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Heat wave 2012: NIU meteorology professor says lives were saved by lessons learned in 1995

July 12, 2012

The heat wave in the Chicago region early this month would likely have been even more deadly if not for lessons learned from the lethal hot spell of 1995, according to NIU Board of Trustees Professor David Changnon.

Dave Changnon

Meteorology Professor David Changnon

Changnon, a professor of meteorology in the Department of Geography who conducted research on the infamous ’95 heat wave, says this month’s string of brutally hot days was remarkably similar in terms of seasonal timing, duration, high temperatures and warm daily low temperatures.

The 2012 heat wave from July 4 to July 7 has been blamed for nearly 20 deaths in the Chicago region. In comparison, the 1995 heat wave from July 12 to July 16 was blamed for more than 700 deaths. It went down as one of the worst weather-related disasters in Illinois history.

“If you were to dissect the two heat waves, they weren’t drastically different,” says Changnon, a leading scholar in applied climatology, which focuses on the human and societal impacts of climate and climate change.

“Still, the 1995 heat was an oh-my-God moment—most people had never lived through anything like that,” he says. “We learned some hard lessons.”

As a result, meteorologists, government agencies and members of the public make more informed decisions, react more quickly and are better prepared. Weather forecasters, for instance, are now better equipped and more proactive with advanced warnings.

“We’ve gotten better at telling the story, not only to the general public but also to key decision makers who need to take precautionary actions on behalf of the public,” he says.

Government agencies nowadays are prepared with emergency plans that identify at-risk populations in advance and provide for accessible, 24-hour cooling centers. “Emergency efforts are much more proactive than in the past,” Changnon says. “They knock on doors.”

Citizens, too, are more aware of the danger.

“The 1995 heat wave shocked the heck out of us,” Changnon says. “People began to realize that hot and humid conditions could kill them. Hot temperatures during the day are bad, but the real problem is when it doesn’t cool down at night. Our bodies don’t have a chance to recover.”

Despite the improved awareness, heat waves still kill more Americans during an average year than hurricanes, tornadoes and blizzards combined.

Is global warming the culprit?

Changnon says it’s not just the July heat wave that has made 2012 an extraordinary year for warmth. In fact, Illinois has experienced the warmest first six months of the year ever recorded (with records dating to 1895).

“It has been warm in every month of the calendar year,” says Changnon, adding that we can expect more heat this summer. “We still haven’t hit the warmest time, which is usually the last couple weeks of July. So chances are good that we’ll see another extended period in the 90s or higher.”

Also of major concern is the agricultural drought, which is drawing comparisons to its 1988 counterpart. That drought caused substantial crop losses for Illinois farmers.

“The hot temperatures and lack of rain wreak havoc on corn crops,” Changnon says. “If we don’t get rain soon, we’re going to be in trouble.”

The sultry summer has many people speculating that global warming is somehow involved. But a single hot spell or warm year can’t be connected to climate change with any certainty.

“This recent heat wave was an extreme climatological event,” Changnon says. “If these types of extreme warm events begin to occur more frequently in years to come, then it would suggest that our temperature distribution has changed and a new climate mean state has developed.”