Industrial hemp’s climate and resource benefits can vary widely, depending on cultivation practices, processing methods, and supply chain design, according to a new U.S.-based report published today.
Hemp & Sustainability, published by Canna Markets Group and HempToday, also points to processing and transport as major emission sources, and notes there are limited recycling options for many hemp products.
The report evaluates hemp across four key areas: carbon sequestration, soil health, water use, and full lifecycle impacts. It draws on peer-reviewed research, government data, and lifecycle analyses to compare hemp’s environmental outcomes with those of other crops and materials.
Benefits and limits
Authored by Lorelei Alvarez, Ph.D., a research data specialist at Canna Markets Group and assistant professor at New Mexico State University, the report confirms what’s generally known among stakeholders: that hemp can sequester significant amounts of carbon, and when grown in diverse crop rotations, can improve soil structure, microbial activity, and water infiltration.
Fiber hemp generally requires less water and fewer chemical inputs than other fiber crops, and applications such as hempcrete and insulation can store carbon for extended periods, the report also confirms.
No guaranteed outcomes
However, these outcomes are not guaranteed. Soil type, climate, cultivar selection, nutrient management, and post-harvest handling all influence environmental performance, with some production systems negating field-level gains, Alvarez writes.
Get this report and other intelligence reports from the HempToday library
The energy needed to process hemp emerges as a major factor in hemp’s lifecycle footprint. The report said retting, decortication, and production of such things as binders needed for some final products, can account for up to 45% of greenhouse gas emissions in some product categories. Shifting to renewable energy during processing significantly reduces these impacts, the report suggests.
Transportation of hemp material also contributes to emissions, an impact the report says can be overcome by developing tightly organized regional processing capacity.
End-of-life challenges
End-of-life is described in the report as a weak link for many hemp-based construction and composite materials, which often lack recycling pathways and may not compost under typical conditions. Durable products, while beneficial for long-term carbon storage, require intentional design-for-disposal approaches and expanded recovery infrastructure, the report urges.
Hemp’s environmental performance is determined by the broader system in which it is grown, processed, and distributed, Alvarez writes. She identifies key priorities, including developing regionally adapted cultivars, expanding co-located processing facilities, improving low-impact processing methods, and building end-of-life infrastructure for durable hemp goods.