Monthly-updated territorial fossil CO2 emissions estimates for Japan

This dataset provides monthly-updated territorial fossil CO2 emissions estimates for Japan, currently up to May 2026. An accompanying paper with the details of the dataset has been submitted to Earth System Science Data, and is currently under open discussion at https://doi.org/10.5194/essd-2026-417. Note that the preprint currently describes v1 and does not reflect updates in later versions. There are two data files in the dataset: One contains the main CO2 emissions estimates by month and emission source category. The period covered starts in April 2007. The other file contains the monthly input data, from which the emissions estimates are derived. Each category and month contains values for a subset of production, import, export, inventory, consumption, and non-energy usage, depending on what is used to derive the estimates. It also contains the conversion factors needed to estimate CO2 emissions from the activity data. For categories where an annual value is used directly to estimate the monthly values, we show the already-adjusted monthly values. The starting month differs by category, depending on data availability. Units are documented in the README.md file, while other details including the data processing are provided in the accompanying paper. --- Updates to this version: Updated all monthly data for May 2026. Added update log including previous updates to the dataset.