Cumulative Impacts

EnerGeo acknowledges the consideration of cumulative impacts as an important component of environmental assessment and environmental decision-making. Environmental systems are influenced by multiple natural and anthropogenic factors that vary across space and time. Understanding how a proposed activity may contribute to broader environmental change requires consideration of other past, present, and reasonably foreseeable activities that may affect the same environmental receptors.

Cumulative impact assessment is intended to evaluate whether the effects of a proposed activity, when considered together with other relevant activities and environmental influences, may result in meaningful impacts on environmental receptors. Effective cumulative impact assessment should be based on plausible impact pathways, the best available scientific information, and a clear understanding of the mechanisms through which effects may interact. Assessments should consider the nature, magnitude, duration, frequency, and geographic extent of effects, as well as the degree to which effects overlap in space and time.

The existence of multiple activities or stressors within a region does not, by itself, demonstrate the presence of significant cumulative impacts. Rather, cumulative effects should be based on whether combined effects are likely to result in measurable changes to the affected receptor. Assessment should distinguish between exposure, response, and impact, and should appropriately characterize uncertainty using the best available scientific information.

As a transient and mobile activity, seismic surveying generally has limited cumulative impacts at a specific location. Survey operations move through the environment rather than remaining in one place, resulting in exposures that are typically temporary and localized. The mobility of both the survey source and environmental receptors (e.g., marine mammal) further reduces the extent to which exposures overlap and accumulate over time. Current metrics to assess cumulative exposure are limited in their applicability to transient activities. Modeling frameworks, including the Population Consequences of Disturbance (PCoD) and Population Consequences of Acoustic Disturbance (PCAD), attempt to examine the potential impact of both individual and cumulative activities, requiring extensive input data to understand the range of stressors, their interaction, and accumulation.

EnerGeo supports cumulative impact assessments that are scientifically robust, transparent, proportionate to the scale and nature of the proposed activity, and focused on evaluating meaningful environmental outcomes. A science-based, receptor-focused approach helps ensure that cumulative impact assessments provide useful information for environmental decision-making while maintaining transparency, consistency, and scientific credibility.