Food to Fumes
Aquaculture and mariculture are methods of food cultivation that are becoming increasingly important for food supplies across the globe. While these methods have led to greater accessibility to food sources, their expansion has resulted in an increase in greenhouse gas (GHG) emissions. The influx of these gases, including methane and carbon dioxide, are large contributors to climate change. With China being the leading producer of agricultural and mariculture cultivation, UCSB Bren School of Environmental Science & Management visiting scholar Kangshun Zhao worked with researchers from the Institute of Hydrobiology, Chinese Academy of Sciences to conduct a study that quantified GHG emission levels that were directly from aquaculture and mariculture production in China. They analyzed the carbon footprint of the four phases of the production process (feed, energy use, nitrous oxide and fertilizers) over the course of 10 years to show the spatial distribution of the emissions. The findings showed that feed production was the greatest contributor to GHG emissions as a result of crop energy use, crop land-use changes, fertilizer production and rice methane production. The regional gross domestic product was positively correlated with emissions in every province, with a correlation coefficient greater than 0.6. These results revealed that China’s aquaculture had a lower emission intensity compared to the findings of Macleod et al (2020) due to the higher percentage of bivalve (an aquatic mollusk) production. The results suggest that China’s carbon footprint can be reduced by adjusting the relative proportion of species-group production and decreasing the amount of energy use.