Mangrove productivity is crucial for the global carbon cycle, yet previous research has mostly focused on small-scale temporal changes or static global patterns, with limited investigation into global or regional temporal trends. This study used existing data on mangrove leaf litter to model mangrove Net Primary Productivity (NPP) on a monthly timescale from 1980 to 2094 across global regions defined by the Marine Ecoregions of the World framework. The models showed a slight global decrease in NPP of approximately 1.4 %, from 239.2 ± 87.6 Tg yr−1 (1980–1990) to 235.9 ± 81.9 Tg yr−1 (2085–2094). However, significant regional changes were identified, including substantial increases in NPP in the Southwest Australian Shelf (60.58 ± 97.9 %), the Warm Temperate Northeast Pacific (43.75 ± 65.7 %), and the Warm Temperate Northwest Pacific (31.55 ± 55.7 %), as well as decreases in Southeast Asian provinces like the Java Transitional (11.45 ± 6.2 %) and Western Coral Triangle (7.61 ± 9.6 %). These findings highlight previously unreported regional shifts in mangrove productivity, which could significantly impact carbon sequestration and the transfer of organic matter to adjacent ecosystems.