TY - JOUR

T1 - Human total fertility rate affected by ambient temperatures in both the present and previous generations

AU - Jensen, Per M.

AU - Sørensen, Marten

AU - Weiner, Jacob

N1 - Publisher Copyright: © 2021, ISB.

PY - 2021

Y1 - 2021

N2 - Elevated temperatures negatively affect human reproduction through several processes that regulate nutrient uptake and resource allocation in pregnant women. These can interfere with foetal development, resulting in low birth weight neonates with altered development trajectories. Temperatures that affect the current generation could, therefore, also have an impact on the following generation. We asked whether heat stress affected offspring fertility by asking if current and past ambient temperatures influenced total fertility rates (TFR) in human populations distributed across the world. We analysed time series data in 65 countries using simple regression analyses based on maximum temperatures and temperature amplitudes over 55 years. Supplemental longer time series (up to 100 years) provided information on response patterns in Northern Europe and Greenland’s colder climates. There were clear and strong effects of temperatures on the TFR in the concurrent and the previous generation. Our temperature-based models account for 71–95% of the variation in TRF in European countries and Greenland, and 56–99% of the variation in 65 countries worldwide. Our findings are consistent with studies of seasonal variation in fertility and suggest that increased temperatures will negatively influence populations subjected to monthly maximum temperatures above 15–20 °C, while fertility in colder climates benefits from elevated temperatures. Our results provide strong evidence that ambient temperatures have important effects on human fertility, and that these effects persist into the following generation.

AB - Elevated temperatures negatively affect human reproduction through several processes that regulate nutrient uptake and resource allocation in pregnant women. These can interfere with foetal development, resulting in low birth weight neonates with altered development trajectories. Temperatures that affect the current generation could, therefore, also have an impact on the following generation. We asked whether heat stress affected offspring fertility by asking if current and past ambient temperatures influenced total fertility rates (TFR) in human populations distributed across the world. We analysed time series data in 65 countries using simple regression analyses based on maximum temperatures and temperature amplitudes over 55 years. Supplemental longer time series (up to 100 years) provided information on response patterns in Northern Europe and Greenland’s colder climates. There were clear and strong effects of temperatures on the TFR in the concurrent and the previous generation. Our temperature-based models account for 71–95% of the variation in TRF in European countries and Greenland, and 56–99% of the variation in 65 countries worldwide. Our findings are consistent with studies of seasonal variation in fertility and suggest that increased temperatures will negatively influence populations subjected to monthly maximum temperatures above 15–20 °C, while fertility in colder climates benefits from elevated temperatures. Our results provide strong evidence that ambient temperatures have important effects on human fertility, and that these effects persist into the following generation.

KW - Fertility

KW - Heat stress

KW - Intergenerational effect

KW - TFR, Temperatures

U2 - 10.1007/s00484-021-02140-x

DO - 10.1007/s00484-021-02140-x

M3 - Journal article

C2 - 33990870

AN - SCOPUS:85105916538

VL - 65

SP - 1837

EP - 1848

JO - International Journal of Biometeorology

JF - International Journal of Biometeorology

SN - 0020-7128

ER -