The Impact of a Six‐Year Climate Anomaly on the “Spanish Flu” Pandemic and WWI

Abstract

The H1N1 "Spanish influenza" pandemic of 1918-1919 caused the highest known number of deaths recorded for a single pandemic in human history. Several theories have been offered to explain the virulence and spread of the disease, but the environmental context remains underexamined. In this study, we present a new environmental record from a European, Alpine ice core, showing a significant climate anomaly that affected the continent from 1914 to 1919. Incessant torrential rain and declining temperatures increased casualties in the battlefields of World War I (WWI), setting the stage for the spread of the pandemic at the end of the conflict. Multiple independent records of temperature, precipitation, and mortality corroborate these findings. Plain Language Summary A new, high-resolution climate record from Europe shows a once-in-a-century climate anomaly that occurred during the years of World War I and the Spanish flu pandemic. Mortality data from all causes show increases in times of worsening weather, precipitation, and temperatures, a factor in many of the major battles of WWI, as well as a possible exacerbating factor for the virulence of the pandemic.

Weather Variability and COVID-19 Transmission: A Review of Recent Research

“…This outbreak is suspected to have first emerged in the autumn/winter period of 1917 and spread through troop movements and deployments during the First World War across Europe, North America and Asia [ 16 ]. This pandemic exhibited three distinct waves of outbreaks with very high mortality rates and virulence associated with cold temperatures and increased precipitation in each of the peaks in Spring 1918, Autumn 1918 and Winter 1918–1919 [ 17 ]. Since the 1918 Influenza Pandemic, influenza A and B strains continue to circulate the globe with distinct seasonal patterns of outbreaks associated with varying climate regions, and in recent history, novel viruses have emerged, also showing an association with weather variables—2009 H1N1 (Swine Flu) Pandemic, SARS 2003 and MERS 2012, among these.…”

Membrane tension may define the deadliest virus infection

“…However, another study found positive association of diurnal temperature and negative association of humidity with COVID-19 deaths (January 20, 2020 to February 29, 2020 in Wuhan, China) [ 47 ]. Another study found a link between decreasing temperatures and high precipitation with the spread of the Spanish flu pandemic in 1918 and 1919 [ 48 ]. Perhaps, heavy rainfall, particularly in mid- to and low-latitude regions, significantly lowered local temperatures [ 49 ] which may have caused right condition for virus replication.…”

Health impacts of daily weather fluctuations: Empirical evidence from COVID-19 in U.S. counties

“…Besides, a dyad of studies, Barreca and Shimshack (2012) ; Deschênes and Greenstone (2011) , use mortality and daily weather changes from U.S. counties to show that annual weather fluctuations, especially temperature and humidity, significantly influence mortality from infectious diseases such as influenza. Recent studies have linked the spike in Spanish flu deaths to declining temperature and torrential rainfall ( More et al, 2020 ). 4 Further, there is documentation that weather patterns affect the viability, activity, and transmission efficiency of viruses, 5 hence there is need for more extensive discussion on how and which environmental variables influence coronavirus activities.…”