Here we employ a cumulative effects model to examine and compare the relative contribution of climate change and planned industrial development to cumulative effects in a northern temperate region of British Columbia, Canada. We focus on this region because it is under considerable pressure from planned developments such as oil pipelines and liquefied natural gas facilities, and their associated marine shipping activities—representing many of the pressures that exist in other regions. Also, past marine cumulative effects analyses in this region facilitated our analysis. We present the cumulative effects of current human activities and investigate the addition of three stressors associated with global climate change: sea surface temperature, acidification and ultraviolet light. We then include potential industrial development in a future development scenario in order to compare the two drivers of change and discuss implications for management of marine ecosystems.