A carbon label is a question, not a verdict

A product carbon number becomes useful only when its unit, function, boundary, and assumptions are understood. This practice essay draws on the GHG Protocol Product Standard and the Green Claims Code to explain why superficially similar labels may not support a fair numerical ranking. It examines use-stage scenarios, named comparators, assessment dates, evidence links, and the distinction between emissions and claimed compensation. A general standard alone does not guarantee product-specific comparability. For workplace purchasing, the discussion recommends seeking matching documentation rather than forcing uncertain estimates into a precise league table. Carbon remains one consideration alongside suitability, repair access, cost, and other impacts. The conclusion supports proportionate decisions with visible unknowns, not personal verdicts or an expectation that shoppers audit entire supply chains.