Climate change will have a range of impacts on Victoria’s communities, on industries and on the environment. While there will always be some uncertainty over the precise scale and timing of climate change impacts, current trends suggest a warmer, drier and more extreme climate for Victoria in the future. There is growing understanding of the potential impacts of climate change.
The information below summarises some of the potential impacts we can expect from these changes, informed by both actual research and examples described overseas. It is hoped that by exploring these potential impacts that we can facilitate thinking on how we can begin to moderate risks and prepare for change.
Victoria's water resources are likely to become increasingly vulnerable to climate change, due to projected drying trends over much of the state. At the same time, demand for water may grow as a result of increasi ng population, warmer temperatures and higher evaporation rates. These impacts could, however, be offset if we get more rain in summer.
Water quality may be affected by changes in the number and types of organisms, water temperature, carbon dioxide concentration, transportation of water sediment and chemicals, and the volume of water flow.
Decreases in stream flow, impacts on coastal underground water and intertidal habitats, and increased salinity will be critical issues for the management of our water supply and natural resources.
Climate change may affect crops and livestock, depending on their tolerance to increased maximum and minimum temperatures, moisture availability and tolerance of water stress, changes in exposure to pests, impacts of storms, and elevated concentrations of carbon dioxide. Climate change could also have indirect social and economic effects, as regional and international markets respond to climate change.
Projected warming would also increase the ability of some pest species to survive in winter. For example, fruit fly numbers could increase under warmer conditions. A warmer climate would also enable more tropical species to spread southwards. There is also a greater likelihood of invasion and establishment of exotic animal and plant species.
Future forest productivity will depend in part on the balance between the benefits of increased carbon dioxide concentrations, and the patterns of change in rainfall and temperature. For example, a doubling of carbon dioxide with a warming of 3°C and no significant changes in rainfall would encourage tree growth in much of southern Australia. However, higher temperatures, limited nutrients and reduced rainfall, as well as increases in pests and bushfire risk, are likely to limit these benefits.
Increased sea surface temperatures, and changes in coastal processes, such as nutrient upwelling and seabed sedimentation, could have significant effects on our fisheries and aquaculture systems.
In their Implications of Climate Change for Australian Fisheries and Aquaculture report, CSIRO concludes that Victoria's south eastern coastal waters are among the most vulnerable in Australia to the impacts of climate change and the drought conditions already being experienced in Victoria's inland waterways are expected to continue.
Broad acre cropping is likely to benefit from higher carbon dioxide concentrations, but these benefits may be limited or overwhelmed by higher temperatures and reduced rainfall. Likely reductions in water resources may reduce the amount of water available for irrigation, while at the same time, irrigation requirements may increase as temperatures and evaporation rates increase.
Pastures in higher rainfall areas are likely to benefit from higher carbon dioxide concentrations, but benefits may be negated by higher temperatures and decreases in rainfall. If rainfall decreased by more than 10 per cent in winter and spring - the main growing season for pastures – forage and animal production would decline, despite the higher concentrations of carbon dioxide.
Warmer temperatures will also increase the risk of heat stress in sheep and cattle. In dairy cattle, productivity is likely to decrease as temperatures increase.
A projected decrease in frost frequency and severity would reduce the risk of damage to those fruits that are sensitive to frost late in the growing season. However, temperate fruits that require winter chilling to ensure normal bud-burst and fruit set are at risk of lower yields and reduced fruit quality.
Climate change is likely to affect Victoria's wine regions - including accelerated ripening, the need for increased irrigation, and opportunities for cultivating new grape varieties.
Human settlement has dominated environmental change in Victoria, and will continue to be a significant issue in the future. With the additional effects of climate change, human influences will become more severe as ecosystems progressively lose their natural protective mechanisms.
Climate change is already affecting Victoria’s plants and animals. Preliminary research of the potential effect on the distribution of 42 fauna species in south-eastern Australia indicated that 41 are likely to suffer reduced habitat ranges under climate change scenarios. Of those 41 species, 57 per cent are predicted to lose between 90 and 100 per cent of their range, with a warming of 3 degrees C. Studies of selected flora suggest there may also be reductions in the ranges of plant habitats.
Ecosystems and species will be forced to respond directly to changing climatic conditions, and, at the same time will have to cope with, and adapt to, other climate-induced changes in land use and pests and diseases, particularly invasions by introduced species.
Many of Victoria's ecosystems have a limited ability to adapt to climate change. Those restricted to small geographic areas, or unable to migrate fast enough to keep pace with shifting climatic zones, will be particularly vulnerable. However, some ecosystems and species will be advantaged or unaffected by climate change.
Climate change will impact on Victoria's coastal areas through sea-level rise, increased temperatures and changing storm patterns. Although the exact nature of impacts are difficult to predict, many natural systems, including estuaries, coastal vegetation, wetlands and reefs are likely to have difficulty adapting to climate change, and may become increasingly vulnerable. Current settlement and development trends in coastal areas are likely to lead to greater community risk and insurance exposure to current and future hazards.
Australian alpine ecosystems and species are highly adapted to their environment, and are extremely sensitive to changes in climate. Decreasing snow cover, increasing risk of fire and invasion by weeds and other species will have a serious impact. Species whose habitat is located in the highest elevations and coldest environments will have nowhere to retreat to as the climate warms.
A range of direct and indirect climate change impacts may affect Victorian communities. Flooding and sea-level rise, heatwaves, water shortages, increased frequency and intensity of storms, greater air pollution and higher urban temperatures pose the greatest threats.
Climate change may have wide-ranging effects on human health. There is concern over the direct effects of higher summer temperatures and heatwaves; increased risk of respiratory problems, water quality issues for drinking water; and higher levels of food- and water-borne disease.
Climate change could also significantly impact on buildings and infrastructure. Higher temperatures and humidity, and greater risk of flooding and subsidence could lead to the deterioration of buildings, bridges and other structures, and the disruption of road, rail and power supplies. These impacts would carry significant economic costs. The insurance and finance industries are starting to re-evaluate risks, due to the possibility of more frequent and destructive storms.
The impacts of climate change on other parts of the world may also affect Australia and Victoria. For example, the impacts of climate change on many low-lying Pacific Islands, which are highly vulnerable to climate change, could have serious flow-on effects for Australia. Climate change in other parts of the world may affect Australia through changes in agricultural production, market prices and access to financial services, as well as the potential for flows of environmental refugees. Market changes in particular, offer both risks and opportunities for Victorian businesses.
Find out how the climate in each region of Victoria will change under different greenhouse emission scenarios.