Will global warming endanger the U.S. corn belt, a key source of calories for the growing global population (?)

It would be more accurate to say that American corn is a major source of calories for American internal combustion engines.  It has virtually nothing to do with feeding the world.  Only 17% of the crop is exported, mostly to Mexico and Japan.

Africa has a variety of climates but Africans mostly live on self-grown corn in the form of "mealie pap".  They don't rely on American corn.

And the experiment described below is stupid.  To expose a cultivar designed for a cold climate to unusually high temperatures is simply irrelevant.  Corn is grown all around the world in a variety of climates, mostly warm.  Some cultivars grown in India, for instance, are very heat tolerant -- up to 35° C.

So in the event of global warming, farmers would just have to order seed of a more heat tolerant cultivar.  If the Midwest warmed up a bit, use of tropical cultivars would probably INCREASE production

The article below also ignores other factors of production.  CO2 is a plant food so more CO2 in the air would also increase corn production.  And a warmer world would be more rainy, which again favours plant growth. Farmers might have to look more to their drainage but that is a lot better than suffering drought, which is the current most common problem for corn farmers. Corn likes a lot of water.

So if you look at the full picture, a warmer world would be most likely to lead to a GLUT of corn, not a shortage. It never ceases to amaze me how dishonest Warmist articles are.  Is there such a thing as an honest Warmist?

It’s a bitter cold March morning in Ames, Iowa, and the sprawling cornfields outside of town are buried beneath a couple of inches of ice and snow. But it’s hot and humid inside the custom-built grow chambers on the campus of Iowa State University.

Blindingly bright lights beat down on a trio of squares, each containing close to 7,000 pounds (3,175 kilograms) of soil, sunk five feet (1.5 meters) into the floor. The steady churning of fans, ensuring air circulation and uniform temperatures throughout the room, echoes off the walls. Every few inches, a suite of infrared thermometers and moisture sensors track the microclimates surrounding the leaves of the plants.

Inside these growth chambers, it’s the future. And Jerry Hatfield, an affable agronomist who heads the US Department of Agriculture’s National Laboratory for Agriculture and the Environment, doesn’t like what he sees.

“Either we’re going to change the crops that we produce or we’re going to have to think about how we genetically manipulate that plant to have a higher tolerance to higher temperature.”
Three years ago, Hatfield used the growth chambers to find out how local crops would perform under the temperatures predicted for the region in 2100, which are expected to rise roughly 4 °C on average, or about 7.2 °F. He simulated a growing season, from April 1 through October 30, for three different strains of corn used by farmers in the area. In one chamber, Hatfield started the temperature at just around 50 °F (10 °C) to mimic conditions in early April, raised it well above 100 °F (38 °C) to simulate the hot summer days (as high as 114 °F in the chamber with 2100 conditions), and then brought it back down again for autumn. In a second chamber, he simulated the region’s current, cooler climate norms.

The differences between the plants in the two chambers were stark. While the leaves looked the same, the impact of that extra 7.2 °F was far worse than projected by even the most pessimistic scientific literature. The number of corn kernels per plant plummeted, in some cases by 84%. Some plants produced no kernels at all.

It was just the first in a series of alarming results. In the months that followed, Hatfield and his colleagues simulated the rising temperatures and altered rainfall patterns expected to hit the wheat fields of Salina, Kansas, as soon as 2050. Yields fell as much as 30% with low precipitation and as much as 70% with the combination of high temperatures and low precipitation expected in the decades ahead.

To date, it’s been relatively easy for American farmers to shrug off climate change. After all, under the most optimistic models, projected US yields for corn and soybeans — which are grown on 75% of the arable land in the Midwest — are actually expected to increase through 2050, thanks to warmer weather that will benefit the relatively cool northern climes. But after that, if Hatfield is right, yields will fall off a cliff, devastating farmers and leaving much of the world hungrier.

By 2050, the world’s population is expected to grow to 9.7 billion. As living standards and diets also improve around the world, food production will have to increase by 50% at a time when climate change will help make both sub-Saharan African and East Asia unable to meet their own needs without imports. Already US corn and soybeans account for 17% of the world’s caloric output. The UN Food and Agriculture Organization projects that American exports of corn must almost triple by 2050 to meet the shortfall, while US soy exports would have to rise by more than 50%. All this extra food has to be grown without using significantly more land. That means it’s going to be all about yield — the productivity of the crop.

And that is what has Hatfield so worried. A growing body of scientific literature suggests that climate change is likely to decimate yields unless we can find new ways to help plants cope with the droughts, vast temperature fluctuations, and other extreme weather that’s likely to become commonplace in the decades ahead.

“If something isn’t done, we will see major drops in production across large areas of the corn belt and Great Plains,” Hatfield says. “Either we’re going to change the crops that we produce or we’re going to have to think about how we genetically manipulate that plant to have a higher tolerance to higher temperature.”


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