VAST STRETCHES OF AMERICA are dominated by corn, nearly 100 million acres of it, stretching from Ohio to the Dakotas. What once was forest or open prairie today produces the corn that feeds people, cattle and, when made into ethanol, cars.

 

Now, the nation’s airlines want to power their planes with corn, too.

 

Their ambitious goals would likely require nearly doubling ethanol production, which airlines say would slash their greenhouse gas emissions. If they succeed it could transform America’s Corn Belt yet again, boosting farmers and ethanol producers alike, but also potentially further damaging one of the nation’s most important resources: groundwater.

 

Corn is a water-intensive crop and it can take hundreds of gallons to produce a single gallon of ethanol. But as airlines embrace the idea of ethanol, prompting lobbyists for ethanol makers and corn growers alike to push for clean-energy tax credits in Washington, vital aquifers face serious risks.

 

“We’re on track to massively increase water usage without any real sense of how sensitive our aquifers are,” said Jeffrey Broberg, who is concerned about groundwater in Minnesota, a major corn state, where he is a water-use consultant and founder of the Minnesota Well Owners Organization.

 

United Airlines this year signed a deal with a Nebraska ethanol company to buy enough sustainable aviation fuel, as the biofuel is known, to power 50,000 flights a year. In August, Delta announced a plan to create a sustainable fuel hub in Minnesota. The Biden administration could decide on its tax incentives for the industry as soon as December.

 

“Mark my words, the next 20 years, farmers are going to provide 95 percent of all the sustainable airline fuel,” President Biden said in July.

 

This year a New York Times data investigation found that groundwater is being dangerously depleted nationwide, largely by agricultural overuse. As climate change makes rainfall less reliable and intensifies droughts, rising demand for ethanol could put even more pressure on America’s fragile aquifers to be used for irrigation.

 

It’s a powerful example of tradeoffs that can arise as the world tries to transition away from fossil fuels. Other energy sources can have their own environmental cost, whether it’s mining the minerals and metals required to build more car batteries, or straining groundwater reserves to produce ethanol.

 

Farmers can still rely on rain in most parts of corn country, but elsewhere irrigation has been surging, driven by the climate threat and the pursuit of more reliable yields.

 

Between 1964 and 2017 irrigated acres for corn jumped nearly 500 percent, and groundwater strain is showing in some areas, particularly where underground aquifers take a long time to refill once they’re depleted. Pockets of western and southwestern Nebraska saw aquifer levels fall due to irrigation, prompting local regulators to restrict use.

 

In Kansas, past reports from the Department of Agriculture on corn farming have noted that “ever-depleting groundwater sources for irrigation continue to be a threat to farmers.” Officials there say improvements in irrigation and other technology will help farmers keep growing corn.

 

In parts of Minnesota, sandy soil needs irrigation to produce high yields. While digging wells and installing irrigation systems is expensive, higher corn prices make the investment worth it, said Jake Wildman, a farmer outside Glenwood, Minn., his hands chapped and brown from a day spent loading freshly harvested corn into 18-wheelers.

 

“I can say confidently that without irrigation you just wouldn’t have corn on this farm,” said Mr. Wildman, who is president of the state’s irrigators association. “And the market tells us to raise corn. So you could say that the market is also telling us to irrigate.”

 

The Department of Energy, which is helping draft the rules that would allow biofuels to be considered sustainable aviation fuel, said in a statement that “water use is a critical component of the conversation surrounding bioenergy sustainability.”

 

It pointed to a 2016 department study that concluded that the United States could significantly reduce strain on aquifers by shifting biofuel production away from water-intensive crops like corn, instead growing more crops that don't require irrigation, like various types of straw, grasses and trees.

 

Today, nearly 40 percent of America’s corn crop is turned into ethanol, up from around 10 percent in the mid-2000s. This was largely because of government mandates that began in 2005 requiring gasoline to be mixed with minimum amounts of renewable fuel.

 

After that mandate, groundwater use jumped in some places as corn prices skyrocketed. Farmers added millions of new acres by switching to corn or rotating it into their crops year-to-year.

 

Scientific studies have long questioned whether ethanol made from corn is in fact more climate-friendly than fossil fuels. Among other things, corn requires a huge amount of land, and it absorbs relatively little carbon dioxide out of the atmosphere as it grows. Planting, fertilizing, watering, harvesting, transporting and distilling corn into ethanol all requires energy, most of which currently comes from fossil fuels.

 

The race toward fueling jets with ethanol comes as air travel is rapidly expanding worldwide, bringing greater environmental pressure on the airline industry.

 

Flying is one of the most polluting ways to travel: If global commercial aviation were a country, it would rank as the sixth biggest polluter, between Japan and Germany, by one estimate. Aviation produces about 2.5 percent of total carbon emissions in the world, a number that experts expect to triple by 2050. Right now, on any given day in America alone, more than 45,000 flights take to the air.

 

But there are few options for powering aircraft without fossil fuels. Ethanol, advocates say, is the best solution to reduce greenhouse gas emissions from aviation. Farmers argue that agriculture has become much more efficient — and will continue to do so — and will not necessarily require huge amounts of additional water. Ethanol makers also say the industry has gotten cleaner over the years, and that government incentives would further help.

 

The airlines say the renewable fuel options that exist for powering planes today are too expensive and would force them to raise ticket prices if mandated. Adding ethanol into the mix, they argue, would significantly reduce those costs and allow them to more quickly start blending renewables into jet fuel.

 

“Sustainable aviation fuel is the best tool we have to decarbonize airplanes,” said Lauren Riley, United’s chief sustainability officer. Her counterpart at Delta Air Lines, Amelia DeLuca, called for federal support “like the incentives that already exist in the automotive industry.”

 

Most major U.S. airlines have pledged to stop adding additional carbon dioxide to the atmosphere by 2050.

 

Ethanol producers, meanwhile, are keen to find new markets as electric vehicles threaten demand for ethanol-infused gasoline. And with national elections looming, politicians will likely feel pressure to broaden incentives that are politically popular in Corn Belt states.

 

Todd Becker, the CEO of Omaha-based Green Plains, one of the country’s biggest ethanol producers and United’s joint-venture partner, called ethanol for jets “the next revolution of renewables.”

 

Ethanol is produced in more than 170 industrial distilleries that now dot America’s corn country. The distilleries require a predictable supply of corn, putting pressure on farmers to produce crops on time and when needed.

 

For farmers, having a consistent water supply is key to achieving steady yields — yet there are major parts of the Corn Belt that lack reliable precipitation. In places like these, including stretches of Nebraska and Minnesota, farmers often use powerful irrigation wells that tap groundwater.

 

Adding to the pressure on farmers to irrigate: Global warming means that drier weather patterns historically concentrated in Western states are pushing eastward, deeper into the Corn Belt.

 

The booming market for ethanol has given people like Roy Stoltenberg, a 72-year-old farmer in the central Nebraska community of Cairo, an income lift and the feeling that he has helped reduce America’s dependence on fossil fuels. “It’s brought a tremendous amount of employment to the area,” he said. “It’s added to the value of our land.”

 

“I don’t see any drawbacks,” Mr. Stoltenberg said.

 

In 49 years of farming, Mr. Stoltenberg has weathered an economic crisis that wiped out neighboring farms, watched fertilizer costs spiral upward and faced down a six-year stretch of fall harvests so warm and dry he didn’t even need to wear coveralls in his cornfields. His years of lucrative sales to a nearby ethanol plant means his son, John, will be able to keep working the land.

 

Across his 1,600 acres, Mr. Stoltenberg douses his fields with water pumped from 21 wells. A few seasons ago, after one well coughed up sand, workers had to dig down an additional 80 feet to get to more water, so deep they turned up seashells, evidence of the ocean that once covered this Plains state.

 

“Out here in central Nebraska, we can go weeks without rain,” he said. “Everything that could have been irrigated has been.”

 

This article was originally written by The New York Times. Read More here.