A new study published in Global Biogeochemical Cycles tracked gross primary productivity (GPP) in tidal wetlands across the contiguous United States from 2001 to 2020. Researchers found that overall carbon fixation increased by 6% over the two decades, driven primarily by warming temperatures and increased solar radiation rather than changes in vegetation. The strongest gains were in the Gulf and southern Atlantic regions, while year-to-year variation was highest in the western Gulf of Mexico due to hurricanes and storms. These findings matter for carbon cycle models and wetland management. The study used satellite data at 250-meter resolution and kept wetland extent fixed at 2000 levels, so the productivity increase is purely a climate-driven effect. Temperature was the strongest driver of variability, followed by shortwave radiation. The research suggests that as climate conditions shift, tidal wetlands may become more productive carbon sinks, but that also means their future depends on how warming and sunlight patterns evolve.
