Print PageBiofuel production has drawn great attention worldwide in recent decade since it has the potential to offset substantial use of fossil fuels and to reduce associated greenhouse gas emissions. Given the land availability, marginal land has been regarded as a more favorable option for biofuel production without threatening conservation areas and food security. It is estimated that the global marginal land covers about 1,107-1,141 M ha2 and may fulfill 26-55% of the current world liquid fuel consumption. However, very few studies have been launched to investigate potential impacts of biofuel from marginal land on terrestrial carbon sequestration capacity under future climate change. A big gap still exists in how to compromise between maximizing the benefit of biofuel production and minimizing its negative effects. To narrow this gap, we applied a global process-based ecosystem model DLEM (Dynamic Land Ecosystem Model) in conjunction with global databases, including three climate scenarios, to estimate changes in carbon fluxes and storages induced by biofuel production on marginal land in the 21st century. Several simulation experiments were designed to identify relative contributions of climate change, land use, and agriculture managements to changes in the carbon cycle.
Results/Conclusions
Our preliminary results suggest that large scale utilization of marginal land for biofuel production would greatly enhance the carbon loss from terrestrial ecosystems in some regions, especially under the A1B climate scenario characterized by the rapid economic growth. Therefore, biofuel-related policy making must take the potential decrease of carbon sequestration capacity into account. To balance the benifits of a biofuel policy against its environmental costs, we need to identify the most productive biofuel crop species and optimize associated-land management practices.
