The Paris Agreement encourages countries to develop “ mid-century, long-term low greenhouse gas emission development strategies” (long-term strategies) taking into consideration their respective capabilities (Article 4.19). Despite various potential benefits of having such long-term strategies, countries may find it very difficult to develop one that is realistic and feasible, and consequently think twice about embarking on the task.
One of the major causes of such difficulties is the existence of a great deal of uncertainty that affects the future and, in turn, the strategy. Due to its long-term time horizon and an economy-wide coverage, the strategy is inevitably exposed to various uncertain factors. For instance, decarbonizing economy in alignment with the goals of Paris Agreement will not be achievable without a number of technological innovations, including those for drastic cost reduction, but it is difficult to foresee what technology will become available and when. Designing a strategy for a climate resilient economy will face challenges with understanding what, when, where and to what extent future climate impacts will be. The sources of uncertainties are not limited to those directly related to climate issues. Both global and domestic political environments, economic development, and demographic changes, among many others, could significantly impact such a long-term strategy but they are all difficult to foresee in the future, especially decades out.
The vast uncertainty may well overwhelm countries and make them wonder if developing a long-term strategy is meaningful at all. With this expert perspective, we would like to explore effective and practical approaches to addressing uncertainty in developing long-term strategies, which may help countries overcome, or at least get along with, uncertainty.
For this expert perspective, we ask authors to consider the following questions when writing their expert perspective (but it is not necessary to respond to all the questions):
How can those charged with developing the long-term strategy identify and narrow down uncertain factors that are the most material and relevant to the strategy?
What typically are the main sources of uncertainty relevant to developing long-term strategies? Although there are almost infinite uncertain factors that could influence the long-term strategy in some way or another, what is an effective approach to capturing the most important ones? Or is there a better approach to coping with uncertainty without specifying which factors are the most relevant?
What principles could be embraced by decision makers for addressing uncertainty?
Long-term strategies must be able to guide actions and investments without knowing the future for sure. Then, what should be kept in mind in developing them? Although there may be no one-size-fits-all prescriptions applicable under diverse circumstances, could there be some high-level principles that are useful across different situations?
What frameworks or tools are available to help us address uncertainty in developing long-term strategies, particularly with regard to goal/target setting, options analysis, priority setting, trade-off management, and identifying the implementation pathway?
What advantages and disadvantages are observed in applying such frameworks and tools to the development of long-term strategies?
How can the long-term strategy factor in future technological advancement?
Achieving low or net zero greenhouse gas emissions is an indispensable aspect of the long-term strategy expected in the context of Paris Agreement. Therefore, uncertainty with regard to the development and availability of emission reduction/removal approaches will be a common challenge for all countries. What would be an effective approach to handle the uncertainty with regard to future technological advancements? Are there any useful insights or lessons we can learn from the history of technological development?
What is an effective approach to building a long-term resilience strategy in the face of uncertain climate impacts?
Countries may choose to integrate climate resilience goals into the long-term strategies. While some climate change effects, such as global average temperature increase and sea level rise, are relatively straightforward, many effects that emerge as a result of interactions of complex systems are deeply uncertain and the translation of future global impacts to local settings is also riddled with uncertainty. Some climate impacts are new to human history (e.g. seawater acidification), whereas many impacts appear in the amplified form of existing stressors, such as tropical cyclones, floods, and droughts. Compounding uncertainty is how societies and ecosystems will be able to withstand and adapt to such impacts. What measures should be built into the strategy and/or its governing mechanism to address the uncertainty of climate impacts?