Socio-economic trajectories, urban area expansion and ecosystem conservation affect global potential supply of bioenergy

Biomass energy is projected to be a critical resource for defossilization of the energy system. While urban area extension and land conservation would constrain potential biomass supply, there is little understanding of their impacts. This paper presents global and regional bioenergy supply potential estimates by newly implementing urban area expansion in an integrated assessment model AIM (Asia-Pacific Integrated Model). Scenarios were investigated as combinations of shared socio-economic pathways (SSPs) with default and expanded urban area and conservation. The bioenergy potentials in 2050 with fixed urban area at base year level were in the range of 228 (SSP3) to 292 (SSP1) exajoules per year (EJ yr-1), corresponding to differences in fraction of land available for bioenergy crop production. The bioenergy potentials under urban expansion closely tracked trends in the reference SSP cases, but with decreases ranging from 4.48 (SSP1) to 6.95 (SSP5) EJ yr-1. While global total effects were small, regions experienced mixed results and in some cases a reversal of trends. Under conservation scenarios, reductions in bioenergy potential caused by urban expansion were observed to be lower except in some regions and scenarios. These results enhance the understanding of SSP patterns of bioenergy potential while at the same time revealing how global trends may fail to capture region-specific trends. The study concluded that: 1) urbanization may lack relevance for bioenergy at the global scale but becomes important for some regions, 2) loss of bioenergy potential can be curbed by encouraging compact urbanization as in SSP1 (Sustainable Development), zoning, and pursuing joint energy-conservation policies.

Automated summary

This paper analyzes the impacts of urban area extension and land conservation on bioenergy supply potential using an integrated assessment model. It finds that while the global effects are small, the impacts vary in different regions and urbanization becomes important for some regions. The study suggests promoting compact urbanization, regional planning, and energy conservation policies to mitigate the loss of bioenergy potential.