Source: AGU Advances
As the war in the Ukraine reminds us, the threat of a nuclear conflict is real. What consequences would such a war have for life in the ocean? Harrison et al.  report on results from model simulations where they looked at the impact of a large-scale war that would deposit 150 Tg (150 billion kg) of sunlight-absorbing black carbon into the atmosphere. This scenario causes a global-scale cooling of sea-surface temperature of nearly 6°C. Even though the associated deepening of the mixed layer brings additional nutrients to the surface, the lack of light reduces net primary production (NPP) by more than 50% globally, with some regions experiencing a complete collapse of biological productivity. NPP recovers slowly after a decade alongside sea-surface temperature, but does not return to pre-war levels even after many decades. This highlights the long-lasting threats of a nuclear war, especially through the non-linear response of the ocean.
Citation: Harrison, C. S., Rohr, T., DuVivier, A., Maroon, E. A., Bachman, S., Bardeen, C. G., et al. (2022). A new ocean state after nuclear war. AGU Advances, 3, e2021AV000610. https://doi.org/10.1029/2021AV000610
—Nicolas Gruber, Editor, AGU Advances