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This review evaluates the sustainability of tomato production in four greenhouse systems: high-tech (The Netherlands) and low-tech (Spain) combined with two ways of cultivation (conventional or organic). The Sustainable Development Goals (SDGs), as defined by the United Nations, were used as a lens to assess the sustainability of these four greenhouse production systems. In total seven SDGs, including 14 targets, were assessed through 12 quantitative and two descriptive indicators. Conventional, high-tech greenhouse systems showed the greatest potential for positive contributions towards four of the SDGs. However, their relatively high energy use makes it difficult to achieve SDG7 on affordable and clean energy, where low-tech systems perform better due to lower energy use from relatively cleaner sources. Lower water use efficiency and higher nutrient losses in all soil-based cultivation systems are barriers to achieving some targets under most of the selected SDGs. Organic cultivation systems showed relatively high water and land use, based on the limited data available. Our review highlights the existence of substantial synergies, but also considerable trade-offs between SDGs. This needs to be considered when making policy, investment and management decisions related to greenhouse production.

Elevated CO2 enhances the rate with which photosynthesis responds to stepwise irradiance increases, regardless of the initial photosynthetic induction state, and slows down induction loss after switches to low irradiance., Leaves are often exposed to fluctuating irradiance, which limits assimilation. Elevated CO2 enhances dynamic photosynthesis (i.e. photosynthesis in fluctuating irradiance) beyond its effects on steady-state photosynthesis rates. Studying the role of CO2 in dynamic photosynthesis is important for understanding plant responses to changing atmospheric CO2 partial pressures. The rise of photosynthesis after a step-wise increase to 1000 μmol m–2 s–1, the loss of photosynthetic induction after irradiance decreases, and rates of photosynthesis during sinusoidal changes in irradiance were studied in tomato (Solanum lycopersicum L.) leaves, using three CO2 partial pressures (200, 400, and 800 µbar). Initial irradiance was set to 0, 50, 100, and 200 μmol m–2 s–1 to vary the initial induction state. Most responses at 200 µbar were not different from those at 400 µbar. In contrast, CO2 at 800 µbar increased the relative carbon gain by 12% after an increase in irradiance, decreased the loss of photosynthetic induction by 14%, and increased dynamic photosynthesis during sine waves by 17%, compared with 400 µbar. These effects were additional to steady-state effects of elevated CO2 on photosynthesis. The enhancement of dynamic photosynthesis rates by elevated CO2 may therefore additionally increase photosynthesis in a future, CO2-enriched climate.