Sequestering carbon dioxide by the use of the energy crop miscanthus: quantifying the energy production and sequestration potential of Europe

Global warming caused by anthropological emissions of greenhouse gas (GHG) is now an inconvenient reality. CO₂, the largest contributor, was emitted at the rate of 6 Gt C y^-1 by burning fossil fuels in 1990, which are projected to rise to around 10 Gt C y^-1 by 2020. Using bio-fuels, such as bioethanol or bio-diesel in transportation, or biomass in power generation reduces CO₂ emissions as the carbon is fixed by the plants from the atmosphere and saves the equivalent fossil fuel. The biospheric flux of carbon from the soil and terrestrial biota to the atmosphere is about 120 Gt C y^-1 and is roughly balanced by the fixation of carbon by photosynthesis. However, anthropological land use change, through increased agriculture and forestry, resulted in atmospheric emissions of 1.1 Gt C in 1990, projected to rise to 1.5 Gt C in 2020, so the production of biofuels is not GHG emission free if land use change is involved. This paper explores the GHG emission cost of the production of bio-fuels derived from energy crops and compares them to fossil fuels used in transport and electricity generation. The bio-fuels emission cost are presented for several land use scenarios showing that highest sequestration can be achieved by using existing arable land for bio-fuel production and not land with a currently undisturbed ecosystem. Considering these drivers and the GHG emissions, we model the future potential of Europe to produce bio-fuels with four different future land use and climate change scenarios and conclude that up to 20% of Europe's current primary energy consumption could be provided by bio-fuels by the year 2080 with a corresponding reduction in carbon emissions, taking into account the GHG cost of production.