The Kitchen – Carbon Footprint of Water Use
Water use in the home has a significant carbon footprint because of the energy needed to treat water and to heat water for domestic use. In a newer house, the shower is the device with the highest emissions. But, the kitchen sink[1] is the source of the most water-related carbon emissions in the home. If we keep the kitchen tap running, this can lead to about 150 kg of CO2 being released per year. The dishwasher generates to about 140 kg of CO2, and the washing machine 118 kg. By putting dirty dishes and utensils though into a dishwasher, you use less energy and less water than doing them by hand. According to a BBC report, using a dishwasher could reduce greenhouse gas emissions from washing up by 72% compared to doing them by hand.[2] You might be surprised to learn that pre-rinsing dishes, can reduce these savings considerably. So too can running a dishwasher that is only half full.
It is a good idea to use a bowl for washing up, rather than a running tap. This could save about 650 kg of CO2 a year – roughly the same as a return-trip flight between London and Oslo.
Because water use in the home is so significant, we should not underestimate the potential for changes we can make in the kitchen, to improve our overall domestic carbon footprint.
[1] NewYork City Library: Plate 7059 – A. Chelsea kitchen sink ; Plate 7300 – A. Beekman roll-rim iron kitchen sink
[2] https://www.bbc.com/future/article/20200326-the-hidden-impact-of-your-daily-water-use