http://www.swissinfo.org/sen/swissin...43&sid=5141817

Heat waves to worsen across Europe

By Maggie Fox, Health and Science Correspondent

WASHINGTON (Reuters) - Heat waves like those that have hit Paris and
Chicago in recent years are likely to get worse, roasting more and
more cities with ever-higher temperatures, climate researchers have
predicted.

While some may like it hot, the forecast means misery for many, and
hotter weather can affect crops, drive up fuel prices and can kill the
old
and weak. The heat wave that hit France a year ago killed an estimated
15,000 people.

A similar heat wave that hit the U.S. Midwest last year damaged the
corn and soy crops, and 739 people died in a head wave that broiled
Chicago in 1995.

Using a new computer model that takes into account increasing levels
of greenhouse gases such as carbon dioxide, Gerald Meehl and
Claudia Tebaldi of the National Centre for Atmospheric Research in
Boulder, Colorado, found heat waves might become more common as
global warming heats the Earth.

Writing in the journal Science, they said they tried to see if other
pollutants such as sulphur dioxide might reflect sunlight away from
the
planet and perhaps offset some of the heat-trapping properties of
carbon dioxide. But their model shows no such effects.

Regions already prone to heat waves, such as the U.S. Midwest and
Southeast and Europe's Mediterranean areas, will suffer even more,
and longer, the model predicts.

The average Paris heat wave lasting eight to 13 days, they predict,
will last 11 to 17 days. In Chicago, heat waves will last on average a
day
longer, from eight days to nine days, and there will be two a year by
2080 instead of about one.

"But other areas (e.g. northwest United States, France, Germany and
the Balkans) could see increases of heat wave intensity that could
have more serious impacts because these areas are not currently as
well adapted to heat waves," the researchers wrote.

For their study, Meehl and Tebaldi used data from 1961 to 1990 to
predict future weather patterns in 2080 to 2099. They assumed there
will
be few policy changes to affect global warming.

During the Paris and Chicago heat waves, atmospheric pressure was
higher than usual over Lake Michigan and Paris, producing clear
skies and hot days, with little relief when the sun went down.

A COOLING SOLUTION

Another team of scientists said that governments can turn this pattern
around right now, if they choose to.

Stephen Pacala and Robert Socolow of Princeton University identified
15 technologies, from wind, solar and nuclear energy to conservation
techniques, that could each help reduce global warming.

Their report, also published in Science, counters the common argument
that a major new technology needs to be developed before
greenhouse gases can be controlled, said Pacala.

"It certainly explodes the idea that we need to do research for a long
time before getting started," Pacala said in a statement.

"If we decide to act, we will need to reduce carbon emissions across
the whole global economy," added Socolow.