Earth Overshoot Day is calculated by the Global Footprint Network using UN and other official datasets to estimate two big numbers: the Earth’s annual “biocapacity” (how much biological resource nature can renew in a year) and humanity’s ecological footprint (our demand for land, food, energy and materials during the same period). Dividing one by the other and converting the result into a calendar date gives Overshoot Day, and the 2026 date suggests we are using nature roughly 1.7 times faster than ecosystems can regenerate.
That is a planetary average, layered with assumptions about land productivity, carbon sinks and consumption patterns. It does not detail precisely how much a particular business contributes to…