If Sterl's predictions hold true, what might the impact be? Looking at
historical records, a good comparison point would be the French heat wave of
2003, in which temperatures hit 104° F, killing nearly 15,000, with mortality
rates especially high among the elderly. A similar heat wave in Chicago
in 1995 raised temperatures to 106° F killing about 600 people.
Mr. Sterl remarks jokingly that in the future we will look back on these heat
waves, "And we will laugh. We will find (those temperatures) lovely
The computer model developed by Sterl is cutting edge and draws on his team's
sizable climatological experience to model the past, present, and future.
While the study does not disagree with the international scientific consensus
on the more moderate standard temperature rises, it reveals an interesting
previously unconsidered aspect of the warming process -- its effect on heat
The new study found that for normal temperature rises, heat wave temperature
rises will increase twice as fast. Once-in-a-generation heat waves in
Chicago will reach 115° F according to the model, in Paris 109° F, and Lyon
When these heat waves hit, according to Sterl they will be particularly
damaging due to their drying effects. They will do much more damage
than daily temperatures, he indicates.
He finds that LA will be at 117° F during a heat wave and Atlanta may seem
temperatures of 110° F; in each case, this is 5 degrees higher than either city
has ever seen. Kansas City could get as hot as 116° F, 7 degrees hotter
than the current high of 109° F, according to the National Climactic Data Center.
New York will have a more modest jump from an all time high of 104° F to 106°
F. Some cities will not get much hotter, but will just see highs more
frequently, such as Phoenix, Arizona, which has hit 122° F, and will be
regularly hitting in the 120s.
Worldwide, other countries will be hit much harder. Delhi, India will
reach 120, Belem, Brazil 121, and Baghdad a toasty 122. Ken Kunkel, a top
Midwestern climate scientist and interim director of the Illinois Water Survey,
says that the figures derived from the study check out.
University of Wisconsin environmental health professor Dr. Jonathan Patz
comments that the results disturb him as those temperatures are extremely
dangerous to the human body. Said Patz, "Extreme temperature
puts a huge demand on the body, especially anyone with heart problems.
The elderly are the most vulnerable because they don't sense temperature as
Even before the end of the century, we should be seeing similar effects says
Sterl. By 2050, heat waves will rise 3 to 5 degrees in temperature and
will "probably be longer lasting", according to his findings.
Sterl used France as a benchmark for the increases. In the 1950s, the
worst heat wave expected was 91° F, by 1990s it rose to 104° F. By 2050
he expects the worst heat wave to be at 111° F, and by the end of the century
southern France will likely hit 118° F during a heat wave.
As human body temperatures of 104° F are considered life threatening and 113° F
typically fatal, if such heat waves occur the human body will likely sweat
excessively to try to exhaust heat. This can lead to dehydration and
drops in blood pressure. Many medications taken for common illnesses
interfere with the body's ability to perspire, which could yield death under
such extreme conditions.
There have also been numerous studies linking heat wave temperatures to crime sprees;
as it appears abnormally high temperatures have psychological effects,
increasing the rate of criminal acts.
The study will soon be published in the Geophysical
Research Letters journal.