Triggers for Future Action and Limits of Acceptable Change
A key challenge to both attracting funding for planning and implementing measures to building resilience and more active climate change adaptation responses is that the impacts in many cases are not yet apparent or otherwise masked by natural variability in natural systems. The application of the toolkit presented in Table 26.3 can be assisted by a simple decision support system taking into account the risks of climate change impacts over time.
This approach draws from observations made in Australian climate risk literature about the need for triggers for future action with respect to climate change (refer, in particular, Atwater et al. 2008) but also draws on similar trigger approaches that can be found within an increasing number of natural resource management planning and assessment frameworks (Fisk and Kay 2010).
Specifically the tool uses a process of setting of ‘limits of acceptable change’ for wetland values as outlined by the National Framework and Guidance for the Preparation of Ecological Character Descriptions (ECD) for Australia’s Ramsar Wetland (DEWHA 2008). Under the Framework, indicators of change are defined for wetland components and processes such as bird numbers and habitat extent based on an understanding of the natural variability of those populations and systems over time. These indicators are framed as ‘limits of acceptable change’ that guide the future management of the wetland by defining the quantitative limit of impact that can be accepted before the ecological values of the wetland are diminished or lost. In the future, if there is an exceedance of one or more of the limits of acceptable change set out in the ECD (e.g. there is a change outside of natural variability or a change beyond the limit set for the indicator) then this serves as a trigger that an ecological character change has occurred within the wetland that must be halted or reversed.
This approach of defining undesirable impacts (as opposed to desirable conditions) has some attraction for assessing and addressing future climate change which is also based on the notion of trying to avoid or otherwise minimise future impacts (see Fig. 26.2).
Information from vulnerability studies about current condition and the potential effects of climate change on coastal natural assets can be used to: (a) define a profile for each climate change risk over time (e.g. along a continuum) based on the
Fig. 26.2 Climate change risk continuum (adapted from Fisk and Kay 2010)
projection or prediction of future climate change impacts; and (b) consider how various adaptation actions developed to treat the risk should be applied over time.
For each climate change risk issue or parameter that is being considered as part of the climate change vulnerability or risk assessment, there is an assumption that three points (or stages) along the continuum can be defined (see Fig. 26.2):
- • Stage (1) The baseline (present day/current condition) of the climate change parameter or risk being examined;
- • Stage (2) The identification of one or more ‘trigger’ points along this time continuum that serve as a flag to management agencies that the impacts associated with the risk are occurring and that an undesirable impact is being approached; and
- • Stage (3) The undesirable impact or end state of the climate change parameter or risk being examined (e.g. what are the impacts that are trying to be avoided).
Linking to the discussion about the ECD framework above, a key innovation of the tool is the approach of seeking the coastal management agency to define—at the present time—what it believes to be the unacceptable future impact from climate change.
Once this undesirable end state is established and agreed, the planning or management agency can consider, in a more practical sense, what are the most appropriate adaptation actions that can be undertaken to either avoid the impact from occurring or otherwise to minimise or mitigate the future impact and when such interventions need to be considered and implemented.
Use of the tool can also help decision-makers to align perceived risk with the selection of the most appropriate adaptation measures and actions. Importantly, such an approach can guide agencies to differentiate between ‘no-regrets’ and other resilience building actions that can be undertaken in the short term (period of acceptable risk shown in green in Fig. 26.2) versus the more difficult decisions and options that deliver adaptive action in the medium to long term (shown in orange and red zones in Fig. 26.2).
In a similar fashion, the adaptation toolkit discussed in the previous section of this paper can also be aligned with the continuum. While it may be appropriate to implement ‘accommodation’ actions in the green zone of acceptable risk; ‘protection’ or ‘planned retreat’ actions may be needed to be implemented in the orange zone of the continuum to avoid the undesirable impact shown in the red zone.
Overall, the approach assumes that while a range of resilience building actions may be appropriate to develop and implement while the risk is at an acceptable level, there will need to be consideration of more direct actions to address the risk as the likelihood and severity increases.
Some other advantages to setting some form of a trigger level for adaptation actions are as follows:
- • Assuming the trigger is set effectively it should give management agencies adequate time to act prior to realising the undesirable impact. This could include for example, development of a response plan, time to run an adequate public consultation programme, and sufficient time to more quantitatively assess the various adaptation options such the feasibility of constructing works (or other expensive and/or controversial adaptation response);
- • It prevents the management agency from acting too early. Premature action in response to climate change can have significant cost and political implications such as exposing the management agency to appeals against development decisions and compensation claims. This is termed ‘over-adaptation’ to climate change (Willows and Connell 2003). Acting too early also does not take advantage of any research and technological advancements that have occurred during the period of acceptable risk (e.g. the period leading up to the trigger point);
- • The approach can help to ‘lock’ decision makers into an action plan over a longer period of time and facilitate evaluation of plans and strategies. This is especially important given the invariable turnover of staff from management agencies, election and re-election of political leaders and similar issues; and
- • The approach demonstrates to the broader community a level of preparedness and a willingness to act as climate change impacts are realised and as trigger points are approached in the future.