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

Reservoirs are significant contributors to anthropogenic greenhouse gas (GHG) emissions, whose broad impacts on the climate warrant appropriate assessment and reporting. However, existing tools for estimating reservoir emissions are often limited in scope or require extensive input data and manual processing, restricting their application to small sets of reservoirs. Here, we present Re-Emission, a free and open-source tool that streamlines the modelling of reservoir emissions, offers custom configuration options, and enables estimation at regional to national scales. We demonstrate its utility through two case studies involving approximately 250 reservoirs. Re-Emission can be integrated into broader multi-domain frameworks, supporting applications in domains such as water resources and energy planning. It interfaces with a catchment analysis tool to automate reservoir emission assessments, eliminating the need for extensive user input – a key barrier to a wider adoption of spatially-explicit emission models.