US Midwest cities to sweat - experts

2012-07-25 10:27

Chicago - Dangerously hot summer days have become more common across the US Midwest in the last 60 years, and the region will face more potentially deadly weather as the climate warms, according to a report issued by the Union of Concerned Scientists on Wednesday.

The report looked at weather trends in five major urban areas - Chicago, Cincinnati, Detroit, Minneapolis and St Louis - along with weather in nearby smaller cities such as Peoria, Illinois, and Toledo, Ohio. The report focused on the Midwest because of its numerous major population centres, and because it is projected to face more heat waves with climate change.

The report found that the number of hot, humid days has increased, on average, across the Midwest since the 1940s and 1950s, while hot, dry days have become hotter.

Finding relief from the heat during the summer has become more difficult, as all the cities studied now have fewer cool, dry days in the summer, and night time temperatures during hot periods have risen.

"Night time is typically when people get relief, especially those who don't have air conditioning," said Steve Frenkel, Union of Concerned Scientists' Midwest office director. "The risks of heat-related illness and death increase with high night time temperatures."

Heat waves

The report found that heat waves lasting three days or longer have become more common. St Louis, for example, has more than doubled its number of three-day heat waves since the 1940s. Studies have linked at least three consecutive days of high temperature and humidity to more deaths.

Extreme heat and humidity can be lethal. In Chicago, more than 700 deaths were attributed to a heat wave in July 1995. More recently, extreme heat in Russia in 2010 led to an estimated 55 000 deaths.

With more extreme summertime heat, annual deaths in Chicago are projected to increase from 143 from 2020 - 2029 to 300 between 2090 - 2099, according to the report.

The report warned that conditions could get much worse if emissions of gases believed to cause global warming continue at their current pace, or at a higher pace.

Chicago, for example, could see more than 70 days with temperatures of 32°C each year toward the end of the century, on average, if emissions continue at the current pace.

Under a higher-emissions scenario, dangerously hot days over 38°C in Chicago could increase dramatically, producing a month of such days, the report said.

Hot, humid temperatures are tougher on the elderly, whose percentage in the population is increasing. About 20% of US residents are projected to be over age 65 by 2030, up from about 13% now, according to the report.

Warming trend

"We must take preventative measures to protect public health during extreme heat events, but the only way to ensure these heat waves are not a threat in the future is by reducing the harmful emissions that are driving them in the first place," said Frenkel.

Though the study focused on weather in the last six decades through 2011, the summer of 2012 has so far reflected a continued warming trend.

June temperatures contributed to a record-warm first half of the year and the warmest 12-month period the nation has experienced since recordkeeping began in 1895, according to the National Oceanic and Atmospheric Administration.

In the Midwest, the US corn yield is seen at a 10-year low due to an expanding drought.

  • robin.stobbs.9 - 2012-07-25 10:48

    Beware of 'experts'! These are the people who get to know more and more about less and less until they know everything about nothing! 'It's true that the U.S. droughts of 1950s and 1930s were worse than the current one, at least so far' ...... And this was written by a warmist/alarmist!

      robin.stobbs.9 - 2012-07-25 11:04

      And more .......the assertion of the National Aeronautics and Space Administration, a chief purveyor of the man-is-guilty hypothesis. Its website states: "… temperature anomaly in one place in one season has limited relevance to global trends. Unfortunately it is common for the public to take the most recent local seasonal temperature anomaly as indicative of long-term (global) climate trends." While the US Mid-West sweats Europe has shivered - go figure!

      ernst.j.joubert - 2012-07-25 11:49

      @Robin: Robin may I make a suggestion to you: Contact the top scientists in the world that are working in climate science and ask them what their opinions are on the issue.

  • ernst.j.joubert - 2012-07-25 11:32

    @Robin.stobbs: "While the US Mid-West sweats Europe has shivered - go figure!" You clearly dont understand the concept of average. Didnt they teach you that in school? The global average temperatures are going up. This does not mean that there will be no cold days across the globe.

      robin.stobbs.9 - 2012-07-25 11:54

      Oh shame! Since when does one use averages for global temperature variations? If your room is 20°C at the ceiling and 30°C at floor lever how can you possibly say that the average temperature of this room is 25°C? Come on man - do some real reading - there are no averages (sic) in the natural sciences.

      ernst.j.joubert - 2012-07-25 12:28

      @Robin: Global average temperatures are going up. Mathematically, the only way that this can happen is if your record highs start overshadowing your record lows; meaning that there is a warming trend. Your logic of "Well Europe is freezing therefore there is no global warming" is incorrect.

      ludlowdj - 2012-07-25 12:33

      There is no global increase in temperature, while some localized areas are experiencing higher temperatures other areas are experiencing much colder than normal temperatures. The GLOBAL average has not changed in 10 years, as verified and published by the 16 top climate and earth science scientists who are active in this field.

  • ludlowdj - 2012-07-25 12:28

    Global warming?? there has been no increase in the global temperature in the last 10 years, just because the mid west sweats doesn't mean that any other area is suffering the same fate or that there will be any increase in the annual temperature for this year either.

      robin.stobbs.9 - 2012-07-25 13:59

      Right. There is no such thing as a "global" temperature. Gee! Which orifice would one insert the "global thermometer"? Again; there is no global "average" temperature though we often think of an 'average' when we mean a 'mean'. Glad there are more thinking people here!

      Stirrer - 2012-07-25 17:02

      @Robin: "Which orifice would one insert the 'global thermometer'?" Pretoria. It's a s#!thole.

      douglas.hollis.7 - 2012-07-30 23:50

      I refer you to the following articles: I'd be interested to hear your thoughts?

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