A robust methodology for long-term sustainability evaluation of Machine Learning models

Among the many desirable properties of Artificial Intelligence systems, sustainability and efficiency have become increasingly important in the context of worsening climate change, massive water use in data centres, and the need for simpler, faster models in IoT settings. Consequently, there have been not few attempts to both promote and regulate the sustainability of Machine Learning models; the EU's AI Act indicates that the sustainability of AI - in terms of its environmental and social footprint-should be considered when developing and deploying AI pipelines [1], and manifests like that of UNESCO highlight sustainability as one of the core principles of the broader Responsible AI paradigm [2]. However, this seemingly consensual agreement on the importance of sustainability and efficiency for real-world AI systems and the social and regulatory efforts heavily contrasts with the practical applicability of such regulations; without looking further, the AI Act itself defines the requirement for sustainability, but does not indicate what metrics and evaluation pipelines should be considered for a robust, reliable, and practically relevant assessment of the environmental impact of a model. We argue that this lack of comprehensiveness in sustainability recommendations for AI systems does not stem from a careless or sloppy construction of the regulations themselves, but rather from an actual absence of suitable evaluation protocols that are formal, model-agnostic, reproducible, and grounded in real-life usage protocols for the ML lifecycle. The authors of this preprint are aware of a single regulatory standard for measuring AI sustainability, namely UNE 0086 [3], which limits evaluation to the epoch-batch training paradigm of supervised learning systems, rendering it useless for any task or type of learning that deviates from that standard. Although many researchers and companies have made it a habit to report efficiency figures and comparisons (e.g., in terms of emitted CO