Research says region's crops will feel impact of global warming

Research says region's crops will feel impact of global warming

July 23rd, 2017 by Tyler Jett in Local Regional News

Alan Scoggins walks past a field of soybeans on the Scoggins family farm on Friday, July 21, 2017, in LaFayette, Ga. Last year, the farm's yield was badly impacted by an exceptionally dry summer, and this year's wet weather has also effected the amount of soybeans they could plant.

Photo by Doug Strickland /Times Free Press.

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LAFAYETTE, Ga. — Sonny Scoggins never envisioned catfish among his crops.

But last month, there they were, 3 feet long, about 7 pounds, wiggling and flopping among budding soybean plants. A heavy storm had finally ceased, and Scoggins and his brother wanted to inspect their crops. They found the pond overflowing, the water spilling through the rows of stalks, forming small, shin-high streams.

"It's just, you know — it's just something to see," said Scoggins, 83.

Temperatures rose. The water evaporated. The catfish retreated. And then another heavy storm hit, and the water spilled out, and the whole thing happened again.

This time last year, Scoggins was praying for rain. With rolling hills and no clear access to a river, the farm doesn't have an irrigation system. And the hot, dry weather oppressed his summer crop, allowing the family to harvest only 6,000 bushels of soybeans. Typically, they grow 40,000 bushels, selling them to Cargill Corp. for about $10 each. He said it costs about $120 an acre to plant his 650 or so acres.

This year, though, the weather was too wet. The family lost half their straw crop, which they grow from October through May. And they cut short their soybean planting by about 100 acres. The rain has subsided for now, though, and the year could end with a bit of an upswing, Scoggins hopes.

"These past two years are the worst years I've ever seen," he said.

Scoggins' father, Julius, started this farm on West Armuchee Road in the 1940s. His son works here now. He wants his grandchildren to take ownership of it one day. But a local farmer can't afford too many bad years.

Until recently, Scoggins hadn't considered global warming too deeply. But he's heard climate scientists are predicting more intensely hot days in the future. And when it rains, they say, the downpours will be consistently heavy — like, catfish-flopping-in-the-crops heavy.

Nevertheless, most people around here aren't too concerned. A survey released in March by the Yale Program on Climate Communications found that 56 percent of people in Walker County are not worried about global warming. In all of the counties where the Times Free Press delivers newspapers, that figure is 54 percent. Nationally, it is 42 percent.

Meanwhile, a team of climate scientists published a study in the magazine Science last month, attempting to break down how global warming could impact the local economy in every county. Not surprisingly, they concluded that people in the South will be most affected.

According to the study, counties in the Times Free Press delivery area would see damage to the tune of 7.8 percent of their economy. Nationally, the figure is 4.6 percent. Locally, Walker County would be the most affected, with a damage rate of 11 percent of its economy. (Some areas in the North would actually see slightly positive bumps, with those cold winters going away.)

The study considered the labor force that would be available under extremely hot weather, as well as crime rates. But the sectors that changed the most? Energy expenses, our ability to grow crops, and mortality rates.

The estimates come with plenty of caveats. First, nailing down specific impacts of climate change is difficult, especially when it comes to precipitation — an important factor if you're looking at farming. Also, the study attempts to estimate what the U.S. economy is going to look like in 2080, when today's babies will be grandparents.

The researchers don't know how technology will have upended the economy at that point. Also, they don't factor in our abilities to adapt to environments. For example, farms in 2080 may look different. Ted Terry, the Sierra Club's Georgia Chapter director, is pushing for more more farmers to produce energy through solar panels or wind turbines.

Said Amir Jina, an assistant professor at the University of Chicago: "Our research can't answer this next question, but it is worth considering: Where do people and businesses in the most affected parts of Georgia go? How will they invest to reduce the impacts?"

Percent of adults who think climate change will hurt them personally

Times Free Press coverage area: 32.57 percent

Nationally: 40 percent

Source: Yale Program on Climate Communication

Percent of adults who are worried about climate change

Times Free Press coverage area: 46.86 percent

Nationally: 58 percent

Source: Yale Program on Climate Communication

 

Agriculture

To predict global warming's impact on farming, researchers first looked at the growth of four crops in every county: corn, cotton, soybean and wheat.

In Walker County, they estimated farmers typically grow 875 acres of corn, 1,475 acres of wheat and 1,450 acres of soybeans. There is no cotton. Some farmers, like Scoggins, also grow hay. But researchers did not have good enough data to draw estimates for the future of that crop, said James Rising, a fellow at the Energy & Resources Group of the University of California at Berkeley.

The researchers then looked at what the weather in Walker County could be like by 2080, based on 44 climate models. They didn't look so much at the range of temperatures you would see at different points of the year. Instead, they focused on extremely hot days, when temperatures spike north of 95 degrees.

Right now, on average, Walker County sees 10-20 of those per year. But in this study, Rising said, researchers estimated 75-100 days above 95 degrees are likely to occur annually by the end of the decade.

Looking at farms, the researchers considered tipping points, the temperatures at which crops suffer. As the temperatures rise to these points, Jina said, productivity slowly improves: Farmers historically have been able to yield more of the crop. But beyond the tipping point, productivity plummets.

In corn, for example, Jina said the tipping point is 95 degrees. In soybeans, it's 86 degrees.

"Many places in the South are quite close to this and other thresholds," Jina said. "So as the temperature warms, even a little, Georgia starts to see damages."

But temperature in and of itself is not a perfect way to predict crop growth. Scoggins said his soybeans thrive even in particularly hot summers, so long as they get consistent rain.

This is where the researchers found another potential problem. Precipitation is going to increase, and the rain could overwhelm crops.

Rising said the research team's models predicted annual precipitation will increase in Walker County from 49 inches to 54 inches. Most of the extra rain would come in the spring.

The total amount isn't necessarily the problem for farmers. The problem is actually the size of the storms.

Hotter temperatures lead to more water vapor in the atmosphere. Kim Cobb, a climate scientist at Georgia Tech who did not work on this particular project, said extra water vapor means more potential for heavy rain.

The research in this area is developing, Cobb said, "but we do know precipitation impacts will occur, and we need to consider our vulnerabilities."

Overall, the research team predicted a 30 percent drop in agricultural production in Walker County. That's an impact twice as severe as the national average.

Energy expenses

Nationally, people will spend less money heating their homes. But the savings will be more than offset on the other end, through air conditioning.

According to the researchers' estimates, the country will spend about 9.2 percent more on energy than they do now. In the Times Free Press delivery area, spending will increase slightly more: 11.5 percent.

The researchers came to this data by estimating future heat and rain levels. They then looked at how people have historically responded. Karen Utt, senior program manager for climate policy at the Tennessee Valley Authority, said this is only one slice of future estimates.

"Those results are a good visualization of what might happen if we did nothing," Utt said, "if we did not plan for it."

Energy companies have a big say on what could happen. If they can adapt and help others adapt, energy costs might remain steady in the future.

She said TVA is expecting more heat waves and more storms, as well as a larger population. Researchers, then, need to figure out how to offset those changes, making resources like air conditioning more affordable. She pointed to TVA's partnership with the Electric Power Resource Institution.

Utt said researchers will continue to push for more electric technology that is more efficient and less damaging to the environment. As an example, she pointed to Internet-ready water heaters, which give homeowners more control and save everybody money. Likewise, she pointed to advancing technologies in transportation, with electricity powering bigger vehicles such as buses, forklifts or bucket trucks.

She said smart manufacturing companies will move to electric equipment and already put employees to work at hours that are more efficient for the energy bill — when most people are sleeping, for example.

Look for appliance makers to take advantage of this, too. A device could draw up power during at a cheaper time of day and store it for when it's actually used.

"That will change the grid mix (of energy sources)," she said. "Right now, the grid mix is determined largely by demand: by what our customers do, and when they do it."

Death rates

And then there is mortality, the most obvious threat. Rising said researchers based their estimates on the number of days above 95 degrees. Historically, extreme heat has caused more deaths, particularly among those older than 65.

In the researchers' estimates, death rates in the Times Free Press delivery area will grow by about 17 people per 100,000. This is almost twice the national average. Locally, Walker County received the worst prediction, with an increase of about 25 extra deaths per 100,000 people.

Adjusted for Walker County's population — 68,000 — global warming would account for an extra 17 deaths every year.

Areas up north may actually benefit from global warming, at least with respect to death rates. Fewer people would die from extreme cold. By and large, though, that would not apply here.

"Georgia doesn't have many cold days that harm people," Jina said, "so all that Walker County will see is an increase in harmful hot days."

Again, though, the researchers say this prediction is based on a future more than six decades away. So many things can change from now until then, they say. The future is hard to empirically predict.

But, Rising said, staring down these predictions is useful. Jina compared the death rate statistics to that of driving. From 2010-14, according to the Governor's Office of Highway Safety, about 6.6 people in Walker County died every year in fatal car crashes.

"An enormous amount is spent on policies to protect people from dying on our roads," he said.

Contact staff writer Tyler Jett at 423-757-6476 or tjett@timesfreepress.com. Follow him on Twitter @LetsJett.

 

Economic damage of climate change, 2080

Walker County, Ga.: 11.04 percent

Grundy County: 10.90 percent

Gordon County, Ga.: 9.16 percent

Chattooga County, Ga.: 9.13 percent

Polk County, Ga.: 8.35 percent

Catoosa County, Ga.: 8.33 percent

Whitfield County, Ga.: 8.23 percent

Bledsoe County: 8.20 percent

Dade County: 8.05 percent

DeKalb County, Ala.: 7.91 percent

Jackson County, Ala.: 7.77 percent

Marion County: 7.71 percent

Murray County, Ga.: 7.38 percent

Rhea County: 7.35 percent

Meigs County: 7.08 percent

McMinn County: 6.77 percent

Hamilton County: 6.74 percent

Franklin County: 6.55 percent

Sequatchie County: 6.19 percent

Coffee County: 6.08 percent

Bradley County: 5.58 percent

*As a percentage of the average income in the county, as of 2012

Source: Science magazine