From an economic standpoint, Earth Overshoot Day (EOD) is the day when humanity reaches a deficit in its ecological spending. This deficit is maintained by humanity in a number of ways, such as accumulating waste (especially carbon dioxide) and liquidating ecological resources. From an ecological perspective, EOD represents the day when humanity simply exceeds the environment. In 2018, EOD occurred on August 1st. However, this date varies by year, since human use of Earth’s resources is not consistent every year.
Calculating Earth Overshoot Day
Previously named Ecological Debt Day (EDD), Earth Overshoot Day (EOD) is the day when humanity's use of resources surpasses Earth's renewal capacity for that year. The date is calculated by dividing the natural resources generated by Earth in that year, which is referred to as biocapacity, by the human consumption of these resources in that year, referred to as the world's ecological footprint. The resulting figure is then multiplied by the number of days in that year, which is usually 365 in the Gregorian calendar. The resources of Earth include fish and other marine life, forests, food, and water. The Global Footprint Network is the organization responsible for calculating the date of Earth Overshoot Day.
Date of Earth Overshoot Day
Ideally, Earth Overshoot Day should occur on the last day of December, meaning that resource spending did not exceed Earth’s capacity to regenerate those resources. This ideal date was nearly attained in 1970, when EOD occurred on December 29, just two days before the end of the year. In the following years, the date has steadily pulled away from December, as humanity’s resource spending increases. In 1975, 1980, and 1985, the EOD occurred on November 30th, 3rd, and 4th, respectively. In 1990 and 1995, the date occurred on October 11th and 5th, respectively, and then on September 23rd in 2000. Since then, Earth Overshoot Day has occurred in August, which is a worrying trend.
Significance of Earth Overshoot Day
The problem with this trend of increasingly early Earth Overshoot Days is that Earth's resources are finite, and if depleted completely, Earth will lose its ability to sustain life. The effects of this problem can be observed in a number of ways, the most notable being climate change, which is evident by factors such as increasing temperatures and melting glaciers. Additionally, extreme heat is causing droughts, wildfires, increased frequency of flooding and hurricanes, and heat waves. Places that have experienced wildfires due to climate change include Scandinavia and the US state of California. By 2100, Earth’s temperature is projected to be 15% higher than the highest forecasts by the Intergovernmental Panel on Climate Change (IPCC).
Fortunately, there are a number of potential solutions that have been identified to help move Earth Overshoot Day closer to December. One option is to rethink how cities are planned. For example, designing cities to be more compact and integrated helps ensure that needs such as transportation, cooling, and heating become less resource intensive. Another option is regulating the world's population so that it does not exceed Earth's capacity to replenish its resources. Other solutions include rethinking how humanity produces, distributes, and consumes food, as well as developing more efficient energy sources.