Abstract

The legalization of cannabis has caused a substantial increase in commercial production, yet the magnitude of the industry’s environmental impact has not been fully quantified. A considerable amount of legal cannabis is cultivated indoors primarily for quality control and security.

In this study we analysed the energy and materials required to grow cannabis indoors and quantified the corresponding greenhouse gas (GHG) emissions using life cycle assessment methodology for a cradle-to-gate system boundary.

The analysis was performed across the United States, accounting for geographic variations in meteorological and electrical grid emissions data.

The resulting life cycle GHG emissions range, based on location, from 2,283 to 5,184 kg CO2-equivalent per kg of dried flower.

The life cycle GHG emissions are largely attributed to electricity production and natural gas consumption from indoor environmental controls, high-intensity grow lights and the supply of carbon dioxide for accelerated plant growth.

The discussion focuses on the technological solutions and policy adaptation that can improve the environmental impact of commercial indoor cannabis production.

 

 

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Acknowledgements

We acknowledge the Colorado State University GIS Centroid for generating the US results maps, specifically E. Tulanowski, S. Linn and C. Norris. We also acknowledge individuals for their continued support in reviewing this work, namely D. Browning, D. Quinn, J. Barlow, D. Trinko, K. DeRose and W. Stainsby.

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Contributions

J.C.Q. conceived the study. H.M.S., J.C.Q. and E.S. designed the study. H.M.S. and E.S. developed the HVAC modelling approach and LCA framework. H.M.S. developed the code, performed the analysis, wrote the initial manuscript and designed figures, excluding the US maps, with contributions from E.S. and J.C.Q. All authors contributed to the interpretation of the results, discussion, revisions and messaging of the paper.

Corresponding author

Correspondence to Jason C. Quinn.

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Competing interests

The authors declare no competing interests.

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Peer review information Nature Sustainability thanks Melissa Bilec, Michael Martin and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

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Supplementary information

Supplementary Information

Supplementary Figs. 1–11, Method 1 and Tables 1–12.

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