Every year, the Global Footprint Network calculates Earth Overshoot Day: the day when humanity’s use of ecological resources exceeds what the earth can regenerate that year. This year Earth Overshoot Day is on the 8th of August, the earliest it has ever been.
Earth Overshoot Day can be thought of like a profit and loss account: on the expenses side we have the area of land and water needed to produce the resources we consume, and absorb our waste. On the revenue side, we have biocapacity, which is the amount of biologically-productive area (such as cropland, forests, fresh water etc.) that the earth can regenerate each year.
Earth Overshoot Day happens because we use more resources than the earth can produce — meaning that, in ecological terms, we are running at a loss. Not just a small loss, either; in fact, we would need the equivalent biocapacity of 1.6 planet earths to support our existing level of consumption.
Some positive action has been taken in this regard with the signing of the COP21 Paris Agreement, where signatories pledged to reduce emissions to keep climate change below two degrees Celsius. This is important because our carbon footprint makes up 60 per cent of the world’s ecological footprint. However, research has suggested that there are still likely to be significant levels of emissions causing between 2.6 and 3.1 degrees Celsius of warming with the agreement in place, with a 10 per cent risk of temperature rising over four degrees, which would likely be catastrophic.
It is therefore important we do more work towards ending Earth Overshoot Day.
Our Overshoot Index, calculated using data from the Global Footprint Network, provides a country-by-country assessment of per capita consumption against per capita biocapacity. At current levels of consumption, there are 2.7 billion people more than the earth can sustainably support; a number that will increase as world population continues to rise by around 80 million per year.
From this it can be seen that overshoot needs to be tackled in two ways: the first way is by moving towards more sustainable lifestyles to reduce our per capita consumption. The second way is to tackle population growth so that there is a larger share of biocapacity for each of us.
Only by pursuing both of these goals together can we hope to one day end Earth Overshoot Day.