This masterclass will bring participants up to speed with process emissions of nitrous oxide and methane from wastewater treatment through presenting the key findings from a newly (April 2022) launched IWA publication and sharing the experience of progressive utilities around the world. Four masterclasses will be organised in 2022 by the Climate Smart Utilities Initiative. This first masterclass will set the scene and provide an overview of what process emissions are, an introduction to the IWA Specialist Groups working in the area and a summary of what the series will cover.