According to Global Footprint Network’s calculations, human demand for renewable ecological resources is now equivalent to more than 1.5 Earths. In planetary terms, the cost of our ecological overspending is becoming more continuously evident. They argue that their data shows that unchecked humankind is on track by 2050 to requiring the resources of two planets. Climate change as a result of greenhouse gases being emitted faster than they can be absorbed by forests and oceans is the most obvious aspect. However, the Global Footprint Network point to others—shrinking forests, species loss, fisheries collapse, higher commodity prices, population growth and civil unrest. In short, we are using, or “spending,” our natural capital faster than it can replenish. This is similar to having expenditures that continuously exceed income and the environmental and financial crises we are experiencing are symptoms of looming catastrophe. Humanity is simply using more than what the planet can provide.
Earth Overshoot Day, first observed in 1987, marks the annual point in the calendar when humans has exhausted the Earth's budget for the year, putting our ecological economy into deficit. It is an estimate, not an exact date and is arrived at through a calculation. In 1992, this date was in October. Adjustments of the date that we go into overshoot are due to revised calculations, not ecological advances on the part of humanity. This trend demonstrates a moving back through the year on the annual overspend and for the rest of the year, we will maintain an ecological deficit by drawing down local resource stocks and accumulating carbon dioxide in the atmosphere. I would be amongst the first to admit that there is much scaremongering. That said, if this model is to be considered, then last year, in 2012, humanity went into overspend in August. The rest of our time was living off 'borrowed' time and resources without any plan to pay this back.