Environmental Impact of the Production of Mealworms as a Protein Source for Humans – A Life Cycle Assessment

If the world's population reaches ten billion by mid-century, and if people keep eating meat at current rates, we'll need seventy to eighty percent more animal protein than we produce today. That's not a projection from an advocacy group — that's the baseline from a life cycle assessment published by Oonincx and de Boer. The system we'd be scaling up already consumes about seventy percent of all agricultural land and contributes around fifteen percent of total human greenhouse gas emissions. More demand, finite land, and a climate already under pressure. The counterproposal Oonincx and de Boer put forward is a worm. A mealworm, specifically — Tenebrio molitor — farmed in a climate-controlled shed, eating grain and carrots. The idea is not whimsical. It's a hypothesis, and they test it with hard numbers. The tool they use is life cycle assessment, or LCA. LCA is a standardized method that tracks preselected environmental parameters across an entire product's life cycle — from feed production and transport through the rearing facility all the way to the farm gate. For mealworms, that means accounting for every input: the mixed grain diet of wheat bran, oats, soy, rye, corn, and beer yeast; the fresh carrots; the cardboard egg trays the larvae live on; the natural gas that heats the rearing building; and the electricity that runs ventilation. Nothing is assumed away. The question is whether this system, measured rigorously, actually beats the conventional alternatives. To make the comparison meaningful, the team uses two functional units — two different ways of expressing what a kilogram of product actually delivers. The first is simply one kilogram of fresh mealworms. The second, and more important one, is one kilogram of edible protein. That second unit is what lets you put a worm next to a chicken next to a cow on equal terms. Mealworms are eaten whole, so the edible fraction is one hundred percent of the animal. To convert fresh weight to protein, Oonincx and de Boer use a dry matter content of thirty-eight percent and a crude protein content of fifty-three percent of that dry matter — numbers that come from the biology of Tenebrio molitor itself. One efficiency metric sits at the center of the analysis: feed conversion ratio, or FCR. FCR is simply the kilograms of feed required to produce one kilogram of live animal. For the mealworms in this study, the FCR for concentrates was 2.2. That puts them right alongside chickens, which average 2.3, and well ahead of pigs at 4.0 and beef systems, which range from 2.7 to 8.8. Mealworms are also biologically unusual in one important way: they produce no enteric methane. Cattle and pigs generate methane as a byproduct of digestion — beef can produce over 2,800 grams of methane per kilogram of mass gain. Mealworms, in the range measured across insect species, produce between 2 and 122. That difference matters enormously when you start tallying greenhouse gases. Now for the numbers themselves. Per kilogram of edible protein, mealworm production generates a global warming potential — GWP, the standard measure that converts methane and nitrous oxide into carbon dioxide equivalents — of fourteen kilograms of carbon dioxide equivalents. It uses one hundred seventy-three megajoules of fossil energy. And it requires eighteen square meters of land per year. On GWP, the literature ranges for conventional proteins tell the story clearly: milk runs one point seventy-seven to two point eighty times higher than mealworms, chicken one point thirty-two to two point sixty-seven times higher, pork one point fifty-one to three point eighty-seven times higher, and beef five point fifty-two to twelve point fifty-one times higher. Mealworms beat all four, and it's not close at the beef end of the range. Land use is even more striking. Mealworm production requires only forty-three percent of the land needed to produce the same edible protein from milk and just ten percent of the land required for beef. The ratio for chicken and pork falls between those extremes, but the direction is consistent: mealworms use far less land per gram of protein delivered. The reason is mostly feed. Within the mealworm system, feed grain cultivation accounts for eighty-five percent of land use, and carrots for another fourteen percent. The system's land footprint is almost entirely a function of what the worms eat. Energy use is where mealworms look less flattering, and the study doesn't hide it. At one hundred seventy-three megajoules per kilogram of edible protein, mealworm production uses more energy than milk — whose energy demand is only twenty-one to eighty-three percent of the mealworm figure — and more than chicken, at forty-six to eighty-eight percent of mealworm levels. Pork is roughly comparable, ranging from fifty-five to one hundred thirty-seven percent. Beef is the one category where mealworms clearly win on energy too, at one point zero two to one point fifty-eight times the mealworm figure. So the energy story is mixed: better than beef, worse than milk and chicken, on par with pork. That's an honest result, and it points directly to what's driving the energy demand within the system. Within the mealworm farm, GWP breaks down like this: forty-two percent from feed grain production and transport, twenty-six percent from natural gas used to heat the facility, seventeen percent from electricity, and fourteen percent from carrots. For energy use, the split is similar: thirty-one percent feed grains, thirty-five percent heating gas, twenty-one percent electricity, and thirteen percent carrots. That means more than half the energy demand — and more than a third of the greenhouse gas footprint — comes from keeping the building warm and lit. The biology of mealworms requires a controlled thermal environment, and in this Dutch facility, that environment runs on fossil fuels. Oonincx and de Boer treat this as a lever, not a fixed constraint. They note that larger larvae produce surplus metabolic heat that could be redirected to heat the more temperature-sensitive younger larvae — essentially using the animals themselves as part of the heating system. They also point to alternative energy sources as a general pathway for reducing both GWP and energy use, though they don't quantify those scenarios within this paper. Feed composition is the other major lever: the grain-heavy diet drives both GWP and land use, and the paper flags feed optimization as an avenue for further improvement. What they're describing is a snapshot of a young industry, not a fixed endpoint. The allocation method the team uses deserves a brief note because it affects how you read the numbers. When a production process generates multiple outputs, you have to decide how to assign environmental burden between them. Oonincx and de Boer use economic allocation — distributing burden according to the relative market value of the outputs — which they note allows direct comparison with other published animal protein studies. The manure produced alongside the mealworms is not assigned environmental burden under this method. The authors acknowledge that other allocation approaches exist, though they don't provide a full quantitative sensitivity analysis in this paper. So what does the full picture say? Mealworm production, as measured in this study, has substantially lower greenhouse gas emissions than all four conventional protein sources and requires far less land than any of them. On energy, it sits in the middle of the pack — better than beef, worse than milk and chicken. Oonincx and de Boer identify land availability, not greenhouse gas intensity, as the binding constraint for sustainable protein supply at scale. By that measure, mealworms clear the bar by a wide margin. This is one species, one facility, and one production system measured at one point in time. The paper is careful not to overread beyond its data. But what Oonincx and de Boer have done is make the comparison empirical. The question of whether insects can serve as a serious protein source for humans is no longer purely theoretical — it now has a life cycle assessment attached to it, with feed conversion ratios, energy balances, and land use figures that can be set directly alongside the numbers for milk, chicken, pork, and beef. The worm turns out to be worth measuring. This lecture was created by ennepō. Go to https://ennepo.ai to Discover, Create and Follow the latest research in your field. Read when you can. Listen when you want to.