This data set is a product obtained from the Carbon Cycle Data Assimilation System (CCDAS) within the SMOS+VEG study (http://smos-veg.inversion-lab.com), funded by the European Space Agency through its Support to Science Element. It provides monthly global Net Ecosystem Productivity (NEP) maps at 0.25 degree resolution for the period 2010-2015 as simulated by the terrestrial biosphere model BETHY after assimilation of SMOS Soil Moisture, SMOS Vegetation Optical Depth, and atmospheric CO2 observations and includes per-pixel uncertainty ranges derived through error propagation consistent with the observational uncertainties.