As many as a 10th of the world’s 7 billion people suffer from chronic hunger and malnutrition, according to the Food and Agriculture Organization of the United Nations, and the challenge of feeding them grows exponentially as populations increase and climate change poses new threats to agriculture from droughts to flooding.

Most scientists believe that a critical factor in addressing this problem, and other global issues, is the development and sustainability of genetically modified organisms, or GMOs. Yet there remains widespread skepticism and fear from a wary public.

Are GMOs safe for human consumption?

“Yeah, absolutely,” said Richard Roush, the dean of Penn State University’s College of Agriculture Sciences. “Genetically modified crops are at least as safe as crops produced by traditional breeding and technological methods.”

Roush will discuss the subject July 29 at 3:30 p.m. at the Hall of Christ in a presentation called “The History of Genetically Modified Organisms,” part of the Oliver Archives Heritage Lecture Series.

Organisms have always been subject to change, whether through evolution or through selective breeding by farmers over the last 10,000 years, Roush said. The advent of modern genetic modification in the 1970s meant that these changes could be accomplished much faster and with far greater precision, he said.

GMOs are created by transferring genes from one organism into another to produce desired characteristics. The process is much like editing, moving words on a computer screen to change the meaning of a sentence by highlighting, cutting and pasting. Scientists identify a specific fragment of DNA, cut it out and insert it into another organism, a plant or animal, creating a new trait in that organism, Roush said.

These modifications can produce foods, like strawberries, potatoes and tomatoes, that are hardier, tastier and less susceptible to pests and weather. Since 1996, the technology has been used widely, accounting for about 500 million acres of genetically modified crops in 28 countries, according to a Penn State report.

And genetic modification has other applications beyond agriculture. Roush points to Humulin, a form of insulin created by genetically modifying bacteria. Since it was introduced in 1982, Roush said, Humulin has almost completely replaced traditional insulin that was isolated from animals.

“It’s much cleaner,” he said.

The vast majority of scientists, about 90 percent, maintain that GMOs are safe, while only about 37 percent of average Americans believe they are, a survey by the Pew Research Center found in 2015. Roush sees several reasons for this discrepancy.

Scientists pioneering GMO technology in the 1970s and ’80s thought they were merely continuing an age-old practice, he said.

“If you were working in the 1980s, you would not have seen this as all that different or unusual as an extension of breeding techniques,” he said. “You would be surprised by the criticism.”

Roush ascribes much of the opposition to GMOs to fear of expanded industrialized agriculture, to a romantic attachment to organic farming — which he argues has not adopted new techniques in the past 60 to 80 years — to a general distrust of science, like that evidenced by climate-change denial or anti-vaccine beliefs.

To make his case, he points to exhaustive studies worldwide that have consistently found GMOs safe.

“The European Union spent 350 million euros trying to find dangers in genetic modification,” Roush said. “They were acting on a political imperative, and they found nothing.”

He also cites extensive regulations by government and scientific agencies worldwide, one of which he served on for four years in Australia.

“The level of scrutiny by the FDA and its counterparts and by the best scientists is much higher than in the scientific literature,” Roush said.

With the issues of safety largely settled, Roush said, it is imperative that the promise of GMO technology be harnessed to address the pressing issues facing an expanding global population with limited resources.

“Genetic modification dramatically reduces the use of pesticides and greenhouse gasses,” he said. “Water has always been an issue. Now drought-resistant corn is expanding to drier areas and countering the effects of drought. The real challenge to the world is how do you feed billions of people without causing more environmental damage?”