A vibrant display of hot pink and canary-colored lights shining from the greenhouses in southwestern Ontario can be seen from space. This remarkable spectacle, emanating from the largest concentration of greenhouses in North America, has significantly impacted the local agriculture sector.
In recent years, the installation of thousands of lights inside greenhouses in Leamington and Kingsville, Ont., has enabled vegetable and cannabis producers to cultivate plants year-round. However, the intense glow from this region, visible even from Michigan and the International Space Station, has raised both admiration and concern. Consequently, local communities have implemented bylaws to regulate the brightness of the greenhouse lights at night.
Richard Lee, the executive director of the Ontario Greenhouse Vegetable Growers, acknowledges the challenges in responding to the rapid technological advancements that led to the light pollution issues. Despite efforts to reduce light spillage into the sky, the luminous glow remains visible across the region.
The greenhouse expansion in Kingsville and Leamington, as evidenced by satellite photos from NASA, has been fueled by various factors, including the legalization of cannabis in Canada and the adoption of lighting technology for year-round plant growth. The demand for fresh produce, especially during the disruptions caused by COVID-19, has also played a significant role in driving greenhouse expansion.
While the adoption of grow light technology has enhanced productivity, it has faced criticism for ecological concerns due to the region’s unique ecosystems and migratory paths for birds and monarch butterflies. Consequently, both Kingsville and Leamington have enacted bylaws to address the growing light pollution from greenhouses.
Bylaws in Leamington require growers to install light-blocking curtains and regulate the opening of curtains at specific times. In contrast, Kingsville prohibits any curtain “gapping,” prompting growers to explore alternative cooling methods that do not involve opening the curtains.
Efforts to enforce compliance with the bylaws have yielded mixed results, with some challenges in achieving full light abatement due to the need for ventilation in the greenhouses. Despite ongoing concerns, recent reports indicate a decrease in complaints related to greenhouse lighting in the region.
Studies on greenhouse light pollution have highlighted the impact of factors such as curtain effectiveness, weather conditions, and the brightness of the moon on the perception of light emissions. While efforts to minimize light pollution have shown some success, additional measures may be necessary to address concerns and maintain a balance between agricultural productivity and environmental considerations.