Change in the IV Southern Gulf region pest and fire management; and to encourage Climate change and livelihoods conservation agreements over high-conservation value area. For marine conservation, climate Impacts of climate change on the environment change resilience will be enhanced by efforts and human health and well-being will flow on to to reduce predation on turtle nests, reduce impacts on livelihoods. Pastoral operations will marine debris and improve the sustainability of be affected by heat stress on cattle, degradation of commercial and recreational fishing. resources (water, soil and grass) as a result of CO2 fertilisation (which reduces the nutritional value Climate change and human capacity of the grass), temperature increases, increased and community well-being disturbance from floods and wildfires, and opportunistic spread of weeds and cattle ticks. Climate change will directly affect the capacity of Southern Gulf natural resource managers to Building climate-resilience