Key messages

• Insect farming often falls short of its environmental promise. Greenhouse gas emissions generated per kilogram of protein from insect production in temperate climates vary, but they can approach those of chicken and pork, and exceed those of soymeal and fishmeal.

• Favourable environmental results depend on conditions rarely met in practice. Low-emission insect farming requires organic waste as feed, minimal heating and renewable energy – a combination seldom achieved in temperate countries.

• Insect farming reinforces conventional animal agriculture rather than replacing it. A substantial proportion of insects are farmed for feed for farmed animals and aquaculture, not to substitute for meat in human diets.

• The sector poses underexamined risks. Insect farming introduces potential biodiversity threats from accidental releases and emerging animal welfare concerns, given growing evidence that at least some insect species may be capable of suffering.

• Investment in insect farming carries opportunity costs. To date, major companies, accounting for more than a third of total investment, have failed or have entered restructuring. Resources directed towards insect protein may divert funding, policy attention, and public goodwill from plant-based, fermentation-derived, and cultivated proteins: alternatives that may offer clearer sustainability benefits, with fewer drawbacks.