NASA IN GENERAL AND CMS IN PARTICULAR HAVE DEVOTED CONSIDERABLE RESOURCES TO DEVELOPING REMOTE SENSING DATA PRODUCTS AIMED AT QUANTIFYING AND UNDERSTANDING THE TERRESTRIAL CARBON (C) CYCLE. SIMILAR EFFORTS HAVE BEEN TAKEN THROUGHOUT THE RESEARCH COMMUNITY GENERATING BOTTOM-UP ESTIMATES BASED ON INVENTORY DATA EDDY COVARIANCE PROCESS-BASED MODELS ETC. WHILE THESE EFFORTS COLLECTIVELY SPAN A WIDE RANGE OF OBSERVATIONS (OPTICAL LIDAR RADAR FIELD-MEASUREMENTS) AND RESPONSE VARIABLES (COVER POOLS FLUXES DISTURBANCES) EACH DATA PRODUCT TYPICALLY ONLY LEVERAGES ONE OR TWO DATA SOURCES. HOWEVER WHAT IS FUNDAMENTALLY NEEDED TO IMPROVE MONITORING REPORTING AND VERIFICATION (MRV) ISN T NUMEROUS ALTERNATIVE C ESTIMATES BUT A SYNTHETIC VIEW OF THE WHOLE. FURTHERMORE ANY APPROACH TO SYNTHESIS NEEDS TO BE FLEXIBLE AND EXTENSIBLE SO THAT IT CAN DEAL WITH DIFFERENT DATA SOURCES WITH DIFFERENT SPATIAL AND TEMPORAL RESOLUTIONS EXTENTS AND UNCERTAINTIES AS WELL AS NEW SENSORS AND PRODUCTS AS THEY ARE BROUGHT ONLINE. FINALLY IT NEEDS TO INFORM TOP-DOWN ATMOSPHERIC INVERSIONS WHICH CURRENTLY CANNOT INGEST THESE BOTTOM-UP C ESTIMATES AN A CONSTRAINT.