Comfort Indices

Warmer days are ahead

Illinoisans may more frequently experience high temperatures that we now see only rarely and are not used to. The Union of Concerned Scientists predicts that:

• Chicago's current 8 days above 90 degrees may increase to 30 days with moderate temperature increases, or 70 days per year under high emissions scenarios by the year 2100.
• Instead of our average of one day per year above 97 degrees, we could see between 15 days (moderate temperature changes) to 50 days (substantial temperature changes).

Definitions of extreme weather will change

Illinois will see more extreme weather events as the temperature increases. These include heat waves, extended heavy rainfall periods, and flooding. However, the frequency of severe thunderstorms and tornadoes is not expected to be affected by climate change.

Increasing temperatures and flooding will cause us to redefine terms such as "100-year flood" and "20-year heat wave," events that happen statistically only every 20 or 100 years. Our changing adaptations will mean adaptation to new conditions and could pose a problem for insurance companies, who use these standard definitions in calculating risk.

Part of this adaptation will include shifting our energy use from heating to cooling. A 3-degree Fahrenheit temperature increase is expected to cause cooling energy demands to increase 5 to 20%, while heating energy demands would decrease by 3 to 15%, according to the U.S. Climate Change Science Program.

Our streets may flood

Flooding is a particularly significant problem, as it may block roadways and could cause sewer backups. Champaign experienced such backups in February of 2008 and following Hurricane Ike in September 2008.

The Union of Concerned Scientists predicts that by the end of the century, we will see a doubling of frequency of heavy rainfall events. These events are defined as extreme amounts of rain over both 24-hour and 7-day periods.

Infrastructure

Extreme weather events, such as floods, may cause more property damage, which will increase the cost of cleanup and rebuilding. These events will place larger burdens on emergency management services, forcing us to adapt our infrastructure.

In addition, we will need to update water-related infrastructure, such as levees, sewer pipes, and water-treatment plants to cope with flooding and increased pollution due to runoff.

Tourism

The summer recreation season is expected to see increases as warmer temperatures will last longer. This may bring increases in revenue from fishing, beach visitors, boaters, and birders.

However, increased pollution may affect Lake Michigan and other vacation lakes, and changing fish populations may affect the fishing industry.

The quick gauge

• We could see 30 to 70 days per year above 90 degrees.
• Energy costs will shift from heating to cooling.
• Flooding problems may force changes in infrastructure.
• Summer tourism may benefit, provided pollution of lakes isn't a problem.

Over 50 home-related sanitary and storm sewer backups were reported by residents."

-The City of Champaign on its September 14, 2008 flooding.

"The next several decades will almost certainly see continued increases in heavy rainfall."

• The Union of Concerned Scientists