On paper, the numbers look reassuring. Install a smart energy system at home. Order online instead of driving to the mall. Swap a steak for lab-grown meat. The graphs bend downward; the emissions shrink. But somewhere between the spreadsheet and the living room, something shifts. A window is opened because the automated system detects it is too cold and turns on the heating. Three dresses are ordered instead of one, “just to see,” and two are sent back. The steak grown in a lab tastes fine, but dinner habits remain stubbornly intact. Prof. Tamar Makov has built her career on that slippage.
From her office at Ben-Gurion University of the Negev, she studies the distance between environmental promise and environmental reality – the gap between what a technology is supposed to save and what human beings actually end up doing with it. “Even if we have sustainable versions for all products out there,” she says, “there’s still human behavior, which can mess things up.”
Makov did not set out to become the kind of scholar who dissects supply chains and consumer heuristics. “Classic academia, classic professor… I never thought I…” she says, laughing. As a child, she imagined herself as a flight attendant, or “living my life in some caravan in Montana.”
The Negev, with its desert winds and research labs, was not part of the fantasy. What was real and persistent were stomach aches. “I always suffered from stomach aches as a kid, and then I realized it was probably related to what I was eating. I had it in my head that I was going to invent new dairy free ice creams.” She smiles, but by her third year studying for a B.Sc. in nutrition, the romance had faded. Being a clinical dietitian meant coaxing individuals to change their diets. “At this point it was clear that this profession wasn’t what I was meant to do.”
Food, however, never left her horizon. While working as a flight attendant to support herself, she joined a side research project comparing the environmental impacts of different animal-based foods. “And I got hooked.” The project led to a Milken fellowship at Israel’s Ministry of Environmental Protection, and eventually to a formative encounter with the concept of industrial symbiosis. The idea, articulated by Yale Prof. Marian Chertow, is disarmingly simple: in nature, the waste of one organism becomes the resource of another. Why not design industry the same way? “The simplicity!” Makov recalls. “You don’t need to reinvent the wheel. Everything already exists. We have all the inspiration we want in nature.”
The metaphor that captured her imagination was almost childlike: cleaner fish feeding on parasites from whales, both benefiting. Industry, she believed, could learn to behave less like a linear machine and more like an ecosystem. She went on to complete her master’s and PhD at Yale under Prof. Chertow, initially drawn to greener manufacturing and circular systems. But over time, she found herself returning to a more elusive question. If the technologies exist, if the efficiencies are real – why doesn’t the impact always materialize? “In the end,” she says, “the hardest thing is to predict how people will interact with these new ‘greener’ options and how these shifts will affect consumption more broadly.”
Today, Prof. Makov’s research sits at the intersection of environmental assessment and behavioral science. She is less interested in ideal scenarios than in what she calls “a realistic portrayal of human behavior.” That means integrating hard industrial data with the messy ways people shop, eat, drive, and discard. Take clothing. Results based on a calculator developed at her lab reveal that producing a single T-shirt requires roughly 4,400 liters of water, about nine square meters of land, and emits around 20 kilograms of greenhouse gases. “And we wear this shirt only two to seven times in total,” she says. The scandal, in her view, is not only fast fashion but also underuse. “The problem is that we don’t use the things we produce enough.”
Her work on digitalization sharpens the message. Online shopping is frequently described as greener than traditional retail: fewer stores, less lighting, reduced commuting. And indeed, when researchers model the full lifecycle, one factor dominates. “You know what the most significant part is in terms of greenhouse gases?” she asks. “It’s how you travel to the store.” Walk, and the physical shop may be preferable. Drive, and e-commerce can come out ahead; the decisive variable is how people do the “last mile.”
But Makov is wary of one-to-one comparisons. Her team analyzed data on 630,000 items returned to global brands across Europe, and their findings were sobering. Return rates for online purchases hover around 30 percent, compared to roughly 10 percent in-store. And of those returns, “in the best case, 25 percent went to the trash,” she says, “without ever being worn!” In less sustainable contexts, the proportion that fails to reach a second consumer can rise to nearly 50 percent. The move online didn't simply replace one shirt-buying pathway with another, but changed how much people order, how casually they return, and how quickly products become waste. “The transition from one system to another… it changes how we consume, how much we consume, and what we consume.”
Makov’s preference for industry data over abstract modeling is deliberate. “I basically like data. I don’t like expert opinion because that is often biased. I want to get the real data from the industry, and then I analyze it.” The same empirical rigor informs her research on cultivated meat and fish. Israel has emerged as a global hub for alternative proteins, with companies such as Aleph Farms developing lab-grown steaks. The logic is straightforward: raising animals for food is resource-intensive and polluting. “Instead of growing the cow’s head and brain and eyes, let’s grow just the steak,” Makov says. Fish farming and overfishing bring their own environmental burdens, from depleted stocks to mercury contamination. Shira Shabtai, a PhD student at the Makov lab, conducted a full lifecycle assessment (LCA) of cultivated fish production, accounting for all inputs including energy, amino acids and sugar used to feed cells as they grow, and for waste streams that must be treated.
The results suggest that lab-grown fish can be environmentally competitive with, or superior to conventional fishing. But again, the real story lies at the system level. If alternative sources reduce demand for wild-caught species, marine ecosystems could recover. If fish can be produced domestically rather than imported, food security improves, especially in import-dependent countries like Israel. And in controlled environments, heavy metals and microplastics can potentially be minimized. As for the taste? "The difference is the seasoning. I didn’t like the seasoning; there was too much paprika,” she laughs.
Yet Makov resists the temptation to frame sustainability as a moral crusade aimed at individual consumers. “We are trying very hard to change behavior and we are not succeeding because the whole system around us directs us somewhere,” she says. Advertising, pricing structures, infrastructure... none of these are accidental. “It happens deliberately.” Sometimes, the most dramatic behavioral shifts occur without environmental intent. In a recent paper under review, her team examined the ecological implications of widely used weight-loss drugs, and the conclusion surprised even her. “The impact is unequivocally positive,” she says. Reduced caloric intake translates into lower demand for land, water, and emissions-intensive production. “It’s a revolution that is already underway without us having to convince anyone to eat this way or another.”
Makov’s work ultimately challenges both techno-optimists and moral purists. Technological efficiency does not guarantee reduced impact; people may simply consume more. Sharing platforms are not inherently green, and buying secondhand doesn’t always reduce new clothing purchases. Her ambition is to keep widening the frame, to really look at things at the system level, which means embedding behavioral data into environmental assessments and refusing to assume that humans will behave like the rational agents of economic models. The question is whether our industries, policies, and digital platforms can be structured with that craving in mind and still leave the planet a little less burdened.
Written in collaboration with Ben Gurion University
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.
