On a world map colored by gradients of greenhouse gas emissions, the Middle East often looks strangely smooth. No spikes, no surprises, just modeled estimates filling in for missing data. “Those colors,” Prof. Ilya Gelfand says with a half-smile, “are mostly assumptions.”
Gelfand, an associate professor at Ben-Gurion University of the Negev and a researcher at the French Associates Institute for Agriculture and Biotechnology of Drylands, has spent much of his career challenging those assumptions.
His work focuses on what scientists call trace gases – nitrous oxide, nitrogen oxides, methane – emitted from soils into the atmosphere. These gases are harder to measure than carbon dioxide, less discussed in public discourse, and vastly under-sampled in large parts of the world, including Israel’s deserts.
“If you look at global databases,” Gelfand explains, “there is data from the U.S., Europe, China. Even Russia. But from North Africa, the Middle East, Central Asia? Almost nothing. And yet these regions cover enormous areas.” It is into this scientific blind spot that Gelfand has deliberately stepped to measure what is happening between soil and sky.
From fish to forests
Gelfand’s journey into climate science was quite unconventional. After his military service, he joined the inaugural cohort of environmental science students at the Hebrew University of Jerusalem in the mid-1990s, a pioneering program blending biology and environmental studies.
“It was entirely new. No one was certain what environmental science would evolve into." His early research was not related to deserts or climate change. As a master’s student in microbiology at the Faculty of Agriculture, he worked on water filtration systems, creating closed-loop aquaculture setups capable of growing fish without water exchange.
“We cultivated gilthead seabream on land, with seawater, avoiding ocean pollution," he states. “It was genuine agriculture, just with fish.” What captivated him was not the fish but the chemistry underlying the process. “Water filtration truly involves nitrogen,” he elaborates. “Removing nitrogen compounds via microbial processes – that’s what sparked my interest in the nitrogen cycle.”
Despite its essential role as a life-sustaining element, nitrogen is frequently overlooked and disrupted by human activities, including fertilization, industry, and land use. “Most of the nitrogen cycle is microbial,” Gelfand says. “And humans interfere with it massively.”
That interest carried him from the greenhouses of agriculture into the forests of basic science. For his PhD at the Weizmann Institute of Science, under renowned ecologist Prof. Dan Yakir, Gelfand crossed institutional and conceptual boundaries. “I wanted to move out of agriculture and water,” he says. “I wanted to work in forests.”
His research site was the Yatir Forest, on the edge of the Negev, a planted forest rising improbably from semi-arid land. There, amid pines and a towering flux-measurement tower, Gelfand undertook what became an especially comprehensive study of the nitrogen cycle in an Israeli ecosystem. “At the time,” he says, “almost no one in Israel was working on nitrogen budgets in natural systems.” He pauses, characteristically modest. “I don’t know if I was the first. But there were very few.”
Gelfand’s initial doctoral focus was on nitrous oxide (N₂O), a greenhouse gas then less well-known than carbon dioxide but more potent per molecule. It also harms the ozone layer. “It’s the third most important greenhouse gas,” he explains, “after CO₂ and methane. But in Israel, it wasn’t widely discussed."
In the early 2000s, nitrous oxide started gaining global interest, especially after a key Science article by Prof. Phil Robertson from Michigan State University, who challenged prevailing ideas by attempting at that time a comprehensive calculation of greenhouse gas budgets for agriculture.
After earning his PhD, Gelfand moved to Michigan to work with Robertson, where he learned direct measurement techniques for soil gas emissions. “That’s where I truly learned how to work with gases,” he recalls, "measuring fluxes, not just concentrations.”
When he returned to Israel in 2017 to join the Jacob Blaustein Institutes for Desert Research at Ben-Gurion University, the circle was complete. "I brought that expertise back," he states, "and suddenly, we could do things almost no one else in Israel was doing.”
Today, Gelfand’s lab employs advanced laser-based tools to measure trace gases in the field, in real time. “We no longer take samples to the lab," he says. “We measure concentrations down to parts per billion right there in the desert.”
Popular perceptions aside, the Negev is not empty space, Gelfand declares. Scientifically, it is among the least well understood environments on Earth. “This is a cold, high-elevation desert with hot summers and cold winters,” he says. “It’s its own category.” And it behaves differently from what models predict.
One of Gelfand’s most provocative findings concerns methane. Conventional wisdom holds that dry soils absorb methane from the atmosphere, acting as a sink. “That’s what all the models say,” he notes. “Dry soil equals methane uptake.” But his measurements showed the opposite – methane emissions from dry desert soils during summer. “We see positive fluxes,” he says. “Methane going into the atmosphere.”
The implication is profound: if deserts emit methane under certain conditions, global climate models may systematically underestimate emissions from vast regions of the planet. However, since the mechanism is not yet fully understood, we need to be cautious in our interpretations, warns Prof. Gelfand.
Filling in the map
“I feel a lot like an explorer,” he admits. “Not in a romantic sense, but scientifically. We’re filling in parts of the map that were blank.” This role is amplified by Israel’s geography. Situated between Africa and Asia, with desert, Mediterranean, and agricultural systems packed into a small area, the country is uniquely positioned to provide data relevant far beyond its borders.
“People doing global climate models need ground truth,” Gelfand says. “They need real measurements. Our job is to give them that.” If Gelfand’s desert research is about understanding the planet, his agricultural work is about changing practices on the ground. Israeli agriculture, he says bluntly, uses too much nitrogen.
“We have some of the highest fertilization rates in the world,” he explains. “China, the Netherlands, the U.S., and Israel.” The consequences are well known: nitrate contamination of groundwater, environmental degradation, and unnecessary greenhouse-gas emissions.
“Before desalination,” he recalls, “our drinking water nitrate standards were double those of Europe." One of his flagship applied projects focuses on date palms, a crop synonymous with Israeli agriculture. “Dates are amazing,” he says, laughing. “Very tasty, very productive, and incredibly thirsty.”
A single date palm can receive up to 150 and more, tons of water per year, along with nitrogen fertilization rates that shocked even Gelfand’s European collaborators. “When I sent the numbers to a German colleague, he told me I must be mistaken,” he says.
In a large-scale, multi-year field experiment involving hundreds of mature palms, Gelfand’s team tested different fertilization regimes. The result: optimal yields with less than half the nitrogen currently used. “In the Arava valley it is about two to two-and-a-half kilograms per tree,” he says. “Not six.”
The implications go beyond farming efficiency. As carbon pricing and environmental regulations tighten globally, agriculture will increasingly be taxed based on emissions. “Only research that measures real emissions can tell us what’s actually happening,” Gelfand says. And here, too, reality defies expectations.
“We found that nitrous oxide emissions from Israeli agriculture are actually quite low,” he says. “Much lower than I thought when we started.” Looking back, Gelfand smiles, almost apologetically, when praised for being groundbreaking.
But the quiet persistence of his work – measuring what others model, questioning what others assume – has made him one of the few scientists systematically documenting trace-gas dynamics in one of the world’s most understudied regions. “We need to understand what’s happening in our deserts,” he says simply. “Because they’re not empty. And they matter. For Israel, and for the climate of the whole planet.”
The Environment and Climate Change portal is produced in cooperation with the Goldman Sonnenfeldt School of Sustainability and Climate Change at Ben-Gurion University of the Negev. The Jerusalem Post maintains all editorial decisions related to the content.
