In
environmental science
Environmental science is an interdisciplinary academic field that integrates physics, biology, and geography (including ecology, chemistry, plant science, zoology, mineralogy, oceanography, limnology, soil science, geology and physical geograp ...
, 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 population
Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, ...
s through their
resource consumption Resource consumption is about the consumption of non-renewable, or less often, renewable resources. Specifically, it may refer to:
* water consumption
* energy consumption
** electric energy consumption
** world energy consumption
* natural gas co ...
have risen above the
sustainable
Specific definitions of sustainability are difficult to agree on and have varied in the literature and over time. The concept of sustainability can be used to guide decisions at the global, national, and individual levels (e.g. sustainable livin ...
use of resources. For people, "overshoot" is that portion of their demand or
ecological footprint
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 accounti ...
which must be eliminated to be sustainable. Excessive demand leading to overshoot is driven by both
consumption
Consumption may refer to:
*Resource consumption
*Tuberculosis, an infectious disease, historically
* Consumption (ecology), receipt of energy by consuming other organisms
* Consumption (economics), the purchasing of newly produced goods for curren ...
and
population
Population typically refers to the number of people in a single area, whether it be a city or town, region, country, continent, or the world. Governments typically quantify the size of the resident population within their jurisdiction using a ...
.
A decline in
population
Population typically refers to the number of people in a single area, whether it be a city or town, region, country, continent, or the world. Governments typically quantify the size of the resident population within their jurisdiction using a ...
as a consequence of overshoot has been termed 'collapse'. The trajectory undergone by such a population has been called 'overshoot-and-collapse'. A collapse, as much as overshoot, can be the result of different conditions, a particular but not synonymous case of collapse is the
Malthusian catastrophe
Malthusianism is the idea that population growth is potentially exponential while the growth of the food supply or other resources is linear, which eventually reduces living standards to the point of triggering a population die off. This event, c ...
.
Overshoot can occur due to lag effects.
Reproduction
Reproduction (or procreation or breeding) is the biological process by which new individual organisms – "offspring" – are produced from their "parent" or parents. Reproduction is a fundamental feature of all known life; each individual or ...
rates may remain high relative to the
death rate
Mortality rate, or death rate, is a measure of the number of deaths (in general, or due to a specific cause) in a particular population, scaled to the size of that population, per unit of time. Mortality rate is typically expressed in units of de ...
.
Entire
ecosystem
An ecosystem (or ecological system) consists of all the organisms and the physical environment with which they interact. These biotic and abiotic components are linked together through nutrient cycles and energy flows. Energy enters the syste ...
s may be severely affected and sometimes reduced to less-
complex
Complex commonly refers to:
* Complexity, the behaviour of a system whose components interact in multiple ways so possible interactions are difficult to describe
** Complex system, a system composed of many components which may interact with each ...
states due to prolonged overshoot.
The eradication of disease can trigger overshoot when a population suddenly exceeds the land's carrying capacity. An example of this occurred on the
Horn of Africa
The Horn of Africa (HoA), also known as the Somali Peninsula, is a large peninsula and geopolitical region in East Africa.Robert Stock, ''Africa South of the Sahara, Second Edition: A Geographical Interpretation'', (The Guilford Press; 2004), ...
when
smallpox
Smallpox was an infectious disease caused by variola virus (often called smallpox virus) which belongs to the genus Orthopoxvirus. The last naturally occurring case was diagnosed in October 1977, and the World Health Organization (WHO) c ...
was eliminated. A region that had supported around 1 million
pastoralists
Pastoralism is a form of animal husbandry where domesticated animals (known as "livestock") are released onto large vegetated outdoor lands (pastures) for grazing, historically by nomadic people who moved around with their herds. The animal ...
for centuries was suddenly expected to support 14 million people. The result was
overgrazing
Overgrazing occurs when plants are exposed to intensive grazing for extended periods of time, or without sufficient recovery periods. It can be caused by either livestock in poorly managed agricultural applications, game reserves, or nature res ...
, which led to
soil erosion
Soil erosion is the denudation or wearing away of the upper layer of soil. It is a form of soil degradation. This natural process is caused by the dynamic activity of erosive agents, that is, water, ice (glaciers), snow, air (wind), plants, and ...
.
Human overshoot
The 1972 book ''
The Limits to 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 simula ...
'' discussed the limits to growth of society as a whole. This book included a computer-based model which predicted that the Earth would reach a
carrying capacity
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 t ...
of ten to fourteen billion people after some two hundred years, after which the human population would collapse. The model was based on five variables: "
population
Population typically refers to the number of people in a single area, whether it be a city or town, region, country, continent, or the world. Governments typically quantify the size of the resident population within their jurisdiction using a ...
, food production, industrialization, pollution, and
consumption of non-renewable natural resources".
This simulation modelled human populations after the overshoot and collapse seen in all unmoderated species. It was highly controversial and generally dismissed by economists.
William R. Catton, Jr., a
sociologist, wrote about relationships between human societies and their environment, as well as his beliefs that there were too many people and more needed to die, in his 1980 book ''Overshoot: The Ecological Basis of Revolutionary Change''. He wrote that humanity would overshoot Earth's carrying capacity, due to both
overpopulation
Overpopulation or overabundance is a phenomenon in which a species' population becomes larger than the carrying capacity of its environment. This may be caused by increased birth rates, lowered mortality rates, reduced predation or large scale m ...
and
overconsumption
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 ...
.
The
Global Footprint Network
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 ...
purports to be able to measure how much the human economy demands against what the Earth can renew. The Optimum Population Trust (now called
Population Matters
Population Matters, formerly known as the Optimum Population Trust, is a UK-based charity that addresses population size and its effects on environmental sustainability. It considers population growth as a major contributor to environmental degr ...
) has listed what they believe is the overshoot (overpopulation) of a number of countries, based on the above.
A widely discussed study published in January 2021 in ''Frontiers in Conservation Science,'' emphasizes the significance of overshoot stating that "simultaneous with population growth, humanity's consumption as a fraction of Earth's regenerative capacity has grown from ~ 73% in 1960 to 170% in 2016, with substantially greater per-person consumption in countries with highest income."
These numbers are based on recent
Ecological Footprint
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 accounti ...
studies. The ''Frontiers in Conservation Science'' publication explains that "
is massive ecological overshoot is largely enabled by the increasing use of fossil fuels. These convenient fuels have allowed us to decouple human demand from biological regeneration: 85% of commercial energy, 65% of fibers, and most plastics are now produced from fossil fuels."
As a possible cause for
societal collapse
Societal collapse (also known as civilizational collapse) is the fall of a complex human society characterized by the loss of cultural identity and of socioeconomic complexity, the downfall of government, and the rise of violence. Possible causes ...
, overshoot has been scholarly discussed, but has not been found having been the cause for historic cases of collapse.
Predictions of scarcity
![Los Angeles Aerial view 2013](https://upload.wikimedia.org/wikipedia/commons/3/39/Los_Angeles_Aerial_view_2013.jpg)
In his 1798 work ''
An Essay on the Principle of Population
An, AN, aN, or an may refer to:
Businesses and organizations
* Airlinair (IATA airline code AN)
* Alleanza Nazionale, a former political party in Italy
* AnimeNEXT, an annual anime convention located in New Jersey
* Anime North, a Canadian an ...
'', the British scholar
Thomas Malthus
Thomas Robert Malthus (; 13/14 February 1766 – 29 December 1834) was an English cleric, scholar and influential economist in the fields of political economy and demography.
In his 1798 book '' An Essay on the Principle of Population'', Mal ...
incorrectly predicted that continued population growth would exhaust the global food supply by the mid-19th century. Malthus wrote the essay to refute what he considered the unattainable
utopian
A utopia ( ) typically describes an imaginary community or society that possesses highly desirable or nearly perfect qualities for its members. It was coined by Sir Thomas More for his 1516 book ''Utopia'', describing a fictional island society ...
ideas of
William Godwin
William Godwin (3 March 1756 – 7 April 1836) was an English journalist, political philosopher and novelist. He is considered one of the first exponents of utilitarianism and the first modern proponent of anarchism. Godwin is most famous for ...
and
Marquis de Condorcet
Marie Jean Antoine Nicolas de Caritat, Marquis of Condorcet (; 17 September 1743 – 29 March 1794), known as Nicolas de Condorcet, was a French philosopher and mathematician. His ideas, including support for a liberal economy, free and equal pu ...
, as presented in ''
Political Justice
''Enquiry Concerning Political Justice and its Influence on Morals and Happiness'' is a 1793 book by the philosopher William Godwin, in which the author outlines his political philosophy. It is the first modern work to expound anarchism.
Backg ...
'' and ''
The Future Progress of the Human Mind''. In 1968,
Paul R. Ehrlich
Paul Ralph Ehrlich (born May 29, 1932) is an American biologist known for his warnings about the consequences of population growth and limited resources. He is the Bing Professor Emeritus of Population Studies of the Department of Biology of St ...
reprised Malthus' argument in ''
The Population Bomb
''The Population Bomb'' is a 1968 book co-authored by Stanford University Professor emeritus Paul R. Ehrlich and Stanford senior researcher emeritus in conservation biology Anne Howland Ehrlich. It predicted worldwide famine due to overpopulatio ...
'', predicting that mass global
famine
A famine is a widespread scarcity of food, caused by several factors including war, natural disasters, crop failure, Demographic trap, population imbalance, widespread poverty, an Financial crisis, economic catastrophe or government policies. Th ...
would occur in the 1970s and 1980s.
The predictions of Ehrlich and other
neo-Malthusians
Malthusianism is the idea that population growth is potentially exponential while the growth of the food supply or other resources is linear, which eventually reduces living standards to the point of triggering a population die off. This event, c ...
were vigorously challenged by a number of economists, notably
Julian Lincoln Simon
Julian Lincoln Simon (February 12, 1932 – February 8, 1998) was an American professor of business administration at the University of Maryland and a Senior Fellow at the Cato Institute at the time of his death, after previously serving as a ...
, and advances in agriculture, collectively known as the
Green Revolution
The Green Revolution, also known as the Third Agricultural Revolution, was a period of technology transfer initiatives that saw greatly increased crop yields and agricultural production. These changes in agriculture began in developed countrie ...
, forestalled any potential global famine in the late 20th century. Between 1950 and 1984, as the Green Revolution transformed agriculture around the world, grain production increased by over 250%. The world population has grown by over four billion since the beginning of the Green Revolution, but food production has so far kept pace with population growth. Most scholars believe that, without the Revolution, there would be greater levels of famine and malnutrition than the UN presently documents. However, neo-Malthusians point out that
fossil fuel
A fossil fuel is a hydrocarbon-containing material formed naturally in the Earth's crust from the remains of dead plants and animals that is extracted and burned as a fuel. The main fossil fuels are coal, oil, and natural gas. Fossil fuels m ...
s provided the energy for the Green Revolution, in the form of natural gas-derived
fertilizers
A fertilizer (American English) or fertiliser (British English; see spelling differences) is any material of natural or synthetic origin that is applied to soil or to plant tissues to supply plant nutrients. Fertilizers may be distinct from ...
, oil-derived
pesticides
Pesticides are substances that are meant to control pests. This includes herbicide, insecticide, nematicide, molluscicide, piscicide, avicide, rodenticide, bactericide, insect repellent, animal repellent, microbicide, fungicide, and lampric ...
, and
hydrocarbon
In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons are examples of group 14 hydrides. Hydrocarbons are generally colourless and hydrophobic, and their odors are usually weak or ex ...
-fueled
irrigation
Irrigation (also referred to as watering) is the practice of applying controlled amounts of water to land to help grow Crop, crops, Landscape plant, landscape plants, and Lawn, lawns. Irrigation has been a key aspect of agriculture for over 5,00 ...
, and that many crops have become so genetically uniform that a crop failure in any one country could potentially have global repercussions.
In May 2008, the price of grain was pushed up severely by the increased cultivation of
biofuel
Biofuel is a fuel that is produced over a short time span from biomass, rather than by the very slow natural processes involved in the formation of fossil fuels, such as oil. According to the United States Energy Information Administration (E ...
s, the increase of world
oil prices
The price of oil, or the oil price, generally refers to the spot price of a barrel () of benchmark crude oil—a reference price for buyers and sellers of crude oil such as West Texas Intermediate (WTI), Brent Crude, Dubai Crude, OPEC Refe ...
to over $140 per barrel ($880/m
3), global population growth, the effects of
climate change
In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to E ...
, the loss of agricultural land to residential and industrial development, and growing consumer demand in the population centres of China and India.
Food riots
Food riots may occur when there is a shortage and/or unequal distribution of food. Causes can be food price rises, harvest failures, incompetent food storage, transport problems, food speculation, hoarding, poisoning of food, or attacks by pe ...
subsequently occurred in some countries. However, oil prices then fell sharply. Resource demands are expected to ease as population growth declines, but it is unclear whether mass
food wastage and rising living standards in developing countries will once again create resource shortages.
David Pimentel, professor of ecology and agriculture at
Cornell University
Cornell University is a private statutory land-grant research university based in Ithaca, New York. It is a member of the Ivy League. Founded in 1865 by Ezra Cornell and Andrew Dickson White, Cornell was founded with the intention to teach an ...
, estimates that the sustainable agricultural carrying capacity for the United States is about 200 million people; its population as of 2015 is over 300 million. In 2009, the UK government's chief scientific advisor, Professor
John Beddington
Sir John Rex Beddington HonFREng (born 13 October 1945) is a British population biologist and Senior Adviser at the Oxford Martin School, and was previously Professor of Applied Population Biology at Imperial College London, and the UK Govern ...
, warned that growing populations, falling energy reserves and food shortages would create a "perfect storm" of shortages of food, water, and energy by 2030.
According to a 2009 report by the United Nations
Food and Agriculture Organization
The Food and Agriculture Organization of the United Nations (FAO)french: link=no, Organisation des Nations unies pour l'alimentation et l'agriculture; it, Organizzazione delle Nazioni Unite per l'Alimentazione e l'Agricoltura is an intern ...
(FAO), the world will have to produce 70% more food by 2050 to feed a projected extra 2.3 billion people.
The observed figures for 2007 showed an actual increase in absolute numbers of undernourished people in the world, with 923 million undernourished in 2007, versus 832 million in 1995. The 2009 FAO estimates showed an even more dramatic increase, to 1.02 billion.
Human impact on the environment
![Manantenina bushfire](https://upload.wikimedia.org/wikipedia/commons/1/17/Manantenina_bushfire.jpg)
A number of scientists have argued that the looming
human impact on the environment
Human impact on the environment (or anthropogenic impact) refers to changes to biophysical environments and to ecosystems, biodiversity, and natural resources caused directly or indirectly by humans. Modifying the environment to fit the need ...
and accompanying increase in
resource consumption Resource consumption is about the consumption of non-renewable, or less often, renewable resources. Specifically, it may refer to:
* water consumption
* energy consumption
** electric energy consumption
** world energy consumption
* natural gas co ...
threatens the world's
ecosystem
An ecosystem (or ecological system) consists of all the organisms and the physical environment with which they interact. These biotic and abiotic components are linked together through nutrient cycles and energy flows. Energy enters the syste ...
and the survival of human civilization.
Scientists contend that continued human
population growth
Population growth is the increase in the number of people in a population or dispersed group. Actual global human population growth amounts to around 83 million annually, or 1.1% per year. The global population has grown from 1 billion in 1800 to ...
and
overconsumption
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 ...
, particularly by the wealthy, are the primary drivers of
mass species extinction and some suggesting
human overpopulation
Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, ...
as a driver.
Human population planning
Human population planning
Human population planning is the practice of intentionally controlling the growth rate of a human population. The practice, traditionally referred to as population control, had historically been implemented mainly with the goal of increasing po ...
is the practice of intervening to alter the rate of population growth. Historically, human population control has been implemented by limiting a region's
birth rate
The birth rate for a given period is the total number of live human births per 1,000 population divided by the length of the period in years. The number of live births is normally taken from a universal registration system for births; populati ...
, by voluntary contraception or by government mandate. It has been undertaken as a response to factors including high or increasing levels of poverty,
environmental concerns
Environmental issues are effects of human activity on the biophysical environment, most often of which are harmful effects that cause environmental degradation. Environmental protection is the practice of protecting the natural environment on th ...
, and
religious reasons. The use of
abortion
Abortion is the termination of a pregnancy by removal or expulsion of an embryo or fetus. An abortion that occurs without intervention is known as a miscarriage or "spontaneous abortion"; these occur in approximately 30% to 40% of pregn ...
in some population control strategies has caused controversy, with religious organizations such as the
Roman Catholic Church
The Catholic Church, also known as the Roman Catholic Church, is the largest Christian church, with 1.3 billion baptized Catholics worldwide . It is among the world's oldest and largest international institutions, and has played a ...
explicitly opposing any intervention in the human reproductive process.
The
University of Nebraska
A university () is an institution of higher (or tertiary) education and research which awards academic degrees in several academic disciplines. Universities typically offer both undergraduate and postgraduate programs. In the United States, the ...
publication ''
Green Illusions
''Green Illusions: The Dirty Secrets of Clean Energy and the Future of Environmentalism'' (), by Ozzie Zehner, was published in 2012 by the University of Nebraska Press. It discusses various approaches to "clean energy", and why they do not provi ...
'' argues that population control to alleviate environmental pressures need not be coercive. It states that "Women who are educated, economically engaged, and in control of their own bodies can enjoy the freedom of bearing children at their own pace, which happens to be a rate that is appropriate for the aggregate ecological endowment of our planet." The book ''
Fatal Misconception'' by Matthew Connelly similarly points to the importance of supporting the rights of women in bringing population levels down over time.
Paul Ehrlich
Paul Ehrlich (; 14 March 1854 – 20 August 1915) was a Nobel Prize-winning German physician and scientist who worked in the fields of hematology, immunology, and antimicrobial chemotherapy. Among his foremost achievements were finding a cure ...
also advocates making "modern contraception and back-up abortion available to all and give women full equal rights, pay and opportunities with men," noting that it could possibly "lead to a low enough total fertility rate that the needed shrinkage of population would follow.
utit will take a very long time to humanely reduce total population to a size that is sustainable." Ehrlich places the optimum global population size at 1.5 to 2 billion people.
Other academicians and public figures have pointed to the role of agriculture and
agricultural productivity
Agricultural productivity is measured as the ratio of agricultural outputs to inputs. While individual products are usually measured by weight, which is known as crop yield, varying products make measuring overall agricultural output difficu ...
of increasing human
carrying capacity
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 t ...
, which results in
population overshoot
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 ris ...
, as with any other species when their food supply experiences an increase, which in turn results in resource depletion and mass poverty and starvation in the case of humans.
See also
*
Overconsumption
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 ...
*
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 h ...
*
Ecological overshoot
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 ...
*
Planetary boundaries
Planetary boundaries is a concept highlighting human-caused perturbations of Earth systems making them relevant in a way not accommodated by the environmental boundaries separating the three ages within the Holocene epoch. Crossing a planetary ...
*
Planetary management Planetary management is intentional global-scale management of Earth's biological, chemical and physical processes and cycles (water, carbon, nitrogen, sulfur, phosphorus, and others). Planetary management also includes managing humanity’s influe ...
*
Malthusianism
Malthusianism is the idea that population growth is potentially exponential while the growth of the food supply or other resources is linear, which eventually reduces living standards to the point of triggering a population die off. This event, c ...
*
Food race
Daniel Clarence Quinn (October 11, 1935 – February 17, 2018) was an American author (primarily, novelist and fabulist), cultural critic, and publisher of educational texts, best known for his novel ''Ishmael'', which won the Turner Tomorrow ...
References
Further reading
*''
The Population Bomb
''The Population Bomb'' is a 1968 book co-authored by Stanford University Professor emeritus Paul R. Ehrlich and Stanford senior researcher emeritus in conservation biology Anne Howland Ehrlich. It predicted worldwide famine due to overpopulatio ...
'', by
Paul R. Ehrlich
Paul Ralph Ehrlich (born May 29, 1932) is an American biologist known for his warnings about the consequences of population growth and limited resources. He is the Bing Professor Emeritus of Population Studies of the Department of Biology of St ...
*
*
External links
EarthOvershoot.org
{{Population
Population ecology
Ecology terminology
Human overpopulation
Environmental social science concepts