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Cited by 540Geology and Paleoclimatology ResearchEnvironmental, Ecological, and Cultural StudiesArchaeology and ancient environmental studies

Global climate change, war, and population decline in recent human history

Open access
Zhang, David D., Brecke, Peter, Lee, Harry F., He, Yuan-Qing, Zhang, Jane·2007·Proceedings of the National Academy of Sciences
DOI 10.1073/pnas.0703073104PMC PMC2148270
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Abstract

Although scientists have warned of possible social perils resulting from climate change, the impacts of long-term climate change on social unrest and population collapse have not been quantitatively investigated. In this study, high-resolution paleo-climatic data have been used to explore at a macroscale the effects of climate change on the outbreak of war and population decline in the preindustrial era. We show that long-term fluctuations of war frequency and population changes followed the cycles of temperature change. Further analyses show that cooling impeded agricultural production, which brought about a series of serious social problems, including price inflation, then successively war outbreak, famine, and population decline successively. The findings suggest that worldwide and synchronistic war–peace, population, and price cycles in recent centuries have been driven mainly by long-term climate change. The findings also imply that social mechanisms that might mitigate the impact of climate change were not significantly effective during the study period. Climate change may thus have played a more important role and imposed a wider ranging effect on human civilization than has so far been suggested. Findings of this research may lend an additional dimension to the classic concepts of Malthusianism and Darwinism.

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Crossref · 10.1073/pnas.0703073104

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  • Climate-induced food shortages increased the risk of conflict when climate variation undermined agricultural production in agriculture-dominated societies and economies.

    “For example, Zhang et al (2007) and Jun and Sethi (2021) showed that climate-induced food shortages increased the risk of conflict when climate variation undermined agricultural production in agriculture-dominated societies and economies.”

    From The impacts of climate change on violent conflict risk: a review of causal pathways (2024) · cites this paper as Zhang et al 2007

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Authors
Zhang, D. D., Brecke, P., Lee, H. F., He, Y.-Q., & Zhang, J.
Affiliations
  • University of Hong Kong (HK)
  • Georgia Institute of Technology (US)
  • Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Science, Lanzhou 730000, Gansu, China; and
  • University College London (GB)
Corresponding author
Zhang, David D.
ORCID
Venue
Proceedings of the National Academy of Sciences
Publisher
National Academy of Sciences
Published
2007-12-04
Volume
104
Issue
49
Pages
19214-19219
ISSN
  • 0027-8424 (ISSN-L)
  • 1091-6490
DOI
10.1073/pnas.0703073104
PMC
PMC2148270
OpenAlex
W2154040214
Cited by
540
References
48
Citations by year
2026: 13 · 2025: 28 · 2024: 33 · 2023: 34 · 2022: 29 · 2021: 34 · 2020: 27 · 2019: 21 · 2018: 27 · 2017: 27 · 2016: 30 · 2015: 28 · 2014: 39 · 2013: 32 · 2012: 57
FWCI
12.45
Type
journal article
Language
en
Open access
Locations
  • Proceedings of the National Academy of Sciences (publishedVersion)
  • PubMed Central (publishedVersion)
  • PubMed (publishedVersion)
  • The HKU Scholars Hub (University of Hong Kong) (submittedVersion)
Topics
  • Physical Sciences › Earth and Planetary Sciences › Atmospheric Science › Geology and Paleoclimatology Research
  • Social Sciences › Sociology and Political Science › Environmental, Ecological, and Cultural Studies
  • Physical Sciences › Earth and Planetary Sciences › Paleontology › Archaeology and ancient environmental studies
Keywords
climate change, population decline, paleoclimate, temperature fluctuations, agricultural production, inflation, famine, social unrest, Malthusianism, Darwinism, climate change mitigation
MeSH terms
Climate, Humans, Population Density, Temperature, Warfare, Greenhouse Effect, History, 15th Century, History, 16th Century, History, 17th Century, History, 18th Century, History, 19th Century, History, 20th Century, History, 21st Century, History, Ancient, History, Medieval

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