GRL：Carbon Sequestration of the Middle Miocene Sunda Shelf Facilitated Global Climate Change

Pengfei Ma¹ , Zhifei Liu¹ , Meichen Jiang² , Han Cheng³ , Lin Zhang⁴ , and Dizhu Cai⁴

1State Key Laboratory of Marine Geology, Tongji University, Shanghai 200092, China, 

2School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China,

3State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing 100083, China

4Haikou Marine Geological Survey Center, China Geological Survey, Haikou 571127, China 

Abstract：

 Long-term organic carbon (OC) burial on continental shelves has been widely recognized for regulating atmospheric CO₂ (pCO₂) and the global climate. However, quantitatively assessing shelf OC burial's role and process in prominent climate transitions is challenging. Using 367 drilling sites, we evaluated the impact of OC burial on the Sunda Shelf, the world's largest tropical shelf, on the middle Miocene carbon perturbation and climate change. Comparing the Miocene Climatic Optimum (MCO) and the middle Miocene Climate Transition (MMCT) results demonstrated that OC was faster buried during the MMCT with an increment of 0.07- 0.14×10³ GtC/Myr. This would cause an additional 34.77-69.16 ppm pCO₂ sequestration, contributing at least one-sixth of the global pCO₂ reduction. We found OC burial regulated the long-standing Monterey carbon isotope excursion via negative and positive feedbacks during the MCO and MMCT, respectively. Expanded terrestrial carbon reservoirs and enhanced burial efficiency were key steps in the latter positive feedback.

Full Article：https://doi.org/10.1029/2022GL100638