Global Declines in Mangrove Area and Carbon-Stock From 1985 to 2020

Abstract

Mangroves are one of Earth's “blue lungs” due to their exceptional carbon-storage capabilities amidst rapidly increasing carbon dioxide. Despite providing numerous ecological services, their global distribution and carbon-storage capacities have severely declined over the past 35 years (1985–2020). Here, we quantify spatio-temporal changes in global and national carbon-stocks that include this period. We found that global mangrove area decreased from 17.35 million-hectares in 1985 (carbon-storage of 6.84 Pg) to 13.61 million-hectares in 2020 (carbon-storage of 5.72 Pg). Significant losses occurred in Saudi Arabia and Indonesia, with a global reduction of 21.6% in area and 16.5% in carbon-stocks. Potential maximum loss of accumulated carbon-storage in mangroves was equivalent to 4.13 Pg of CO₂, accounting for 0.4% of the global cumulative fossil CO₂ emissions (1,009 Pg) during 1985–2020. This study provides more comprehensive and accurate statistics, maps, and insights on estimating and reducing mangrove carbon emissions to support global and national protection policies.