On August 2, 2017, we have used more from nature than our planet can renew in the whole year. We are using 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.
Earth Overshoot Day, previously known as Ecological Debt Day, is the calculated illustrative calendar date on which humanity’s resource consumption for the year exceeds Earth’s capacity to regenerate those resources that year. Earth Overshoot Day is calculated by dividing the world biocapacity (the amount of natural resources generated by Earth that year), by the world ecological footprint (humanity’s consumption of Earth’s natural resources for that year), and multiplying by 365, the number of days in one Gregorian common calendar year.
The Ecological Footprint measures the demand on and supply of nature. On the demand side, the Ecological Footprint measures the ecological assets that a given population requires to produce the natural resources it consumes. This includes plant-based food and fiber products, livestock and fish products, timber and other forest products, space for urban infrastructure, and to absorb its waste, especially carbon emissions. In addition, it also tracks the use of six categories of productive surface areas: cropland, grazing land, fishing grounds, built-up land, forest area, and carbon demand on land.
On the supply side, a city, state or nation’s biocapacity represents the productivity of its ecological assets. This includes cropland, grazing land, forest land, fishing grounds, and built-up land. These areas, especially if left unharvested, can also absorb much of the waste we generate, especially our carbon emissions.
When a nation’s Ecological Footprint exceeds its biocapacity, the nation is running an “ecological deficit.” Unfortunately, this date has come very early for the following industrialized world leaders:
United States – June 10
China – April 5
United Kingdom – April 2
India – May 30