Past decade above-ground biomass change comparisons from four multi-temporal global maps

Above-ground biomass (AGB) is considered an essential climate variable that underpins our knowledge and information about the role of forests in mitigating change. The availability satellite-based AGB change (ΔAGB) products has increased recent years. Here we assessed past decade net ΔAGB derived from four global multi-date maps: ESA-CCI maps, WRI-Flux model, JPL time series, SMOS-LVOD series. Our assessments explore use different reference data sources with re-measurements within decade. comprise National Forest Inventory (NFI) plot data, local maps airborne LiDAR, selected Resource Assessment country countries well-developed monitoring capacities. Map to comparisons were performed at levels ranging 100 m 25 km spatial scale. revealed LiDAR compared most reasonably while using NFI only showed some agreements aggregation <10 km. Regardless level, losses gains according map consistently smaller than data. Map-map highlighted captured known deforestation hotspots. also identified several carbon sink regions detected by all maps. However, disagreement between still large key forest such as Amazon basin. overall cross-correlation varied range 0.11–0.29 (r). Reported magnitudes largest high-resolution datasets including CCI differencing (stock change) Flux model (gain-loss) methods, they smallest coarser-resolution LVOD series products, especially for gains. results suggest current can be biased any estimates should take into account. Currently, are sparse tropics but deficit alleviated upcoming networks context Supersites GEO-Trees.