Re-Emission: A free open-source software for estimating, reporting, and visualizing greenhouse gas emissions from reservoirs

Reservoirs are significant contributors to anthropogenic greenhouse gas emissions, whose climate impacts require appropriate assessment and reporting. Existing emission modelling tools often demand extensive input data and manual processing, limiting their application to small sets of reservoirs. Moreover, no frameworks currently enable experimentation with new emission models and custom configurations. Here, we present Re-Emission — a free, open-source Python library and command-line tool for streamlined reservoir-emission modelling, including batch processing of multiple reservoirs, custom configurations, and integration with third-party libraries. Its utility is demonstrated through two case studies involving about 250 reservoirs. Re-Emission integrates with a catchment-analysis tool to automate spatially explicit emission assessments and can be embedded in multi-domain frameworks for water-resource and energy planning, addressing a key barrier to the wider adoption of reservoir emission models.