Climate change threatens food production


Tyler Chalfant | August 14th, 2019

A report released Thursday by the Intergovernmental Panel on Climate Change warned that climate change will make crops scarcer and less nutritious. Even as the global population rises, the number of people without enough to eat has been shrinking in recent decades, but rising temperatures, increased flooding, and more extreme weather patterns could reverse that progress.

Staple crops like wheat have been found to offer less protein, iron, and other important nutrients when grown at high carbon dioxide levels. A study earlier this year found that the world is already losing 35 trillion calories from crops each year. That amounts to about 1% of all food calories, or enough to feed 50 million people. 

The effects of climate change vary by region, however, with the greatest loss of food production happening in Europe, Southern Africa, South Asia, and Australia. While Illinois has seen an 8% production in corn yield, Iowa has actually seen gains in production due to climate change, according to Deepak Ray, a senior scientist with the University of Minnesota. 


A part of the problem is that food production contributes to the very process that is harming it. Depending on the accounting method, the industry contributes somewhere between a quarter and a third of global greenhouse gas emissions. That footprint can be reduced by farming in ways that are better for the land, including limiting the use of fertilizers and planting crops that add carbon to the soil, rather than releasing it into the atmosphere.

The impact of climate change on food yield and nutrition


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Leafy greens can provide calcium, magnesium, and potassium. (ccharmon/flickr)

Eden DeWald | June 13th, 2018

A new study, conducted by a team from the London School of Hygiene & Tropical Medicine, studies the effect that consequences of climate change will have on the yield and nutritional content of vegetables and legumes. The environmental changes analyzed in the study include any change found in ambient temperature, salinity, water availability, and concentration of carbon dioxide and ozone in the atmosphere. The study complied information from 174 published papers, which utilized a total of 1,540 studies, and conclusions based on the information which encompassed data from 40 different counties.

Variations of each environmental factor analyzed changed prospective vegetable and legume yields in different ways. For example, an increase in carbon dioxide levels was found to increase the mean yields overall, whereas an increase in tropospheric ozone concentration was found to decrease mean yields overall. However, an increase in carbon dioxide was the only factor studied that would produced an increase in mean yields, and all others were found to incur a decrease in average yields. The study could not make an overall comment about a change in food nutrition, but two papers that were analyzed found that an increase in carbon dioxide and ozone resulted significantly  decreased nutrient concentrations within root vegetables.

Vegetables and legumes provide many vital nutrients such as potassium, vitamin C, folate, and dietary fiber. They are cost effective diet staples for many people around the world. A decrease in means yields could negatively affect public health, decrease agriculture revenues, and make living a healthy life style even more expensive.

 

Climate change affects crop yields in varying ways


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Soybeans are less sensitive to temperature and precipitation changes than corn plants. (Kevin Dooley/flickr)

Jenna Ladd | March 23, 2018

Researchers at the University of Nebraska recently published a study which details how climate change impacts crop yield variance on a hyper-local level.

The study analyzed U.S. Department of Agriculture data from more than 800 counties across North Dakota, South Dakota, Wyoming, Nebraska, Iowa, Colorado, Kansas, Oklahoma and Texas from 1968 through 2013. Collectively, they found that climate change caused about 25 percent of crop yield variance during that time. While temperature and precipitation changes were responsibile for 52 percent of crop fluctuations in some counties, they did not have any effect in others.

Similarly, the three crops that were studied: corn, soy and sorghum, all responded to the changing climate differently. Corn is more likely than the other two to be impacted by rising temperatures. When corn plants are not irrigated, yields are twice as likely to be harmed by increased temperatures. However, irrigated corn seemed to do relatively well in these conditions. Irrigated soy and sorghum plants were much less likely than non-irrigated plants to be negatively impacted by precipitation and temperature shifts too.

Suat Irmak and Meetpal Kukal are the study’s authors. They say that their work makes the case for continued climate change studies which consider different climate variables, crop types and growing conditions.

“I hope we are successful in getting across the message that there are changes in temperature and precipitation, (but) those changes are different over time and location, and they are having different impacts on our agricultural productivity,” Dr. Irmak said to the University of Nebraska. “That can help high-level advisers, decision-makers and policymakers to identify locations where those impacts are greatest so that resource allocation or re-allocation can make (fields) even more productive.”

The full study can be found in the journal Scientific Reports.

Crop production linked to regional changes in climate


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Corn and soy plants can cool the climate on a regional level, but intensified conventional agriculture can harm water and soil quality. (Lana/flickr)

Jenna Ladd | February 14, 2018

A new study by researchers at Massachusetts Institute of Technology and Dartmouth College detail the way intensive agriculture has influenced precipitation and temperature patterns in the midwest.

During the second half of the 20th century, corn production in the midwest increased by 400 percent and soybean yields doubled due to more intensive agricultural practices. The study, which was published in Geophysical Research Letters, found that the midwest also saw significantly more precipitation and lower temperatures during the summer months over the same period of time. They concluded that the changes were not merely correlated, but that the land use change actually caused the regional climate changes.

The authors explain that each time plants take in carbon dioxide, they release moisture into the atmosphere through pore-like structures called stoma. With more plentiful and robust plants due to intensive agriculture, the amount of moisture corn and soy crops collectively release into the atmosphere has increased in the midwest since the 1950’s. This extra moisture, the study found, has caused summer air to cool and more precipitation to fall. In the last fifty years, average summertime rainfall in the midwest has increased by 15 percent and average summer temperatures have dropped by 0.5 degrees Celsius.

Roger Pielke Sr., a senior researcher at the University of Colorado at Boulder commented on the study, he said, “This is a really important, excellent study. The leadership of the climate science community has not yet accepted that human land management is at least as important on regional and local climate as the addition of carbon dioxide and other greenhouse gases into the atmosphere by human activities.”

Since completing the study, the researchers have developed a formula that accounts for the causative relationship between plants and regional climate changes that can be entered into U.S. regional climate models. It correctly predicted those changes that have been observed in the midwest over the last 50 years.

The study opens the door for further research into land use changes and how they can affect local climate.

Iowans ask to halt CAFO construction until water is clean


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Large livestock feeding operations often pollute local waterways with organic waste. (Waterkeeper Alliance/flickr)

Jenna Ladd | January 19, 2017

Local, state and national organizations showed up at the capitol in Des Moines this week to ask lawmakers to halt Confined Animal Feeding Operation (CAFO) construction until fewer than 100 of Iowa’s waterways are impaired.

Called Iowa Alliance for Responsible Agriculture, the coalition rallied behind Independent Senator David Johnson of Ocheyedan as he introduced a group of 15 bills designed to tighten environmental regulations on large hog farms. At present, 750 of the state’s waterways are polluted to the point of impairment due to industrial agriculture byproducts.

Bill Stowe, CEO of the Des Moines Water Works and member of the coalition, said that industrial agriculture is making Iowa’s “rivers, lakes and streams filthy — filthy with nutrients, filthy with bacteria, filthy with organic matter,” according to the Register.

He added, “Iowans need to push back on this and join together with leaders here in the Legislature to stop the status quo.”

There are 13,000 CAFOs in the state of Iowa and that number continues to grow. The current regulatory document for new hog facilities was developed in 2002 and only requires CAFOs to meet 50 percent of its requirements to be approved for construction.

Senator Johnson’s package of bills would also require CAFO applicants to notify nearby landowners and give county supervisors the power to determine CAFO locations. Johnson said, “It’s time to get tough on the poor siting of hog confinements, including those being built in environmentally sensitive areas, where the smell and sound of someone else’s money is in your bedroom every night.”

A spokesperson for Gov. Reynolds has said that she would consider the legislation if it reaches her desk.

Tom Vilsack to deliver lecture next month


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Tom Vilsack currently leads the U.S. Dairy Export Council. (Iowa State University)

Jenna Ladd | October 25, 2017

Tom Vilsack will deliver a lecture at Iowa State University as a part of the National Affairs Series: “When American Values Are in Conflict” next month.

Vilsack served as Governor of Iowa from 1999 through 2007. His lecture, titled “Agriculture and Climate Change,” however, will center more around his work as Secretary of the U.S. Department of Agriculture (USDA) during the Obama administration. As USDA Secretary, Vilsack helped to develop and manage programs related to rural electrification, community mental health and refinancing farm homes, to name a few. He also managed the federal school lunch program and the Supplemental Nutrition Assistance Program (SNAP).

Vilsack currently serves as president and CEO of the U.S. Dairy Export Council, “a non-profit, independent membership organization that represents the global trade interests of U.S. dairy producers, proprietary processors and cooperatives, ingredient suppliers and export traders.”

Additional details about the lecture can be found here.

What: “Agriculture and Climate Change” lecture by Tom Vilsack

Where: Iowa State University Memorial Union-Great Hall

When: Thursday, November 16 at 7:00 pm

Cost: free, open to public

Solutions presented for nitrate runoff at Iowa Ideas conference


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Cover crops like rye and clover are alternatives for fall tilling. (Chesapeake Bay Program/flickr)

Jenna Ladd | September 28, 2017

Experts in fields from agriculture, energy and environment, higher education and healthcare gathered in Cedar Rapids for The Gazette’s Iowa Ideas Conference September 21 and 22.

The two day conference was presented as an opportunity “to connect with fellow Iowans and develop solutions for key issues facing our state.”

Dr. Chris Jones, a University of Iowa researcher and CGRER member proposed one solution that would reduce nitrate runoff in Iowa’s waterways by 10 to 20 percent within one year. The IIHR-Hydroscience and Engineering research engineer stated that Iowa farmers should avoid planting crops on flood plains and stop tilling their land in the fall because it makes soil more susceptible to erosion if they want to see a reduction in nutrient runoff.

According to a report in The Gazette, Jones said, “It’s difficult for me to understand why these things continue. If we could do those two things, we would have a 10 to 20 percent reduction in one year.”

The Iowa Department of Natural Resources reports that there has been a 6 million acre increase in no-till farmland since 1987.

Chris Jones further discusses the science behind nitrate pollution and what it means for Iowa’s natural resources in episode one of Iowa Environmental Focus’ Nitrate Series.