Global bioenergy resources

Abstract

Using biomass to provide energy services is a strategically important option for increasing the global uptake of renewable energy. Yet the practicalities of accelerating deployment are mired in controversy over the potential resource conflicts that might occur, in particular conflicts over land, water, and biodiversity conservation. This calls into question whether policies to promote bioenergy are justified. Here we examine the assumptions on which global bioenergy resource estimates are predicated. We find there is a disjunct between the evidence that global bioenergy studies can provide and policy makers' desire for estimates that can straightforwardly guide policy targets. We highlight the need for bottom-up assessments informed by empirical studies, experimentation, and cross disciplinary learning in order to better inform the policy debate. 1 Conflicting aspirations for bioenergyUsing biomass to provide energy services is one of the most versatile options for increasing the global uptake of renewable energy and an important component in many climate change mitigation and energy supply scenarios [1][2][3][4] . The International Energy Agency (IEA), for example, estimates that biomass could contribute an additional 50EJ (~10%) to global primary energy supply by 2035, and states that "the potential supply could be an order of magnitude higher" 4 . Governments of the world's largest economies have also introduced policies to incentivise bioenergy deployment, motivated by concerns about energy security and climate change, and by the desire to stimulate rural development 5,6 . Yet the potential contribution from biomass to global energy supply is controversial. Sources of contention include concern about the inter-linkages between biomass, bioenergy and other systems. Most notably, land and resource conflicts are foreseen between bioenergy and food supply, water use, and biodiversity conservation. The fear is that the benefits offered by increased biomass use will be outweighed by the costs [7][8][9][10] . It is also argued that the wide range of estimates of biomass potential and the lack of standardised assessment methodologies confuses policy makers, impedes effective action and fosters uncertainty and ambivalence 11 . These broad points contribute to a general sense of unease about the future role of bioenergy, and whether it presents a genuine opportunity or is a utopian (or for some dystopian) vision that stands little chance of being realised.Here we analyse how scenarios for increasing bioenergy deployment are contingent on anticipated demand for food, energy, and environmental protection, and expectations of technological advances. We use a systematic review methodology 12,13 to identify and analyse the most influential estimates of the global bioenergy potential that have been published over the last 20 years. The technical and sustainability assumptions that lie behind these estimates are exposed and their influence on calculations of potential described. We find that the range of estimates is primar...

Global consequences of afforestation and bioenergy cultivation on ecosystem service indicators

“…Reported yields of dedicated bioenergy crops under present-day conditions show large variability (miscanthus × giganteus: 5-44 t dry mass ha −1 yr −1 ; switchgrass: 1-35 t ha −1 yr −1 ; woody species: 0-51 t ha −1 yr −1 ), depending on location, plot size, and management (Searle and Malins, 2014). By the end of the century, the LUMs report average bioenergy yields of ∼ 15.0 t ha −1 yr −1 (IMAGE) and ∼ 20.3 t ha −1 yr −1 (MAgPIE), but how bioenergy yields will evolve in reality when averaged across regions (including more marginal land) is highly uncertain (Creutzig, 2016;Searle and Malins, 2014;Slade et al, 2014).…”

“…The total land demand and spatial patterns of these mitigation strategies are highly uncertain due to strong dependencies on underlying assumptions about future environmental and socio-economic changes (Boysen et al, 2017;Slade et al, 2014). BECCS and ADAFF will likely increase pressure on food-producing agricultural areas and, in the case of BECCS, natural ecosystems.…”

Achieving net-zero emissions through the reframing of UK national targets in the post-Paris Agreement era

“…Additionally, future bioenergy resources are likely to be constrained by biophysical and socioeconomic factors, with a wide range of estimates reflecting uncertainties around food security and diets, land use dynamics, and water use 29 .…”

Energy balance of chosen crops and their potential to saturate energy consumption in Slovakia

“…Slade et al, 2014, Tilman et al, 2009) and with economics and sustainability science (e.g. Burger et al, 2012).…”

“…Relationships among global demand for the food (and feed), biofuel (or bioenergy) and environmental conservation was named by Tilman et al (2009) as the food, energy and environment trilemma. The same Slade et al (2014) stated that biomass potential can be broadly divided into those that test the boundaries of what might be physically possible, and those that explore the boundaries of what might be socially acceptable or environmentally responsible. As it was shown above, three major crops are not able to saturate energy consumption (expressed either electricity or natural gas) in Slovakia.…”