November 23, 2000

Officials Say Heat-Related
Deaths Expected to Climb

By Jim Fuller
Washington File Science Correspondent

The Hague -- Officials of the World Meteorlogical Organization (WMO) report that the number of heat waves worldwide and accompanying heat-related deaths are expected to continue increasing due to global warming.

The WMO report, made available November 22 at the climate change conference in The Hague, was followed by another study released by the World Health Organzation (WHO) saying that reducing fossil-fuel emissions, especially from cars and trucks, would have significant and immediate health benefits.

Godwin Obasi, WMO secretary general, reported that small increases in global temperatures due the heat-trapping greenhouse gases are amplified in big cities, and that deaths from heat waves in major cities worldwide are expected to double over the next 20 years if global warming isn't curbed.

WMO officials said that it is not the direct sunlight that kills, but the air temperature which causes the body to overheat and then induces heart attacks, strokes and respiratory failure. People over 65 are the most vulnerable.

Obasi said concern about heat waves was triggered partly because in 15 large U.S. cities last year there were, on average, 1,500 more deaths during heat waves than there were in 1990. "The projection is that by the year 2020 this will increase to three to four thousand" deaths per year, just in the United States alone, Obasi said.

Over the last 50 years, the occurrence of four-day heat waves has nearly tripled in the United States, according to data collected by the U.S. National Oceanic and Atmospheric Administration.

WMO officials believe that heat waves already cost tens of thousands of lives worldwide and that this could double by 2020 as climate change takes hold. For Shanghai, researchers estimate that the present summer average of about 400 deaths will increase to over 1,000 by 2050, and in Cairo the average summer death total of 280 could also increase to about 1,000.

"This serious threat to human mortality and well-being is all the incentive delegates at The Hague should need to negotiate a climate agreement in real carbon reductions that will help to curb this trend," said Karen Hopfl-Harris, associate director of environmental policy with the Physicians for Social Responsibility, a non-profit organization that conducted the study for WMO.

Delegates from more than 160 countries have been meeting in The Hague to decide rules for reducing worldwide emissions of heat-trapping gases -- mainly carbon dioxide from the burning of fossil fuels -- that are blamed for global warming.

A new draft report released recently by the Intergovernmental Panel on Climate Change (IPCC), considered the most authoritative scientific voice on the issue, concluded that if greenhouse emissions are not curtailed the Earth's average surface temperatures could be expected to increase anywhere from 1.5 to 6 degrees Centigrade by the end of this century -- substantially more than estimated in an IPCC report released five years ago.

Laurence Kalkstein, associate director of the Center for Climatic Research at the University of Delaware, said he and other researchers are studying death rates in major cities during heat waves to find the local trigger temperature for increased deaths so they can design a "heat-watch" warning system for weather forecasts.

A warning system for hot weather and advice to put on telephone help lines is already being formulated by WMO. Kalkstein said health officials in the American city of Philadelphia, one of eight cities around the world that already has a warning system, believe that the timely alerts are saving 300 lives a year.

"It is not necessarily the hottest places on Earth that exhibit the greatest numbers of heat related deaths and illnesses," Kalkstein said. "In fact, it is weather variability rather than heat intensity that is the most important factor in defining human sensitivity to heat. People living in highly variable summer climates are ill-adapted to extreme heat, mainly because it occurs irregularly."

He said that in New York, a temperate city, normal summer temperatures range from 28 to 30 degrees Centigrade, but when the temperature suddenly reaches 40 degrees Centigrade "people die very rapidly." The most vulnerable cities to heat include Shanghai, Chicago and Rome.

Also at The Hague conference, representatives of the World Health Organization's Regional Office for Europe told delegates that rapid measures to reduce greenhouse gases, especially in the transport and industry sectors, would produce immediate health benefits for the global popultion.

"It is now clear that taking strong pre-emptive measures that directly reduce greenhouse gases will also result in other immediate and important health benefits for us all, for example, through cleaner air," Roberto Bertollini, director of technical services and strategic development at the WHO Europe Office, told reporters. "Taking measures now to limit the damage from climate change will bring immediate benefits to our health."

Bertollini's remarks were based on a Swiss study which found the countries that directly target fossil-fuel emissions, especially from transportation vehicles, would provide the biggest health benefits for their populations.

"The greatest health benefits will stem from integrated policies covering technology, urban planning, the speed and safety of traffic, and the promotion of walking, cycling and the use of public transport," said Nino Kunzli, a researcher at the Institute for Social and Preventive Medicine in Basle, Switzerland.

Kunzli referred to data from the Swiss study as well as other European studies showing that when air pollution from fossil-fuel burning is eased, health benefits quickly follow. Globally, he said, it has been estimated that strategic climate policies could prevent about 8 million deaths that would occur between 2000 and 2020 as a result of pursuing business as usual.

Bertollini said analyses of various international studies have shown that there is a direct, linear relationship between particulate concentration in the air and ill health. He said health effects range from an increased frequency and severity of respiratory symptoms to an increased risk of premature death.

He said a recent WHO analysis of current data indicates that between 95,000 and 382,000 premature deaths per year are associated with exposure to small particles in the air in Europe. Sources include transport, stationary combustion, industry and re-suspension of dust.

The researchers emphasized that raod transport was a key area in which both to reduce greenhouse gas emissions and to curb the harm to health caused by factors related to traffic -- other air pollutants, noise, accidents and reduced opportunities for physical exercise through walking and cycling.

They said studies show transport is now the fastest growing source of carbon dioxide emissions. In the European Union, the transport sector causes about 26 percent of all carbon emissions. Further, emissions from transport increased by 30 percent between 1985 and 1996 in the European Union, and the use of passenger cars is projected to increase by 30 percent by 2010.