How global container shipping emissions and marine primary production are related to: A geographically and temporally weighted analysis.

Ocean sustainability is a critical global issue. However, increasing CO2 emissions from container shipping have adversely impacted marine ecosystems. Oceanic net primary production (NPP) is a key indicator of marine ecosystem health. Despite abundant research showing a relationship between CO2 and NPP, limited attention has been given to the relationship between CO2 emissions from ships and NPP. This study estimates global CO2 emissions from container shipping from 2018 to 2021 using the Ship Traffic Emission Assessment Model (STEAM), then combines remote sensing NPP data and applies a geographically and temporally weighted regression (GTWR) model to explore their spatiotemporal relationship. The results reveal the temporal variation patterns, hotspot regions, and clustering characteristics of CO2 emissions from container shipping and NPP. Furthermore, the findings indicate that NPP's response to CO2 emissions shows varying correlations. In western South America, southwestern Africa, the equatorial Atlantic, and the southern Greenland Sea, CO2 emissions from container shipping promote NPP, while in the Indian Ocean, Black Sea, Mediterranean Sea, and North Atlantic, CO2 emissions inhibit NPP. That implies differing environmental sensitivities and the variations in balance between the positive effects of increased dissolved inorganic carbon (DIC) and the negative effects of ocean acidification. This study clarifies the spatiotemporal heterogeneous relationship between CO2 emissions from container shipping and NPP, providing strong support for the development of sustainable oceans.