Bioenergy and Land use change: Local to Global Challenges
- 1. Bioenergy and Land use: Local to Global Challenges Dr Jeanette Whitaker Centre for Ecology & Hydrology, Lancaster
- 2. Contents 1. Background I. Types of bioenergy, global use and potential benefits II. Overview of the historical context of bioenergy policy III. Potential environmental risks 2. Assessing carbon savings from bioenergy production I. Bioenergy life-cycle II. Land use, soil carbon and greenhouse gas emissions III. Ecosystem Land use Model for UK bioenergy 3. Communicating research on bioenergy I. Synthesising evidence through Knowledge Exchange II. Consensus, uncertainties and challenges for perennial bioenergy crops
- 3. Diverse feedstocks 1st generation Wheat, sugar-beet, oilseed rape Sugar-cane, oil palm, soy, maize, jatropha Transport fuel Biogas 2nd generation Perennial grasses: Miscanthus, switchgrass Woody crops: Short rotation coppice (SRC) willow, SRC poplar Forest biomass and forest residues Maize stover, wheat stalks Transport fuel, Heat Electricity Biogas Waste tallow, municipal solid waste, recycled vegetable oil Transport fuel Biogas Bioenergy Diversity Bioenergy is energy derived from biomass including: food crops, perennial energy crops, forest and crop residues and organic waste
- 4. Bioenergy statistics Biomass 10% world energy supply (58 EJ, traditional and modern) Modern bioenergy 2% of world electricity generation 4% of world road transport fuel UK in 2015 Bioenergy contributes: 71% of renewable energy use 4.4% of UK electricity 4.5 % road transport fuel 2.4% heat https://www.gov.uk/government/collections/renewables-statistics
- 5. Bioenergy: Political and historical context 1974 1978 1985 1989 1992 1997 2001 2003 IEA established IEA Bioenergy set-up IEA “environmentally acceptable manner” “integrated policies which further energy security, environmental protection and economic growth” UNFCCC Rio Summit Kyoto protocol EU white paper and directives 1997 - target to increase proportion of renewable energy to 12% by 2010 2001 - electricity from renewable sources 2003 - promotion of biofuels
- 6. Carbon reductions and carbon neutrality 1997 2001 2003 2009 EU white paper and directives • C reductions assumed • no criteria for sourcing sustainable biomass monitor/report on C emission reductions and crop sustainability EU Climate and Energy Package RED (2020 targets) • Renewables must contribute to carbon reduction targets • quantified and reported • minimum sustainability criteria (solid and gaseous biomass excluded) 2008 UK Gallagher review: indirect effects of biofuels 2015 RED amended to avoid ILUC 2016 REDII – 2030 targets
- 7. Land Use, Bioenergy and the Energy Trilemma Bioenergy could deliver upto 50% of global primary energy by 2100 (IEA/IPCC scenarios) Keeping warming below 2oC is almost impossible without bioenergy and more costly (Integrated Assessment Modelling) But significant land-use change required globally Land Food Fibre Energy Climate change Biodiversity Environmental degradation Energy Technologies Institute 2016
- 8. Bioenergy and land-use: potential risks Requires significant land-use change Feedstock type Land management Land type converted Direct land use change (dLUC) Indirect land use change (iLUC) Bioenergy crop cultivation displaces food production resulting in conversion of natural ecosystems e.g. deforestation and increased GHG emissions
- 9. Bioenergy life-cycle carbon balance combustion N-fertilizer production, harvesting, drying, processing, transport Soil carbon stock change CO2 CH4 N2O GHG balance from cultivation Co-products from biofuel production Indirect N2O
- 10. straw strawwoodywoodygrassesgrasses gCO2eq.MJ -1 fuel 0 20 40 60 80 100 120 Wheat-grain Sugarbeet Variability in bioenergy life-cycle assessment Real Fertiliser use Crop yields Feedstock drying method LCA methodology System boundaries Co-product credit method Uncertainty N2O emissions from field Soil carbon stock change ? Bioethanol GHG emissions GWP of petrol 60% GHG saving 21 Whitaker et al 2010, GCB Bioenergy Rowe et al 2011, Biofuels No co-products DDGS DDGS/straw All co-products
- 11. Bioenergy life-cycle carbon balance combustion harvesting, drying, processing (chipping/fuel production), transport Soil carbon stock change CO2 CH4 N2O GHG balance from cultivation Uncertainties • Effects of land-use change • Effects of land use and management Co-products from biofuel production Indirect N2O
- 12. Aim to reduce uncertainty in carbon savings from perennial bioenergy feedstocks in the UK Quantify the impact of direct land-use change to bioenergy on soil carbon and GHGs (CO2, CH4 and N2O) Test land management and mitigation strategies Develop a knowledge exchange network to increase impact CEH Bioenergy and Land Use Research
- 13. Measurement Framework Miscanthus (perennial grass) Short rotation coppice willow Short rotation forestry Measurements on commercial farms: • Intensive soil carbon and greenhouse gas monitoring sites (4) • Soil carbon stock assessments (~70 paired sites) • Carbon isotope techniques to improve mechanistic understanding 18 Land use change scenarios for the UK Original land use Bioenergy land use Arable Wheat, sugar beet, OSR, SRC willow, SRF, Miscanthus Grassland Wheat, sugar beet, OSR, SRC willow, SRF, Miscanthus Forestry Wheat, sugar beet, OSR, SRC willow, SRF, Miscanthus www.elum.ac.uk
- 14. Met StationEddy TowerPower Static Chambers Miscanthus 11.5 ha SRC-Willow 9.5 ha Arable 8 ha Miscanthus 11.5 ha SRC-Willow 9.5 ha Arable (OSR-barley- wheat) 8 ha Eddy covariance Net Ecosystem Exchange (NEE): balance between photosynthesis and plant and soil respiration GHG emissions Measurements of CO, CH4 and N2O Lincolnshire: Arable to Miscanthus /short rotation coppice willow Soil carbon stock change 30 cm and 1 m depth sampling
- 15. Grassland 2 Grassland 1 Willow Met StationEddy TowerPower Static Chambers 2.82ha 8.13ha 7.44ha West Sussex: Grassland to short rotation coppice willow
- 16. East Grange, Fife: grassland & arable to Short rotation forest pine, Short rotation coppice willow
- 17. Aberystwyth: grassland to Miscanthus
- 18. LUC Aberystwyth GHG emissions: Grassland to Miscanthus GHG emissions were significantly higher from grassland compared to Miscanthus McCalmont et al 2016 GCB Bioenergy
- 19. Soil carbon stock change following LUC to bioenergy 0 100 200 300 400 0 100 200 300 400 BioenergytCha-1 Reference t C ha-1 SRC 0 100 200 300 400 0 100 200 300 400 BioenergytCha-1 Reference t C ha-1 Miscanthus Rowe et al. (2016) GCB Bioenergy Miscanthus Ex-grass = -16.2 t C ha-1 Ex-arable= 3.3 t C ha-1 SRC willow / poplar Ex-grass = -30.3 t C ha-1 Ex-arable= 9.7 t C ha-1 Planting on arable land = soil carbon gain Planting on grassland = soil carbon loss
- 20. The Ecosystem Land Use Modelling Tool A user-friendly spatial tool to explore the consequences of land use change to bioenergy, in terms of soil carbon and GHG emissions to 2050 Available to download from the CEH website in 2017 All publications available on www.elum.ac.uk
- 21. LUC from arable to bioenergy: net GHG balance MiscanthusSRC willow Net GWP t CO2e ha-1
- 22. GCB Bioenergy Volume 9, Issue 3, pages 627-644, 23 APR 2016 DOI: 10.1111/gcbb.12360 http://onlinelibrary.wiley.com/doi/10.1111/gcbb.12360/full#gcbb12360-fig-0007 Impact of bioenergy land-use change in the UK to 2050 on field GHG emissions Changes in soil carbon stocks determine the field GHG balance Knowledge gaps - conversion and reversion impacts on N2O emissions and soil carbon stocks
- 23. Quantify ‘temporal GHG hotspots’ over the life cycle of perennial energy crops • Land use conversion and reversion Test management strategies to mitigate hotspot emissions • New planting and crop removal methods International case studies e.g. GHG balance of sugarcane and N. American wood pellets LAND-USE CHANGE Fertiliser N Planting Drought Flood Harvesting Fertiliser P Harrowing
- 24. Cross-council UK Researchers Policy International Industry International Stakeholder and Researcher Network Knowledge Exchange Fellow
- 25. Compare outcomes from UK and global research on bioenergy and land-use change and identify areas of consensus and uncertainty Bioenergy and land-use change workshop Ecosystem Land-use Modelling (ETI-ELUM) UK Niall McNamara Miscanthus, SRC willow, Short rotation forestry POPFULL (ERC) Belgium Reinhart Ceulemans SRC poplar and willow Energy Biosciences Institute, Illinois USA Evan DeLucia Carl Bernacchi Miscanthus, switchgrass Soil carbon & Land-use change Brazil Ado Cerri Sugarcane Researchers: Brazil, USA, Belgium and UK Policymakers: DECC, EU JRC and UNCCD Industry: Shell, BP, AHDB
- 26. Consensus, uncertainties, opportunities facts knowns / certainties risks hurdles / barriers / issues in approaches used unknowns uncertainties/gaps in data or knowledge opportunities future research needs / maximising impact of current knowledge decisions what should we be doing, changes to policy needed
- 27. Annual cropland Grassland • Reviewed 28 publications 2008-2016 • 87 scenarios of crop / prior land-use / fertilizer • SRC willow and poplar, Miscanthus and switchgrass Uncertainties: • N2O emissions during establishment • Grassland conversion to bioenergy Consensus: N2O emissions vary dependent on prior land-use, fertilizer use and crop age N2O emissions from perennial bioenergy crops are small but strongly depend on the previous land use Challenges: • Higher resolution data needed • Mitigation should target N efficiency and planting methods
- 28. Changes in soil carbon stocks depend partly on prior land use GrasslandAnnual cropland SRC willow Miscanthus Qin et al (2016) GCB Bioenergy, 8, 66-80 SRC willow Miscanthus Soil carbon gain Soil carbon loss SoilCsequestration(tCha-1yr-1) Increase or negligible change in soil carbon stocks is more likely if crops are planted onto annual cropland
- 29. Pre-conversion soil carbon stock is a better predictor of soil carbon stock change, than prior land use Uncertainties: • the permanence of gains in soil carbon • Inconsistent measurement methodology Carbon stock change following conversion from arable (red) or grassland (green) to SRC willow Rowe et al 2016, GCB Bioenergy Planting perennial bioenergy crops on low carbon soils will deliver greater soil carbon sequestration potential
- 30. Conclusions and remaining uncertaintiesBiofuel life-cycle emissions: Soil carbon and N2O GWP of petrol 60% GHG saving N-related emissions are significant and variable Soil C changes are highly variable and significantly affect the net global warming intensity Miscanthus SRC Poplar Arable - fertilized Grassland - unfertilized Ethanol Renewable gasoline
- 31. Perennial bioenergy crops marginally reduce water availability but improve water quality through reduced nitrate leaching Consensus: • Perennial crops use more water than annual crops at a landscape scale but have greater water-use efficiency • Lower nitrate leaching (upto 22%) from Miscanthus and switchgrass compared to annual crops grown for biofuel production Uncertainties: Regional scale effects on hydrological processes and nitrogen flows require modelling Carl Bernacchi and Evan DeLucia, University of Illinois
- 32. Bioenergy deployment can be optimised through landscape scale assessment using ecosystem process models Consensus: • The use of ecosystem models is essential for synthesising site- specific, intensive and sometimes contradictory field observations • This enables the production potential and environmental impacts of real-world bioenergy systems to be assessed Uncertainties and challenges: • Ensuring realism in scenarios e.g. marginal land deployment • Delivering broad spatial assessments integrated with LCAs and economic analyses
- 33. Conclusions • Perennial bioenergy crops can deliver significant GHG savings and additional benefits e.g. water quality • Soil type, climate, prior land-use and land management affect GHG intensity of perennial bioenergy crops • Maximum GHG savings achievable where crops are grown on low carbon soils with conservative nutrient application • Reducing uncertainty in soil carbon stock change should be a higher priority than refining N2O emission estimates Whole-system conclusions are needed for policymakers, setting soil carbon and GHG emissions in the context of energy balance, economic viability and wider ecosystem service valuations
- 34. Climate change and GHG mitigation require an approach where all reduction measures that are feasible, cost-effective and environmentally sustainable should be pursued. Evidence is available to design safeguards which are needed to support sustainable bioenergy supply chains which include: • sustainable management of natural resources • avoid unintended consequences Robust assessment of trade-offs is needed to enable policy which: • supports options that mitigate risks • provides co-benefits for environment and society Bioenergy: yes or no?
- 35. Further information and publications www.ke4be.ceh.ac.uk www.elum.ac.uk Contact details jhart@ceh.ac.uk @jen1whitaker http://www.raeng.org.uk/publications/ reports/biofuels www.elum.ac.uk