Landauer as a Bounding Assumption: Information-Processing Energy Limits, the REC Accounting Gap, and What Cannot Be Concluded

Abstract. Claims that artificial intelligence approaches a planetary thermodynamic boundary routinely conflate four quantities: the Landauer lower bound per irreversible bit erasure (Q1), measured hardware efficiency η (Q2), physically available electricity (Q3), and renewable-energy-certificate accounting (Q4). This paper separates them, corrects arithmetic and unit errors from an earlier draft, and replaces point predictions with a scenario band. With 2024 renewable generation of 8,500 TWh and an assumed CMOS η = 10⁷, the energy-budget capacity is 1.07×10³³ erased bits (1.07×10⁴⁰ at η = 1); 2030 scenarios give 2.47–3.18×10³³ bits. Current AI electricity (50 TWh in 2024) is 0.59% of same-year renewable generation. The earlier '5–8 years' claim is one point in a band running from ~4 to ~33 years depending on an unestablished growth assumption. RECs are accounting instruments, not physical supply. The paper closes with an explicit list of statements the evidence cannot support and a reporting checklist. Contents. Markdown source, DOCX and PDF; three figures; reproducible calculation script and the corrected section draft. Companion artifacts. This record is part of the SMMB long-term program together with P1 (two-node systems prototype) and P2 (control-theory assumptions, counterexamples and a fair-baseline negative result). Cross-paper claims are limited to each paper's scope; see the claim-boundary table in the manuscript. Status. Working draft; not peer reviewed. Published as a preprint for citation and reproducibility. No venue deadline is implied.