Environmental impact of Danish organic tomatoes grown in greenhouses: quantifying the reduction potential from changes in energy supply towards 2030

Summary

The demand for organic food products, including tomatoes (Solanum lycopersicum, L. 1753), is growing. Heated greenhouse production is well described through life cycle assessment (LCA), but inventories reflecting organic production conditions are inadequate or missing. At the same time, energy systems in Europe are changing, which is expected to have a considerable impact on the emissions from the energy intensive greenhouse production. Thus, this study is assessing the current environmental impacts using LCA of an organic tomato production in a heated greenhouse, and estimate the expected changes to impacts due to changes in energy supply. The assessment is based on activity data from a commercial greenhouse production. Current organic tomato production where plants are transplanted into the greenhouse in the late winter has impacts of 1.06 kg CO2 eq., 7.22x10-4 N eq., 3.49x10-5 kg Sb eq., and result in 3.12 kg C deficit from land use while consuming 24.58 MJ of energy per kg organic tomato. The impacts from earlier started tomato cultures are higher, as increased yield does not remedy increased energy use. The result from current production
22 shows that direct energy consumption is responsible for the main impact on climate change (78%), cumulative energy demand (75%), marine eutrophication (56%) and land use (62%). However, expected future changes in the energy system towards 2030 are likely to reduce life cycle environmental impacts considerably (reduction potential for climate change impact: 69%, cumulative energy demand: 48%, eutrophication potential: 47%, mineral, fossil and renewable resource depletion: 4%, land use: 48%) as intensity of the energy supply changes. Mitigation options such as increased energy efficiency, alternative heat sources and agronomic management decisions are further discussed.