Geospatial analysis found that licensed cannabis cultivation in Colorado caused over 67 hectares of land use change, new fencing, and vegetation clearing in areas harboring threatened and endangered species.
Environmental policymakers, cannabis regulators, conservation biologists, and advocates for sustainable cannabis cultivation.
67+ hectares of habitat change; threatened species areas affected
What the researchers found
From 2011 to 2016, licensed cannabis cultivation resulted in over 67 hectares of land use change toward more developed uses. Nearly 15 km of new fencing was constructed establishing over 38 hectares of fenced areas, and nearly 60 hectares of vegetation was cleared. Much of this change occurred within habitats of threatened and endangered species.
Why it matters
Legalization is often framed as environmentally beneficial by moving cultivation indoors and under regulation. This study shows that legal outdoor and greenhouse cultivation can still cause significant habitat encroachment.
The numbers in context
67+ hectares of LULC change. 15 km of new fencing. 38+ hectares fenced. ~60 hectares vegetation cleared. Changes primarily from outdoor and greenhouse facilities in rural areas.
How the study worked
Geospatial analysis of licensed recreational cannabis cultivator locations in Colorado. Examined distribution of cultivators, potential habitat infringement of threatened and endangered species, and land use/land cover (LULC) change from 2011 to 2016.
What this study cannot tell us
Single state (Colorado). LULC analysis may not capture all environmental impacts. 2011-2016 timeframe may not reflect current patterns. Cannot determine species-level impacts from habitat proximity alone.
How to read the evidence
Detailed geospatial analysis with specific land use measurements, but single state and limited timeframe.
When this study was published
Published in 2022, covering 2011-2016.
The bigger picture
Cannabis legalization creates a new agricultural industry competing for land. Without policies specifically directing cultivation to urban indoor facilities, habitat loss may be an unintended consequence of liberalized cannabis laws.
Questions still open
- Would mandating indoor urban cultivation prevent habitat encroachment? How do environmental impacts of legal cannabis compare to other new agricultural crops?
Common questions
Does legal cannabis farming harm the environment?
Can cannabis legalization be environmentally friendly?
Read the original research
Legalization of Cannabis and Agricultural Frontier Expansion.
Environmental management, 69(2), 333-352
Citation
Klassen, Mark; Anthony, Brandon P. (2022). Legalization of Cannabis and Agricultural Frontier Expansion.. Environmental management, 69(2), 333-352. https://doi.org/10.1007/s00267-021-01555-x