Fact Check: Drop in climate-related disaster deaths not evidence ... - Reuters

Fact Check: Drop in climate-related disaster deaths not evidence against climate ‘emergency’ | Reuters

Fact Check: Drop in climate-related disaster deaths not evidence against climate ‘emergency’

Social media posts are recirculating a bar chart that depicts falling numbers of deaths due to weather-related disasters over the last century alongside comments suggesting that the significance of climate-driven weather changes is exaggerated.

Mortality, however, is not a useful measure of the number or severity of weather-related events including the floods, droughts, storms, wildfire, and extreme temperatures listed in the graph, experts told Reuters.

Although deaths from these disasters have decreased, due in part to better forecasting and preparedness, the number, intensity, and cost of climatic and meteorological hazards have all increased over the last hundred years.

The graph showing annual averages of global deaths from weather disasters by decade between the 1920s and 2020 is labelled “Climate-related Disasters Kill Ever Fewer”. Deaths are at their highest in the 1920s with an average of around 480,000, then decrease decade-upon-decade thereafter. From the 1990s onwards, the figures are consistently under an average of 50,000.

Comments accompanying the graph online include: “ Where is the ‘#ClimateEmergency’? I don’t see it. You?”, “ We don’t have a climate change problem, we have a climate education problem” and “ More facts to blow away the climate change bollocks”.

MISLEADING METRIC

Charting death numbers alone and aggregating them by decade does not capture the number or nature of weather-related disasters.

For instance, during the period between the 1920s and 1960s shown in the graph, several “mega-disasters” with remarkably high reported death tolls contribute to the high average decadal mortalities in that period, despite the appearance of an overall decline in mortality.

There were seven famines, each driven by large-impact events such as droughts and floods, that killed at least one million people each, according to data from the Emergency Events Database(EM-DAT), the source credited on the graph.

Two examples include the 1923 famine in Ukraine which led to 1.2 million deaths and the Chinese famine in 1928 which led to 3 million deaths, according to EM-DAT.

Although these events were climate-driven, their significant impacts on human life were made worse by a lack of visibility (reporting), conflict or policies affecting socio-demographic conditions (vulnerability), and an inability to provide aid (capacity), said Damien Delforge, senior researcher at the Centre for Research on the Epidemiology of Disasters (CRED) at the University of Louvain in Belgium.

For example, the relief effort for the China floods in 1931 was hampered by the Japanese invasion of Manchuria.

The impression of a steady downward trend in the graph is also due to the 100-year period selected, Delforge noted. If one were to take the 1910s as the comparison baseline instead of the 1920s, the decrease in mortality up to the decade 2010-2020 would be 30% instead of 96%, as outlined on page seven of the “2022 Disasters in Numbers” report.

IMPROVED RESILIENCE

Declining death tolls can also be explained in part by systems and societies with increased resilience to disasters rather than fewer disasters, experts said.

“The death toll is falling because of improved forecasts and early warnings, and more coordinated risk and disaster management and response,” a spokesperson for the World Meteorological Organization (WMO) said.

Improved resilience to disasters has occurred in the form of reduction of poverty, early detection systems, disaster responses, and improved infrastructure, said Hannah Ritchie, deputy editor and science outreach lead at Our World in Data.

Even if there was an increase in deaths over time, this in itself would not be conclusive evidence for the existence of climate change, Delforge said. Other factors that can influence disaster impact figures include hazard attributes, exposure to hazards, environmental susceptibility, socio-demographic factors, management factors and reporting.

Disasters are also one of many pathways by which climate change can affect human health, said Sir Andy Haines, professor of environmental change and public health at the London School of Hygiene and Tropical Medicine. Other examples include extreme heat, food security and infectious diseases.

ESCALATING CLIMATE IMPACTS

Weather-related disasters have become more frequent, intense, and costly in recent decades as documented by many different sources and analyses. Climate change is already disrupting billions of lives, with nearly half of the world’s population vulnerable to increasingly dangerous climate impacts.

For example, despite global deaths decreasing since the 1950s, the number of reported disasters has increased fivefold, driven by climate change, more extreme weather, and improved reporting, the WMO has shown.

The Intergovernmental Panel on Climate Change (IPCC) AR6 report states with a certainty of over 99% probability that hot extremes have increased in intensity and frequency globally since 1950, as have the duration and intensity of heatwaves.

Losses and damages from climate change are escalating, too.

For example, a 2017 UN report on economic losses from disasters charted climate-related incidents accounting for $2,245 billion in the period 1998-2017, 77% of the total costs from all disasters. Between 1978 and 1997, they accounted for $895 billion, 68% of the total.

Reported losses from extreme weather events (a subset of climate-related disasters) increased by 151%, adjusted to 2017 U.S. dollars.

The bar graph circulating online first appeared in a newsletter by climate change sceptic Bjorn Lomborg in response to the UN’s 2022 “Global Assessment Report on Disaster Risk Reduction”.

VERDICT

Misleading. Disaster mortality is not a useful metric for quantifying climate change, and climate-related disasters have increased in number, intensity, and economic cost.

This article was produced by the Reuters Fact Check team. Read more about our fact-checking work.

Our Standards: The Thomson Reuters Trust Principles.