Earth Overshoot Day

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Past Earth Overshoot Days [1]
YearOvershoot DateYearOvershoot Date
1987October 232013August 3
1990October 112014August 5
1995October 52015August 6
2000September 232016August 5
2005August 262017August 3
2010August 82018August 1
2011August 42019July 29
2012August 42020August 22

Earth Overshoot Day (EOD) 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. The term "overshoot" represents the level by which human population overshoots the sustainable amount of resources on Earth. When viewed through an economic perspective, EOD represents the day in which humanity enters environmental deficit spending. EOD 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 a year:


In 2020 EOD lands on August 22 more than three weeks later than 2019, due to coronavirus induced lockdowns around the world. [2]

Earth Overshoot Day is calculated by Global Footprint Network and is a campaign supported by dozens of other nonprofit organizations. [3] Information about Global Footprint Network's calculations [4] and national Ecological Footprints are available online. [5]


Andrew Simms of UK think tank New Economics Foundation originally developed the concept of Earth Overshoot Day. Global Footprint Network, a partner organization of New Economics Foundation, launches a campaign every year for EOD to raise awareness of Earth's limited resources. Global Footprint Network measures humanity's demand for and supply of natural resources and ecological services. Global Footprint Network estimates that in less than eight months, we demand more renewable resources and CO2 sequestration than what the planet can provide for an entire year. [3]

According to Global Footprint Network, throughout most of history, humanity has used nature's resources to build cities and roads, to provide food and create products, and to release carbon dioxide at a rate that was well within Earth's budget. But by the early 1970s, that critical threshold had been crossed: Human consumption began outstripping what the planet could reproduce. According to their model, our demand for resources is now equivalent to that of more than 1.5 earths. The data shows us on track to require the resources of two planets well before mid-21st century. They state that the costs of resource depletion are becoming more evident. Climate change — a result of greenhouse gases being emitted — is the most obvious result and widespread effects. Other cited effects include: deforestation, species loss, fisheries collapse, monetary inflation and civil unrest. [3]

Global Footprint Network maintains that the ecological footprint model illustrates the gap between human demand and regeneration. According to them, demand is now exceeding what the planet renews. They admit that the accounting can be improved, and more details added, believing that in its current applications to countries the accounts typically underestimate human demand as not all aspects are measured (there are gaps in UN data). They also claim to overestimate biocapacity because it is ambiguous to determine how much of current yields are enabled by reduced future yield (for instance as in the case of overuse of groundwater, or erosion). [6] Mathis Wackernagel, founder and president of the Global Footprint Network, states that depletion of crop land could be included in the Ecological Footprint accounts informing EOD, but that would "require data sets that do not exist within the UN data set". [7] Thus, they claim ecological footprint accounts are metrics that merely define minimal conditions for sustainability, and that humans are likely worse for the planet than their model predicts.


The Breakthrough Institute regards the idea of Earth Overshoot Day and how many earths we consume as "a nice publicity stunt". [7] According to United Nations data, forests and fisheries are, as a whole, regenerating faster than they are depleted (but admitting that "the surplus might be more a reflection of poor UN fisheries data than healthy fisheries"), while cropland and pasture use is equal to what is available. [7] Hence, EOD does a poor job at measuring water and land mismanagement (e.g., soil erosion) and only highlights the excess of carbon dioxide that humanity releases above what the ecosystem can absorb. In other words, the additional equivalent number of Earths that humanity requires is equivalent to a land area that, if filled with carbon sinks like forests, would balance carbon dioxide emissions. [8]

See also

Related Research Articles


I = PAT is the mathematical notation of a formula put forward to describe the impact of human activity on the environment.

Overconsumption Situation where resource use has outpaced the sustainable capacity of the ecosystem

Overconsumption is a situation where resource use has outpaced the sustainable capacity of the ecosystem. A prolonged pattern of overconsumption leads to environmental degradation and the eventual loss of resource bases.

Ecological footprint An individuals or a groups human demand on nature

The ecological footprint is a method promoted by the Global Footprint Network to measure human demand on natural capital, i.e. the quantity of nature it takes to support people or an economy. It tracks this demand through an ecological accounting system. The accounts contrast the biologically productive area people use for their consumption to the biologically productive area available within a region or the world. In short, it is a measure of human impact on the environment.

Ecological yield is the harvestable population growth of an ecosystem. It is most commonly measured in forestry: sustainable forestry is defined as that which does not harvest more wood in a year than has grown in that year, within a given patch of forest.

Environmental degradation deterioration of the environment through depletion of resources such as air, water and soil; the destruction of ecosystems; habitat destruction; the extinction of wildlife; and pollution

Environmental degradation is the deterioration of the environment through depletion of resources such as air, water and soil; the destruction of ecosystems; habitat destruction; the extinction of wildlife; and pollution. It is defined as any change or disturbance to the environment perceived to be deleterious or undesirable. As indicated by the I=PAT equation, environmental impact (I) or degradation is caused by the combination of an already very large and increasing human population (P), continually increasing economic growth or per capita affluence (A), and the application of resource-depleting and polluting technology (T).

Human impact on the environment Impact of human life on Earth

Human impact on the environment or anthropogenic impact on the environment includes changes to biophysical environments and ecosystems, biodiversity, and natural resources caused directly or indirectly by humans, including global warming, environmental degradation, mass extinction and biodiversity loss, ecological crisis, and ecological collapse. Modifying the environment to fit the needs of society is causing severe effects, which become worse as the problem of human overpopulation continues. Some human activities that cause damage to the environment on a global scale include population growth, overconsumption, overexploitation, pollution, and deforestation, to name but a few. Some of the problems, including global warming and biodiversity loss pose an existential risk to the human race, and human overpopulation causes those problems.

Carbon footprint Total set of greenhouse gas emissions caused by an individual, event, organisation, or product, expressed as carbon dioxide equivalent

A carbon footprint is the total greenhouse gas (GHG) emissions caused by an individual, event, organization, service, or product, expressed as carbon dioxide equivalent. Greenhouse gases, including the carbon-containing gases carbon dioxide and methane, can be emitted through the burning of fossil fuels, land clearance and the production and consumption of food, manufactured goods, materials, wood, roads, buildings, transportation and other services.

William E. Rees Canadian ecologist

William Rees, FRSC, is Professor Emeritus at the University of British Columbia and former director of the School of Community and Regional Planning (SCARP) at UBC.

Ecological debt

Ecological debt refers to the accumulated debt of wealthier countries for having plundered poorer countries by the exploitation of their resources, the degradation of their natural habitat, the beggaring of local people and/or the free occupation of environmental space for waste discharge. The definition in itself has varied over the years and several scholars have attempted a greater specification of the concept.

Human overpopulation Condition where human numbers exceed the short or long-term carrying capacity of the environment

Human overpopulation is when there are too many people for the environment to sustain. In more scientific terms, there is overshoot when the ecological footprint of a human population in a geographical area exceeds that place's carrying capacity, damaging the environment faster than it can be repaired by nature, potentially leading to an ecological and societal collapse. Overpopulation could apply to the population of a specific region, or to world population as a whole.

The global hectare (gha) is a measurement unit for the ecological footprint of people or activities and the biocapacity of the earth or its regions. One global hectare is the world's annual amount of biological production for human use and human waste assimilation, per hectare of biologically productive land and fisheries.

Mathis Wackernagel is a Swiss-born sustainability advocate. He is President of Global Footprint Network, an international sustainability think tank with offices in Oakland, California; Brussels, Belgium, and Geneva, Switzerland. The think-tank is a non-profit that focuses on developing and promoting metrics for sustainability.

Sustainability metrics and indices are measures of sustainability, and attempt to quantify beyond the generic concept. Though there are disagreements among those from different disciplines, these disciplines and international organizations have each offered measures or indicators of how to measure the concept.

Sustainability Process of maintaining change in a balanced fashion

Sustainability is the ability to exist constantly. In the 21st century, it refers generally to the capacity for the biosphere and human civilization to coexist. It is also defined as the process of people maintaining change in a homeostasis balanced environment, in which the exploitation of resources, the direction of investments, the orientation of technological development and institutional change are all in harmony and enhance both current and future potential to meet human needs and aspirations. For many in the field, sustainability is defined through the following interconnected domains or pillars: environment, economic and social, which according to Fritjof Capra is based on the principles of Systems Thinking. Sub-domains of sustainable development have been considered also: cultural, technological and political. According to Our Common Future, sustainable development is defined as development that "meets the needs of the present without compromising the ability of future generations to meet their own needs." Sustainable development may be the organizing principle of sustainability, yet others may view the two terms as paradoxical.

Water footprint The extent of water use in relation to consumption by people

A water footprint shows the extent of water use in relation to consumption by people. The water footprint of an individual, community or business is defined as the total volume of fresh water used to produce the goods and services consumed by the individual or community or produced by the business. Water use is measured in water volume consumed (evaporated) and/or polluted per unit of time. A water footprint can be calculated for any well-defined group of consumers or producers, for a single process or for any product or service.

In environmentalism, the concept of overshoot is the belief that the human population, or its resource consumption patterns, has or in the future may rise above the sustainable use of resources. The "overshoot" is that proportion of the population or environmental footprint which must be eliminated in order for human society on Earth to be sustainable.

Global Footprint Network organization

Global Footprint Network, founded in 2003, is an independent think tank originally based in the United States, Belgium and Switzerland. It was established as a charitable not-for-profit organization in each of those three countries.

The biocapacity or biological capacity of an ecosystem is an estimate of its production of certain biological materials such as natural resources, and its absorption and filtering of other materials such as carbon dioxide from the atmosphere.

Natural capital accounting is the process of calculating the total stocks and flows of natural resources and services in a given ecosystem or region. Accounting for such goods may occur in physical or monetary terms. This process can subsequently inform government, corporate and consumer decision making as each relates to the use or consumption of natural resources and land, and sustainable behaviour.


  1. "Past Earth Overshoot Days". Global Footprint Network. Retrieved 2020-06-06.
  2. "Earth Overshoot Day June Press Release". Global Footprint Network. Retrieved 2020-08-10.
  3. 1 2 3 "About Earth Overshoot Day". Global Footprint Network. Retrieved July 15, 2018.
  4. "Ecological Footprint: data and accounting methodology". Global Footprint Network.
  5. "Biocapacity and Ecological Footprint: open data platform". Global Footprint Network.
  6. Wackernagel, Mathis; et al. Handbook of Sustainability Indicators – Chapter 16 – Ecological Footprint: Principles & Chapter 33 – Ecological Footprint: Criticisms and applications. Routledge.
  7. 1 2 3 Pearce, Fred. "Admit it: we can't measure our ecological footprint". New Scientist. Retrieved 2 August 2017.
  8. Blomqvist, Linus; Brook, Barry W.; Ellis, Erle C.; Kareiva, Peter M.; Nordhaus, Ted; Shellenberger, Michael (5 November 2013). "Does the Shoe Fit? Real versus Imagined Ecological Footprints". PLOS Biology. 11 (11): e1001700. doi: 10.1371/journal.pbio.1001700 . PMC   3818165 . PMID   24223517 . Retrieved 28 October 2019.

Further reading