This topic aims to quickly and accurately understand the current status of GHG and SLCF emissions and absorption from observational data (Figure 2). It consists of three sub-themes: (1) development of a method to estimate surface fluxes (emissions and absorption) using atmospheric transport models (National Institute for Environmental Studies), (2) data preparation and analysis utilizing observation networks centered on the Asia-Pacific region (National Institute for Environmental Studies), and (3) evaluation of fluxes between the atmosphere and ocean based on observations of CO₂ concentrations in seawater by ships (Meteorological Research Institute). Furthermore, this topic as a whole will establish a system to integrate various information obtained from models and observations for comprehensive flux assessment. The characteristics of this topic include utilizing observational data obtained from various platforms such as ground stations, towers, ships, aircraft, and satellites; enhancing model resolution to extract maximum information from these data; and advancing research through close collaboration between observations and models.