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  • Published: 17 June 2020

Half the world’s population are exposed to increasing air pollution

  • G. Shaddick   ORCID: 1 ,
  • M. L. Thomas 2 ,
  • P. Mudu 3 ,
  • G. Ruggeri 3 &
  • S. Gumy 3  

npj Climate and Atmospheric Science volume  3 , Article number:  23 ( 2020 ) Cite this article

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Air pollution is high on the global agenda and is widely recognised as a threat to both public health and economic progress. The World Health Organization (WHO) estimates that 4.2 million deaths annually can be attributed to outdoor air pollution. Recently, there have been major advances in methods that allow the quantification of air pollution-related indicators to track progress towards the Sustainable Development Goals and that expand the evidence base of the impacts of air pollution on health. Despite efforts to reduce air pollution in many countries there are regions, notably Central and Southern Asia and Sub-Saharan Africa, in which populations continue to be exposed to increasing levels of air pollution. The majority of the world’s population continue to be exposed to levels of air pollution substantially above WHO Air Quality Guidelines and, as such, air pollution constitutes a major, and in many areas, increasing threat to public health.


In 2016, the WHO estimated that 4.2 million deaths annually could be attributed to ambient (outdoor) fine particulate matter air pollution, or PM 2.5 (particles smaller than 2.5 μm in diameter) 1 . PM 2.5 comes from a wide range of sources, including energy production, households, industry, transport, waste, agriculture, desert dust and forest fires and particles can travel in the atmosphere for hundreds of kilometres and their chemical and physical characteristics may vary greatly over time and space. The WHO developed Air Quality Guidelines (AQG) to offer guidance for reducing the health impacts of air pollution. The first edition, the WHO AQG for Europe, was published in 1987 with a global update (in 2005) reflecting the increased scientific evidence of the health risks of air pollution worldwide and the growing appreciation of the global scale of the problem 2 . The current WHO AQG states that annual mean concentration should not exceed 10 μg/m 3  2 .

The adoption and implementation of policy interventions have proved to be effective in improving air quality 3 , 4 , 5 , 6 , 7 . There are at least three examples of enforcement of long-term policies that have reduced concentration of air pollutants in Europe and North America: (i) the Clean Air Act in 1963 and its subsequent amendments in the USA; (ii) the Convention on Long-range Transboundary Air Pollution (LRTAP) with protocols enforced since the beginning of the 1980s in Europe and North America 8 ; and (iii) the European emission standards passed in the European Union in the early 1990s 9 . However, between 1960 and 2009 concentrations of PM 2.5 globally increased by 38%, due in large part to increases in China and India, with deaths attributable to air pollution increasing by 124% between 1960 and 2009 10 .

The momentum behind the air pollution and climate change agendas, and the synergies between them, together with the Sustainable Development Goals (SDGs) provide an opportunity to address air pollution and the related burden of disease. Here, trends in global air quality between 2010 and 2016 are examined in the context of attempts to reduce air pollution, both through long-term policies and more recent attempts to reduce levels of air pollution. Particular focus is given to providing comprehensive coverage of estimated concentrations and obtaining (national-level) distributions of population exposures for health impact assessment. Traditionally, the primary source of information has been measurements from ground monitoring networks but, although coverage is increasing, there remain regions in which monitoring is sparse, or even non-existent (see Supplementary Information) 11 . The Data Integration Model for Air Quality (DIMAQ) was developed by the WHO Data Integration Task Force (see Acknowledgements for details) to respond to the need for improved estimates of exposures to PM 2.5 at high spatial resolution (0.1° × 0.1°) globally 11 . DIMAQ calibrates ground monitoring data with information from satellite retrievals of aerosol optical depth, chemical transport models and other sources to provide yearly air quality profiles for individual countries, regions and globally 11 . Estimates of PM 2.5 concentrations have been compared with previous studies and a good quantitative agreement in the direction and magnitude of trends has been found. This is especially valid in data rich settings (North America, Western Europe and China) where trends results are consistent with what has been found from the analysis of ground level PM 2.5 measurements.

Figure 1a shows average annual concentrations of PM 2.5 for 2016, estimated using DIMAQ,; and Fig. 1b the differences in concentrations between 2010 and 2016. Although air pollution affects high and low-income countries alike, low- and middle-income countries experience the highest burden, with the highest concentrations being seen in Central, Eastern Southern and South-Eastern Asia 12 .

figure 1

a Concentrations in 2016. b Changes in concentrations between 2010 and 2016.

The high concentrations observed across parts of the Middle East, parts of Asia and Sub-Saharan regions of Africa are associated with sand and desert dust. Desert dust has received increasing attention due to the magnitude of its concentration and the capacity to be transported over very long distances in particular areas of the world 13 , 14 . The Sahara is one of the biggest global source of desert dust 15 and the increase of PM 2.5 in this region is consistent with the prediction of an increase of desert dust due to climate change 16 , 17 .

Globally, 55.3% of the world’s population were exposed to increased levels of PM 2.5 , between 2010 and 2016, however there are marked differences in the direction and magnitude of trends across the world. For example, in North America and Europe annual average population-weighted concentrations decreased from 12.4 to 9.8 μg/m 3 while in Central and Southern Asia they rose from 54.8 to 61.5 μg/m 3 . Reductions in concentrations observed in North America and Europe align with those reported by the US Environmental Protection Agency and European Environmental Agency (EEA) 18 , 19 . The lower values observed in these regions reflect substantial regulatory processes that were implemented thirty years ago that have led to substantial decreases in air pollution over previous decades 18 , 20 , 21 . In high-income countries, the extent of air pollution from widespread coal and other solid-fuel burning, together with other toxic emissions from largely unregulated industrial processes, declined markedly with Clean Air Acts and similar ‘smoke control’ legislation introduced from the mid-20th century. However, these remain important sources of air pollution in other parts of the world 22 . In North America and Europe, the rates of improvements are small reflecting the difficulties in reducing concentrations at lower levels.

Assessing the health impacts of air pollution requires detailed information of the levels to which specific populations are exposed. Specifically, it is important to identify whether areas where there are high concentrations are co-located with high populations within a country or region. Population-weighted concentrations, often referred to as population-weighted exposures, are calculated by spatially aligning concentrations of PM 2.5 with population estimates (see Supplementary Information).

Figure 2 shows global trends in estimated concentrations and population-weighted concentrations of PM 2.5 for 2010–2016, together with trends for SDG regions (see Supplementary Fig. 1.1 ). Where population-weighted exposures are higher than concentrations, as seen in Central Asia and Southern Asia, this indicates that higher levels of air pollution coincide with highly populated areas. Globally, whilst concentrations have reduced slightly (from 12.8 μg/m 3 in 2010 to 11.7 in 2016), population-weighted concentrations have increased slightly (33.5 μg/m 3 in 2010, 34.6 μg/m 3 in 2016). In North America and Europe both concentrations and population-weighted concentrations have decreased (6.1–4.9 and 12.4–9.8 μg/m 3 , respectively). The association between concentrations and population can be clearly seen for Central Asia and Southern Asia where concentrations increased from 29.6 to 31.7 μg/m 3 (a 7% increase) while population-weighted concentrations were higher both in magnitude and in percentage of increase, increasing from 54.8 to 61.5 μg/m 3 (a 12% increase).

figure 2

a Concentrations. b Population-weighted concentrations.

For the Eastern Asia and South Eastern Asia concentrations increase from 2010 to 2013 and then decrease from 2013 to 2016, a result of the implementation of the ‘Air Pollution Prevention and Control Action Plan’ 21 and the transition to cleaner energy mix due to increased urbanization in China 23 , 24 , 25 . Population-weighted concentrations for urban areas in this region are strongly influenced by China, which comprises 62.6% of the population in the region. Population-weighted concentrations are higher than the concentrations and the decrease is more marked (in the population-weighted concentrations), indicating that the implementation of policies has been successful in terms of the number of people affected. The opposite effect of population-weighting is observed in areas within Western Asia and Northern Africa where an increasing trend in population-weighted concentrations (from 42.0 to 43.1. μg/m 3 ) contains lower values than for concentrations (from 50.7 to 52.6 μg/m 3 ). In this region, concentrations are inversely correlated with population, reflecting the high concentrations associated with desert dust in areas of lower population density.

Long-term policies to reduce air pollution have been shown to be effective and have been implemented in many countries, notably in Europe and the United States. However, even in countries with the cleanest air there are large numbers of people exposed to harmful levels of air pollution. Although precise quantification of the outcomes of specific policies is difficult, coupling the evidence for effective interventions with global, regional and local trends in air pollution can provide essential information for the evidence base that is key in informing and monitoring future policies. There have been major advances in methods that expand the knowledge base about impacts of air pollution on health, from evidence on the health effects 26 , modelling levels of air pollution 1 , 11 and quantification of health impacts that can be used to monitor and report on progress towards the air pollution-related indicators of the Sustainable Development Goals: SDG 3.9.1 (mortality rate attributed to household and ambient air pollution); SDG 7.1.2 (proportion of population with primary reliance on clean fuels and technology); and SDG 11.6.2 (annual mean levels of fine particulate matter (e.g., PM 2.5 and PM 10 ) in cities (population weighted)) 1 . There is a continuing need for further research, collaboration and sharing of good practice between scientists and international organisations, for example the WHO and the World Meteorological Organization, to improve modelling of global air pollution and the assessment of its impact on health. This will include developing models that address specific questions, including for example the effects of transboundary air pollution and desert dust, and to produce tools that provide policy makers with the ability to assess the effects of interventions and to accurately predict the potential effects of proposed policies.

Globally, the population exposed to PM 2.5 levels above the current WHO AQG (annual average of 10 μg/m 3 ) has fallen from 94.2% in 2010 to 90.0% in 2016, driven largely by decreases in North America and Europe (from 71.0% in 2010 to 48.6% in 2016). However, no such improvements are seen in other regions where the proportion has remained virtually constant and extremely high (e.g., greater than 99% in Central, Southern, Eastern and South-Eastern Asia Sustainable Development Goal (SDG) regions. See Supplementary Information for more details).

The problem, and the need for solutions, is not confined to cities: across much of the world the vast majority of people living in rural areas are also exposed to levels above the guidelines. Although there are differences when considering urban and rural areas in North America and Europe, in the vast majority of the world populations living in both urban and rural areas are exposed to levels that are above the AQGs. However, in other regions the story is very different (see Supplementary Information Fig. 7.1 and Supplementary Information Sections 7 and 8), for example population-weighted concentrations in rural areas in the Central and Southern Asia (55.5 μg/m 3 ), Sub-Saharan Africa (39.1 μg/m 3 ), Western Asia and Northern Africa (42.7 μg/m 3 ) and Eastern Asia and South-Eastern Asia (34.3 μg/m 3 ) regions (in 2016) were all considerably above the AQG. From 2010 to 2016 population-weighted concentrations in rural areas in the Central and Southern Asia region rose by approximately 11% (from 49.8 to 55.5 μg/m 3 ; see Supplementary Information Fig. 7.1 and Supplementary Information Sections 7 and 8). This is largely driven by large rural populations in India where 67.2% of the population live in rural areas 27 . Addressing air pollution in both rural and urban settings should therefore be a key priority in effectively reducing the burden of disease associated with air pollution.

Attempts to mitigate the effects of air pollution have varied according to its source and local conditions, but in all cases cooperation across sectors and at different levels, urban, regional, national and international, is crucial 28 . Policies and investments supporting affordable and sustainable access to clean energy, cleaner transport and power generation, as well as energy-efficient housing and municipal waste management can reduce key sources of outdoor air pollution. Interventions would not only improve health but also reduce climate pollutants and serve as a catalyst for local economic development and the promotion of healthy lifestyles.

Assessment of trends in global air pollution requires comprehensive information on concentrations over time for every country. This information is primarily based on ground monitoring (GM) from 9690 monitoring locations around the world from the WHO cities database for 2010–2016. However, there are regions in this may be limited if not completely unavailable, particularly for earlier years (see Supplementary Information). Even in countries where GM networks are well established, there will still be gaps in spatial coverage and missing data over time. The Data Integration Model for Air Quality (DIMAQ) supplements GM with information from other sources including estimates of PM2.5 from satellite retrievals and chemical transport models, population estimates and topography (e.g., elevation). Specifically, satellite-based estimates that combine aerosol optical depth retrievals with information from the GEOS-Chem chemical transport model 29 were used, together with estimates of sulfate, nitrate, ammonium, organic carbon and mineral dust 30 .

The most recent release of the WHO ambient air quality database, for the first time, contains data from GM for multiple years, where available The version of DIMAQ used here builds on the original version 11 , 30 by allowing data from multiple years to be modelled simultaneously, with the relationship between GMs and satellite-based estimates allowed to vary (smoothly) over time. The result is a comprehensive set of high-resolution (10 km × 10 km) estimates of PM2.5 for each year (2010–2016) for every country.

In order to produce population-weighted concentrations, a comprehensive set of population data on a high-resolution grid (Gridded Population of the World (GPW v4) database 31 ) was combined with estimates from DIMAQ. In addition, the Global Human Settlement Layer 32 was used to define areas as either urban, sub-urban or rural (based on land-use, derived from satellite images, and population estimates). A further dichotomous classification of whether grid-cells within a particular country were urban or rural (allocating sub-urban as either urban or rural) was based on providing the best alignment (at the country-level) to the estimates of urban-rural populations produced by the United Nations 27 .

It is noted that the estimates from DIMAQ used in this article may differ slightly from those used in the WHO estimates of the global burden of disease associated with ambient air pollution 1 , and the associated estimates of air pollution related SDG indicators, due to recent updates in the database and further quality assurance procedures.

Data availability

The estimates of PM 2.5 data that support the findings of this work are available from .

Ambient air pollution: Global assessment of exposure and BOD, update 2018. WHO (2020) (In press).

Krzyzanowski, M. & Cohen, A. Update of WHO air quality guidelines. Air Qual. Atmosphere Health 1 , 7–13 (2008).

Article   Google Scholar  

Zheng, Y. et al. Air quality improvements and health benefits from China’s clean air action since 2013. Environ. Res. Lett. 12 , 114020 (2017).

Turnock, S. T. et al. The impact of European legislative and technology measures to reduce air pollutants on air quality, human health and climate. Environ. Res. Lett. 11 , 024010 (2016).

Zhang, Y. et al. Long-term trends in the ambient PM 2.5 - and O 3 -related mortality burdens in the United States under emission reductions from 1990 to 2010. Atmos. Chem. Phys. 18 , 15003–15016 (2018).

Kuklinska, K., Wolska, L. & Namiesnik, J. Air quality policy in the U.S. and the EU – a review. Atmos. Pollut. Res 6 , 129–137 (2015).

Guerreiro, C. B. B., Foltescu, V. & de Leeuw, F. Air quality status and trends in Europe. Atmos. Environ. 98 , 376–384 (2014).

Byrne, A. The 1979 convention on long-range transboundary air pollution: assessing its effectiveness as a multilateral environmental regime after 35 Years. Transnatl. Environ. Law 4 , 37–67 (2015).

Crippa, M. et al. Forty years of improvements in European air quality: regional policy-industry interactions with global impacts. Atmos. Chem. Phys. 16 , 3825–3841 (2016).

Butt, E. W. et al. Global and regional trends in particulate air pollution and attributable health burden over the past 50 years. Environ. Res. Lett. 12 , 104017 (2017).

Shaddick, G. et al. Data integration model for air quality: a hierarchical approach to the global estimation of exposures to ambient air pollution. J. R. Stat. Soc. Ser. C. Appl. Stat. 67 , 231–253 (2018).

World Bank Country and Lending Groups—World Bank data. (Accessed 3rd December 2018).

Guo, H. et al. Assessment of PM2.5 concentrations and exposure throughout China using ground observations. Sci. Total Environ. 601–602 , 1024–1030 (2017).

Ganor, E., Osetinsky, I., Stupp, A. & Alpert, P. Increasing trend of African dust, over 49 years, in the eastern Mediterranean. J. Geophys. Res. 115 , 1–7 (2010).

Google Scholar  

Goudie, A. S. & Middleton, N. J. Desert Dust in the Global System . (Springer Science & Business Media, 2006).

Mahowald, N. M. et al. Observed 20th century desert dust variability: impact on climate and biogeochemistry. Atmos. Chem. Phys. 10 , 10875–10893 (2010).

Stanelle, T., Bey, I., Raddatz, T., Reick, C. & Tegen, I. Anthropogenically induced changes in twentieth century mineral dust burden and the associated impact on radiative forcing. J. Geophys. Res. Atmosph 119 , 13526–13546 (2014).

Air quality in Europe (European Environment Agency, 2018). .

Particulate Matter (PM2.5) Trends | National Air Quality: Status and Trends of Key Air Pollutants | US EPA. .

Chay, K., Dobkin, C. & Greenstone, M. The clean air act of 1970 and adult mortality. J. Risk Uncertain. 27 , 279–300 (2003).

Huang, J., Pan, X., Guo, X. & Li, G. Health impact of China’s air pollution prevention and control action plan: an analysis of national air quality monitoring and mortality data. Lancet Planet. Health 2 , e313–e323 (2018).

Heal, M. R., Kumar, P. & Harrison, R. M. Particles, air quality, policy and health. Chem. Soc. Rev. 41 , 6606–6630 (2012).

Chen, J. et al. A review of biomass burning: emissions and impacts on air quality, health and climate in China. Sci. Total Environ. 579 , 1000–1034 (2017).

Zhao, B. et al. Change in household fuels dominates the decrease in PM2.5 exposure and premature mortality in China in 2005–2015. Proc. Natl. Acad. Sci . 201812955 (2018). .

Shen, H. et al. Urbanization-induced population migration has reduced ambient PM2.5 concentrations in China. Sci. Adv. 3 , e1700300 (2017).

Burnett, R. et al. Global estimates of mortality associated with long-term exposure to outdoor fine particulate matter. Proc. Natl Acad. Sci. 115 , 9592–9597 (2018).

World Urbanization Prospects - Population Division - United Nations. (Accessed: 10th December 2018).

Towards Cleaner Air Scientific Assessment Report 2016- UNECE (2016). .

van Donkelaar, A. et al. Global estimates of fine particulate matter using a combined geophysical-statistical method with information from satellites, models, and monitors. Environ. Sci. Technol. 50 , 3762–3772 (2016).

Shaddick, G. et al. Data Integration for the assessment for population exposure to ambient air pollution for global burden of disease assessment. Environ. Sci. Technol. 52 , 9069–9078 (2018).

Center for International Earth Science Information Network (CIESIN) Columbia University. 2016. Gridded Population of the World, Version 4 (GPWv4): Population Count. NASA Socioeconomic Data and Applications Center (SEDAC), Palisades, NY. . Accessed 3rd December 2018.

Pesaresi, M. et al. GHS Settlement grid following the REGIO model 2014 in application to GHSL Landsat and CIESIN GPW v4- multitemporal (1975-1990-2000-2015). European Commission, Joint Research Centre (JRC)[Dataset] . Accessed: 3rd December 2018.

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The authors would like to thank the WHO Data Integration Task Force, a multi-disciplinary group of experts established as part of the recommendations from the first meeting of the WHO Global Platform for Air Quality, Geneva, January 2014. The Task Force developed the Data Integration Model for Air Quality and consists of the first author, Michael Brauer, Aaron van Donkelaar, Rick Burnett, Howard H. Chang, Aaron Cohen, Rita Van Dingenen, Yang Liu, Randall Martin, Lance A. Waller, Jason West, James V. Zidek and Annette Pruss-Ustun. The authors would like to give particular thanks to Michael Brauer who provided specialist expertise, together with data on ground measurements, and Aaron van Donkelaar and the Atmospheric Composition Analysis Group at Dalhousie University for providing estimates from satellite remote sensing. The authors would also like to thank Dan Simpson for technical expertise on implementing extensions to DIMAQ. Matthew L Thomas is supported by a scholarship from the EPSRC Centre for Doctoral Training in Statistical Applied Mathematics at Bath (SAMBa), under the project EP/L015684/1. The views expressed in this article are those of the authors and they do not necessarily represent the views, decisions or policies to institutions with which they are affiliated.

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GS, PM, and SG conceived the project and led the writing of the manuscript. MLT and GR performed the data analysis. GS and MLT developed the statistical model used to produce the estimates. All authors contributed to the writing of the manuscript.

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Shaddick, G., Thomas, M.L., Mudu, P. et al. Half the world’s population are exposed to increasing air pollution. npj Clim Atmos Sci 3 , 23 (2020).

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Matthew Selinske , RMIT University ; Leejiah Dorward , Bangor University ; Paul Barnes , UCL , and Stephanie Brittain , University of Oxford

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8 billion people: why trying to control the population is often futile – and harmful

Melanie Channon , University of Bath and Jasmine Fledderjohann , Lancaster University

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Matthew E. Kahn , USC Dornsife College of Letters, Arts and Sciences

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Michael P. Cameron , University of Waikato

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Corey J. A. Bradshaw , Flinders University ; Daniel T. Blumstein , University of California, Los Angeles , and Paul Ehrlich , Stanford University

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Colin D. Butler , Australian National University

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Heather Alberro , Nottingham Trent University

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Pasha 45: Spotlight on population growth in Africa

Ozayr Patel, The Conversation

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Stabilising the global population is not a solution to the climate emergency – but we should do it anyway

Mark Maslin , UCL

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Want to live longer? Consider the ethics

John K. Davis , California State University, Fullerton

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Here’s what a population policy for Australia could look like

Liz Allen , Australian National University

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‘Overpopulation’ and the environment: three ideas on how to discuss it in a sensitive way

Rebecca Laycock Pedersen , Keele University and David P. M. Lam , Leuphana University

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Australia could house around 900,000 more migrants if we no longer let in tourists

Raja Junankar , UNSW Sydney

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Making small cities bigger will help better distribute Australia’s 25 million people

Glen Searle , University of Sydney

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A long fuse: ‘The Population Bomb’ is still ticking 50 years after its publication

Derek Hoff , University of Utah

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Dissertations, Theses, and Capstone Projects

Overpopulation and the impact on the environment.

Doris Baus , The Graduate Center, City University of New York Follow

Date of Degree

Document type, degree name.

Liberal Studies

Sophia Perdikaris

Subject Categories

Agricultural and Resource Economics | Demography, Population, and Ecology | Economics | Education Policy | Environmental Policy | Environmental Studies | Family, Life Course, and Society | Growth and Development | Health Economics | Health Policy | International and Area Studies | International Relations | Place and Environment | Politics and Social Change | Social and Behavioral Sciences | Urban Studies | Urban Studies and Planning

overpopulation, environmental impact, malthus, population growth, environmental issues, causes of overpopulation

In this research paper, the main focus is on the issue of overpopulation and its impact on the environment. The growing size of the global population is not an issue that appeared within the past couple of decades, but its origins come from the prehistoric time and extend to the very present day. Throughout the history, acknowledged scientists introduced the concept of “overpopulation” and predicted the future consequences if the world follows the same behavioral pattern. According to predictions, scientists invented the birth control pill and set population control through eugenics. Despite that, population continued to increase and fight with constant diseases. Migration was another component that encouraged population rise, which imposes severe threats to the environment. Urbanization destroys natural habitats and reinforces carbon dioxide emissions, which cause climate change and global warming. Species are becoming extinct and humanity is at threat that it set up for itself. Food scarcity and shortage of water as well as lack of job opportunities and inadequate education are the results of global inequality. Uneven distribution of natural resources, financial means, and individual rights give rise to poverty and define the global culture as greedy, despite the aid of international organizations and agencies. Solutions to overpopulation lie in the efforts of national institutions to implement policies that will correspond to the guidelines given by international institutions that work for the best of the global community. Within this global network, individuals act in their best interest, leaving the rest in extreme poverty and shortage. The inequality supports issues that contribute to overpopulation and leads to a humanity’s extinction.

Recommended Citation

Baus, Doris, "Overpopulation and the Impact on the Environment" (2017). CUNY Academic Works.

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Harvard International Review

Public Health and Overpopulation: The United Nations Takes Action

With the world’s population rising faster than ever before, will our population growth outpace our resource reserves? How can the dangerous effects of overpopulation be managed without diminishing the major improvements in our quality of life that come about thanks to population growth?

The UN projects that over half of the Earth’s population growth in the next three decades will occur in the continent of Africa. This is due to the fact that, from 2010 to 2015, Africa’s population grew at a rate of 2.55 percent annually, with the continent still maintaining the highest pace of population growth among other continents. The UN predicts that, behind Africa, Asia will be the second greatest donor to future international population growth, with an expected addition of approximately one billion people by 2050. In contrast, within every European nation, fertility rates are currently below the population replacement level, which is approximately two children per woman. In most of Europe, fertility rates have remained beneath replacement level for decades. The global population grew fourfold in the past 100 years, so what impact could increased population growth have in the future? Will there be mass-migration? Overcrowding in already densely populated or resource-rich areas? Poor living conditions and sanitation similar to Industrial Revolution era slums?

The global population is currently rising at a steady rate. The number of humans existing on Earth has never been as high as it is now. In 1800, Earth had approximately 1 billion inhabitants, which rose to 2.3 billion in 1940, then 3.7 billion in 1970, and approximately 7.5 billion today. In the last five decades, Earth has experienced an extreme population boom. This phenomenon is known as overpopulation, where the condition in which the amount of humans currently existing on Earth outstrips future resource availability and earth’s carrying capacity. Throughout human history, birth and death rates have always counterbalanced each other, which ensured that Earth had a maintainable population growth level. However, in the 1960s, the global population increased at an unparalleled rate. This brought about a variety of apocalyptic predictions, most prominently, a revival of the Malthusian trap panic.

Paul R. Ehrlich’s 1968 novel, The Population Bomb , eerily echoes Thomas R. Malthus’s landmark 1798 Essay on the Principle of Population . Ehrlich’s novel proposes theories regarding potential outcomes for when agricultural growth does not keep pace with population growth. Ultimately his theories say that the world’s food supply will inevitably become inadequate for feeding the general population, whose numbers would continue to swell until famine, disease epidemics, war, or other calamities took root. These Malthusian predictions about out-of-control population growth have resulted in a variety of detrimental global impacts, particularly the emergence of extreme reproductive control measures, which have taken center stage on an international scale. Today, despite the fact that population scientists mostly agree that Malthus’s forecasts were overblown, the lingering prevalence of these fears have contributed to millions of forced sterilizations in Mexico, Bolivia, Peru, Indonesia, Bangladesh and India, as well as China’s two-child policy . Overall, this has left many wondering whether extreme population growth projections are legitimate or merely groundless panic perpetuated by alarmists.

The Demographic Transition

In reality, rising birth rates and population booms are components of a four-step process called the demographic transition, which the Earth is currently undergoing. Most developed nations have already made this transition, but other countries are currently experiencing this change. In the 1700s, the entire world was undergoing the first stage of the demographic transition. During this time, the continent of Europe was in even poorer condition than the modern-day definition of a developing region, and was afflicted with inferior public health, sustenance, and medical facilities. Birth rates were higher; however, death rates were also higher. For this reason, population growth remained largely stagnant.

Statistically, in the 1700s, women birthed four to six children. However, on average, only two survived to adulthood. When the Industrial Revolution began in Great Britain in the mid-18th century, the Earth experienced the most significant shift in human lifestyles since the Agricultural Revolution. The Industrial Revolution altered every aspect of society, and fostered a greater sense of global interconnectedness. For example, many peasants became factory workers, manufactured products became widely available due to mass production, and countless scientific advancements improved existing methods of transportation, communication, and medicine.

Gradually, this economic development created a middle class and, after the work of union activists, ultimately raised the standard of living and health care for the impoverished labor demographic. Thus began the second transition stage. The increased availability of better foodstuffs, sanitation, and medicine directly contributed to lower death rates, causing a population explosion that doubled Great Britain’s population from 1750 to 1850. In the past, families tended to have more children because not all were expected to survive, but when child mortality rates decreased, the third transition stage was launched. This stage involves reduced conception rates and slowing population growth. Ultimately, a balance was established, with fewer deaths and births, creating a stable population growth rate and signifying the attainment of the fourth and final stage of the demographic transition.

Even as birth rates have decreased dramatically, Earth’s population is still rising at an alarming rate because the humans conceived during the population boom of the 1970s and 1980s are currently having more children; however, the current average number of children per family remains two and a half, while it was five during the late 1970s. As this generation ages and its fertility diminishes, the rate of population growth will likely continue to decrease in every nation. Most of the world’s countries have reached the fourth stage of the demographic transition. In approximately 80 years, developed countries will experience a reduction in fertility from over six children to fewer than three children. Malaysia and South Africa reached this point in 34 years, Bangladesh in 20 years,  and Iran in 10 years. If developing countries are afforded more support, they will reach this point much faster.

Overall, most scientists postulate that human population growth will eventually come to an end, and the UN predicts that Earth’s population will not exceed twelve billion. Some of the major causes of population growth are reduced infant mortality rates, increased lifespans, higher fertility rates, advances in science and technology, and improved access to proper medical care. With the UN’s continued assistance, concurrent with overpopulation, the development level of the global community will increase, and the number of people living in poverty will decrease. Nonetheless, an ever-expanding human population is an immense social and economic challenge that necessitates the alignment of different national interests, especially with regards to reproductive rights, resource availability, and environmental concerns.

The United Nations Takes Action

In 1969, the United Nations Population Fund (UNFPA) was established in order to lead the UN in implementing population programs fundamentally based on the notion of family planning, or the “human right of individuals and couples to freely determine the size of their families” without governmental interference or legislation. In 1994, at the International Conference on Population and Development in Cairo, Egypt, the designated objectives of the UNFPA were determined in greater depth. It was decided that the UNFPA would specifically focus on the gender and human rights elements of population issues; consequently, the UN Population Fund was granted the lead role in aiding nations in fulfilling the Conference’s Programme of Action.

The three most significant sections of the UN Population Fund mandate are “Reproductive Health,” “Gender Equality,” and “Population and Development.” The United Nations Population Division (UNPD) works to confront the interconnected global issues posed by population growth, which is primarily fueled by rising fertility rates, increased longevity, and greater international migration. The UN produces the official demographic approximations and predictions for every country and all regions of the world. The UNFPA specifically addresses global population by compiling data and statistics regarding migration, fertility, marriage, regional development, urbanization, world population projections, and national population policies.

In November 2012, the UNFPA declared family planning a global human right; however, approximately 12 percent of 15 to 49-year-old women internationally are not afforded access to family planning. This is considered an egregious modern-day human rights infringement. The UNFPA aids various UN bodies like the Commission on Population and Development, and endorses the implementation of the Programme of Action undertaken by the International Conference on Population and Development (IPCD) in 1994. The UNFPA has been successful in urging international cooperation on the issue of securing family planning as a human right, pushing the UN to hold three conferences concerning the issue of population, along with two special sessions of the General Assembly and a summit in 2019 .

The Way Forward

Ultimately, apocalyptic population growth fears are overblown, and as such, draconian population control regulations are unnecessary. We have witnessed progress on an international scale in this area, perhaps most notably with China revoking its infamous, longstanding one-child policy just seven years ago. However, a broader global focus on guaranteeing family planning as a human right remains essential. In the words of economist Julian Simon, “Whatever the rate of population growth is, historically it has been that the food supply increases at least as fast, if not faster.” Since Ehrlich’s initial fear-mongering regarding an overpopulation-​induced Armageddon, the planet’s population has more than doubled . However, annually, famine deaths have dropped by millions. Today’s famines are war-induced, not caused by natural resource consumption. As production rose, prices fell and calorie consumption increased, which decreased malnutrition worldwide. In Simon’s words, human ingenuity is the “ ultimate resource .” Therefore, the enactment of heavy-handed population-​control regulations is not only abhorrent, but is also irrational and unsupported by scientific evidence.

Sophia Scott

Sophia Scott

Sophia Scott is a staff writer for the Harvard International Review. She is interested in global health & health equity, along with the intersections between science and policy.

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Epidemics and pandemics: Is human overpopulation the elephant in the room?

N. spernovasilis.

a School of Medicine, University of Crete, Voutes, P.C, 71003 Heraklion, Greece

b “Trifyllio” General Hospital of Kythira, Kythira, Greece

M. Papadakis

c Department of Surgery II, University Hospital Witten-Herdecke, Wuppertal, Germany

C. Tsioutis

d School of Medicine, European University Cyprus, Nicosia, Cyprus

e “Agia Sofia” Children's Hospital, Athens, Greece

Dear Editor,

On the 11th of March 2020 the World Health Organization (WHO) declared the Coronavirus disease 19 (COVID-19) outbreak a global pandemic. Since then, COVID-19 has highlighted the weaknesses of the healthcare systems worldwide as well as the lack of coordination between governments in the face of a global health crisis. It has also emphasised how reluctant citizens can be to follow guidelines and make personal sacrifices for the common good. Now, more than ever, it is evident that action is required to prevent future pandemics by targeting the roots of the problem rather than the problem itself. By analysing this and several other past health crises, it appears that human overpopulation and everything it entails may be the core issue.

Epidemics have ravaged humanity throughout its existence. However, infectious disease outbreaks have been increasing over the last decades [1] . The exponential growth of human population has led to increased urbanization which acts as an accelerant of epidemics, as was the case with COVID-19 in Wuhan. In addition, the continuously increasing pursuit for natural resources has led to the expansion of humans in wild habitats where they are more likely to come into contact with animals that act as reservoirs or vectors of previously unknown infectious agents. Approximately 1.67 million yet-to-be-discovered viral species exist in mammalian and bird hosts and many of these unknown viruses may have zoonotic potential [2] . It is not a coincidence that recent outbreaks such as Severe Acute Respiratory Syndrome (SARS), Middle East Respiratory Syndrome (MERS) and Ebola virus disease, were all zoonotic diseases. According to a report by the WHO, the Ebola outbreak was probably the result of exploitation of a densely forested area in Guinea by timber and mining companies [3] . This allowed fruit bats, which are considered the natural reservoir of the virus, to live in close proximity to humans and thus facilitated the transmission of the virus between the two different species. The loss of biodiversity owing to increased human activity is another factor that seems to contribute to the accelerated spread of infectious diseases. Studies have shown that loss of avian biodiversity in certain regions correlates with an increased incidence of West Nile encephalitis [4] . More specifically, areas with low avian diversity appear to be dominated by species that amplify the virus thus aiding human infection, as opposed to areas with a higher avian diversity that also contain species that are less competent hosts [4] . These examples clearly indicate that the degradation of natural habitats and the destabilization of ecosystems may play a determining role in the development of epidemics and pandemics.

Overpopulation has also generated a rise in food demands. The upsurge of malaria in Borneo eventuated due to the excessive deforestation in order to support the steadily increasing demands for palm oil production through the creation of palm oil plantations [1] . In another example, most of the constantly growing global meat production comes from structures that are called Concentrated Animal Feeding Operations (CAFOs) [5] . In these structures, specific species of animals are tightly packed together and kept in suboptimal conditions. Setting aside issues like animal welfare, CAFOs also constitute the perfect environment for the emergence and spread of infections, including zoonoses [5] . Moreover, the existence of overcrowded live animal markets in many parts of the developing world, where wild and domestic animals are caged in close proximity and are sold for human consumption, poses a significant risk for emerging infectious diseases. Some of these markets in Wuhan have been connected with early cases of COVID-19, although a firm conclusion cannot currently be drawn [6] . In addition, livestock trading across international borders further promotes the spread of infections such as the H5N1 influenza [7] . Finally, the use of antibiotics to compensate for unsanitary conditions and to augment livestock production is a major driving force for the development of drug-resistant bacterial zoonoses [1] .

Cross-border migration which may aid in the spread of infectious diseases is also driven by overpopulation. Most people will migrate in search for labour or better economic prospects due to the increasing stress that population growth exerts on the financial system of their home countries [8] . Others will migrate in order to evade climate change and natural disasters. Finally, disruptions and conflicts that will arise over the exploitation of the earth's finite natural resources will also result in people seeking refuge in other countries [8] .

The human population now is 7.7 billion people and the United Nations estimate that it will rise to 9.7 billion by 2050 [9] . The aforementioned issues are only expected to be exacerbated by this estimation. Perhaps it is time to start addressing the problem of human overpopulation using modest solutions. Taking into account that every year a significant proportion of pregnancies worldwide are unintended [10] , simple actions such as comprehensive sexuality education, improving the status of women in terms of human rights and education and employment opportunities in certain countries, and contraception availability, may all be useful. Also, new methods of contraception that are more easily accessible and effective ought to be sought out. In addition to the proposed measures above, the scale and the nature of the consumption in the developed countries should be modified. The sooner we address these problems and advocate for solutions, the more likely we are to avoid extreme measures like one-child policy, which has been enforced in China in the past, or worse, a catastrophic pandemic that will act as human population's equilibrator.

In conclusion, epidemics and pandemics seem to be fuelled by human overpopulation and the elicited disruption of the balance between humankind and nature. If action is not taken to address the various factors that affect this balance, the COVID-19 pandemic will probably be just the beginning of many more to come.

Human and animal rights

The authors declare that the work described has not involved experimentation on humans or animals.

Informed consent and patient details

The authors declare that the work described does not involve patients or volunteers.

Disclosure of interest

The authors declare that they have no competing interest.

This work did not receive any grant from funding agencies in the public, commercial, or not-for-profit sectors.

Author contributions

All authors attest that they meet the current International Committee of Medical Journal Editors (ICMJE) criteria for Authorship.

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A Brief on Overpopulation – Why it Matters and What You Can Do About It

Erin Brown | April 4, 2023 | Leave a Comment

overpopulation research paper

Photo by Candace McDaniel on StockSnap

As humanity has surpassed the 8 billion people milestone, it is more important now than ever to talk about population. What will we do if we continue to grow at exponential rates? What are ethical, viable strategies to decrease population?

“First off, let me get this straight, discussing addressing overpopulation does not mean discussing killing people. The goal is actually to prevent it.” – Dr. Jane O’Sullivan

Current world population in January 2023: 8 billion

The current rate of population growth is around 80 million people per year. There are over 8 billion people on the planet, the last billion added in less than the last 12 years. 

The Earth’s first billion people milestone took from the beginning of human history until the 1800s to be achieved. Then, due to the industrial revolution, humanity reached the second billion mark by 1930 (taking only 130 years), reached the third billion in 1960 (only took 30 years), then reached the fourth billion by 1974 (only took 14 years), and the fifth billion by 1987 (only took 13 years). We hit 6 billion in 1999 (which took 12 years) and hit 7 billion in 2011 (which took about 12 years). At the current growth rate, the world population will reach 9 billion by 2037 and 10 billion by 2057.

The growth rate is declining, but not at a fast enough rate to combat the exponential compound growth. The growth rate was 2% in the 1970s. Now it is 1.05%. Any growth rate above 1% means we are still adding more people to the planet every year. 

What is overpopulation? 

Overpopulation is a human population in numbers high enough to cause environmental deterioration, impaired quality of life, or population crash. 

Why is overpopulation an issue? 

Overrun natural resources can only lead to death by starvation, conflict, and disease, and the only viable alternative is voluntary restraint on human births.

What is carrying capacity?

Carrying capacity is defined as the maximum population of a species that an area will support without undergoing deterioration. 

Paul R. Ehrlich and other scientists estimate the world’s optimum population for carrying capacity (at a comfortable standard of living – editor’s note) to be less than two billion people – 6 billion fewer than on the planet today. “But the longer humanity pursues business as usual, the smaller the sustainable society is likely to prove to be. We’re continuously harvesting the low-hanging fruit, for example by driving fisheries stocks to extinction” – Paul Ehrlich says.

How do we revert population overshoot to a sustainable population level? 

Geologist Art Berman explains population overshoot this way: “Overshoot means that humans are using natural resources and polluting at rates beyond the planet’s capacity to recover. The main cause of overshoot is the extraordinary growth of the human population made possible by fossil energy. Concerns about overshoot and population raised more than 40 years ago were dismissed. Climate change has captured public awareness more recently although many doubt that it is an emergency. Overshoot is more difficult to dispute; it destroys rainforests, leads to the extinction of other species, the pollution of land, rivers, and seas, the acidification of the oceans, and the loss of fisheries and coral reefs. People understandably want to know the solutions. Overshoot is the problem we must address. Any plan that includes continued growth is doomed to fail.”

What can we do?  Jane O’Sullivan outlines the two options for addressing population overshoot – i ncrease the Earth’s carrying capacity or decrease population.

Increasing Earth’s carrying capacity

We are already doing this by (a) using fewer natural resources per person, or (b) increasing productivity by finding more ways to use resources. This only defers the problem and creates collateral damage. 

Decreasing population numbers

If we talk about this now, the hope is to increase our options for solutions. One of the biggest challenges to facing overpopulation head-on and discussing a decreasing population are the stigmas and myths associated with reducing human population numbers. An elaborate set of myths has emerged in opposition to reducing population levels. These myths may prevent even environmentalists from viewing overpopulation as an issue.  Jane O’Sullivan elucidates on the following six myths that make inaction a virtue.

Myth 1 – The human population is stabilizing, and birth rates are decreasing

Truth – Birth rates started declining in the 1970s-90s due to family planning, but not low enough. The number of mothers is still increasing faster than family planning is decreasing the birth rate .  We are still having more births per year than ever before. The total fertility rate has decreased, but as fertility decline has slowed to a trickle, the number of total births has continued to increase. 

Myth 2  – China is the only one with the problem and they used cruel methods (one-child policy)

Truth – Family planning programs have helped many countries successfully reduce births through voluntary means, including China, before the one-child policy.

Myth 3 – Poverty causes population growth, therefore development is the best contraceptive

I.e., family planning is unnecessary and inefficient as long as there is development.

Truth – If this was true, we would see the population decline as development increases. However, it is the decrease in fertility rates that drove economic development, not the other way around. This myth is therefore “correlation implying causation” in the wrong direction. The poorest countries could lower their population by family planning just as quickly as rich countries if they choose to prioritize it.

Countries of families with four or more children, on average, have the lowest level of development; in families with 3 children or fewer the level goes up by some degree, and with two or fewer children development soars. The current focus should be on expanding provisions for teachers, doctors, equality, etc. instead of just giving people what they need. 

Myth 4 – Educating girls is the key to ending population growth

Truth – Another indirect approach that excludes a discussion on the benefit of small families and ending population growth. Educating girls helps but not much unless it is also flanked by family planning efforts. Family planning has a stronger effect on women regulating their fertility, decreasing the fertility gap between the educated and uneducated, and with family planning, girls are more likely to stay in school.

Myth 5 – Population growth is good for the economy

Truth – This makes people poorer as shown under Myth #3. 

Myth 6 – Population growth in poor nations does not matter because of their “tiny carbon footprint”

Truth –  Population growth is a greater threat than climate change. The best way for anyone to decrease their carbon footprint is to have one less kid.

Therefore, family planning is the most economical way to a sustainable future.

What action can each of us take?

1. Discuss smaller family sizes with your partner, family, and friends – how do we aim for birth rates lower than two children per couple?

2. Share information about the environmental impacts of population growth with friends and family. Advocate for action to reduce and reverse population growth.

3. Reassess concerns about aging   – how can we shift away from worshipping eternal youth, to accepting and valuing the entire life cycle? 

4. Celebrate population decline – what are possible depopulation dividends? 

5. Support organizations and efforts that support family planning and women’s education.

Damien Carrington, an environmental editor at The Guardian, interviewed Prof. Paul Ehrlich about the solutions:

“The solutions are tough,” Ehrlich says. “To start, make modern contraception and backup abortion available to all and give women full equal rights, pay, and opportunities with men. Focus on overconsumption and equity issues. Specifically women’s rights and the explicit countering of racism.”

Ehrlich also says that an unprecedented redistribution of wealth is needed to end the over-consumption of resources, but “the rich who now run the global system – that hold the annual ‘world destroyer’ meetings in Davos – are unlikely to let it happen…Too many rich people in the world is a major threat to the human future, and cultural and genetic diversity are great human resources… It is a near certainty in the next few decades, and the risk is increasing continually as long as the perpetual growth of the human enterprise remains the goal of economic and political systems. As I’ve said many times, ‘perpetual growth is the creed of the cancer cell’.”

If cultural and genetic diversity are great human resources, how can the rich and the poor come together across the world to solve this issue?

Anne and Paul Ehrlich expand on their “vision for a cure” :

“Rich white people love to hold meetings to discuss the ‘population problem’ which always ends up focusing on the very real demographic difficulties of those with darker skin tones, especially people who live in Africa and Latin America. But isn’t it really time for the poor people of the world, especially those not in need of tanning beds, to extend a helping hand to the major villains of the destruction of humanity’s life-support systems? Could they not hold an educational conference in Washington, D.C. to explain why civilization is going down the drain, to the per-capita most environmentally destructive giant nation on the planet? Leaders from the “South” could both organize the event and supply experts to educate the wealthy and middle class on their ethical responsibilities and ways to meet them. We envision learning sessions on topics such as:

  • Avoiding the second child.
  • The population problem beyond numbers: inequality and waste of talent. 
  • Are borders ethical?
  • Population shrinkage for politicians.
  • GDP shrinkage for economists.
  • Do Trump and his colleagues prove that the lighter your skin, the lighter your brain?
  • Citizens United: It’s time for euthanasia for corporations.
  • Redistribution and survival.
  • Disbanding “Murder Incorporated”: gun manufacturers and big pharma.
  • How to end plastic production.
  • The historical contributions of the global South to the food enjoyed by the North.
  • How biodiversity loss is accompanied by the loss of human cultural diversity.
  • We know our populations are growing too fast; how to help us help ourselves?
  • Why anti-abortion laws kill poor women.

You can doubtless think of others. The possibilities are endless”.


Berman, Art. The Climate-Change Trip to Abilene. July 13, 2022.

Carrington, Damien. Interview with Paul Ehrlich: Collapse of civilization is a near certainty within decades. July 9, 2020.

Ehrlich, Anne H.; Ehrlich, Paul R. Overpopulation In America -And Its Cures. November 14, 2019.

O’Sullivan, Jane. The tenth presentation at the Delivering the Human Future Conference. Titled: The Future of the Human Population. March 21, 2021.

Population Statistics.

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80 Overpopulation Topics & Essay Examples

Looking for interesting overpopulation topics for an essay or research paper? The issue is hot and definitely worth writing about!

  • 🔝 Top 10 Topics to Write About
  • 🏆 Best Essay
  • 📌 Most Interesting Topics to Write about
  • 👍 Research Questions & Topics

Here we’ve gathered a list of overpopulation essay examples, title ideas, and research questions related to the field. Get inspired with us!

🔝 Top 10 Overpopulation Topics to Write About

  • Population dynamics in the world
  • The role of medical advancements in human overpopulation
  • Overpopulation: causes and effects
  • Overpopulation and poverty: the correlation
  • Does overpopulation threaten democracy?
  • Social conflict and population growth: is there a connection?
  • Overpopulation and pandemics today
  • Population growth and human impact on environment
  • Do we need to fight overpopulation?
  • Human population planning

🏆 Best Overpopulation Essay

  • The Problem of Global Overpopulation Insights gained from the chapters reveal that the main reason behind the problem of resource overconsumption which threatens the very future of the planet is the rampant overpopulation of humanity which threatens to drain the […]
  • Human Population and the Environment The fertility rate of a given species will depend on the life history characteristics of the species such as the number of reproductive periods in the lifetime of the species and the number of offspring […]
  • Overpopulation Benefits With this in mind, this paper shall set out to evaluate the impacts of overpopulation to the political, cultural, anthropological and economical perspectives to various economies and societies.
  • Impacts of Overpopulation on the Environment Other primary causes of deforestation are construction of roads and residential houses to cater for the increasing population. As the natural habitats are destroyed, many wildlife species have been displaced and many died due to […]
  • The Challenges of Overpopulation: Vertical Cities The design of the building assumes that the structure will have a longer and sustainable life as compared to the degrading city and surroundings.
  • Overpopulation as a Challenge to Management’s Ethos It is based on this that when it comes to the threat of overpopulation as a challenge to management’s ethos of mass-production and mass-consumption, the problem lies in the fact that the ethos of companies […]
  • The Problem of Overpopulation The purpose of this paper is to examine the causes and effects of overpopulation, potential threats to society, and the ecosystem, as well as the ways to overcome the problem.
  • Overpopulation Challenges in China The population crisis in China has become a global issue, owing to the numerous contributions that the country makes towards the activities of the international community.
  • Prison in the USA: Solutions to Reducing Overpopulation First of all, it is necessary to improve the justice system which is the reason of overpopulation in prisons. Secondly, it is necessary to rethink the life of inmates in prison.
  • Overpopulation Effects on the Environment In comparison to the population in 2000, the population in 2050 is predicted to rise by 47 percent. The aim of this research is to describe the effects of overpopulation on land, air, and food […]
  • Overpopulation: Causes, Effects, and Solutions Advances in industry and production provide clothes and items for the growing population to use, thus creating and maintaining a higher standard of living.
  • Overpopulation: Causes, Effects and Consequences The primary objective is to highlight the deplorable consequences of overpopulation and thereby persuade people not to overpopulate. In the past, poor people gave birth to a lot of children to make up for high […]
  • The Impact of Overpopulation on the Global Environment In support of the motion that the global population is too large and that the United States and other industrialized countries should support active measures to control population growth in the developing world, it is […]
  • Birth Control Against Overpopulation Based on the information presented, it can be seen that the current growth of the human population is unsustainable in the long run due to the finite resources on the planet.
  • Overpopulation and Homelessness in the Modern World According to the United Nations, more than half of the population resides in urban areas, making the problem of homelessness visible: cities cannot keep up with the high demand for housing, resulting in people living […]
  • Overpopulation: “Empty Planet” by Bricker & Ibbitson However, while some people are trying in vain to stabilize the average population growth in all parts of the world, others are becoming aware of the implications such drastic changes can bring to the future […]
  • Environmental Problems From Human Overpopulation The significant movement of the population to the suburbs, coupled with economic prosperity and the technological improvement that made it possible, began to take its toll.
  • How Overpopulation Affects Our Economy These are: population dynamics and the demographic concept, reasons for the increase in the size of the population, effects of overpopulation in the economy, food production per capita index, lower national income, increasing burden on […]
  • Does the Overpopulation of Our Planet Pose a Serious Problem? Another concern for the demographers is that while in certain developing nations the rate of population growth has been increasing, in the developed countries it has been found to be declining steadily.
  • The Issue of the Overpopulation Particularly, the proponents of fertility control support their position by the fact that the degrading environment is no longer able to provide for the needs of so many people, and with the duration of time […]
  • The Problem of Overpopulation and How to Fix It It can be stated the confidence that the solution to this global challenge is the primary duty of present and future generations. The purpose of this paper is to discuss the overpopulation phenomenon and propose […]
  • Human Overpopulation and Its Global Impact Overpopulation presents a huge threat to the future of the planet, as the resources of the Earth seem to be at the breaking point because of their overexploitation caused by enormous rates of population increase.
  • Problem of Overpopulation: Proenvironmental Concerns It is necessary to find the ways to solve future problems as the situation is likely to worsen over time. The mentioned quotes prove that it is possible to correct people’s thinking about overpopulation and […]
  • Overpopulation and Food Production Problem Therefore, the issue explored in this paper is the decrease of Earth’s natural resources and capacity to produce food re decreasing, while the problem of hunger remains and the population continues to increase. 3% of […]
  • Managing Overpopulation in India and Caused Problems The death of the aged reduces the population by 10. Employment to the youth reduces poverty.
  • Overpopulation: Is the Small World Getting Smaller? Nevertheless, despite the legitimacy of the concerns raised over the slow availability of numerous resources and the seemingly drastic and steep increase in the number of people worldwide, the issue of overpopulation is likely to […]
  • The Issue of Overpopulation and Human Population Growth Control The consequences of overpopulation include the depletion of natural resources and climate change which have hindered the conservation of natural resources such as water and animals.
  • Global Issues, Climate Justice, and Human Overpopulation On the one hand, globalization has many positive aspects: the mutual enrichment of the world community, the exchange of best practices, and the availability of goods.
  • Overpopulation and Limit on Number of Children Another supporting factor of limiting the number of children is that it allows for more resources to be dedicated to each child both within microenvironments of the family and the macro considerations of the national […]
  • Utilitarian View on Overpopulation and Life Quality Despite the various foundations of utilitarianism, it involves the association of actions based on the good will of the majority, hence the subjective nature to individualized domain.

📌 Most Interesting Overpopulation Topics to Write about

  • The Effects Of Human Overpopulation On The Environment
  • The Threat Of Terrorism And Overpopulation Concerns
  • A Discussion on the Effects of Global Warming and Overpopulation in the World
  • The Population of Our Planet and the Issue of the Overpopulation
  • The View On Overpopulation: Looking Deeper Into The Hardinian Taboo
  • The Growth Population and Problem of Overpopulation During the 20th Century
  • The Effects of Overpopulation on the Economy of China
  • Pet Overpopulation: Cause And Effect Of Homeless Pets
  • The Growing Concerns Regarding the Overpopulation of the World Amid Limited Resources
  • Thomas Malthus Overpopulation Theory
  • The Importance of Slowing Down the Environmental Consequences of Overpopulation
  • The Enviromnetal Degradation as a Result of Overpopulation
  • A Comparison of the Insights on Overpopulation in the Media
  • Problems Created By Overpopulation Population Growth World
  • The United States: Future Contributions to Overpopulation
  • The Growing Concerns over Global Overpopulation Relative to the Depleting Resources
  • Why the Problem of Overpopulation is a Serious Problem Today
  • The World Fastest Gowing Problems: Overpopulation
  • Pet Overpopulation: Negative Effects and Prevention
  • The Issue of Overpopulation and the Main Reasons Why Capital Cities Become Overpopulated

👍 Overpopulation Research Questions & Topics

  • The Cause, Effect, and Solution to Overpopulation in the Philippines
  • A Description of the Problem of Overpopulation of Cats in the United States
  • The Struggle of Overpopulation: China’s Fight Against Numbers
  • We Must Stop Overpopulation and Pollution of Our Environment
  • An Analysis of the Big Concern and the Growth and the Overpopulation of Our Planet
  • An Overview of the Natural Beauty and the Right to Decent, the Issues of Overpopulation
  • An Analysis of Overpopulation and Population Growth
  • Poverty Is Not Caused by Overpopulation, Overpopulation Is Caused by Poverty
  • The Great Human Tumor : Earth ‘s Human Overpopulation Crisis
  • Population Control Measures And Control Overpopulation
  • The Cause and Effects of Pet Overpopulation
  • An Analysis of the Environmental Degradation as a Result of Overpopulation
  • Sociology: Overpopulation and Population Growth
  • An Argument in Favor of Stopping the Environmental Problem of Overpopulation
  • An Analysis of the Theme of Overpopulation in Population Bomb by Ehrlich
  • The Decline of Environmental Conditions Due to Human Overpopulation
  • Overpopulation: Unemployment and Possible Solutions
  • Prison Alternatives as Possible Solutions to Controlling Overpopulation in American Prisons
  • The Worsening Problem of Earth’s Overpopulation
  • The Negative Impact of Overpopulation on the World
  • Chicago (A-D)
  • Chicago (N-B)

IvyPanda. (2023, October 26). 80 Overpopulation Topics & Essay Examples.

"80 Overpopulation Topics & Essay Examples." IvyPanda , 26 Oct. 2023,

IvyPanda . (2023) '80 Overpopulation Topics & Essay Examples'. 26 October.

IvyPanda . 2023. "80 Overpopulation Topics & Essay Examples." October 26, 2023.

1. IvyPanda . "80 Overpopulation Topics & Essay Examples." October 26, 2023.


IvyPanda . "80 Overpopulation Topics & Essay Examples." October 26, 2023.

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Read our research on: Immigration & Migration | Podcasts | Election 2024

Regions & Countries

2. what americans say is causing a migration surge at the u.s.-mexico border.

Americans see several factors as reasons why there are so many people seeking to migrate to the United States at the southwestern border.

Large bipartisan majorities point to economic factors as major reasons for the surge, with 75% of Americans saying bad economic conditions in migrants’ home countries are a major reason, and 71% saying the same about good economic opportunities in the U.S.

Chart shows Economic factors widely seen as reasons why there are many migrants at the U.S.-Mexico border

Smaller majorities also say violence in migrants’ home countries (65%), and migrants’ belief that U.S. policies allow for them to easily stay once they arrive (58%) are major factors. But there are wide partisan differences in views about the importance of these two factors.

Less than half of adults (44%) view greater political freedoms in the U.S. as a major reason for why people are seeking to migrate to the U.S.

Very few Americans say any of these factors is not a reason at all – fewer than two-in-ten say this about any of the five reasons asked about in the survey.

Republican, Democratic views of the reasons for the migration surge

U.s. immigration policy.

Chart shows Wide partisan gaps over the role of home country violence, U.S. policy in migrant surge

Roughly three-quarters of Republicans and GOP leaners (76%) point to a belief among migrants that U.S. immigration policies will make it easy to stay in the country as a major reason for the situation at the U.S.-Mexico border. Of the five reasons asked about in this survey, this ranks highest among Republicans.

By contrast, a far smaller share of Democrats (39%) point to this as a major reason for the large number of migrants seeking to enter at the U.S.-Mexico border. It is the lowest-ranked item among Democrats.   

Still, an additional 39% of Democrats say this is a minor reason. Another 21% say it is not a reason (compared with just 7% of Republicans).

Violence in home countries

Nearly eight-in-ten Democrats (79%) say violence in migrants’ home countries is a major reason for the number of migrants at the U.S.-Mexico border. This is among the top reasons (alongside economic factors) Democrats see for the migration surge.

Republicans are far less likely to see this as a major factor for the surge in migrants, though about half (49%) say that it is.

Economic factors

Large majorities in both parties identify good economic opportunities in the U.S. and bad economic conditions in migrants’ home countries as major reasons for the migrant situation at the border.

Democrats are slightly more likely than Republicans to say each of these are major reasons.

Political freedoms

About four-in-ten Republicans (41%) and nearly half of Democrats (47%) view greater political freedoms in the U.S. as a major reason for why large numbers of people are seeking to migrate to the U.S. at the southwestern border. More than a third in both parties view this as a minor reason.

Conservative Republicans, liberal Democrats diverge on reasons for the migrant surge

Conservative Republicans (81%) overwhelming say that migrants’ beliefs that U.S. policy will make it easy to stay in the country once they arrive is a major reason for the large number of migrants at the U.S.-Mexico border.

Chart shows partisans point to different factors for why there is a large influx of migrants at the border with Mexico

A smaller – though still substantial – majority of moderate and liberal Republicans (67%) also see this as a major reason for the buildup of migrants.

But Democrats – particularly liberal Democrats – are not nearly as likely to see the belief that U.S. immigration policy is loose as a factor. Just 29% of liberal Democrats say it is a major reason why migrants are seeking to enter, while another 42% say it is a minor factor. Nearly three-in-ten (28%) say this is not a reason at all.

By comparison, more than eight-in-ten liberal Democrats point to violence in the countries migrants are coming from as a major reason for their migration.

About three-quarters of conservative and moderate Democrats (73%), and roughly six-in-ten moderate and liberal Republicans (58%) also view violence as a major factor behind why migrants are coming to the U.S.

But conservative Republicans are less likely to see this as a significant contributing factor: 44% say it is a major reason why migrants at the southwest border seek to enter the U.S., while another 42% say it is a minor reason.

Facts are more important than ever

In times of uncertainty, good decisions demand good data. Please support our research with a financial contribution.

Report Materials

Table of contents, fast facts on how greeks see migrants as greece-turkey border crisis deepens, americans’ immigration policy priorities: divisions between – and within – the two parties, from the archives: in ’60s, americans gave thumbs-up to immigration law that changed the nation, around the world, more say immigrants are a strength than a burden, latinos have become less likely to say there are too many immigrants in u.s., most popular.

About Pew Research Center Pew Research Center is a nonpartisan fact tank that informs the public about the issues, attitudes and trends shaping the world. It conducts public opinion polling, demographic research, media content analysis and other empirical social science research. Pew Research Center does not take policy positions. It is a subsidiary of The Pew Charitable Trusts .


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