Eco-Aware Graph Neural Networks for Sustainable Recommendations
Antonio Purificato, Fabrizio Silvestri
TL;DR
This paper tackles the often-overlooked environmental footprint of Graph Neural Network-based recommender systems by conducting a reproducible, emissions-focused evaluation. It uses CodeCarbon to measure $CO_2$-eq emissions while comparing NGCF, LightGCN, SimGCL, and LightGCL across embedding sizes 32–256 on datasets ML-1M, Amazon Beauty, and DianPing. The results show LightGCN generally offers the best performance with favorable emissions, while larger embeddings raise emissions and some models incur higher compute costs, revealing clear performance–sustainability trade-offs. The study emphasizes the need for eco-aware design in RSs and provides practical guidance for balancing recommendation quality with environmental impact.
Abstract
Recommender systems play a crucial role in alleviating information overload by providing personalized recommendations tailored to users' preferences and interests. Recently, Graph Neural Networks (GNNs) have emerged as a promising approach for recommender systems, leveraging their ability to effectively capture complex relationships and dependencies between users and items by representing them as nodes in a graph structure. In this study, we investigate the environmental impact of GNN-based recommender systems, an aspect that has been largely overlooked in the literature. Specifically, we conduct a comprehensive analysis of the carbon emissions associated with training and deploying GNN models for recommendation tasks. We evaluate the energy consumption and carbon footprint of different GNN architectures and configurations, considering factors such as model complexity, training duration, hardware specifications and embedding size. By addressing the environmental impact of resource-intensive algorithms in recommender systems, this study contributes to the ongoing efforts towards sustainable and responsible artificial intelligence, promoting the development of eco-friendly recommendation technologies that balance performance and environmental considerations. Code is available at: https://github.com/antoniopurificato/gnn_recommendation_and_environment.
