Policy Peril Segment 1: Heat Waves

by Marlo Lewis on July 27, 2009

As announced last Friday, each day this week and next I’ll post an excerpt of CEI’s film Policy Peril: Why Global Warming Policies Are More Dangerous Than Global Warming Itself. The film is our antidote to Al Gore’s An Inconvenient Truth . If you want to watch Policy Peril in its entirety, click here.

Today’s segment is on heat waves. Gore and others claim that global warming will make heat waves more frequent and severe, leading to a massive increase in heat-related mortality. Click here to watch the Policy Peril segment on heat waves.

Here’s the text:

Narrator: We often hear that global warming will increase the frequency and severity of heat waves. People will drop like flies! Sounds plausible, doesn’t it? But wait a minute. Summer air temperatures in U.S. Cities have been rising over the past three decades, in part because cities generate heat islands, which expand as cities grow. Yet heat-related mortality has gone down.

Dr. Patrick Michaels (Cato Institute): Bob Davis and I did some work at UVA [University of Virginia] on heat-related mortality, and published it in the refereed literature, showing that the more frequent heat waves are, the fewer people die. That’s because they adapt. And in the average American city–the average of all American cities–heat-related mortality is going down, significantly, not up.  In fact, in the cities in the southern United States–Phoenix, which has a very old population, Tampa–there’s hardly any heat-related mortality at all.

Narrator: As long as politicians don’t make electricity so costly that low-income households can’t afford to run their air conditioners, heat-related death rates should continue to decline, even in a warming world.


In An Inconvenient Truth (p. 75 of the book version), Gore states, “We have already begun to see the kinds of heat waves that scientists say will become more common if global warming is not addressed. In the summer of 2003 Europe was hit by a massive heat wave that killed 35,000 people.”

Gore implies that global warming killed 35,000 people. Yet heat waves have occurred in Europe (and elsewhere) from time immemorial. How does Gore know that global warming caused the 2003 heat wave? Or, if global warming was a contributing factor, how does Gore know how much extra oomph the 2003 heat wave got from global climate change?

In fact, it is impossible to link any single heat wave or other extreme weather event to global climate change.

However, if global warming were responsible for the 2003 Europe heat wave, we would at least expect that, globally, the summer of 2003 would have been a hot one. In fact, the 2003 summer was about average or slightly cooler than average compared to the previous 23 summers.

During June, July and August of 2003, more than half the planet was cooler than the mean temperature of the period from 1979 through 2003. Europe–a tiny fraction of the Earth’s surface–was the only place experiencing unusual heat. See the Figure below.


Figure description: 1000-500 mb thickness temperature anomalies for June, July, and August 2003. Colors (violet to red) indicate standard deviations below, at, and above the mean summer temperature for 1979-2003. Sources: Chase et al., 2006, World Climate Report

There is a simpler, natural explantion for Europe’s hot summer: An atmospheric circulation anomaly trapped a bubble of hot dry air over Europe for several weeks. Here is what the United Nations Environment Program–hardly a bunch of global warming skeptics–had to say:

This extreme weather was caused by an anti-cyclone [high pressure system] firmly anchored over the Western European land mass holding back the rain-bearing depressions that usually enter the continent from the Atlantic Ocean. This situation was exceptional in the extended length of time (over 20 days) during which it conveyed very hot dry air from south of the Mediterranean.

Chase et al. (2006), a team of scientists from Colorado and France, found nothing “unusual” about the 2003 Europe heat wave that would indicate a change in global climate conditions. Among their conclusions: 

  • Extreme warm anomalies equally, or more unusual, than the 2003 heat wave occur regularly.
  • Extreme cold anomalies in the summer months also occur regularly and occasionally exceed the magnitude of the 2003 warm anomaly in standard deviations from the mean.
  • Natural variability in the form of El Nino and volcanic eruptions appear to be of much greater importance in causing extreme regional temperature anomalies than a simple upward trend in time.
  • Regression analyses do not provide strong support for the idea that regional heat waves are increasing with time.  

The death toll in the Europe 2003 summer heat wave was shockingly high–but part of the blame falls on Europe’s historic distaste for air conditioning and the fact that many able-bodied Europeans go on vacation in August, leaving the elderly and infirm to fend for themselves.

Dr. Patrick Michaels, the expert I interviewed for the Policy Peril segment on heat waves, points out that a heat wave of similar magnitude hit France (the epicenter of the 2003 heat wave) in 2006, yet the death toll was about 2,000 people–almost 4,400 less than the standard weather-mortality model would predict. The reason, Michaels argues, is that the 2003 heat wave taught the French a big fat lesson about air conditioning and spurred public and private action to make people safer:

In response to the tragegy of 2003, the French government implemented the National Heat Wave Plan that included a “set-up of a system of real-time surveillance of health data, compilation of scientific recommendations on the prevention and treatment of heat-related diseases, air conditioning equipment for hospital and retirement homes, drawing up of emergency plans for retirement homes, city-scale censuses of the isolated and vulnerable, visits to those people during the alert periods, and set up of a warming system.” In other words, France adapted to the heat wave by providing information to the population at-large and air conditioning to the most vulnerable. No doubt people were also personally more aware of the dangers of summer heat in 2006 than they were three years earlier.

In the United States, heat-related mortality has been going down, decade by decade, even as urban summer air temperatures have increased.


Figure explanation: Population-adjusted heat-related mortality for 28 maor cities across the United States. Each bar of the histogram for each city represents a different 10-year period. The left bar represents heat-related mortality in the 1960s/70s, the middle bar represents the 1980s, and the right bar is the 1990s. No bar at all (in cities like Phoenix and Tampa) means no statistically significant heat-related mortality during the decade. Source: Davis et al. (2003), Changing heat-related mortality in the United States.

 There is no reason not to expect these trends to continue. Think about it this way. Adaptation is what human beings by nature do. There are very few Eden-like spots on Earth where people can survive and thrive without housing, clothing, and agriculture–all forms of adaptation. In free societies especially, people constantly adapt (innovate, experiment, modify private behavior and public policy) to improve their health, safety, and comfort.

If global warming makes more U.S. cities more like Phoenix or Tampa, we can reasonably anticipate that more cities will have heat-mortality rates like Phoenix and Tampa–practically zero!

For a useful overview of the scientific literature, see the U.S. Chamber of Commerce’s comment on EPA’s proposed endangerment finding. The Chamber draws the common-sense conclusion: “Overall, there is strong evidence that populations can acclimatize to warmer climates via a range of behavioral, physiological, and technological adaptations” (p. 4).

Air conditioning is one of the great health-enhancing, life-saving technologies of the modern world. Air conditioners run on electricity. What we really have to worry about, especially in a warming world, is that politicians will adopt energy policies–actually, anti-energy policies–that force low-income households to turn off their air conditioners in hot weather.

The cap-and-trade bill Congress is now debating, the Waxman-Markey bill, named for its co-sponsors Rep. Henry Waxman (D-CA) and Ed Markey (D-MA), would function as a massive energy tax, driving up the cost of gasoline, heating oil, and electricity. A study by the Heritage Foundation finds that Waxman-Markey would increase annual household electricity costs by $468. At the same time, many household incomes would decline as GDP drops by up to $300 billion per year. Similarly, Charles River Associates, in a study for the U.S. Black Chamber of Commerce, estimates that Waxman-Markey would increase electricity prices while decreasing average household purchasing power by $730 in 2015, $800 in 2020, and $830 in 2030. This is a recipe for sickness and death.

It’s just one reason our film is subtitled, “Why Global Warming Policies Are More Dangerous Than Global Warming Itself.”

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