Arguments
This June was the hottest ever, and July has brought even more heat, particularly in the Midwest. Credit: NOAA
Sizzling Midwest Previews a Hotter Future Climate
Posted on 29 July 2016 by Guest Author
This is a re-post from Inside Climate News by Bob Berwyn
Extreme heat waves like the current string of scorching days in the Midwest have become more frequent worldwide in the last 60 years, and climate scientists expect that human-caused global warming will exacerbate the dangerous trend in coming decades. It comes with potentially life-threatening consequences for millions of people.
Research has shown that overall mortality increases by 4 percent during heat waves compared to normal days in the U.S. A study in the journal Environmental Health Perspectives in 2011 suggested that rising summer temperatures could kill up to 2,200 more people per year in Chicago alone during the last two decades of the 21st century.
"The climate is changing faster than we've ever seen during the history of human civilization on this planet, and climate change is putting heat waves on steroids," Katharine Hayhoe, director of the Climate Science Center at Texas Tech University, said during a news conference on Thursday. "Heat waves are getting more frequent and stronger."
Temperatures this week soared into the 90s from Minnesota to Iowa, combining with high humidity to send heat indices well above the 100-degree Fahrenheit mark, considered a threshold for conditions dangerous to human health.
Current temperatures in large parts of the Midwest have been rising steadily for more than 100 years, with accelerated warming in the past few decades. According to the 2014 National Climate Assessment, the average temperature in the region increased by more than 1.5 degrees Fahrenheit between 1900 and 2010. Between 1950 and 2010, the rate of increase doubled, and since 1980, the pace of warming is three times faster than between 1900 and 2010.
But while the Midwest joins the overall warming trend, it has not been hit frequently by summer heat waves, according to Ken Kunkel of NOAA's National Centers for Environmental Information
"The Midwest has not experienced any substantial summer warming and this spills over into heat waves," he said. "The period of most heatwaves for the Midwest remains the 1930s Dust Bowl era." In North America, there has been an increase in heatwaves west of the Rocky Mountains, but to the east, generally not, he said
That leads to fears that the region is unprepared for the dangerous impacts of a stretch this hot. The lack of preparedness was a big reason a heat wave in Europe in 2003 was so deadly, killing more than 70,000 people.
"We see the biggest impacts when we have multi-day events," Hayhoe said. "And when nighttime temperatures don't cool off enough to give us a respite, that's when we start to see an impact on health. Especially the elderly and people with respiratory problems start flooding emergency rooms."
"The bottom line is we face a new normal and we're adapting to it on the city and regional level," said Christopher B. Coleman, mayor of St. Paul, Minn., and co-chair of the Mississippi River Cities & Towns Initiative. Also speaking during the press conference, he called the Mississippi River Valley an "acute climate impact zone," and said some of the less obvious impacts of extreme heat includes urban stormwater runoff that creates thermal pollution when it hits hot pavement.
The Midwest heatwave is peaking just as NOAA announced that last month was the warmest June on record for Earth. It was the 14th consecutive month that the average global temperature record was broken, making it the longest streak of record-warm months in 137 years, according to the agency's monthly state of the climate report. Averaged across land and sea surfaces, the global temperature was 1.62 degrees Fahrenheit above the 20th century average, topping the record set just last year. The last time the global temperature for June was below average was in 1976.
"The health consequences of climate change run an entire gamut, from worsening chronic disease, to an increase in vector and waterborne illnesses and disruption to food safety," said Rev. Miriam Burnett, president of Resource and Promotion of Health Alliance, Inc, a faith-based nonprofit focusing on public health in African-American communities. Extreme heat events even have social consequences, including putting strain on human interactions and generating anger and hostility, she said.
Scientists say there's little doubt that the buildup of heat trapping greenhouse gases is already causing more deadly heat waves worldwide. The increase has been widely documented and summarized in the latest Intergovernmental Panel on Climate Change assessment.
The heat wave in the mid west is clearly very concerning and very intense. Global warming is expected to significantly increase both numbers of heatwaves, and / or intensity and duration and the science is compelling.
The article seemed to imply numbers of heat waves have not increased in the mid west, but didn't mention intensity and whether theres been an increasing trend measured so far. Does anyone know?
The largest problem is very high temperatures combined with humidity, as its harder to cool down because sweating is reduced. We know atmospheric moisture has increased so it seems inevitable heatwaves will become more uncomfortable, but has any trend been found so far?
Preparedness is the key. Cities such as Dubai experience an average maximum temperature well above 40 degrees in summer but becauise the population has adapted there are far less heat related deaths than we might expect.
I'm surprised that many cities don't invest more in heat reduction strategies given the risks and forecasts. Many major cities are currently several degrees ++ warmer than surrounding rural areas, and UHI accounts for up to 2x the increase due to global climate change.
IOW, Even if we find a cure for climate change there remains a serious problem for major cities during summer months.
@ nigelj : >>The largest problem is very high temperatures combined with humidity, as its harder to cool down because sweating is reduced. <<
I know where you are coming from, but sweating is not reduced - it increases greatly. Evaporation, cooling, is what is reduced.
This discussion of inevitable increase in heat waves and how they affect people provides some insight into a predicament that is bound to get worse in many global regions. However, there is a factor that will make the situation much more serious than depicted n this article. Society is very dependent on the services (such as air conditioning, the water supply, etc) provided by the existing infrastructure. This aging infrastructure uses irreplaceable materials for its operation and maintenance so the ineviable decline in the services it provides will make it harder for society to cope with the increase in heat waves and other manifestations of climate change (such as sea level rise).
I don't understand this quote: The Midwest has not experienced any substantial summer warming and this spills over into heat waves," he said. What spills over into heat waves? The lack of experience?
Also, can someone explain "thermal pollution"?
Thank you!
Eksommer,
As I understand it, the Midwest has warmed more in the Fall, Winter and Spring than it has warmed in the Summer. Since they have not warmed much in the summer yet, they have not seen an increase in summer heat waves. The lack of increase in summer heat spills over into a lack of summer heat waves. Several years ago in spring there was a midwest heat wave where in several locations the minimum temperature at night was higher than the previous highest temperature measured during the day had been. That "heat" wave was not noticed by the general public much because the absolute temperature was not as hot as it gets in summer.
Thermal pollution is heat released into the enviroment. For example a central power plant heats up the cooling water that it returns to the environment. Black streets contribute thermal pollution to urban centers and cars release a lot of heat from the tailpipe. This heat is much less than global warming from carbon dioxide but can have severe local effects (for example if a river is increased in temperature by several degrees that affects the local fish). Occasionally the effects are positive. In Florida manatees like the warm water outflows from power plants in the winter.
"As I understand it, the Midwest has warmed more in the Fall, Winter and Spring than it has warmed in the Summer. Since they have not warmed much in the summer yet, they have not seen an increase in summer heat waves".
Perhaps that's an expected consequence of a falling temperature gradient between the equator and the N pole. (?)
The situation is different in Australia for a variety of reasons but it's nonetheless interesting to note that far more high temperature records are being set in urban areas than rural, and even with "angry summers" the pre 1980 state records have not yet been superseded.