When it comes to weather-related disasters our thoughts normally go to the abrupt, and often dramatic hurricane, tornado, or flood – not to a slow motion events like an extended heat wave. Yet excessive heat has likely killed more Americans over the past 40 years than all of the tornadoes, floods, and hurricanes combined.
Admittedly, counting the number of fatalities due to excessive heat is both difficult and imprecise, as many of those who succumb are elderly, and have other medical conditions.
In 2002 Rupa Basu and Jonathan M. Samet wrote in the Journal Epidemiological Reviews (see Relation between Elevated Ambient Temperature and Mortality: A Review of the Epidemiologic Evidence):
An average of 400 deaths annually are counted as directly related to heat in the United States, with the highest death rates occurring in persons aged 65 years or more (3). The actual magnitude of heat-related mortality may be notably greater than what has been reported, since we do not have widely accepted criteria for determining heat-related death (4, 5–7), and heat may not be listed on the death certificate as causing or contributing to death.
This disparity between counted and estimated heat-related deaths can be illustrated by the reports from the infamous heat wave of 1980, which `officially’ claimed `more than 1250 lives’ (cite NOAA Heat Wave: A Major Summer Killer) but which unofficially may have killed as many as 10,000 (Tracking and Evaluating U.S. Billion Dollar Weather Disasters, 1980-2005 (Lott and Ross, 2006).
Eight years later, a heat wave across the central and eastern part of the nation killed as many as 7,500 people (cite). More recently, in 1999, a prolonged heat wave along the Eastern seaboard is believed to have killed 500 (cite).
Over the past few weeks there have been reports of thousands of heat-related deaths in India and Pakistan, but even these events are dwarfed by the European Heat Wave of 2003 which is estimated to have claimed 70,000 lives and the 2010 Russian Heat Wave that may have killed as many as 56,000.
As weather patterns continue to change around the world, monsoon rains fail to appear on time, and more and more people crowd into urban areas these types of weather-related health disasters are only likely to increase over time.
Today the WMO (World Meteorology Organization) and the WHO (World Health Organization) have released new guidance on Heat Health Warning systems, in the form of a 144 PDF file. Excerpts from the press release, and a link to the guidance, follow:
1 July 2015
Geneva 1 July 2015 (WMO) The World Meteorological Organization (WMO) and the World Health Organization (WHO) have issued new joint guidance on Heat–Health Warning Systems to address the health risks posed by heatwaves, which are becoming more frequent and more intense as a result of climate change.
“Heatwaves are a dangerous natural hazard, and one that requires increased attention,” said Maxx Dilley, Director of WMO’s Climate Prediction and Adaptation Branch, and Maria Neira, Director of WHO’s Department of Public Health, Environmental and Social Determinants of Health. “They lack the spectacular and sudden violence of other hazards, such as tropical cyclones or flash floods but the consequences can be severe.”
Over the past 50 years, hot days, hot nights and heatwaves have become more frequent. The length, frequency and intensity of heatwaves will likely increase over most land areas during this century, according to the Intergovernmental Panel on Climate Change. In addition to the health impact, heatwaves also place an increased strain on infrastructure such as power, water and transport.
In recent weeks alone, both India and Pakistan have been hit by deadly heatwaves, killing hundreds of people. The European heatwaves in the northern hemisphere summer of 2003 was responsible for the deaths of tens of thousands of people, as were the Russian heatwaves, forest fires and associated air pollution in 2010.
Action reduces risks
The good news is that heat-related health risks can be reduced through systematic development of heatwave early warning systems. These provide meteorological and/or climate-prediction-based information on the likelihood of forthcoming hot weather that may have an effect on health. This information is used to alert decision-makers, health services and the general public to trigger timely action to reduce the effects of hot-weather extremes on health.
A number of countries around the world have successfully developed these early warning systems, which necessitates close coordination between meteorological and health services. The WMO-WHO publication Heatwaves and Health: Guidance on Warning-System Development is intended to promote more widespread development and implementation of these warning systems.
Heatwaves and Health: Guidance on Warning System Development is available here