This is distinct from concerns by low emission countries over fairness, where zero by 2050 for a high emitter means they will still emit well more than their fair share of emissions based on almost all apportionments of the remaining global carbon budget. It also tells us the country’s date of zero, but provides a richer analysis, because it not only directly indicates if a country is behind schedule and likely to bust its budget, but also tells us how much time a low emissions country has before it must hit peak emissions.