With the emergence of research on Shared autonomous electric vehicles (SAEVs) as a futuristic transportation option, it becomes important to explore the environmental implications of these types of vehicles before being implemented on a large scale. This work aims to investigate some of the environmental implications of SAEVs compared to privately owned electric vehicles (EVs) through a set of assessment criteria consisting of their life cycle global warming potential (GWP), water footprint and energy demand. In addition, this work examines how different circular economy (CE) practices and energy mixes influence the SAEV's environmental implications. The analysis conducted shows that SAEVs have higher negative environmental effects than private conventional EVs. However, circularity practices were found to decrease these effects. CE practices reduced the GWP, water footprint, and energy demands of SAEVs by 21.4 %, 18.2 %, and 17.3 % respectively. Results have also shown that utilizing the projected 2050 U.S. energy mix and incorporating CE practices throughout the life cycle of an SAEV will decrease the GWP, water footprint, and energy demand by 46 %, 36.2 %, and 39.3 % respectively. In contrast, by utilizing an energy mix that only consists of the clean energy sources of the 2050 U.S. energy mix in the same proportions but forming 100 % of the mix, the GWP, water footprint and energy demand decrease by 73.2 %, 51.2 %, and 29.1 % respectively. The analysis shows that an SAEV will always have higher GWP, water footprint, and energy demand compared to an EV utilizing the same battery due to deadheading and the increased power consumption caused by the additional automation enabling components.