Earth Overshoot Day (EOD) is the date when humans use more natural resources in a year than Earth can replace by that same year. In 2025, this date was July 24. The term "overshoot" means that humans use more resources than Earth can sustainably provide. From an economic viewpoint, Earth Overshoot Day marks the day when Earth's yearly "budget" of natural resources is used up, and humans begin to use more than is available. To calculate Earth Overshoot Day, scientists divide the total amount of natural resources Earth can replace in a year (called biocapacity) by the total amount of resources humans use in that year (called the ecological footprint). This result is then multiplied by 365 (or 366 in a leap year), the number of days in a year. Earth Overshoot Day is calculated by the Global Footprint Network, with support from many other nonprofit groups. More information about these calculations and national ecological footprints can be found online.

Background

Andrew Simms from the UK research group New Economics Foundation first created the idea of Earth Overshoot Day. Global Footprint Network, a partner of New Economics Foundation, starts a yearly campaign for Earth Overshoot Day to help people understand Earth's limited resources. Global Footprint Network studies how much humans use from nature and how much nature can provide. In 2024, they estimate that in about seven months, humans used more from nature than the planet can replace in one full year. Human use includes all activities that take from the planet’s ability to recover, such as using renewable resources, absorbing carbon dioxide, and using land for cities.

For most of history, humans used natural resources to build cities, grow food, and create products at a rate that was within Earth’s limits. However, by the early 1970s, humans began using resources faster than Earth could replace them. Today, human use of resources is equal to the use of more than 1.7 Earths. If this trend continues, humans may need the resources of two Earths by the middle of the 21st century. The effects of using too many resources are becoming clearer. Climate change, caused by greenhouse gases, is the most visible result. Other effects include cutting down forests, losing animal species, losing soil, and overfishing. These problems can lead to economic issues, such as rising prices, and social problems, such as unrest.

Global Footprint Network explains that ecological footprint measurements show the difference between how much humans use and how much Earth can replace. They say humans now use more than Earth can replace. They believe their measurements can be improved because some human use is not fully counted (there are missing data in UN reports). They also say their measurements may overstate Earth’s ability to provide resources because it is hard to know how much future resource use is affected by current actions, like overusing groundwater or eroding soil. Mathis Wackernagel, leader of Global Footprint Network, says soil loss on farmland could be added to Earth Overshoot Day calculations, but this would need data that is not available in UN reports. They explain that their measurements show the smallest level of sustainability and that human impact on Earth is likely greater than their results suggest.

History

In 2020, the calculated overshoot day was on August 22 (more than three weeks later than in 2019) because of lockdowns caused by the coronavirus. The president of the Global Footprint Network claims that the COVID-19 pandemic by itself is one of the signs of "ecological imbalance."

Criticism

In 2017, the ecomodernist Breakthrough Institute called Earth Overshoot Day "a nice publicity stunt." According to United Nations data, forests and fisheries are growing back faster than they are being used up (though the data may not fully reflect the true health of fisheries). Cropland and pasture use matches the amount available. Earth Overshoot Day does not measure water and land mismanagement, such as soil erosion, well. Instead, it only shows the extra carbon dioxide humans release compared to what the environment can absorb. The number of additional Earths needed is equal to the land area required to absorb all extra carbon dioxide if it were covered with forests like trees. Researchers from the Global Footprint Network responded to these criticisms in the same PLOS journal. More detailed information about these discussions is available on the Global Footprint Network website.