Uncertainty in risk issues for carbon capture and geological storage: findings from a structured expert elicitation

Abstract

Carbon capture and geological storage (CCS) is identified within the portfolio of mitigation options for climate change. Each value chain activity of large scale integrated projects (capture, transport, injection and storage) includes uncertainties and hence potential risks with respect to both environmental and human health protection. With a focus on injection and storage, a structured elicitation of international experts provides quantified judgements and uncertainties and understanding of relative risk of CCS activities. In the 0-50 year, 51-499 year and >500 year time periods, the expert panel suggested an almost equal likelihood of storage leakage occurring, with a marked decrease from minor to major to catastrophic leakage (approximately >1 in 30; 1 in 103; 1 in 104, respectively); for the same time periods, the judgement of likelihood for major leakage that would result in measurable negative effects on human health or the environment was the same (approximately 1 in 103). Insights could stimulate further scientific deliberations about the reliable and effective deployment of this complex and interdisciplinary technological process. A companion paper discusses complementary findings for issues in CCS risk management.

Risk management in carbon capture and geological storage: insights from a structured expert elicitation

“…The elicitation methods are described in detail in the companion article that provides findings with respect to important issues in risk assessment (Larkin et al, 2019a).…”

“…For the shorter operations period, the group's performance-weighted median response suggests 88% of effort should be focused on human health compared with environmental protection (TQ56, Table 1). Experts also suggested greater health than environmental risk in capture compared with storage (Larkin et al, 2019a). As an economic risk management option, experts' central estimate was that 5.5% of injection and storage project costs should be mandated by regulatory agencies for both environment and human health protection, with a 90% credible range ~1%-17% (TQ57, Table 1).…”

“…The present paper provides findings related to risk management, including options for addressing low probability high impact events. The elicitation also considered issues in risk assessment, findings for which are detailed in a companion article (Larkin et al, 2019a).…”

Alberta's approach to the transfer of liability for carbon capture and storage projects

“…Possible scenarios include acidification of ground water and mobilisation of trace metals, releases to the surface causing accumulations of CO 2 in low-lying areas, or damage to an oil recovery operation. While the risk of such a release may be low (IPCC, 2005;Larkin et al, 2018b;Haszeldine and Ghaleigh, 2018) much may depend on the characteristics of the individual storage site. Relevant considerations include the existence of natural faults, the characteristics of the geological seals, the tectonic stability of the region and the existence of legacy wells that penetrate the storage complex (Sarkarfarshi et al, 2018;Haszeldine and Ghaleigh, 2018).…”

Potential technical hazards associated with four North American carbon capture and sequestration projects

“…Nevertheless, placing realistic quantitative bounds on event probability and consequence remains a highly contentious process for several reasons, mainly because of a lack of experiential history in the area of georisk, critically important for long-term security. Larkin et al (2019aLarkin et al ( , 2019b discuss findings from a structured expert elicitation on relative risk and uncertainty judgements for potential hazards in injection and storage, and risk management of low probability high impact events.…”