Improving cumulative effects assessment: alternative approaches based upon an expert survey and literature review

ABSTRACT

Cumulative effects assessment has been a longstanding challenge and is perhaps the most crucial component of project-level impact assessment. Alternative approaches to advance project-level cumulative effects assessment are developed based upon the findings of a literature review and key informant interviews. Alternative approaches are organized around key themes and cover: baselines; hybridization of sequential and integrated assessment; regional environmental assessment; the omnipresence of cumulative effects in project-level assessment; professional culture; and value-centrism.

KEYWORDS:

• Cumulative effects assessment
• impact assessment

Acknowledgments

This research was funded by a government entity in Canada that wishes to remain anonymous. We thank this funder, all key informants, as well as Anna Usborne for related and informative discussions.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Notes

1. The study funder wishes to remain anonymous; see Acknowledgements.

2. Human environment VCs include cultural, economic, health, and social VCs.

3. Although there is no statistically derived target for informant interview sample sizes, some researchers recommend between 10 and 17 interviews (Muellmann et al. 2021) and others 15–35 (USAID CDIE 1996). Three past studies on CEA (Harriman and Noble 2008; Olagunju and Gunn 2015; Arnold et al. 2019) relied on 16, 23, and 22 interviewees, respectively.

4. Project-specific effects are defined as the effects of a project on a VC isolated from any interactions these effects may have with other stressors.

5. Recent legal and policy changes in Canada may support such an approach. The new Canadian IA law (IAA) has dropped the requirement in the previous law for proponents to assess significance, instead leaving this judgment to government, though it is unclear whether government will examine project-specific effects in isolation of CEs or not. More concretely, the IA process for the Canadian territory of the Yukon (YESAB 2021) requires that the significance of CEs is considered in judgements of the significance of project-specific effects.