Extreme Rain from Thunderstorms is Rising Due to Climate Change


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Precipitation change in the U.S. from 1991 to 2012. (NASA)
Jake Slobe | Febraury 20, 2017

This week’s On The Radio segment discusses a recent study linking climate change and an increase in heavy rain events.

Transcript: An increase in extreme rain events could change the ways cities handle storm water management and flooding.

This is the Iowa Environmental Focus.

Rain is increasingly falling in the form of short, localized bursts associated with thunderstorms found a new study released in Science Advances late last month.

The study directly links this increase in heavy rain storms to the warming and moistening of the atmosphere caused by rising greenhouse levels.

The results fit with rainfall trends already observed in the U.S., as well as model predictions that massive rains associated with thunderstorms could become both more common and more intense in the U.S. as the world continues to heat up.

Extreme downpours have already been increasing in the U.S., most notably in the Northeast, where they have increased by 71 percent since mid-century, according to the 2014 National Climate Assessment.

Upon previous research which has also predicted an increase in extreme rain events due to climate change.

To learn more about this study, visit iowaenvironmentalfocus.org.

From the UI Center for Global and Regional Environmental Research, I’m Betsy Stone.

Iowa Falls family honored with sustainable agriculture award


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Wetlands can improve water quality and create habitat for wildlife on Iowa farms. (Scott Smithson/flickr)
Jenna Ladd | February 10, 2017

John and Beverly Gilbert were honored with the 2017 Practical Farmers of Iowa Sustainable Agriculture Achievement Award at last month’s Practical Farmers of Iowa Conference.

Practical Farmers of Iowa (PFI) is a non-profit organization dedicated to “strengthening Iowa farms and communities through farmer-led investigation and information sharing.” Each year PFI offers the Sustainable Agricultural Achievement Award to an individual or couple that demonstrates a strong commitment to practicing sustainable agriculture and sharing that knowledge with others, all while fostering community.

John and Beverly Gilbert of Iowa Falls keep a 770-acre farm featuring corn, soybeans, oats, hay, and some annual crops for forage. The family also milks 50 to 60 Brown Swiss cattle and keeps pastured-raised, antibiotic-free pigs that are sold to Niman Ranch.

The Gilberts’ farm borders Southfork stream, a tributary of the Iowa River. They have taken many measures to improve water and soil quality on their land including stream buffers, extensive grass headlands and waterways, and terraces. The farm also features woodland areas, a prairie marsh remnant, and a restored shallow wetland, all a part of the Gilberts’ conservation efforts.

John said, “The mindset has gotten so focused on raising corn and beans that not many understand the potential of this landscape to support people. I have long thought that if we can’t replace the number of people we have farming, there are serious problems ahead for society.”

Wendy Johnson, PFI board member and farmer near Charles City, commended the recognition of the family. She said,

“Their farming system, management and decision-making encompass all that is or should be good about Iowa: its air, water and soil. They protect these elements alongside creating a viable farming business for multiple families. Their farm is what PFI means to me: a sustainable farm on all levels.”

Study finds Iowa groundwater is extracted at unsustainable rate


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The Jordan Aquifer lies beneath most of Iowa; locations with water use permits for tapping into the aquifer are shown above. (Iowa DNR)
Jenna Ladd | February 7, 2017

A recent study found the groundwater in Iowa’s Jordan Aquifer to be much older than previously known, and scientists say that could have implications for water use in the state.

Researchers from the Iowa Geological Survey at the University of Iowa in collaboration with Grinnell College, the UI Geology Department and Iowa Department of Natural Resources used isotopic age dating to estimate the age of groundwater in the Jordan Aquifer. The study measured major and minor ions, stable isotopes (d18O and dD) and
the radioactive isotope Chlorine 36 in eight wells scattered across the aquifer. The peer-reviewed journal article explains that the groundwater in northern and central Iowa is somewhere between 70,000 to nearly 180,000 years old.

The study points out that ethanol production in the state relies heavily on groundwater from the Jordan aquifer, which also provides roughly 300,000 residents with drinking water. From 2003 to 2013, annual use of groundwater from the aquifer for ethanol production increased by 7.4 billion liters per year.

Keith Schilling is a research scientist at the Iowa Geological Survey at the University of Iowa and the study’s leading author. He said,

“The implications for biofuel refineries and any water use of the aquifer is the realization that the groundwater is very old. It is not going to be recharged in any human timeframes so we should make sure that water from the aquifer is being managed appropriately.”

Beyond the lagging groundwater regeneration rate, the study also notes that increased groundwater pumping can result in detrimental water quality changes such as radium contamination. The authors conclude with a call for new ethanol refineries to steer clear of the Jordan Aquifer and utilize more sustainable groundwater sources instead.

Climate change to decrease average number of mild weather days


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Residents enjoy pleasant weather at Noelridge Park in Cedar Rapids, Iowa. (Louis/flickr)
Jenna Ladd | January 24, 2017

The first of its kind, a recent study found that climate change is likely to decrease the number of “nice weather” days worldwide.

The authors of the study, scientists from the National Oceanic and Atmospheric Association and Princeton University, define “nice” or “mild” days as those days when temperatures are between 64 and 86 degrees Fahrenheit, dew points are below 68 degrees Fahrenheit and less than half of an inch of rain falls. Currently there are an average of 74 nice days globally per year, but that number is likely to drop to 70 in the next twenty years and to 64 by 2081.

Karin van der Wiel is a postdoctoral researcher at Princeton University and lead author of the study. She said,

“We used a climate model to simulate the current climate. In that simulation we counted the number of mild days. Then, we increased greenhouse gases in the climate model to simulate the future effects of climate change. This leads to increasing temperatures, changes in humidity, changes in precipitation over the whole world and with very specific patterns. In this new, future climate, we counted the number of mild days again. We could then calculate the change — increase or decrease — of mild weather days for each location globally.”

Not all corners of the Earth will be affected equally, however. Tropical regions are expected to lose the most nice days, with some areas losing up to 50 per year by the end of this century. Meanwhile, London is expected to gain 24 nice days each year.

Predictions for Cedar Rapids, Iowa mirror global averages. Eastern Iowa currently enjoys 76 nice days annually; researchers say that number is expected to drop to an average of 72 between 2016 and 2035 and to 66 each year between 2081 through 2100.

Frequent high humidity makes it tough for Iowa to meet the pleasant weather criteria outlined in the study. Absolute humidity has risen by 13 percent during the summer months in Des Moines since 1970, according to Iowa State climate scientist Gene Takle. Increased humidity also contributes to the extreme rain events that have plagued Iowa in recent years.

van der Wiel said, “Mild weather is something everyone knows, experiences, and has memories of,” she continued, “Our study shows that human-caused climate change is going to lead to changes in mild weather all over… The changes are happening now, and where people live.”

University of Iowa alumnus receives BBVA Frontiers of Knowledge Award


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University of Iowa Alumnus, James Hansen (Columbia University)
Jenna Ladd | January 17, 2017

University of Iowa Alumnus James Hansen has been honored with the BBVA Foundation Frontiers of Knowledge Award in the Climate Change category.

The BBVA Foundation promotes, finances, and developments research projects in Biomedicine and Health, Environment, Economy and Society, Basic Sciences and Technology, and Arts and Humanities on behalf of the BBVA Group, a multinational banking group headquartered in Bilbao, Spain.

Hansen received the Frontiers of Knowledge Award along with Japanese climatologist Syukuro Manabe. The two men independently developed the first computation models with the ability to simulate climate behavior, and pioneered the “use of these models to understand and project how Earth’s climate responds to changing concentrations of atmospheric CO2,” said the BBVA’s prize jury.

Originally from Denison, Iowa, Hansen earned his Bachelors, Masters, and PhD from the University of Iowa in Physics. He studied under renowned physicist James VanAllen in the space studies program in the late 1960’s. In 1967, Hansen joined NASA’s Goddard Institute for Space Studies. While researching planetary atmospheres at the Institute, Hansen was instrumental in establishing that Venus’ extremely hot temperatures were due to a greenhouse gas effect.

As CO2 levels in Earth’s atmosphere continued to rise throughout the 1970’s, Hansen shifted his focus and began to study the effect of CO2 on climate. He developed a computational model independently from Manabe, and his conclusions were published in the Journal of Science in 1981. The BBVA prize jury points out that this research was important because it was the first ever to incorporate global temperature data and to predict how global warming would affect other earth processes such as oceanic circulation and flooding.

Manabe said, “I started working with models earlier, but Hansen was the first to use these models to make predictions.”

Hansen served as Director of NASA’s Goddard Institute for Space Studies from 1981-2013. He is now an adjunct professor at Columbia University’s Earth Institute where he has led the Climate Science, Awareness and Solutions program since 2013.

On The Radio – Flood patterns changing across the U.S.


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The threat of moderate flooding is generally increasing in the northern U.S. and decreasing in the southern U.S., while some regions remain mostly unchanged. (American Geophysical Union)
Jake Slobe | January 9, 2017

This week’s On The Radio segment discusses changing flood patterns found by University of Iowa researchers.

Transcript: The risk of flooding is changing regionally across the United States and the reasons could be shifting rainfall patterns and changes in groundwater.

This is the Iowa Environmental Focus.

University of Iowa engineers, in a new study, have determined that the threat of flooding is growing in the northern half of the U.S. while declining in the southern half. The American Southwest and West, meanwhile, are experiencing decreasing flood risk.

UI engineers Gabriele Villarini and Louise Slater compiled water-height information from 2,042 stream gauges operated by the U.S. Geological Survey. They then compared the data to satellite information gathered over more than a dozen years by NASA’s Gravity Recovery and Climate Experiment mission showing the amount of water stored in the ground.

The study found that northern sections of the country have an increased amount of water stored in the ground and are at increased risk for minor and moderate flooding. Meanwhile, flood risk is decreasing in the southern portions of the U.S., where stored water has declined.

The researchers hope their findings can change how flood patterns are discussed. In the past, flood risk trends have typically been discussed using stream flow, or the amount of water flowing per unit time. The UI study views flood risk through the lens of how it may affect people and property and aligns the results with National Weather Service terminology understood by the general public.

For more information about the flood research, visit iowaenvironmentalfocus.org.

From the UI Center for Global and Regional Environmental Research, I’m Jerry Schnoor.

Natural disasters cost $175 billion in 2016, highest since 2012


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St. Antoine hospital in Jérémie, Haiti was among the structures damaged when Hurricane Matthew ravaged the country earlier this year. (CDC Global/flickr)
Jenna Ladd | January 6, 2017

Shortly after the New Year, German insurance giant Munich Re announced that natural disaster damages were higher in 2016 than they have been since 2012.

Insurance losses totaled $175 billion over the last twelve months, which is two-thirds more than in 2015. The company counted 750 natural disasters internationally, which includes “earthquakes, storms, floods, droughts and heatwaves.” The 6.9 magnitude Earthquake that shook southern Japan was the world’s most costly natural disaster this year, claiming $31 billion in damages.

North America was plagued with the most natural disasters it has seen since the 1980’s, it experienced a total of “160 loss events in 2016.” Spring heat waves in Canada led to wildfires in Alberta, costing the region $4 billion, while August floods in the southern United States racked up $10 billion in losses.

Flood events made up 34 percent of this year’s total losses. Comparatively, these events accounted for 21 percent of total losses over the last ten years. Flash floods in Germany and France cost the region almost $6 billion this year. Peter Hoppe, head of Munich Re’s Geo Risks Research Unit, said these increases are related to “unchecked climate change.”

Hoppe said, “Of course, individual events themselves can never be attributed directly to climate change. But there are now many indications that certain events — such as persistent weather systems or storms bringing torrential rains – are more likely to occur in certain regions as a result of climate change.”

Indeed, a recently published report from the World Meteorological Organization outlines the relationship between human-induced climate change and the increasing frequency and intensity of natural disasters. Among other examples, the authors point out that the 2013 Australian heat wave was made five times more likely because of human-induced warming.

The report said, “Extreme events are always a result of natural variability and human-induced climate change, which cannot be entirely disentangled.”