The environmental impacts of greenhouse vegetable production have garnered increasing attention, while the long-term economic and environmental sustainability of these systems remains largely unquantified. This study employs life cycle assessment (LCA) and cost-benefit analysis to evaluate the sustainability of three typical greenhouse tomato production systems in Northwest China: solar greenhouses, wide-span external thermal insulation plastic greenhouses (WSTP), and plastic sheds. A space-for-time substitution approach was applied to project the dynamics of environmental impacts and net economic benefits with increasing planting years, complemented by a sensitivity analysis assessing the influence of greenhouse-specific emission factors on the LCA outcomes. The results indicate that the solar greenhouse system delivers the highest net economic benefit due to winter production but concurrently exerts the greatest environmental pressure, particularly on land use. According to the projected data, after 15 years of cultivation, tomato yields and net economic benefits significantly decrease by 20-23% and approximately 30%, respectively, in both solar greenhouses and WSTP. Furthermore, the environmental impacts of solar greenhouses increase significantly over time across most indicators. The study reveals that long-term sustainability of solar greenhouses and WSTP, in terms of productivity and economic returns, is limited, primarily due to the enclosed environments and high inputs of chemical fertilizers, manure, and pesticides. Policymakers of these systems must carefully consider the trade-offs between economic benefits and environmental impacts. To enhance long-term sustainability, it is crucial to adopt eco-friendly management practices that reduce reliance on agrochemicals and improve greenhouse ventilation. The findings also highlight the importance of developing and applying emission factors specific to greenhouse systems, rather than relying on default values, to improve the accuracy of LCA for greenhouse systems. • Net economic benefit decreases with increasing planting years in solar greenhouse and WSTP tomato production systems. • Nine of ten environmental impact indicators increase over time in the solar greenhouse system. • Solar greenhouses deliver the highest net economic benefit but exerts the greatest environmental pressure. • Pesticides and manure are the largest contributors to TET and HNCT, respectively. • Greenhouse construction materials significantly contribute to HCT, AD, and GWP.
Wang et al. (Fri,) studied this question.