Presentation on the environmental costs and benefits of land use change to perennial bioenergy crops

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