Taking the spatio-temporal effects of climate change into account for Life Cycle Assessment of prospective scenarios to secure water supplies in agricultural areas.

To cope with climate change, agricultural territories are forced to implement adaptation strategies, including the implementation of irrigation infrastructures. These strategies are deployed over a long term, and their environmental performance may vary in time and space due to climate change. Environmental assessment methods that include spatio-temporal dynamics must be developed to identify long term "no-regret" scenarios. This study proposes an innovative approach based on the coupling between a crop model, i.e. AquaCrop, and the Territorial-Life Cycle Assessment (T-LCA) framework. Results are exemplified and discussed, with comparison of scenarios with or without irrigation, between 1981 and 2099, at six contrasting locations in terms of climate and soil conditions for the Shared Socioeconomic Pathways 5-8.5 scenario developed by the Intergovernmental Panel on Climate Change. The assessments report that climate change can affect the eco-efficiency of irrigated perimeters over time. Moreover, climate change may alter the conclusions of the comparison of scenarios with or without irrigation infrastructure at a given location. Additionally, a sensitivity analysis is performed on key parameters of the study highlighting the importance of the electricity mix. Finally, spatio-temporal dynamics need to be considered to assess the environmental performance of long-term land planning scenarios and account for environmental effects such as climate change.