Indoor urban agriculture carbon footprint depends on clean energy, study finds

A new McGill-led study challenges the assumption that local indoor farming is always low carbon. Researchers tracked a commercial container farm in Montreal for a year and found that the climate impact of indoor lettuce depends almost entirely on the local electricity grid. In Quebec, where hydropower dominates, indoor lettuce matches the carbon footprint of lettuce shipped from California. In Alberta, where fossil fuels power the grid, emissions can be many times higher than conventional farming. The study models the same system across all Canadian provinces and territories. It shows that indoor agriculture uses much less land and water than field farming but requires more energy. The authors argue that controlled environment agriculture still has a role in improving food access, especially in remote northern communities where fresh produce is scarce and supply chains are fragile. But the carbon math only works if the grid is clean.