Beyond Carbon in Socioenvironmental Assessment for Zero Carbon Systems

Abstract:

Decarbonizing the energy system is a crucial task for mitigating climate change. Numerous technological solutions exist for energy system decarbonization, each with its own social and environmental constraints. Although sustainability assessment methods like life cycle assessment (LCA) are designed for multicriteria sustainability evaluation, greenhouse gas (GHG) emissions have long been a dominant indicator in part because of their strong linkage to the many serious impacts of climate change. When faced with a choice among multiple zero-GHG infrastructure options, however, as when designing decarbonization pathways and just transitions away from a fossil energy-based system, GHG emissions become a much less useful proxy for relative sustainability. The socioenvironmental assessment community thus faces a challenge in robustly evaluating relative sustainability for zero carbon energy systems. Specifically, methodological issues like normalization, multicriteria prioritization, data collection and management, and context-specific impact assessment remain underdeveloped in part because they are less important in contexts where GHG intensity is assumed to be the dominant decision-relevant factor. This work uses carbon capture and storage (CCS) as an example to illustrate specific needs for moving “beyond carbon” in socioenvironmental assessment. Even carbon neutral CCS systems incur substantial social and environmental impacts, from mining and health effects to water consumption and solid waste management. Decarbonization exists in the context of socioenvironmental sustainability issues that extend well beyond GHG impacts, and net-zero energy systems will have different levels of impact in these non-GHG arenas. Leveraging existing strengths of multicriteria sustainability assessment methodologies like LCA, and investing effort in strengthening their value for decision support, could improve long-term sustainability outcomes.