An integrative approach to reducing land, water, and carbon footprint of global energy consumption in the transport sector

Water, land, carbon and energy are closely connected by links that are widely recognized but sparsely studied and not sufficiently quantified. More studies focus on quantifying the carbon footprint of different energy sources than on quantifying their land and water footprints. However, land and water footprints of renewable energy sources are becoming key determinants of their long-term sustainability and acceptability. Generally, as a tradeoff for having smaller carbon footprint, the land and water requirements of renewable energy sources are larger compared to fossil fuels. Fossil fuels are currently the dominant energy source in all sectors of the global economy and their use leads to the emission of greenhouse gases (GHG) that are causing climate change. Among the different sectors, the transport sector is a unique case in the sense that it emits a quarter of GHGs but transitioning to low-carbon technologies is very challenging for at least two reasons: (1) to be viable, the energy density of transport fuels needs to be high and this limits the choice of alternative fuels that can be used in the transport sector; and (2) the highly developed infrastructure for fossil fuels production, distribution and usage in the existing fleet of transport modes makes infiltration of renewable energy difficult. The overarching objective of this research is to contribute to the discourse concerning the energy transition to low-carbon fuels in the transport sector in order to meet climate targets, while considering the land and water implications of alternative fuels.