MIT explainer providing physical intuition for the scale of CO₂ emissions — a single metric tonne occupies a 27-foot cube; a typical American generates 15 tonnes annually; steel manufacturing produces nearly 2 tonnes of CO₂ per tonne of steel. The piece is most useful as a reference for communicating the physical scale of the decarbonisation challenge to non-specialist audiences: numbers like 40 billion tonnes of global annual emissions require grounding before they carry any meaning, and Tso’s framework provides that grounding concisely. Electric vehicles, for context, reduce per-kilometre emissions to roughly 22% of a combustion equivalent — but only when charged on a genuinely low-carbon grid.