Blue carbon across a latitudinal gradient in Brazilian mangrove ecosystems

Methods will include direct ecological assessments of above ground biomass in mangrove and varzea ecosystems from north Brazil down to the south working with local partner organisations. Soil organic carbon assessments including 210Pb dating to assess carbon sequestration rates and stable isotope analyses to assess sources of carbon contributing to soil organic carbon stores and changes over time as well as inorganic carbon analysis to evaluate contributions from this source (recently highlighted as important for marine carbon dioxide removal). The project will also include the use of remote sensing (at least SENTINEL 2, but may also include SENTINEL 1, Landsat, Worldview, and Planet datasets) and machine learning mapping and modelling. This will be the first assessment of blue carbon across such a large scale in the southern hemisphere and Brazil has the second largest extent of mangroves in the world, data previously missing from global averages and highlighted as an important data gap in our global carbon accounting. This ecosystem service is vital for climate mitigation and is likely to be on the global agenda following the carbon crediting focus derived from COP29 in 2024.