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Footprints to singularity: A global population model explains late 20th century slow-down and predicts peak within ten years
Projections of future global human population are traditionally made using birth/death trend extrapolations, but these methods ignore limits. Expressing humanity as a K-selected species whose numbers are limited by the global carrying capacity produces a different outlook. Population data for the se...
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Formato: | Online Artículo Texto |
Lenguaje: | English |
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Public Library of Science
2021
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8136733/ https://www.ncbi.nlm.nih.gov/pubmed/34014929 http://dx.doi.org/10.1371/journal.pone.0247214 |
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author | Bystroff, Christopher |
author_facet | Bystroff, Christopher |
author_sort | Bystroff, Christopher |
collection | PubMed |
description | Projections of future global human population are traditionally made using birth/death trend extrapolations, but these methods ignore limits. Expressing humanity as a K-selected species whose numbers are limited by the global carrying capacity produces a different outlook. Population data for the second millennium up to the year 1970 was fit to a hyper-exponential growth equation, where the rate constant for growth itself grows exponentially due to growth of life-saving technology. The discrepancies between the projected growth and the actual population data since 1970 are accounted for by a decrease in the global carrying capacity due to ecosystem degradation. A system dynamics model that best fits recent population numbers suggests that the global biocapacity may already have been reduced to one-half of its historical value and global carrying capacity may be at its 1965 level and falling. Simulations suggest that population may soon peak or may have already peaked. Population projections depend strongly on the unknown fragility or robustness of the Earth’s essential ecosystem services that affect agricultural production. Numbers for the 2020 global census were not available for this study. |
format | Online Article Text |
id | pubmed-8136733 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2021 |
publisher | Public Library of Science |
record_format | MEDLINE/PubMed |
spelling | pubmed-81367332021-06-02 Footprints to singularity: A global population model explains late 20th century slow-down and predicts peak within ten years Bystroff, Christopher PLoS One Research Article Projections of future global human population are traditionally made using birth/death trend extrapolations, but these methods ignore limits. Expressing humanity as a K-selected species whose numbers are limited by the global carrying capacity produces a different outlook. Population data for the second millennium up to the year 1970 was fit to a hyper-exponential growth equation, where the rate constant for growth itself grows exponentially due to growth of life-saving technology. The discrepancies between the projected growth and the actual population data since 1970 are accounted for by a decrease in the global carrying capacity due to ecosystem degradation. A system dynamics model that best fits recent population numbers suggests that the global biocapacity may already have been reduced to one-half of its historical value and global carrying capacity may be at its 1965 level and falling. Simulations suggest that population may soon peak or may have already peaked. Population projections depend strongly on the unknown fragility or robustness of the Earth’s essential ecosystem services that affect agricultural production. Numbers for the 2020 global census were not available for this study. Public Library of Science 2021-05-20 /pmc/articles/PMC8136733/ /pubmed/34014929 http://dx.doi.org/10.1371/journal.pone.0247214 Text en © 2021 Christopher Bystroff https://creativecommons.org/licenses/by/4.0/This is an open access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. |
spellingShingle | Research Article Bystroff, Christopher Footprints to singularity: A global population model explains late 20th century slow-down and predicts peak within ten years |
title | Footprints to singularity: A global population model explains late 20th century slow-down and predicts peak within ten years |
title_full | Footprints to singularity: A global population model explains late 20th century slow-down and predicts peak within ten years |
title_fullStr | Footprints to singularity: A global population model explains late 20th century slow-down and predicts peak within ten years |
title_full_unstemmed | Footprints to singularity: A global population model explains late 20th century slow-down and predicts peak within ten years |
title_short | Footprints to singularity: A global population model explains late 20th century slow-down and predicts peak within ten years |
title_sort | footprints to singularity: a global population model explains late 20th century slow-down and predicts peak within ten years |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8136733/ https://www.ncbi.nlm.nih.gov/pubmed/34014929 http://dx.doi.org/10.1371/journal.pone.0247214 |
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