Reducing emissions across the water system: investigating the role of domestic water demand in UK climate change mitigation

Water-related emissions are a substantial contributor to overall emissions in the UK. Estimates range from 2.4 MtCO2e per annum [1] to 27.7 MtCO2e per annum [2], depending on whether emissions related to water heating are included. The latter estimate, 27.7 MtCO2e per annum, is around 6% of annual overall emission in the UK. Reducing domestic hot water use can reduce emissions while the electrification of domestic water heating and decarbonisation of the electricity sector takes place. However, key policy instruments are limited in their vision for water demand management, focussing on the replacement and upgrade of appliances rather than changing how, when and how much water is used. This report examines different visions for emissions reduction across the water sector, focussing on identifying the role that demand is seen to play as well as various actions that are understood to deliver reductions in demand. In doing so, gaps in our understanding of the role demand in achieving Net Zero in the UK water sector are identified, and recommendations are made for onwards research.