Environmental footprint of cannabis production: life cycle assessment-driven evaluation of pretreatment and drying strategies

Cannabis legalisation in Canada creates economic opportunities but also raises environmental concerns. This study aimed to evaluate and compare the environmental footprints of three drying strategies for the production of 1 kg of dried cannabis: conventional controlled environment drying (CED), and two pretreatment methods—microwave-infrared (MI) and cold plasma (CP)—each followed by CED. IMPACT 2002+ was used to assess the impacts across climate change, ecosystem quality, human health, and resource depletion. Both pretreatment methods substantially reduced the environmental burdens compared to CED alone. In the drying stage, CP-CED reduced environmental impacts to approximately 50% of those associated with CED, while MI-CED achieved an even greater reduction of around 72%. In terms of global warming potential, CED contributed 11.31 kg CO2 eq. whereas CP-CED and MI-CED reduced this to 5.68 and 3.25 kg CO2 eq., respectively. These reductions were primarily driven by lower energy consumption and emissions resulting from pretreatment. Overall, this study highlights both MI and non-thermal (CP) pretreatments as effective strategies to lower the carbon footprint of cannabis drying, offering energy-efficient and sustainable frameworks for industrial postharvest practices.