Introduction
The global demand for food production has led to significant environmental challenges, including greenhouse gas emissions, land degradation, and water depletion. With climate change, urbanization, and population growth, conventional farming practices are becoming increasingly unsustainable. Vertical farming (VF) has emerged as a potential solution to address these challenges by utilizing controlled indoor environments to grow crops. This article explores the environmental implications of producing vegetables using vertical farms compared to conventional open-field (OF) production, focusing on key impact factors such as energy use, greenhouse gas emissions, land and water use, and overall sustainability.
Environmental Performance of Vertical Farming
Vertical farming, an innovative agricultural technique, provides several environmental benefits due to its controlled production system. VF systems use a multi-layered approach to crop production, maximizing space utilization and ensuring a stable supply of crops throughout the year and seasons. One of the key advantages of VF over conventional methods is the reduced need for long transportation chains, leading to a decrease in greenhouse gas emissions. Furthermore, vertical farming minimizes food loss and wastage by ensuring higher product quality and longer shelf life.
However, the controlled environment of VF relies heavily on artificial lighting and temperature regulation, primarily powered by electricity. For instance, VF systems consume around 10 kWh of electricity per kilogram of lettuce, which is significantly higher than conventional farming methods. The energy-intensive nature of vertical farming makes its environmental impact highly dependent on the regional electricity grid. In countries like Sweden, where the electricity mix consists of hydropower and nuclear energy, the negative environmental footprint of VF is lower. In contrast, VFs located in regions with coal-based energy systems would have a higher negative impact due to increased fossil fuel use.
Comparison with Conventional Farming
Conventional open-field farming has been the backbone of global food production, but it comes with several environmental costs. The reliance on vast tracts of land for crop cultivation leads to habitat loss and biodiversity degradation. Additionally, conventional farming is responsible for significant water consumption and fertilizer use, contributing to freshwater depletion and nutrient runoffs that cause eutrophication in nearby water bodies. Conventional systems also require extensive transportation networks to supply urban areas with fresh produce, leading to high greenhouse gas emissions from fossil fuel combustion.
In terms of environmental metrics, conventional vegetable production tends to perform poorly in areas such as greenhouse gas emissions, water use, and land use. The transportation of produce from rural farms to urban centers contributes to 40–69% of environmental impacts in conventional systems. These impacts include increased carbon dioxide emissions from vehicles, nitrogen oxides from fertilizers, and energy consumption for storage and cooling. Packaging( Vertical farming minimizes packaging needs because it’s often located near consumers, reducing transportation and preservation requirements. Its controlled environment also reduces the need for protective packaging, while sustainability efforts promote minimal or reusable packaging.) also plays a role, with conventional farming requiring significant amounts of plastic and cardboard, further adding to the carbon footprint.
Trade-offs and Considerations for Sustainability
While vertical farming shows promise in reducing certain environmental impacts, there are several trade-offs that need to be considered for its sustainability. The energy consumption in VFs is a major challenge. Even with advancements in energy-efficient LED lighting and cooling systems, the reliance on electricity remains a barrier to achieving a fully sustainable system. However, this can be mitigated in regions with renewable energy sources, where the environmental impacts of VFs are considerably lower. In contrast, conventional farming’s environmental impact is more consistent across regions, with land use and water consumption remaining significant challenges regardless of location.
Waste reduction is another area where vertical farming offers clear advantages. Due to the controlled environment in VFs, less bio waste is generated compared to conventional farming, where crops often suffer from damage due to pests, weather conditions, and transportation. Moreover, vertical farms typically eliminate the need for cleaning steps before packaging, further reducing water use and waste generation. This makes VFs a potentially more sustainable solution for high-demand, perishable crops like vegetables.
However, both systems require improvements to achieve long-term sustainability. Vertical farms must adopt renewable energy solutions to offset their high electricity use, while conventional farming needs to focus on improving irrigation techniques and reducing fertilizer runoffs. Policymakers and industry stakeholders need to support the development of sustainable farming practices that balance energy, water, and land use efficiency in both vertical and conventional systems.
Conclusion
The environmental implications of vegetable production using vertical farms, and conventional production systems present a complex set of trade-offs. Vertical farming holds promise for reducing transportation-related emissions, improving food security, and reducing waste. However, its sustainability is heavily influenced by energy use, particularly in regions that rely on fossil fuels for electricity. On the other hand, conventional farming’s major environmental impacts stem from land use, water consumption, and transportation, which can be mitigated through the adoption of more sustainable practices.
In conclusion, vertical farming can be more environmentally beneficial under the right circumstances, particularly in regions with renewable energy sources. Conventional farming, while still essential for global food production, must evolve to meet the growing demand for sustainability. Future research should focus on optimizing both systems to achieve a more sustainable global food supply, with considerations for energy, water, and resource use. By addressing these challenges, the agricultural industry can transition toward more efficient and environmentally friendly practices for vegetables and other crops.
References
- Environmental Implications of Lettuce Sourcing: Comparison of Sourcing from Vertical Farms and Conventional Production by Aina Cabrero Siñol, Michael Martin