Global Patterns in Marine Sediment Carbon Stocks
Trisha B. Atwood, Andrew Witt, Juan Mayorga, Edd Hammill, Enric Sala
Abstract
To develop more accurate global carbon (C) budgets and to better inform management of human activities in the ocean, we need high-resolution estimates of marine C stocks. Here we quantify global marine sedimentary C stocks at a 1-km resolution, and find that marine sediments store 2322 (2239–2391) Pg C in the top 1 m (nearly twice that of terrestrial soils). Sediments in abyss/basin zones account for 79% of the global marine sediment C stock, and 49% of that stock is within the 200-mile Exclusive Economic Zones of countries. Currently, only ∼2% of sediment C stocks are located in highly to fully protected areas that prevent the disturbance of the seafloor. Our results show that marine sediments represent a large and globally important C sink. However, the lack of protection for marine C stocks makes them highly vulnerable to human disturbances that can lead to their remineralization to CO 2 , further aggravating climate change impacts.