Rising temperatures deplete Colorado River


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The Colorado River provides drinking water for 40 million people. (Katie Rompala/flickr)
Jenna Ladd | February 24, 2017

The volume of the Colorado River has decreased by 19 percent since 2000, and recent research shows that climate change is partly to blame.

Two researchers from Colorado State University and University of Arizona compared temperature, precipitation and water volume in the Colorado River basin from 2000-2014 to historical records dating back to 1896. Since 2000, precipitation in region has decreased by 4.6 percent while temperatures have risen 1.6 degrees Fahrenheit above historical averages. Utilizing existing climate models, the scientists found that the river’s flow should have only decreased by roughly 11.6 percent since the drought began in the area in 2000. Instead, the river’s flow decreased by 19.3 percent due to the effects of global warming, they said.

Published last week in the journal Water Resources, the study read,

“Fifteen years into the 21st century, the emerging reality is that climate change is already depleting the Colorado River water supplies at the upper end of the range suggested by previously published projections. Record-setting temperatures are an important and under-appreciated component of the flow reductions now being observed.”

The Colorado River provides drinking water for 40 million people and irrigates 6,300 square miles of agricultural land. Moving forward, the study’s authors said precipitation in the river’s basin would have to increase by 14 percent by the end of the century in order to mitigate the rising temperature’s effects.

Brad Udall of Colorado State University is one of the study’s co-authors. He said, “We can’t say with any certainty that precipitation is going to increase and come to our rescue.”

Warming ponds could speed up climate change


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Small ponds used by researchers at the University of Exeter and Queen Mary University. (University of Exeter)
Jenna Ladd | February 23, 2017

A recent study shows that when freshwater ponds warm, they release more methane and are able to store less carbon dioxide.

Researchers at the University of Exeter and Queen Mary University of London warmed a collection of man-made ponds by four to five degrees Celsius over the course of seven years. The first of its kind, the study found that the amount of methane released by the ponds increased by double while the amount of carbon dioxide the ponds could store decreased by half.

Professor Gabriel Yvon-Durocher was the study’s lead investigator. He said, “Given the substantial contribution small ponds make to the emission of greenhouse gases, it is vital to understand how they might respond to global warming.”

While ponds and lakes only account for about 0.008 percent of the total volume of water on Earth, they are major contributors of carbon dioxide and methane. Greenhouse gases from freshwater sources are mostly the byproduct of organic matter breaking down in low-oxygen environments.

Yvon-Durocher continued, “Our findings show that warming can fundamentally alter the carbon balance of small ponds over a number of years, reducing their capacity to absorb and increasing emissions of methane. This could ultimately accelerate climate change.”

The scientist noted that these findings are different than those normally observed on land, where the effect of rising temperatures lessen over time. In contrast, when ponds warm and release methane, a gas that is known to be 25 times more potent than carbon dioxide, they actually exacerbate warming.

Ponds of less than one meter, such as those used in the study, are responsible for the release of 40 percent of all inland methane emissions.

 

The professor noted, “This accelerating effect in ponds, which could have serious impacts on climate change, is not currently accounted for in Intergovernmental Panel on Climate Change models.”

The complete study can be found in the journal Nature Climate Change.

CGRER co-director delivers UI Presidential Lecture


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Dr. Gregory Carmichael (left) and University of Iowa President Bruce Harreld (right) at the 34th Annual Presidential Lecture on Sunday. (Jake Slobe/CGRER)
Jenna Ladd | February 21, 2017

UI Center for Global and Regional Environmental Research co-director Dr. Gregory Carmichael delivered the 34th Annual Presidential Lecture to a crowded assembly hall at the Levitt Center for University Advancement on Sunday.

The lecture, titled “What Goes Around, Comes Around: The Global Reach of Air Pollution” featured opening remarks from University of Iowa President Bruce Harreld. Quoting Dr. Jerry Schnoor, Carmichael’s co-director at CGRER, President Harreld joked, “Greg is now more traveled than George Clooney’s character in Up in the Air, four million miles and counting.” Carmichael’s extensive research of the long-range transport of air pollution has taken him to many parts of Eastern Asia, South America, Africa and Europe, among other locations.

Carmichael’s lecture was organized into three parts: the global reach of air pollution, the link between climate change and air pollution, and a finally, a discussion about the action necessary to curb air pollution worldwide. The lecturer made a strong case for air pollution research, citing that it is the root cause of 7 million avoidable deaths per year. Carmichael pointed out that air pollution has economic consequences too; each year, it leads to loss of 10 percent of U.S. soybean yields.

The lecture encouraged a sense of urgency when it comes to cleaning up the atmosphere. Carmichael warned, “That molecule that we put in the air today will stay in the air for a long time.” He went on to say that 20 percent of carbon dioxide released into the atmosphere today will remain there for thousands of years. Professor Carmichael’s research focuses primarily on the utilization of comprehensive computer models and big data to simulate the interplay of air pollutants with weather and climate.

His work has been instrumental in understanding the way in which air pollutants from China move across the Pacific Ocean and affect the Western U.S. He said, “Fifteen to twenty percent of clean air policies in the Western U.S. are being offset by Chinese emissions.”

Above all, the Karl Kammermeyer professor of chemical and biochemical engineering emphasized his passion for instructing and advising students. Carmichael has supervised the research of 40 PhD and 35 Masters of Science students at the University of Iowa.

To learn more about Dr. Carmichael’s career, check out episode 5 of CGRER’s EnvIowa podcast.

EnvIowa Podcast: Dr. Gregory Carmichael


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Dr. Gregory Carmichael has worked closely with scientists in East Asia since 1983 to address pressing air quality problems in that region. (Tim Schoon/University of Iowa)
Jenna Ladd | February 17, 2017

In Episode 5 of EnvIowa we speak with Dr. Gregory Carmichael, Karl Kammermeyer Professor of Chemical and Biochemical Engineering and Co-Director of the UI Center for Global and Regional Environmental Research, about his extensive research on global air pollution.

Dr. Carmichael shares his experiences collaborating with scientists in China, explains why air quality issues in East Asia should matter to Iowans and offers some perspective about what climate science research may look under the new federal administration.

Iowa State researchers receive grants to improve glacier flow models and sea level predictions


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                         Calving of the Aialik Glacier in Kenai Fjords National Park in Alaska. (Alaska National Park Service)
Jake Slobe | February 15, 2017

Iowa State University’s Neal Iverson and a team of researchers are working on research that will predict how much glaciers will contribute to the rise of sea levels.

The research will focus on the extent to which glacier-flow to oceans is likely speed up over the next century as the climate warms.

Iverson, an Iowa State University professor of geological and atmospheric sciences who has studied glaciers in Iceland and Norway, and the rest of the research team will look to lab experiments and field work to build more realistic computer models of glacier flow.

Iverson said about the project:

“Glaciologists are trying to predict how fast glaciers will flow to the oceans. To do that, we need new lab and field data to include complexity in models that is usually neglected. These are complicated systems. Modeling them is hard. But we need to include how water in ice affects its flow resistance, and we need sliding laws that are based on the real topography of glacier beds and that include rock friction. Adding these things really matters.”

Two new grants will help Iverson and his team fund their research, both of which grants are from the National Science Foundation.  The research will also receive funding from the United Kingdom’s Natural Environment Research Council to support the work of applied mathematicians at the University of Oxford in England.

Iverson is the lead investigator on both grant proposals. The other researchers are Lucas Zoet, an assistant professor at the University of Wisconsin-Madison and a former postdoctoral research associate at Iowa State; Ian Hewitt, an associate professor and university lecturer at Oxford’s Mathematical Institute; and Richard Katz, a professor of geodynamics at Oxford.

The first project will look at temperate ice, or ice at its melting point, and how this soft, watery ice resists deformation. That’s important because the resistance to deformation of temperate ice at the edges of ice streams – areas of rapid ice flow within the Antarctic ice sheet that can be hundreds of miles long and tens of miles wide – holds back the flowing ice.

The second project will support development of better “sliding laws” to help predict the sliding speeds of glaciers and ice sheets. Sliding laws are the mathematical relationships between the glacier sliding speed and the factors that control it, such as the stresses below the glacier, the water pressure there, the topography of the glacier bed and the concentration of debris in glacier ice.

Both projects will use the glacier sliding simulator Iverson has been using since 2009 to study glacier movement.

The new projects will add complexity to Iverson’s lab experiments. Debris, for example, will be added to the ice ring to study friction between it and the rock bed during sliding. In other experiments, temperate ice will be sheared between rotating plates to study how its resistance to flow depends on its water content.

University of Iowa drinking water exceeds maximum contaminant levels for disinfectant by-products


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Chlorine treatments react with organic matter in waterways to form Total Thihalomethanes, which have been linked to cancer and reproductive problems. (Jenna Ladd/CGRER)
Jenna Ladd | February 14, 2017

University of Iowa facilities management received notice on February 1 that its drinking water system contains levels of Total Trihalomethanes (TTHM) that exceed the federal drinking water standard.

In an email sent out to University faculty, staff and students on February 9, it was reported that the drinking water tested on average between 0.081 and 0.110 mg/L over the last year. The U.S. Environmental Protection Agency’s maximum contaminant level (MCL) for TTHM is 0.08 mg/L.

TTHM is a group of four chemicals: chloroform, bromodichloromethane, dibromochloromethane and bromoform. TTHM form when chlorine reacts with natural organic matter like leaves, algae and river weeds in drinking water. In its statement, the University said that more chlorination was necessary this year because higher than usual temperatures led to more organic waste in waterways.

The notice read, “You do not need to use an alternative (e.g., bottled) water supply. Disease prevention specialists with University of Iowa Hospitals and Clinics say special precautions are not necessary.”

Chloroform and dibromochloromethane are Class B carcinogens, meaning they have been shown to cause cancer in laboratory animals. TTHM has also been linked to heart, lung, kidney, liver, and central nervous system damage, according to a report by the University of West Virginia.

University officials cautioned, “However, some people who drink water-containing trihalomethanes in excess of the MCL over many years may experience problems with their liver, kidneys, or central nervous system, and may have an increased risk of getting cancer.”

A study by the California Department of Health suggests that even short-term exposure to high TTHM levels in drinking water can have serious consequences for pregnant women. Scientists monitored 5,144 women during their first trimester of pregnancy. Participants who drank five or more glasses of cold home tap water containing 0.075 mg/L or more of TTHM had a miscarriage rate of 15.9 percent. Women that drank less than five glasses per day or who had home tap water with less than 0.075 mg/L TTHM had a miscarriage rate of 9.5 percent.

A reverse osmosis filtration system for the University of Iowa drinking water supply is currently in its design phase. Facilities management expects to have the new system up and running within the next 18 months. Officials say it will help address Iowa’s nitrate problem and filter out naturally occurring organic matter, resulting in fewer TTHM.

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.”