The increase of energy and water consumption of artificial intelligence (AI) services,

like GPT, holds significant sustainability challenges. To overcome these challenges

user-centred strategies to reduce the environmental impact without compromising the

user experience are necessary. This study investigates how visual nudges influence

users’ decision making in AI interfaces and explores the trade-offs users make between

processing time, output quality and environmental impact. A between-subjects online

experiment (N = 93) using mock-up AI interface scenarios and a choice-based conjoint

design was conducted. Participants selected among processing options, generating a

specific result of a prompt, with one group exposed to a visual nudge and the other not.

The options to choose varied in processing time, output quality and environmental

impact. Results show that the visual nudge increases the selection of environment

friendlier options, particularly trading off output quality rather than processing time.

The study also found evidence of a compromise effect, where users frequently chose

moderate options to balance sustainability with usability. Environmental attitudes,

measured via the New Ecological Paradigm (NEP) scale, significantly predicted

sustainable choices, though they did not moderate the nudge’s effect. These findings

contribute to sustainable human-computer interaction (HCI) by demonstrating that

visual nudges can support greener computing behaviours, especially when aligned with

acceptable performance trade-offs.