Transition pathways, risks, and uncertainties

The 2018 IPCC Special Report on Global Warming of 1.5 °C once again highlighted (and with increased urgency) the benefits of immediate, extreme decarbonisation efforts in order to minimise the negative impacts of climate change. Achieving such demanding global targets requires concerted national, subnational, and local efforts. In combination, these efforts result in transition pathways. Implementation of the technologies and policies at the heart of such pathways is often considered as inherently positive, thus the immediate risks associated with the pathway are the barriers faced on implementation. However, successful implementation of a climate change mitigation policy may also have potentially negative consequences. On either side a host of more abstract uncertainties increase the difficultly of decision making. In this chapter, we provide a synthesis of eleven low-carbon transition pathways from across the globe and explore the risks and uncertainties associated with them. We structure our discussion around three nested dimensions present in all pathways: technological innovations implemented in a local context; policy mixes promoting these technologies; and society, where social-economic priorities may lead individuals and communities to support or oppose the low-carbon pathway. Across these themes, we also explore the meaning of scale and stakeholders’ perceptions of time in low-carbon pathways. Our discussion reflects the complexity associated with assessing risks in contested settings. While many of these risks are context specific and reflect a broad range of stakeholder perspectives, common risks are found across the case studies, regardless of the local context, the technology promoted, and the policy mix implemented.