Measuring the true cost of heat waves

Posted: 31 July 2006

The recent heatwaves in Europe and California are a reminder that extreme weather events are expected to become ever more frequent as the planet heats up. But what were the real consequences of the last European heat wave in 2003? Health officials now believe they were even more serious than previously thought. Janet Larsen reports.

The severely hot weather that withered crops, dried up rivers, and fueled fires in the summer of 2003 took a massive human toll. The full magnitude of this quiet catastrophe still remains largely an untold story, as data revealing the continent-wide scale have only slowly become available in the years since.

All in all, more than 52,000 Europeans died from heat in the summer of 2003, making the heat wave one of the deadliest climate-related disasters in Western history.

Temperature records were broken in a number of countries in 2003 as Europe experienced its hottest weather in at least 500 years. The unusually warm weather began in June and culminated in an unrelenting heat wave during the first two weeks of August. With both daytime and nighttime temperatures remaining high, large numbers of vulnerable people, particularly the elderly, succumbed to the baking heat.

Hospitals were faced with unusually large burdens, and undertakers and funeral homes were overwhelmed. In France, doctors' warnings of a heat epidemic were largely quashed with the Ministry of Health's refusal to acknowledge the massive problem, reminiscent of the early political denial of the 1995 Chicago heat wave that killed more than 700 people in a matter of days. But as the bodies piled up, requiring makeshift morgues, "ignore and neglect" was no longer a viable option.

Thousands died

While news reports gave estimates of a potentially large human death toll,it wasn't until well after the event that more accurate tallies became available. After facing criticism for its inadequate health facilities and lax government response, France became one of the first countries to release an epidemiological study revealing the true extent of the heat's damage. At the end of September 2003, the French National Institute of Health reported that in the first 20 days of August, heat had killed more than 14,800 people. During the peak of the heat, fatality rates topped2,000 in a day.

Using this French report and other early figures, in October 2003 the Earth Policy Institute detailed a preliminary mortality tally for the 2003 European heat event (see: www.earthpolicy .org. At that time, it appeared that some 35,000 people had died because of high temperatures. We now know that even this was an underestimate.

Of the new information that has trickled out over the last few years, the biggest surprise has come from Italy. According to the Italian National Institute of Statistics, the summer of 2003 yielded more than 18,000 excess deaths when compared with 2002. In August alone, 9,700 fatalities were probably connected to the high temperatures, which in parts of Italyaveraged 16 degrees Fahrenheit warmer than in the preceding year. These elevated numbers far exceed the Italian Health Ministry's early assessment that some 4,000 people died from heat country-wide during the hottest days.

Another upward adjustment was published for Portugal by the European Centre for Disease Prevention and Control, where August 2003 temperatures exceeded 104 degrees Fahrenheit for many days. There, 2,099 deaths have been linked to the hot weather, up from the Portuguese National Institute of Health's preliminary estimate of 1,316 fatalities.

52,000 casualties

In Belgium, where the mercury rose higher than at any time in the Royal Meteorological Society's register dating back to 1833, high temperatures brought 1,250 untimely deaths between June and August, nearly a tenfold increase over what was initially predicted. And more recent information from Switzerland shows that 975 people died from heat in the warmest Swiss summer since 1540.

Altogether, new data boost Europe's heat-related mortality for the summer of 2003 by 17,000 over preliminary estimates, to a record 52,000casualties.

Unlike hurricanes or tornados that leave obvious damage and death in their wake, not to mention vivid images for the media, heat waves are silentkillers. Coroners' reports rarely list "heat" as the primary cause of death, even when high temperatures may have precipitated cardiovascular or respiratory failure or dehydration. Thus it is generally not until a heat wave is long over, when death counts can be compared to what would otherwise be expected in a "normal" year, that we begin to learn the fullhuman toll. Yet governments, reluctant to admit public health failures, often release such numbers with little fanfare.

In late 2005, the world focused on the aftermath of Hurricane Katrina, one of the most destructive storms to ever hit the United States, with massive monetary losses and over 1,300 deaths. While this was a significantcatastrophe, the number of lives taken by Katrina is but a tiny fraction of the toll from Europe's 2003 heat wave. Because reports of the heat wave's casualties trickled out of individual countries over more than twoyears following the actual event and never received widespread media coverage, policymakers and the public at large have not grasped the fulldimensions of the catastrophe and therefore underrate the risk of rising temperatures.

People, particularly government officials, need reliable information on the threat that extreme heat can pose. Indeed, after the 2003 event anumber of European countries beefed up their heat-health alert systems and took additional measures to prepare for future heat waves.

Following the public outrage over its 2003 failures, France's Ministry of Healthannounced increased funding for hospital beds and more jobs for health workers, as well as a renewed focus on care for elderly people who suffer the most during warm spells. The Spanish government's heat wave action plan includes an awareness campaign for social service and health care professionals, a voluntary register for people at high risk to receive special services, and a daily mortality monitoring system.

Climate dice

Projections of the Intergovernmental Panel on Climate Change, a global body of some 2,000 scientists, show more extreme weather events ahead as the planet heats up. By the end of the century, the world's average temperature is projected to increase by 2.5-10.4 degrees Fahrenheit (1.4-5.8 degrees Celsius). As the mercury climbs, more frequent and more severe heat waves are in store. Accordingly, the World Meteorological Organization estimates that the number of heat-related fatalities could double in less than 20 years.

Scientists from the Hadley Centre for Climate Prediction and Research and from Oxford University reported in 2004 that human activity, namely the emissions of greenhouse gases into the atmosphere from fossil fuel burning, doubled the risk of extreme heat waves like the one that cost so many lives in Europe in 2003.

Avoiding "loading the climate dice" evenfurther in favour of future weather calamities will take a concerted effort to cut carbon emissions quickly and dramatically.

Source: Earth Policy Institute, July 28,2006. Reproduced with permission.

July was today officially declared the hottest month ever recorded in the United Kingdom.