It’s hard to put into words how central wheat farming is to Kansas.

It has shaped our self-image. It’s what we’re known for around the globe.

Kansas is usually tops in the nation in wheat production. For those who like a picture: In 2012 Kansas farmers produced enough wheat to bury the entire town of Wellington, county seat in the state’s top wheat-producing county, to a depth of 5 feet – or enough to make 20 billion to 25 billion loaves of bread.

But not last year. Last year was a pretty bad harvest. Too little rain, too much heat.

The year before wasn’t that great, either. In fact, Kansas has had an off-and-on drought since 2011, The Wichita Eagle (http://bit.ly/1wPte8t ) reports.

A team of climate scientists say in a recently published study that we may see that more often.

They say that for every 1 degree increase in average world temperatures, the globe – including our little rectangle of it – will lose 6 percent of its wheat production.

The globe will see temperatures rise 1 to 3 degrees Celsius by the year 2100, according to an optimistic scenario cited by the U.S. Department of Agriculture in its 2013 assessment of the impact of climate change on U.S. agriculture. In a less optimistic scenario the temperature would increase 2 to 5.4 degrees by 2100.

And while the whole subject of climate change is controversial in some places, many farmers acknowledge that they – or their children – expect to have to deal with something, even if they prefer the less politically charged term “extreme weather.”

Farmers are pretty pragmatic, said Tom Giessel, a fourth-generation crop farmer with about 4,500 acres near Larned. Like most people, they tend to deal with the things that will affect them in the near future.

“What convinces most people is money,” he said. “If it starts to hit them in the pocketbook, if they see a financial loss because of this, they’ll do something.

“The problem is that too many people make a lot of decisions short-term. The smart people also think long-term.”

In the study, published in the journal Nature Climate Science, lead author Senthold Asseng, of the University of Florida, and his co-authors – including Kansas State University professor Vara Prasad – studied the impact of just one factor, temperature, on wheat production.

In the paper, the authors concluded that a 1 percent increase in the world average temperature would result in the loss of 40 million tons of wheat, a 6 percent drop in world production. That is the equivalent of a quarter of the amount of wheat traded around the world – and more than the amount produced by all of the Plains states.

The study does not examine how climate change would affect other critical factors: rainfall, soil quality, weeds and insects.

Kansas wheat farmers tend to grow red winter wheat. They plant it in September and October. It grows a few inches in the fall before it goes dormant in the cold. The wheat becomes active again in March, grows steadily and is harvested in June.

Of course, it’s more complicated than that, but the payoff for the wheat farmer is in the final stage. That is when the plant fills out the 40 or so kernels and turns gold.

What concerns Prasad, director of K-State’s Sustainable Intensification Innovation Lab, is the increased possibility of higher temperatures during this final stage.

If the temperature gets over 86 degrees, the wheat starts to struggle in filling out the kernels. When it gets over 95 degrees, it stops.

Kansas never has been ideal for growing wheat, Prasad said. It can sometimes get too hot or too dry, or both, in late May or early June during the kernel-filling stage.

That’s what happened last spring.

“I’m not worried about the average, but the extremes,” he said.

Prasad said he isn’t alarmist. He isn’t calling for any great campaign to save the world.

“There is no dilemma and no argument that extreme weather is happening more frequently,” he said. “The long-term aspects of climate change are more complicated, and the cause of it? For me it doesn’t matter who causes it, it’s happening.”

The challenges are large, but American agriculture has the technology to develop more varieties that are more tolerant to heat, drought, insects and mold. He recommends more money for genetic research to study the vast numbers of wheat varieties to see whether they contain drought or insect resistance.

And American farmers have the money and education to take advantage of new varieties and techniques, he said.

So, in the end, there’s no disaster for Kansas farmers.

“It’s not that bad,” he said. “We just have to prepare for it.”

The USDA agrees – in the short run.

In the USDA assessment, the authors write that U.S. agriculture and farmers will be resilient in the short run. They can switch crop varieties, switch crops, expand irrigation and change timing on inputs. But there are limits.

“By mid-century, when temperature increases are expected to exceed 1 C to 3 C and precipitation extremes intensify, yields of major U.S. crops and farm returns are projected to decline,” the authors write.

But the interactions will certainly be complex, with many trade-offs. For instance, the study notes, increased carbon dioxide will speed plant growth and likely reduce water consumption, but it may reduce grain quality and increase weed growth.

The official position of the American Farm Bureau, the country’s largest farm organization, is that while there may be an increase in extreme weather, it’s unclear whether humans produced the greenhouse gases that caused the extreme weather.

But one thing the Farm Bureau makes clear: It doesn’t want the U.S. government unilaterally to regulate greenhouse gases – such as by regulating emissions from power plants – because it thinks regulations will raise the costs to produce food, feed, fuel and fiber, without fixing the problem globally.

The Kansas Wheat Growers Association, the state’s main wheat farmers group, funds about $2 million worth of research a year, including by Prasad in the past. It wanted to make clear that it didn’t fund this most recent study.

It has no formal position on climate change, said spokeswoman Marsha Boswell, but she did refer questions to board member Justin Knopf, a fifth-generation crop farmer near Salina.

Knopf said he was asked to represent the group on environmental issues because he’s seen as sort of an environmentally aware farmer. He practices no-till farming, where seeds are planted without cutting furrows in the soil and the plant cover is left in place. He was excited to talk about how, through 20 years of no-till practices, he’s been able to replenish some of his soil’s native carbon content.

But climate change, he said, is a further bridge to cross. It’s complicated, abstract, international, involves federal government rules and United Nations commissions, and is pushed by environmentalists who are often unsympathetic to farmers facing higher costs. What’s there to like?

Still, Knopf said, there is a recognition by many farmers that more extreme weather may be coming to Kansas: more spring freezes, more late spring heat waves, more droughts – in short, more seasons like the punishing spring of 2014.

Personally, he said, he believes it’s a critical issue and would like to have a rational discussion about what should be done, but emotions and entrenched cultural attitudes are in the way.

“I think it’s too bad that the issue has become so politicized, so divisive,” he said. “Because I think a conversation about the topic is needed to find the truth. The fact that we’re really not able to have that conversation is too bad.”

Until the sides agree to a rational discussion, he said, farmers will deal with whatever comes on a pragmatic level, by planting more drought- and insect-resistant seeds, employing other practices, plus working with the state of Kansas to improve the rules for the use of groundwater for irrigation.

American farmers have for centuries adapted to changing conditions and technology to become the most productive in the world.

“Honestly,” Knopf said, “if climate change is happening and our temperatures and weather become more dramatic, there’s not a lot that I can do as an individual to keep that from happening, but there are things that I can do on my farm in response.”

Donn Teske would passionately disagree.

Teske is president of the Kansas Farmers Union, a populist farm organization that goes back to 1907. He is mainly a livestock farmer, but does grow some crops on his farm near Wheaton, northeast of Manhattan.

He is passionate about climate change, even testifying about it before Congress in 2007.

“Does climate change worry me? Sure,” he said “It affects all of us. It affects our insurance rates. I have to start planting earlier. I’m planting a month earlier than when I started farming out of high school, and it’s a challenge to get the crops harvested.”

He sees the need for federal action and international agreements. Kansas Farmers Union used to have a program where its members set aside 8 million acres of land for carbon sequestration.

But he acknowledged that his views aren’t often shared by others in his small town.

“I like my neighbors, and I think they like me, but I don’t bring up topics where neither one of us will change our stance,” he said. “So I smile a lot, and we talk about things that don’t cause an argument. Politicians are fair game.”

He, too, regrets that the discussion has become mired in politics, that logic and science aren’t enough to persuade people, but he’s not afraid to say which side he believes to be in the wrong.

“It’s turned into a political thing and that is horrible,” he said. “Climate change doesn’t have parties. It’s something we have to address for our grandkids.”