Our Climate Change Vulnerabilities
A number of vulnerabilities as a result of, or exacerbated by, climate change in the Northern Agricultural Region have been identified and these are shown below.
Although the Australia’s national biosecurity threat is not anticipated to increase as a result of climate change, new and emerging weed species, along with changed levels of invasiveness, will exacerbate the challenges of managing weeds under a changing climate. The number of exotic and naturalised species in Australia that have the potential to become weeds is likely to increase as their areas of climatic suitability expand or shift (mostly southwards in the case of the NAR). The main climate change related drivers for invasive species are increased temperatures and atmospheric carbon dioxide levels, altered rainfall regimes, more extreme weather, more frequent frosts, changed plant phenology, and land use changes. Weeds tend to adapt and respond faster to these changes that native and crop species, and therefore tend to hold the competitive advantage.
Increased connectivity of the landscape – a major adaptation response to climate change – also presents increased opportunities for weed invasion. This increased risk can be combated by adapting quarantine, monitoring and eradication methods to meet these challenges.
Novel ecosystems may also result when new assemblages of native and alien species develop due to a change in species distribution. These novel ecosystems require equally novel management responses, and may also require changes in community perception.
Despite these challenges, Australia has a long history of successful management of weeds species, and this experience will be valuable in combating these increased risks. One way this can be done is by mapping the potential future distribution of weeds through bioclimatic modelling, the outcomes of which can be used to determine areas at risk of invasion and be incorporated into planning and decision making activities (Scott et al. 2014).
Altered Fire Regimes
Warmer, drier conditions and increased fuel loads due to the effect of increased atmospheric carbon dioxide on plant growth, may impact fire management under climate change. In turn, the frequency and intensity of fire can impact plant abundance, distribution and competition between plant species. Weeds, which are also likely to become increasingly challenging to control due to climate change, can also alter fire regimes due to their impact on fuel load and structure.
At the other end of the spectrum, the use of fire as part of strategic weed control, may form an important adaptation response to climate change – although this option may be risky with increased temperatures, and therefore only suitable for use at certain times of the year (Scott et al. 2014).
Coastal and Marine
The impacts of climate change on our ocean and marine environments are both physical and chemical – rising sea levels, warming ocean temperatures and changes to ocean pH and currents are among these impacts. The effect of these changes on marine species will vary depending on their natural tolerance, resilience and adaptive capacity, and there are expected changes to species distribution, abundances and community structure.
Rising Sea Levels
Rising sea levels will directly affect coastal areas within the NAR. Potential impacts include inundation of low-lying areas, increased coastal erosion and recession, and threats to coastal infrastructure and urban areas. As a result, many LGAs are undertaking Coastal Hazard Risk Management and Adaptation Planning (CHRMAP).
Sea level rise may also result in the loss of coastal habitat for inter-tidal and migratory species (Steffen et al. 2009).
Coral bleaching may result when coral species are unable to tolerate increased ocean temperatures, tropical fish species may move further south, while pests and diseases may be exacerbated (NCCARF, 2012a).
Changes to Ocean Chemistry
Ocean acidification affects marine species such as corals and shellfish (NCCARF, 2012a).
Fishing and Aquaculture
Changes in the distribution of fish species may have an impact on fishing activities/industries, which are likely to be reflected in associated policies, regulations and legislation; while changes in diseases, nutrients, algae and storm surges may impact the aquaculture industry (NCCARF, 2012a).
Tourism and Recreation
Tourism values built on natural ecosystems are likely to suffer in areas negatively affected by climate change. Developments close to the ocean may suffer damage and require relocating due to rising sea-levels, and therefore effective planning regulations addressing these risks are crucial.