The vivid pink and canary tones shining brightly from the greenhouses in southwestern Ontario are so intense that astronauts can capture them from space. Positioned above the largest cluster of greenhouses in North America, the colorful lights have not only altered the night sky in a region of Ontario but also revolutionized the multi-billion-dollar agriculture industry in the province.
In recent years, a multitude of lights have been installed inside greenhouses in Leamington and Kingsville, Ontario, by vegetable and cannabis producers to enable year-round plant growth. The radiant glow from this southern Canadian region, visible even from Michigan at times, has evoked a mix of wonder and concern. Consequently, local communities have established bylaws to restrict the brightness of the greenhouse lights after dark.
Richard Lee, the executive director of the Ontario Greenhouse Vegetable Growers, acknowledges the challenges in adapting quickly to address the perceived nuisances caused by the rapid introduction of lighting technology. Despite the regulations reducing light spillage into the sky, the vibrant glow remains visible across the region and, impressively, even from the International Space Station.
Starr Livingstone, the light pollution abatement officer for the Royal Astronomical Society of Canada’s Windsor chapter, highlights the impact of the greenhouse glow on their observatory but notes improvements since the implementation of mitigation strategies. Lee emphasizes the importance of balancing concerns with the benefits of local food production, economic growth, job creation, and food sovereignty in North America.
The exponential growth of greenhouses in Kingsville and Leamington, as indicated by recent satellite images from NASA, can be attributed to various factors, including the legalization of cannabis in Canada and the utilization of lighting technology for year-round plant cultivation. The increased demand for fresh produce, particularly during the disruptions in the food supply chain caused by the COVID-19 pandemic, has also fueled greenhouse expansion.
Despite the economic advantages and enhanced productivity achieved through greenhouse technology, criticisms have emerged within the community, particularly regarding ecological impacts. The unique Carolinian ecosystems and migratory paths for birds and monarch butterflies in the region have prompted concerns and led to the implementation of bylaws in Kingsville and Leamington to address greenhouse light pollution.
The bylaws in Leamington mandate the use of light-blocking curtains in greenhouses during specific hours, with allowances for ventilation needs, while Kingsville prohibits any form of curtain gapping. Enforcement efforts have varied, with instances of charges being levied against greenhouse companies in Leamington, signaling ongoing efforts to ensure compliance with the regulations.
Studies conducted on greenhouse light pollution and curtain effectiveness have shown that the amount of light emitted by greenhouses diminishes when curtains are closed, though practical issues may result in some light leakage. Factors such as weather conditions, moon brightness, and human eye adaptability can influence the perception of brightness despite efforts to minimize light emissions from the greenhouses.
Overall, the balancing act between economic growth and environmental considerations continues to play out in the southwestern Ontario region, as stakeholders strive to mitigate light pollution while sustaining the benefits of greenhouse technology.