Understanding the influence of climate change on the embodied energy of water supply.

The current study aims to advance understandings on how and to what degree climate change will affect the life cycle chemical and energy uses of drinking water supply. A dynamic life cycle assessment was performed to quantify historical monthly operational embodied energy of a selected water supply system located in northeast US. Comprehensive multivariate and regression analyses were then performed to understand the statistical correlation among monthly life cycle energy consumptions, three water quality indicators (UV254, pH, and water temperature), and five climate indicators (monthly mean temperature, monthly mean maximum/minimum temperatures, total precipitation, and total snow fall). Thirdly, a calculation was performed to understand how volumetric and total life cycle energy consumptions will change under two selected IPCC emission scenarios (A2 and B1). It was found that volumetric life cycle energy consumptions are highest in winter months mainly due to the higher uses of natural gas in the case study system, but total monthly life cycle energy consumptions peak in both July and January because of the increasing water demand in summer months. Most of the variations in chemical and energy uses can be interpreted by water quality and climate variations except for the use of soda ash. It was also found that climate change might lead to an average decrease of 3-6% in the volumetric energy use of the case study system by the end of the century. This result combined with conclusions reached by previous climate versus water supply studies indicates that effects of climate change on drinking water supply might be highly dependent on the geographical location and treatment process of individual water supply systems.