Number of days over 350C in Atherton
Figure 4. Number of days over 350C under ‘Business as usual’ emissions scenario (MIROC5 climate model)
People in the Southern Tablelands know that rainfall, temperature and cyclones vary from year to year, but that our ability to live in and manage the landscape is based on long experience of general seasonal patterns. However, with a changing climate, it will become increasingly difficult to rely on our past experience to make decisions about where to build houses and infrastructure, which crops to grow, which pests and diseases to target, and how to manage fire. The science is telling us:
- Less predictable weather: As temperatures and sea levels rise and extreme weather events become more common, knowledge based on past experience is becoming less reliable.
- Climate change and industries: While traditional industries, like agriculture and tourism, are likely to remain important economic contributors to our communities, climate change will have impacts. There may also be new and emerging economic opportunities as a result of a changing climate.
- Climate change and communities: The effects of climate change on our communities will be far-reaching, affecting us all. We already have access to good information, which can support our decisions and enable us to plan and prepare, and for our communities to continue to flourish.
- Climate change and natural systems: Climate change will have complex implications for the management of our natural systems. This makes it vital that we begin to build the new knowledge which will be required to provide our plants, animals and ecosystems with the best opportunity to adapt and thrive.
There are opportunities for everyone to get involved in shaping a resilient and sustainable future for the Southern Tablelands. For more information on climate change, including links to more detailed climate change modelling for our region, go to the Climate Futures page.
Long-term temperature records from Kairi show that average temperatures have been on an increasing trend over the past 20 years, and that during this time, average annual temperatures in the region have been above the long-term average much more often than they have been below it (Figure 1).
Long-term rainfall data from Malanda show that rainfall continues to vary dramatically between years, and that there is no obvious increasing or decreasing trend (Figure 2).
While we are likely to see an increasing trend in temperatures as a result of climate change, one of the most concerning predictions coming from climate scientists is the impact of greater variability and less predictability in our weather patterns, making it harder to plan.
As time goes on, higher temperatures will be reached more frequently. For example, under a business as usual emissions scenario, maximum daily temperatures during January are projected to increase from the current average of 28.3°C to 29.8°C by 2030, 29.9°C by 2070 and 31.2°C by 2090 (Figure 3). Furthermore, there will be a longer season of high temperatures, with average daily maximum temperatures above 30°C during months that have traditionally been cooler.
There is a lack of official long-term temperature records in the Southern Tablelands, and even the Kairi station is no longer active. Sharing reliable information collected by residents of the Southern Tablelands region would help people keep track of how the local climate is changing. Recording and sharing observations about the survival, growth, reproduction, health and so on of native and pest plants and animals would also contribute to local knowledge for our landscape. Having access to this information will make it easier to discuss changes and try possible management responses.
Southern Tablelands dairy and beef grazing, cropping and horticulture enterprises are directly dependent on natural resources and climate conditions. Increasing average temperatures, evaporation, heat waves, extreme rainfall events and atmospheric carbon dioxide will substantially affect these industries. For example, the total volume and the fat and protein content of milk produced by dairy cows declines at high temperatures. Harvest of crops such as potatoes may also be affected by increasing temperatures. As time goes on, higher temperatures will be reached more frequently as both average and extreme temperatures increase (see above). The number of days over 35°C in Atherton is projected to double by 2030 from a current average of one to two (and to four by 2050) under the ‘business as usual’ emissions scenario. Perhaps more concerning for industries on the Tablelands, by the year 2030, the average temperature in the region is projected to increase quite significantly (Figure 3). Climate change impacts will also affect long-lived crops, including forestry timber production, through changing patterns of growth and increased damage and loss during high intensity cyclones. Climate change may also bring new diseases and pests, which we know potentially pose enormous threats to our agricultural industries. Flooding associated with extreme rainfall will also affect waterways and floodplains, potentially increasing erosion in these areas.
The Southern Tablelands landscape is likely to remain an important food production area, especially for the north Queensland region. With higher costs of long-distance transport based on fossil fuels, the cost advantage to local markets of regionally-produced food will further increase, although the economic viability of supplying distant markets may decline and costs of inputs may increase. Regional primary industries may also be impacted by increasing bottlenecks in processing or distribution networks. For example, heat waves, cyclones and floods all have the potential to shut down industrial operations, and facilities such as the Cairns sea and air ports and regional rail lines, potentially interrupting both the import of fuel, food and other supplies, as well as the export of regional produce.
Tourism in the Southern Tablelands landscape is underpinned by the natural values of the area, especially the forested areas. Climate-induced changes in the health and composition of natural systems, including the potential loss of iconic species (see below), will potentially affect where operators can take visitors to see certain species. Since tourism is already very seasonal, prolonged hot weather and less predictable rainfall is likely to affect visitation patterns, while more extreme weather may influence tourists’ perception of their safety in the region.
Changing climatic conditions will challenge our established ways of doing things, but may also present new agricultural and commercial opportunities. For example, it may be necessary to diversify or switch crops or breeds to suit new climatic conditions, or to change practices. In order to adapt to new and changing climatic conditions, we may need to shift farming and other commercial enterprises to different parts of the landscape. This could create opportunities for the restoration of wildlife habitat on former agricultural land, but could also create conflict between the need to protect existing habitat and also maintain production.
Everyone will be affected in one way or another by climate change: some types of farms may not remain viable, certain areas along the coastline may become unsafe to live, and some of our iconic species may not survive in the new conditions. While change can be unsettling, new opportunities may come out of new ways of doing things, especially by working together across sectors and industries.
Fire weather is likely to increase in the Southern Tablelands landscape due to the combination of increased evaporation, higher average temperatures, and more frequent and hotter heatwaves. For example:
- Evaporation is projected to increase on average by around 4% annually in north Queensland.
- Evaporation increases in some months are expected to be even higher (e.g., 7% increase in January, projections from climate model Had GEM2-ES).
- The intensity, frequency and extent of bushfires may increase as a result of these conditions.
- While fire is already a familiar issue around Atherton, Wondecla and Ravenshoe, bushfire risk may increase in areas not currently affected.
- The risk of large, hot fires in the Southern Tablelands will be exacerbated if elevated levels of CO2 promote the growth of native C4 grasses, such as blady grass Imperata cylindrica.
- Fire risk may increase in some parts of the Southern Tablelands, for example on the margins of Mabi forest around Yungaburra, especially if average rainfall declines, or if dry seasons are prolonged.
We can expect that heavy rainfall events will become more frequent and intense, potentially increasing the occurrence and severity of flooding in the Southern Tablelands region. Areas around Malanda, Atherton and Tarzali are likely to be vulnerable, as homes, businesses and roads are already at risk from river flooding. Major roads such as the Millaa Millaa-Malanda Road and Malanda-Atherton Rd are also subject to flooding. Planning for infrastructure such as stormwater drains, roads and bridges will need to account for projected worsening of flooding.
With rising temperatures, some of the features of the Southern Tablelands that currently set it apart from other parts of the region are also likely to change. For example, climatic conditions are expected to become more suitable for mosquitoes, meaning that dengue fever is likely to become more common on the Tablelands rather than being restricted to the coast. Coastal areas tend to bear the worst impacts of tropical cyclones, but cyclone damage on the Southern Tablelands is likely to be more extensive as cyclones become more intense (though less frequent), and therefore retain more energy when they reach the Tablelands. The impacts of sea level rise in coastal parts of our region will be compounded by more frequent and intense heavy rainfall events, as well as more intense tropical cyclones. Working together to address back-up power and supply issues will help build resilience of the Southern Tablelands in the face of these changes.
Natural systems have coped with changing climatic conditions in the past but current changes are happening so fast that some species may not be able to adapt. Because climatic factors such as temperature and rainfall play such an important role in determining the suitability of different areas for plants and animals, we can expect that changes in temperature and rainfall will change the suitability of the landscape for certain species and systems. The result of climate change will be new combinations of plants and animals, sometimes in new locations, challenging our concept of what is ‘natural’. Even fairly small changes, such as the increased recruitment of colonising (or pioneer) rainforest plant species can have a substantial effect on the suitability of an area for other plants and for some animals. It’s also likely that this region will become more attractive to people moving from other areas that become less liveable. Increasing pressure for housing and more infrastructure to support growing populations will potentially lead a push for more clearing of native vegetation.
The Southern Tablelands landscape is likely to retain climate conditions that suit many of the species that are currently found here. However, some animals and plants may no longer be able to survive or reproduce in the area. The most obvious examples are mammals and birds living in the areas around Ravenshoe, Minbun, Tumoulin and Upper Barron which are the only areas certain species can be found in the region, partly because of the cool temperatures they support. Even relatively familiar species such as tree kangaroos are very sensitive to high temperatures, and a few days of hot weather can be fatal to them. Modelling shows (http://climas.hpc.jcu.edu.au/maps/) that the region’s climate will rapidly become less suitable for tree kangaroos within the next two decades. Under a business as usual scenario of greenhouse gas emissions, suitable climatic conditions for TKs will continue to decline and, by the year 2085, there will be only a small area remaining that will support even a marginally-suitable climate. This modelling shows that climatic conditions around Atherton, Wongabel, Upper Barron and Tumoulin will no longer be suitable for this species. The models also project substantial change for the endangered northern bettong, which currently has a stronghold in areas in the northern tablelands, the majority of which are projected to become unsuitable by the year 2085. This modelling shows that climate conditions in areas around Herberton may become suitable for bettongs, even though these areas are not currently part of their core habitat. In reality, changes may not unfold as exactly as these models project, but these projections have complex implications for how we manage landscapes to protect our plants and animals; we have to protect areas that are currently important so that threatened species survive, but also consider where important habitat will likely be in the future, together with whether and how plants and animals would be able to move there and establish. These considerations affect our decisions about which areas to protect and restore, as well as how to manage these areas.
In addition to the direct effects of increased temperatures and changed rainfall, climate change will have a range of indirect effects on other factors that drive natural systems. A major impact of climate change for natural systems will be more frequent and/or more intense disturbances, such as floods, fires, heatwaves and cyclones. For example,increased intensity and frequency of river flooding, together with increased water temperatures, will change aquatic systems, as well as those fringing waterways or on floodplains. Narrow riparian vegetation will be particularly vulnerable. More extreme rainfall events will also increase the frequency of intense disturbance to in-stream invertebrates, animals and plants, and exacerbate the issue of soil and pollutant runoff entering the Great Barrier Reef lagoon. On a national scale, the North and South Johnstone Rivers are among a small number of watercourses identified as being priorities for conservation of freshwater biodiversity under climate change.
Managers of biodiversity are already working to minimise or reverse impacts of land clearing, pollution, introduced plants, animals and diseases on natural systems. Climate change is an additional impact that interacts with these existing pressures. The resilience of natural systems to cyclones and other disturbances is improved by having a large and well-managed network of protected areas. It’s not possible to predict the exact consequences of climate change for plants, animals and their habitats, but sharing observations, trying new management practices and monitoring their outcomes will help build the new knowledge required to promote adaptation of natural systems to climate change.