Report Gives Climate Context to Midwest Storms, Flooding

Island Press released a new technical report detailing climate change impacts in the Midwest that puts recent extreme weather into the climate context. The report is one of a series of technical inputs to the Third National Climate Assessment.

Its timing is especially relevant given the torrential rainfall, two to three times the historical average for June in some areas, which left parts of the region inundated. Cities including Sioux City, Iowa, have set all-time rainfall records. The Midwest technical report warns that climate change may be worsening flood events like this one.

The report states:

• Precipitation in the Midwest has been increasing since the 1930s. This has included both an increase in overall precipitation and an increase in extreme precipitation events.
• Flooding is a major economic risk in the Midwest. The 1993 Mississippi flood was the costliest flood in modern times after Hurricane Katrina. In 2008, another flood in Cedar Rapids incurred over $10 billion in damages.
• These historic floods were caused by persistent heavy rainfall. Research shows that the trend towards heavier rainfall events has resulted in an overall increase in flood risk across the region.
• The risk of levee failure is a significant hazard, as the Midwest contains nearly 4,000 miles of levees, many of which are in poor condition.

The technical report adds more regional detail to the conclusions of the National Climate Assessment, which listed the following as a “Key Message” for the Midwest:

“Extreme rainfall events and flooding have increased during the last century, and these trends are expected to continue, causing erosion, declining water quality, and negative impacts on transportation, agriculture, human health, and infrastructure.”

Climate impacts identified in both reports are already causing trouble in towns like Newport, Minn. The town’s 50-year-old levee is at risk of an abrupt breakage that would endanger homes. Minnesota’s Sen. Amy Klobuchar has called the damage “unprecedented” and said that some counties have lost 40% of their crops due to the floods.

For projections farther into the future, see the recently released “Risky Business” report, led by important economic figures including Michael Bloomberg and Hank Paulsen. Their findings project that under business-as-usual warming and without adaptation, the Midwest region faces a likely 63% decline in agricultural yields by the end of the century.  This projected decline is due to a variety of impacts including extreme precipitation.

Source: Climate Nexus