Climate forcing by battered-and-breaded fillets and crab-flavored sticks from Alaska pollock

Abstract

The food sector is a significant contributor to greenhouse gas emissions, contributing 10–32% of global anthropogenic sources. Compared with land-based food production systems, relatively little is known about the climate impact of seafood products. Previous studies have placed an emphasis on fishing activities, overlooking the contribution of the processing phase in the seafood supply chain. Furthermore, other studies have ignored short-lived climate forcing pollutants which can be particularly large for ship fuels. To address these critical knowledge gaps, we conducted a carbon footprint analysis of seafood products from Alaska pollock, one of the world’s largest fisheries. A holistic assessment was made including all components in the supply chain from fishing through retail display case, including a broad suite of climate forcing pollutants (well-mixed greenhouse gases, sulfur oxides, nitrogen oxides, black carbon and organic carbon), for domestic and top importers. We found that in some instances the processing phase contributed nearly twice the climate impact as the fishing phase of the seafood supply chain. For highly fuel-efficient fisheries, such as the Alaska pollock catcher-processor fleet, including the processing phase of the seafood supply chain is essential. Furthermore, the contribution from cooling emissions (sulfur and nitrogen oxides, and organic carbon) offsets a significant portion of the climate forcing from warming emissions. The estimates that include only greenhouse gases are as much as 2.6 times higher than the cases that include short-lived climate forcing pollutants. This study also advances our understanding of the climate impact of seafood distribution with products for the domestic retail market having a climate impact that is as much as 1.6 times higher than export products that undergo transoceanic shipping. A full accounting of the supply chain and of the impact of the pollutants emitted by food production systems is important for climate change mitigation strategies in the near-term.