Sustainable International Bioenergy Trade. Evaluating the impact of sustainability criteria and policy on past and future bioenergy supply and trade

Abstract

Within a single decade, bioenergy has shifted from a largely local energy source with marginal trade volumes to a globally traded item. The primary objective of this thesis is to evaluate the links between national renewable energy support and trade policies and market forces on past global bioenergy trade volumes and feedstock choices and to sketch possible future trade scenarios under different sustainability criteria.The three supporting objectives, translating into three research questions, are (1) to evaluate the interaction between policies and market forces and their impacts on global bioenergy trade, (2) to analyze the feedstock specific environmental risks for forest biomass with a focus on temporal carbon in order to define potential future environmental criteria, and to (3) simulate how these requirements may influence future woody biomass trade in a global competitive market. Results show that world biofuel production and trade has grown from below 30 PJ in 2000 to 572 PJ in 2009 for biodiesel, and from 340 PJ in 2000 to over 1,540 PJ in 2009 for fuel ethanol. Solid biofuel trade has grown from about 56 to 300 PJ between 2000 and 2010; during which period wood pellets grew strongest from 8.5 to 120 PJ. The defining factor for international trade is economic viability, i.e. the difference between supply, i.e. production, transport, and potential tariff costs vs. destination market prices. The EU has been and is also expected to remain the predominant destination for globally traded biomass for energy (liquid and solid) at least until 2020 due to demand increases under current policy projections and limited regional resources (i.e. land and time constraints to increase productivity levels). The EU sustainability requirements will be the key defining factors for future trade. The key environmental concerns regarding an increased use of forest biomass for energy (excluding deforestation and land-use change) have been found to encompass impacts on soil productivity, biodiversity, and the overall carbon balance. Exact risk levels vary in terms of scientific certainty but are generally site, time, and feedstock dependent. Sustainable forest management is a pre-requisite to avoid most of the risk factors. There are also several mitigation options to reduce short-term soil impacts, e.g. leaving residues on site until foliage has dropped. Regional best management practices and habitat protection are key first order measures to prevent unwanted adverse biodiversity impacts. Current analyses determining the temporal imbalance between the release and sequestration of forest carbon apply different modelling frameworks, the calculated payback and parity times however are typically affected by the same parameters: plant growth rates, and the choice and construction of the forest baseline and the alternative energy system. Comparisons indicate that residue and salvage wood entail shorter payback times than additional fellings of low-grade roundwood. The bulk of forest biomass used for energy today is made up of primary and secondary residues. Timber quality roundwood in particular from less productive or slow growing forest biomes is generally not used for energy due to the higher value for timber (products).