Earth Overshoot Day

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Progression of the dates of Earth Overshoot Day Earth Overshoot Day graph.svg
Progression of the dates of Earth Overshoot Day

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's demand overshoots the sustainable amount of biological resources regenerated on Earth. When viewed through an economic perspective, the annual EOD represents the day by which the planet's annual regenerative budget is spent, and 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 (366 in leap years), the number of days in a year:


In 2020 the calculated overshoot day fell on August 22 (more than three weeks later than 2019) due to coronavirus induced lockdowns around the world. [2] The president of the Global Footprint Network claims that the COVID-19 pandemic by itself is one of the manifestations of "ecological imbalance". [3]

Earth Overshoot Day is calculated by Global Footprint Network and is a campaign supported by dozens of other nonprofit organizations. [4] Information about Global Footprint Network's calculations [5] and national Ecological Footprints are available online. [6]


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 for 2022 that in less than seven months, humanity demanded more from nature than the planet's ecosystems can regenerate in the entire year. [4] Human demand includes all demands that compete for the regenerative capacity of the planet's surface, such as renewable resources, CO2 sequestration, and urban space.

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 accounts, humanity's demand for resources is now equivalent to that of more than 1.7 Earths. [7] 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 biophysical effects include: deforestation, species loss, soil erosion, or fisheries collapse. Such resource insecurity can lead to economic stress (such as monetary inflation) and conflict (such as civil unrest). [4]

Global Footprint Network maintains that ecological footprint accounts document the gap between human demand and regeneration. According to them, demand is now exceeding what the planet renews. They recognize 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). [8] Mathis Wackernagel, founder and president of the Global Footprint Network, states that soil depletion on 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". [9] Thus, they claim ecological footprint accounts are metrics that merely define minimal conditions for sustainability, and that human impact on the planet is likely higher than the results that their accounts reveal.


In 2017, the ecomodernist Breakthrough Institute dismissed the idea of Earth Overshoot Day by calling it "a nice publicity stunt". [9] 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. [9] 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. [10] Researchers associated with Global Footprint Network answered these criticisms in a response in the same PLOS journal. [11] More detailed discussions about criticism is available on Global Footprint Network website. [12]

See also

Related Research Articles

The carrying capacity of an environment is the maximum population size of a biological species that can be sustained by that specific environment, given the food, habitat, water, and other resources available. The carrying capacity is defined as the environment's maximal load, which in population ecology corresponds to the population equilibrium, when the number of deaths in a population equals the number of births. The effect of carrying capacity on population dynamics is modelled with a logistic function. Carrying capacity is applied to the maximum population an environment can support in ecology, agriculture and fisheries. The term carrying capacity has been applied to a few different processes in the past before finally being applied to population limits in the 1950s. The notion of carrying capacity for humans is covered by the notion of sustainable population.

<i>The Limits to Growth</i> 1972 book on economic & population growth

The Limits to Growth (LTG) is a 1972 report that discussed the possibility of exponential economic and population growth with finite supply of resources, studied by computer simulation. The study used the World3 computer model to simulate the consequence of interactions between the earth and human systems. The model was based on the work of Jay Forrester of MIT, as described in his book World Dynamics.

<i>I = PAT</i>

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

Overconsumption describes a situation where a consumer overuses their available goods and services to where they can't, or don't want to, replenish or reuse them. In microeconomics, this may be described as the point where the marginal cost of a consumer is greater than their marginal utility. The term overconsumption is quite controversial in use and does not necessarily have a single unifying definition. When used to refer to natural resources to the point where the environment is negatively affected, is it synonymous with the term overexploitation. However, when used in the broader economic sense, overconsumption can refer to all types of goods and services, including manmade ones, e.g. "the overconsumption of alcohol can lead to alcohol poisoning". Overconsumption is driven by several factors of the current global economy, including forces like consumerism, planned obsolescence, economic materialism, and other unsustainable business models and can be contrasted with sustainable consumption.

<span class="mw-page-title-main">Ecological footprint</span> 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.

<span class="mw-page-title-main">William E. Rees</span>

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.

<span class="mw-page-title-main">Ecological debt</span> Environmental debt between Global North and South

Ecological debt refers to the supposed accumulation of debt of the Global North to Global South countries, due to the net sum of historical environmental injustice, especially through resource exploitation, habitat degradation, and pollution by waste discharge. The concept was coined by Global Southerner non-governmental organizations in the 1990s and its definition has varied over the years, in several attempts of greater specification.

<span class="mw-page-title-main">Human overpopulation</span> Proposed condition wherein human numbers exceed the carrying capacity of the environment

Human overpopulation is the concept of a human population becoming too large to be sustained by its environment or resources in the long term. The idea is usually discussed in the context of world population, though it may also concern regions. Human population growth has increased in recent centuries due to medical advancements and improved agricultural productivity. Those concerned by this trend argue that it results in a level of resource consumption which exceeds the environment's carrying capacity, leading to population overshoot. The concept is often discussed in relation to other population concerns such as demographic push and depopulation, as well as in relation to resource depletion and the human impact on the environment.

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.

<span class="mw-page-title-main">Water footprint</span> 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 environmental science, the concept of overshoot means demand in excess of regeneration. It can apply to animal populations and people. Environmental science studies to what extent human populations through their resource consumption have risen above the sustainable use of resources. For people, "overshoot" is that portion of their demand or ecological footprint which must be eliminated to be sustainable. Excessive demand leading to overshoot is driven by both consumption and population.

The history of environmental pollution traces human-dominated ecological systems from the earliest civilizations to the present day. This history is characterized by the increased regional success of a particular society, followed by crises that were either resolved, producing sustainability, or not, leading to decline. In early human history, the use of fire and desire for specific foods may have altered the natural composition of plant and animal communities. Between 8,000 and 12,000 years ago, agrarian communities emerged which depended largely on their environment and the creation of a "structure of permanence."

<span class="mw-page-title-main">Global Footprint Network</span> Ecological organization

The Global Footprint Network was founded in 2003 and 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. Its aim is to develop and promote tools for advancing sustainability, including the ecological footprint and biocapacity, which measure the amount of resources we use and how much we have. These tools aim at bringing ecological limits to the center of decision-making.

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.

Land footprint is the real amount of land, wherever it is in the world, that is needed to produce a product, or used by an organisation or by a nation.

The Ten Million Club Foundation is a non-governmental organization based in the Netherlands which promotes global overpopulation awareness. For the Netherlands, it advocates to match the population size with the carrying capacity of the area. Initially, the foundation was calling for a shrinking population; later on the emphasis was also put on a reduction of the ecological footprint of the inhabitants of the Netherlands. The Club was set up as a private foundation by the Dutch historian Paul Gerbrands in 1994.

<span class="mw-page-title-main">Ecological overshoot</span> Demands on ecosystem exceeding regeneration

Ecological overshoot is the phenomenon which occurs when the demands made on a natural ecosystem exceed its regenerative capacity. Global ecological overshoot occurs when the demands made by humanity exceed what the biosphere of Earth can provide through its capacity for renewal.


  1. "Past Earth Overshoot Days - #MoveTheDate of Earth Overshoot Day".
  2. "Earth Overshoot Day June Press Release". Global Footprint Network. Retrieved 2020-08-10.
  3. Braun, Stuart (21 August 2020). "Coronavirus Pandemic Delays 2020 Earth Overshoot Day by Three Weeks, But It's Not Sustainable". Deutsche Welle. Ecowatch. Retrieved 23 August 2020.
  4. 1 2 3 "About Earth Overshoot Day". Global Footprint Network. Retrieved July 15, 2018.
  5. "Ecological Footprint: data and accounting methodology". Global Footprint Network.
  6. "Biocapacity and Ecological Footprint: open data platform". Global Footprint Network.
  7. Footprint Open Data Platform,, Global Footprint Network, York University & Fodafo.
  8. Wackernagel, Mathis; et al. Handbook of Sustainability Indicators – Chapter 16 – Ecological Footprint: Principles & Chapter 33 – Ecological Footprint: Criticisms and applications. Routledge.
  9. 1 2 3 Pearce, Fred. "Admit it: we can't measure our ecological footprint". New Scientist. Retrieved 2 August 2017.
  10. 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.
  11. Rees, William E.; Wackernagel, Mathis (5 November 2013). "The Shoe Fits, but the Footprint is Larger than Earth". PLOS Biology. 11 (11): e1001701. doi: 10.1371/journal.pbio.1001701 . PMC   3818166 . PMID   24223518.
  12. "Limitations and Criticism - Global Footprint Network".

Further reading