This week’s episode of EnvIowa features a discussion with CGRER co-director Dr. Jerry Schnoor. He is, among other things, a professor of civil and environmental engineering with a long career studying climate change, water quality and environmental toxicology. Listen to hear Schnoor discuss the urgency of climate change, his efforts to clean up chemical pollution using plants and why he wants our youth to get angry.
Vegetation starts turning green earlier in cities than surrounding rural areas, but urban plants are less sensitive to unseasonable warmth, new Iowa State University-led research found. The authors attribute the difference to the urban “heat island” effect.
Cities typically have somewhat higher temperatures than surrounding rural areas because materials like asphalt and brick absorb heat more readily than natural landscapes. For example, New York City is about 7 degrees Fahrenheit warmer than surrounding areas in summer, according to NASA’s Climate Kids site.
Researchers found this “heat island” phenomenon causes urban vegetation to perceive the start of spring and begin greening an average of six days earlier than surrounding rural plants.
As climate change progresses, however, plants in both rural and urban areas are responding to unseasonably warm temperatures by beginning growth earlier and earlier over time. Pollinators and last frosts have failed to keep up, which has damaged the early bloomers’ ability to survive and reproduce.
The study found that rural vegetation is more sensitive to early spring weather than urban vegetation, perhaps due to the urban heat island effect as well.
ISU Ph.D. student Ling Meng led the research team, which included CGRER member Yuyu Zhou, an ISU geological and atmospheric scientist, among others. The study, published this month in Proceedings of the National Academy of Sciences, was based on satellite images from 85 large U.S. cities from 2001 to 2014.
Zhou told the Iowa State News Service that this sort of research can help predict how plants will respond to climate change and urbanization.
2019 was Iowa’s 12th wettest year on record, with an average of 41.49 inches of rainfall across the state, according to the state Department of Natural Resources. Rainfall in May, September and October was especially high, while the summer months experienced below average rainfall.
The two-year 2018/2019 period was the wettest on record, with 19 more inches of precipitation than average. Stream flows were above normal all 2019 following heavy snow in the winter months. The rainy spring and fall seasons are indicative of projected climate change models for the region.
2019 temperatures in Iowa were cooler than average, however, by 1.2 degrees Fahrenheit. During the January “Polar Vortex,”one station in Emmet County recorded a -59 degree windchill. Summer was slightly cooler than average, though July and September were warm, andChristmas week broke record temperature highs.
High temperatures on Wednesday, December 25 2019 broke records across the state of Iowa and much of the Midwest.
Des Moines reached 60 degrees, breaking the 1936 record of 58 degrees. Cedar Rapids reached 58 degrees, breaking the previous record of 54, according to Weather Underground.
The Christmas day highs were preceded and followed by unseasonably warm weather as well.
Though a 60 degree December day is not unheard of (the Des Moines Registerreports that at least one December day in Iowa has reach 60 degrees 29% of years since 1878), average winter temperatures in the Midwest are undoubtedly rising.
A Union of Concerned Scientists report shares that average annual winter temperatures in the Midwest have risen about 4 degrees since 1980. Winter temperatures are forecast to continue rising, while snow and days below freezing will decrease.
A new report from the Iowa Policy Project considers the roles equity should play when crafting policy for disaster response and mitigation.
“Frontline communities”–which feel the “first and often hardest” direct impact from a disaster like a flood or earthquake–have lower capacity to recover or mitigate, according to the report. This is in part because properties in these high-risk communities are cheaper, so residents are more likely to live below the poverty-line and belong to other disadvantaged socioeconomic groups.
“These communities are themselves set up for a disaster down the road and continuing downward spiral and being trapped where they are until the community can’t take it anymore and has scattered, or they’re just continually suffering over and over as these disasters strike,” the report’s author Joseph Wilensky told Iowa Public Radio.
Wilensky, a graduate student in the University of Iowa School of Urban and Regional Planning, reported that these “frontline” communities are less likely to receive full compensation for damages in as timely a manner as wealthier communities. He pointed to several examples from Iowa’s 2008 flood.
He also reported that allocation of Iowa’s watershed mitigation funds (both past and proposed projects) disproportionately benefits wealthier populations, as the cost-benefit method used favors protecting more expensive property, reducing economic damage.
Wilensky made several policy recommendations in the report as well. These include “rebalancing” the cost-benefit method to consider larger impact, considering whether mitigation efforts located outside of the frontline communities–which may qualify for less federal funding–could be helpful and hiring a state watershed coordinator to guide mitigation project applications.
Rising flood risk in Iowa and the Midwest due to climate change makes this report and its considerations especially pertinent.
FEMA will “de-accredit” 94.5 miles of levees in southwest Iowa and northwest Missouri unless owners make updates that ensure protection within new 100-year flood boundaries, the Des Moines Registerreported Wednesday.
The levees protect parts of Pottawattamie, Mills and Fremont counties, which experienced historic flooding this spring.
Affected communities have historically been located in FEMA’s 500-year floodplain, giving them a 0.2% chance of flooding in a given year (NOT flooding once in 500 years, as is a common misconception). Flood recurrence is calculated from historic averages, and increasing flood frequency due to climate change now puts those areas within the 100-year flood plain, making flood risk 5 times higher.
The floodplain updates take effect in the spring but levee owners have a few years to make updates before official losing accreditation. The Register reports, “It’s estimated that work to meet FEMA’s standards could cost upwards of $1 million per mile of levee,” a steep price for an area still recovering from the last round of floods.
The Register reported that nearly 1,500 home and business owners would need to purchase flood insurance in the spring the levees don’t receive updates. In such a high-risk area, insurance would become mandatory, and rates in some areas could increase 2600%, according to the Register.
A North Carolina mayor hopes to make his city more resilient against flooding following hurricanes using a method he learned from Iowa experts.
At the end of August, the Iowa Flood Center hosted a “flood resilience learning exchange” for 20 scientists, conservationists, farmers and officials from North Carolina communities impacted by devastating flooding from recent hurricanes. The two-day event featured talks from Iowan experts, a tour of Cedar Rapids’ flood infrastructure and a visit to a farm implementing such strategies.
News source kinston.com reported this week that Mayor Dontario Hardy of Kinston, North Carolina had been advocating for increased funding for flood resiliency projects since attending the event almost two months ago.
In just the past few years, Kinston–located along the Neuse River– faced widespread flooding after Hurricanes Matthew (2016) and Florence (2018). Though the Iowa Watershed Approach was not developed with hurricanes in mind, the basic concept–implementing conservation practices on land that will reduce the speed at which precipitation enters and floods our waterways– can apply to all types of flooding.