Health Fears About Global Warming Are Unfounded

Health Fears About Global Warming Are Unfounded
October 1, 2007

Health care providers are buying into alarmist global warming theory and are concerned about the potential negative health effects of warmer temperatures, reported the August 12 Washington Post.

According to the Post, "Spurred by what they see as an increasing number of illnesses, injuries, and deaths related to global warming, a growing number of public health professionals are campaigning for a reduction in carbon dioxide emissions. They think of it as a form of preventive medicine: Stop carbon dioxide emissions and global warming, they say, and the risk of severe heat waves and tropical storms will diminish."

In Unstoppable Global Warming Every 1,500 Years, climate experts S. Fred Singer and Dennis Avery report just the opposite--that the Earth's moderate warming has been and will continue to be a net benefit to human health.

The following article, based on a chapter of Unstoppable Global Warming, provides the scientific evidence regarding warming temperatures and human health.


There are certainly deaths and illnesses due to heat waves. These typically include heat stroke, heart attacks, and asthma attacks. Deaths and hospitalizations from heat waves make headlines whenever the temperature hits very high levels.

Yet we see the same sort of headlines during cold waves. The elderly die in inadequately heated homes. People get skull fractures from falls on the ice. Men die of heart attacks while shoveling snow. People get colds, flu, pneumonia, and other respiratory diseases. Infectious diseases proliferate. Hospital admissions rise.

Global warming alarmists present the fairly simplistic theory that higher temperatures will drive more extreme weather events, and these events will raise human death rates. But overall, cold weather is more effective at killing people than heat waves.

Global warming would raise maximum summer temperatures modestly while it would raise winter minimum temperatures significantly. Both factors should help reduce human death rates.

Cold Twice as Deadly

From 1979 to 1997, extreme cold killed roughly twice as many Americans as heat waves, according to Indur Goklany of the U.S. Department of the Interior. Cold spells, in other words, are twice as dangerous to our health as hot weather.

Heat is becoming a less important factor in human health as air conditioning spreads. Heat-related mortality in 28 major U.S. cities from 1964 through 1998 dropped from 41 deaths per day in the 1960s to only 10.5 per day in the 1990s.

A large cohort study comparing households with and without air conditioning in the early 1980s found a 41 percent lower death rate for the air-conditioned households during hot months.

Heat Waves Reduced Deaths

In Germany, heat waves were found to reduce overall mortality rates slightly, while cold spells led to a significant increase in deaths.

The German authors say the longer a cold spell lasts, the more pronounced the excess mortality--and the higher death rates seem to persist for weeks.

Hot spells, in contrast, cause a short surge in deaths followed by a period of lower death rates that persists for more than two weeks.

Cold Elevates Heart Risks

A high proportion of modern deaths is due to cardiovascular problems, and cold weather is far more dangerous than warm weather for people with heart problems. In cold weather, the body automatically constricts blood vessels to conserve body heat. That raises blood pressure and doubles the heart attack risks of people with high blood pressure.

People with hypertension also suffer increased risk because they have over-reactive blood vessels; their blood vessels constrict even more than the average person's when temperatures drop suddenly.

A study of Siberian health records between 1982 and 1993, where stroke rates are among the highest in the world, found a 32 percent higher stroke risk on cold days than on warm ones.

Korean evidence shows much the same pattern. Cold periods were associated with higher risks of strokes, "with the strongest effect being seen on the day after exposure to cold weather."

Cold Causes Respiratory Problems

Similarly, numerous studies from around the world show a connection between cold weather and respiratory diseases.

A Norwegian study found 47 percent more respiratory deaths in winter than in summer. In London, a 1º C drop in mean temperature (below 5º C) was associated with a 10.5 percent increase in all respiratory disease consultations. In Brazil, the adult death rate changes due to a 1º C cooling were twice as great as death rate changes due to a similar warming--and 2.8 times greater among the elderly.

In the United States, temperature variability is the most important element of climate change related to respiratory deaths, though the reasons for this do not seem to be clear to physicians. The risk from temperature variability is important to our analysis, nonetheless, because a 50-year study of 1,000 U.S. weather stations found temperature variability declines very substantially with climate warming. This means the benefit of warming should extend throughout the entire year.

Warmer Is Healthier

In London, low temperatures made the only significant weather-related impact on both immediate deaths (one day after the temperature extreme) and medium-term mortality (up to 24 days after the extreme).

Closely allied studies looked at mortality of the elderly (65 to 74 years) in north Finland, south Finland, southwest Germany, the Netherlands, greater London, northern Italy, and Athens, Greece. They found annual cold-related deaths were nearly 10 times greater than annual heat-related deaths.

All this evidence makes clear the fact that warmer is healthier than colder. Yet alarmists persist in claiming a moderate warming trend is bad for people, even killing some of us. The truth, surely, is the opposite.


Unstoppable Global Warming Every 1,500 Years, by S. Fred Singer and Dennis T. Avery, is available from Rowman & Littlefield publishers.