The adaptation options are largely incremental in nature. They either involve doing incrementally more of what is being done to manage existing pressures on natural resources or making incremental modifications to the existing suite of management actions. Incremental adaptations are likely to be at least partly effective responses to climate change over short to medium term NRM planning timeframes (around 5 to 20 years). Climate change projections suggest little change in annual or seasonal rainfall and only modest increases in temperature (~1°C) over this period. These changes may push some aspects of climate variability (particularly extreme high temperatures) outside historic ranges and may affect particularly sensitive natural systems. However, they are unlikely to drive most natural systems beyond their coping ranges or resilience thresholds. The state of natural resources and systems may be more influenced by non-climate change pressures over this timeframe.
The climate is projected to change profoundly over the 50 year vision timeframe of the Goulburn Broken RCS, particularly under high greenhouse gas emissions pathways. Under such circumstances, climate change is likely to exert increasing influence on the condition of natural resources and systems.
It is likely that at least some of the impacts of climate change will not be able to be mitigated through incremental modifications to conventional responses. Transformational responses to climate change may be required.
Kates et al. (2012) recognise three classes of transformational adaptation:
- Transformational scale: existing adaptations that are adopted at a much larger scale or intensity.
- Transformative idea: adaptations that are truly new to a particular region or resource system.
- Transformation of location: adaptations that transform place-based social-ecological systems or shift such systems to other locations. These are more extreme examples of the “reduce the risk” adaptation options described above.
Several scenarios can be envisaged where there is a requirement for transformational adaptation, particularly for the Great Dividing Range forests and alpine priority landscape. These include:
- Snow-dependent ecosystems of the Australian Alps: increasing temperature is anticipated to increase the height of the snow line and reduce the incidence of snow and depth and duration of snow cover. Under long-term, upper range climate change scenarios, it is unlikely that incremental autonomous adaptation will be sufficient to maintain these ecosystems in place. Transformational adaptation will most likely be required if they are to do so and may be required to sustain key ecosystem services in these areas if these ecosystems cannot be retained in place.
- Fire-sensitive wet sclerophyll forests: greatly increased temperatures and declining rainfall with long-term, upper range climate change scenarios will greatly increase the frequency of extreme fire weather and may lead to more frequent fires in the fire-sensitive wet sclerophyll forests that comprise much of mountain forests. If fire frequency falls below the tolerable fire interval for these forest types, key fire-sensitive species may be lost. Again, transformational adaptation may be required to avoid this outcome or because it cannot be avoided.
Because of the value of natural resources and the ecosystem services provided by these areas, long-term adaptation planning will need to consider and develop transformational options.