In the future, heatwaves are very likely to be longer and occur more often, according to the Intergovernmental Panel on Climate Change. CSIRO and the Bureau of Meteorology have estimated that in Adelaide the annual average number of days over 35°C may increase from 17 days to 24–47 days by 2070.
This means that we need to take action now to reduce greenhouse gas emissions, both at an individual and at a collective level. We also need to work together to understand how climate change will affect the different aspects of our lives, and how we are going to deal with these impacts.
While the thought of change often makes people feel unsettled, there are many ways we can improve our lives and the way we go about our business. We need to work together to identify opportunities for positive change.
The challenge that climate change brings is that we don’t know precisely what is going to happen or exactly how natural systems will respond. We therefore need to be more flexible in our thinking, increasing our capacity to adapt our responses and behaviour as required, and to imagine and create a better future.
What does climate change mean for Australia?
Of all the world’s developed nations, Australia is among the most exposed to extremes. The storms and flooding of December 2010 and January 2011 caused economic losses of $8.6 billion and insured losses of $4.3 billion. The increasing exposure of Australia to climate events in future will occur in many different ways, with differing effects across locations, and with varying consequences for businesses, governments and communities.
What does climate change mean for Kangaroo Island?
The impacts of climate change on our industry, economy, society and environment are far wider ranging and potentially devastating than just the prospect of balmier, tropical weather. While the global impacts of climate change are indisputable, specific impacts can vary at local and regional levels.
• Sea level rise: This will be felt both through changes in mean sea level and through changes in frequency of extreme storm surge events. Depending on local conditions, events that currently occur once every 100 years could increase dramatically and occur many times per year by 2100. Many homes, roads and coastal structures are at risk and significant planning and subsequent action is required to reduce and mitigate these risks. On KI, apart from houses and infrastructure in low lying areas, sandy coastlines and limestone cliffs are particularly vulnerable and may retreat by hundreds of metres.
• Ocean acidification: The ocean absorbs about a quarter of the CO2 we release into the atmosphere every year, so as atmospheric CO2 levels increase, so too do the levels of CO2 in the ocean. When CO2 is absorbed by seawater, it becomes more acidic. Since the beginning of the Industrial Revolution, the acidity of surface ocean waters has increased by about 30%. Studies have shown that a more acidic environment has a dramatic effect on the ability of species with hard shells to build and maintain those shells. This includes oysters, cockles, sea urchins, corals and vast numbers of plankton. When shelled organisms are at risk, the entire marine food web is also at risk. More than a billion people on the planet are currently reliant on fish and seafood for their primary source of protein and will also be affected.
• Water supply: Projections of future rainfall indicate that there will be declines across South Australia, most notably in winter and spring. This will lead to a greater frequency and/or severity of drought, with decreased flows in water supply catchments. However, despite a drier average there may also be more floods due to an increase in extreme rainfall events.
• Extreme weather events and fire risk: Extreme hot days in Australia are getting hotter, with the rate of very hot (greater than 35°C) daytime temperatures increasing since the 1990s. Heat waves are forecast to become more frequent and intense, with the number of very hot days in major cities doubling by 2070. This will have consequential effects on heat-related deaths, infrastructure performance, energy demand, housing design and urban planning. In addition weather associated with high fire danger has shown a rapid increase and will continue to rise. Bushfire risk is expected to increase strongly in south-east Australia with the number of very high and extreme fire danger days growing by 15–70% by 2050.
• Native species distribution: Species and ecosystems restricted to Kangaroo Island are likely to be among the most vulnerable to climate change. Organisms that have adapted to the prevailing climate over thousands of years will have limited room to move given the large extent of the coastline and limited altitudinal gradient, and will have little time to evolve as the world changes rapidly around them.
• Agriculture: The productivity of many crops and foods is likely to be negatively impacted by higher temperatures, higher evapotranspiration, reduced rainfall and more frequent extreme weather events, as well as by natural resource degradation such as soil erosion and salinity, and increases in pests and diseases. Since 1997, South Australia’s agricultural regions have experienced a marked decline in growing season (April–September) rainfall. Season breaks are occurring later, and bringing less rainfall. Rising temperatures are likely to have a major influence on wine grapes, bringing the harvest forward by a month and yielding lower quality grapes. Erratic and high temperatures also have an effect on flowering plants, the production of honey and on pollinators such as bees. Weeds and weed management may be affected.
• Human health and wellbeing: As the number of very hot days increases, more people are vulnerable to heat-related illnesses and death, particularly the elderly. There may also be a higher prevalence of certain debilitating diseases such as dengue fever in certain regions and disease vectors such as mosquitoes.
Mitigation and adaptation
Australia’s climate will change in increasingly significant ways over the coming decades due to global emissions of greenhouse gases. The impacts of climate change present substantial new risks for most sectors of business, across all levels of government, and to all communities. Kangaroo Islanders have started thinking about these future challenges but there is much work to be done if we are to be proactive in minimising future risk and cost.
There are two main categories of human responses to climate change: mitigation and adaptation. Both types of response help to reduce the risks of climate change.
Mitigation refers to actions we can individually and collectively take to reduce the future magnitude and rate of climate change. This means drastically reducing our emissions of greenhouse gases, especially carbon dioxide and methane, to reduce future risk and future cost.
As Australians are currently amongst the world’s highest per capita emitters of greenhouse gases, mitigation is the globally responsible thing to do and provides us with a great way to lead the change.
Adaptation refers to measures we can take to prepare for and cope with the climate change that can no longer be avoided. Actions aim to reduce the impacts of a warming climate on humans and the natural world. Adaptation presents new challenges for business and policy decision-makers - it will take time to build the skills and knowledge needed to make the best decisions. Adaptation planning will enable Australia to reduce negative impacts of climate change and to take advantage of any positive effects.
As humans have already released enough greenhouse gases to alter the climate for decades or centuries to come, adaptation is the locally responsible thing to do.
If decisions about major infrastructure investment, land use planning and building design don’t take climate change into account, they may create greater costs and risks in the future. Different planning tools are available to consider climate change, such as the adaptive pathways approach.
Joint KI NRM Board and KI Council Position Statement
In response to the looming challenges posed by climate change and the need for solid leadership on the matter, the board and the council have developed a joint climate change position statement.
BIG issue paper on climate change
A BIG issue paper has been developed on climate change strategies for Kangaroo Island as an outcome of community consultations in 2014.