Earth Overshoot Day is when;
“We use more ecological resources and services than nature can regenerate through overfishing, overharvesting forests, and emitting more carbon dioxide into the atmosphere than forests can sequester.”
Ideally, Earth Overshoot Day would never occur, with each year our civilization extracting less than the planet can produce. At a perfect sustainable balance, Earth Overshoot Day would be midnight, New Year’s Eve. In 2017, Earth Overshoot Day was August 2. That’s using 365 days of planetary productivity in 213 days, 58% of the year. Just like with financial systems, such a deficit is unsustainable.