ecological aspects of large-scale bioenergy with ccs...
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Ecological aspects of large-scale bioenergy with CCS (BECCS)
Umakant Mishra�
February 8, 2017
Lydia Smith Jim WilliamsDaniel Sanchez
Margaret Torn�Berkeley Lab and UC Berkeley
Berkeley Lab�UC Berkeley
Stanford U Argonne National�Laboratory
Deep Decarbonization Pathways Project
U.S. energy system in 2014
Williams et al. 2014. Pathways to Deep Decarbonization in the United States. �http://unsdsn.org
deep decarbonization
US 2050 Report
pathways to
in the United States
Decarbonized energy system in 2050
, Mixed case results
Williams et al. 2014. Pathways to Deep Decarbonization in the United States. �http://unsdsn.org
deep decarbonization
US 2050 Report
pathways to
in the United States
3. Soil Sequestration • Agriculture & grazing management
What are the ecological constraints to large scale BECCS? Land, Water, Nutrients
1. Forestry-Based Sequestration • Afforestation • Reforestation • Forest management
Estimates as high as 5 Gt C y-1 thru 2100 (Azar et al. 2006; Lenton &Vaughan 2009)
1 Gt C y-1 thru 2100 (Nilsson and Schopfhauser 1995)
1Gt C y-1 thru 2055 (Lal 2004)
www.mnn.com/local-reports/illinois/local-blog/miscnthus-poten5al-biofuel-sourceSmith and Torn, 2013
Cellulosic Biofuels with Carbon Capture and Storage (BECS)
h8p://www.kgs.ku.edu/Publica5ons/PIC/pic27.html
CO2
Power Generation
CO2
C
• Land, Water, Nutrients
Presenta5on:Tornetal.Ecologicalaspectsoflarge-scalebioenergywithCCS(BECCS),CarbonDioxideRemoval/Nega5veEmissionsTechnologiesWorkshop,BerkeleyCA,Feb8,2017,
There is strong competition for terrestrial carbon and the land resource
Millennium Ecosystem Assessment
Competition for Land & Productivity
Land use and land cover change
Humans have preferentially converted the most fertile, accessible, and useful biomes
Presenta5on:Tornetal.Ecologicalaspectsoflarge-scalebioenergywithCCS(BECCS),CarbonDioxideRemoval/Nega5veEmissionsTechnologiesWorkshop,BerkeleyCA,Feb8,2017,
Unappropriated 61% Croplands 11% Converted pastures 8% Cleared land 8% Lost to poor ecosystem management 2% Tree plantations 2% Consumed by domestic animals 2% Consumed by humans (wood) 2% Consumed by humans (non-wood) 1% Human-occupied lands <1%
Humans already appropriate 40% of Biomass Production (NPP)
Global Terrestrial NPP
Data from Vitousek 1994
• Consumption • Cooptation • Degradation
Competition for Land & Productivity
Total Human-appropriated NPP as a percentage of NPP0, excluding fires. Negative (blue) values: NPPanthro > NPP0
Positive values: low-high HANPP
Haberl et al. 2007 PNAS
Human-appropriated NPP
• Consumption• Cooptation• Degradation
Presenta5on:Tornetal.Ecologicalaspectsoflarge-scalebioenergywithCCS(BECCS),CarbonDioxideRemoval/Nega5veEmissionsTechnologiesWorkshop,BerkeleyCA,Feb8,2017,
Afforestation can reduce: • Runoff • Surface Flows • Groundwater Recharge
http://stepinplease.files.wordpress.com/2011/03/three-leaf-clover-in-rain.jpg
Plant carbon-capture takes water, and freshwater is already a scarce resource
Ecological Limits: Water
Increasing plant productivity requires more evapotranspiration*
Jobbagy and Jackson 2004, Global Change Biology
*absent gains in water use efficiency from elevated CO2 or modified plants
Presenta5on:Tornetal.Ecologicalaspectsoflarge-scalebioenergywithCCS(BECCS),CarbonDioxideRemoval/Nega5veEmissionsTechnologiesWorkshop,BerkeleyCA,Feb8,2017,
Plant carbon-capture takes water, and freshwater is already a scarce resource
Ecological Limits: Water
At risk: • Runoff • Surface Flows • Groundwater Recharge
Jobbagy and Jackson 2004, Global Change Biology
Presenta5on:Tornetal.Ecologicalaspectsoflarge-scalebioenergywithCCS(BECCS),CarbonDioxideRemoval/Nega5veEmissionsTechnologiesWorkshop,BerkeleyCA,Feb8,2017,
Plant carbon-capture takes nutrients
• Productivity in most ecosystems is nutrient limited
• Global fertilizer use is increasing by >1% per year
C : N : P Foliage 200 : 5 : 0.17 Wood 200 : 1 : − Roots 200 : 4 : 0.25
Soil org matter 200 : 10 : 1 Example Biomolecule gamedia.org/faculty/rdcormia/NANO/nanostructures/biomolecules.htm
Ecological Limits: Nutrients
Stoichiometry
Presenta5on:Tornetal.Ecologicalaspectsoflarge-scalebioenergywithCCS(BECCS),CarbonDioxideRemoval/Nega5veEmissionsTechnologiesWorkshop,BerkeleyCA,Feb8,2017,
Overcoming nitrogen limitation has environmental impacts
• Human activities double the natural rate of nitrogen fixation.
• Reactive nitrogen damages ecosystems, climate, and human health:
- N2O (GHG) - Air pollution: O3, aerosols - Water pollution: NO3
-
- Species composition
PamMatson
ContemporaryandPreindustrialLoadingsofMobileNitrogenontoLandFigure12.3andGeographyofRela5veIncreasesinRiverborneNitrogenFluxesResul5ngfromAnthropogenicAccelera5onofCycle.Contemporary5meisfromthemid-1990s.(MillenniumEcosystemAssessment)
Mill
enni
um E
cosy
stem
Ass
essm
ent
Ecological Limits: nutrients
PreindustrialContemporary
NitrogenLoadingonLand 0
40
80
120
160
Fertilizer
Legume crops
combustion Lightning N-fixers
Anthropogenic Natural
Global N Fixation (Tg N/y)
Presenta5on:Tornetal.Ecologicalaspectsoflarge-scalebioenergywithCCS(BECCS),CarbonDioxideRemoval/Nega5veEmissionsTechnologiesWorkshop,BerkeleyCA,Feb8,2017,
Tropical plantations require phosphorus
• Pfer5lizeruseincreased5-foldbetween1960and2000to30Tg/yandisprojectedtoincreaseto50Tg/yby2030
• Inexpensiverockreservesdepletedin~60y(ThepriceofPmorethandoubledinthelastdecade)
• Prunoffisprimarycauseofeutrophica5oninlakesandestuaries
Plant growth in tropics is P-limited
Phosphate prices are highly volatile
Ecological Limits: nutrients
h8p://www.indexmundi.com/commodi5es/?commodity=dap-fer5lizer&months=240
Presenta5on:Tornetal.Ecologicalaspectsoflarge-scalebioenergywithCCS(BECCS),CarbonDioxideRemoval/Nega5veEmissionsTechnologiesWorkshop,BerkeleyCA,Feb8,2017,
The land, water, and nutrient requirements for:
• Temperate BECCS at 1 Gt C y-1
Could BECCS be implemented at the scale needed for �climate change mitigation?
Update: 44% higher CCS efficiency Presenta5on:Tornetal.Ecologicalaspectsoflarge-scalebioenergywithCCS(BECCS),CarbonDioxideRemoval/Nega5veEmissionsTechnologiesWorkshop,BerkeleyCA,Feb8,2017,
Land, Fertilizer, and Water Intensity
Switchgrass productivity
N fertilizer addition
Water consumption
(ET) Miscanthus productivity
10 t biomass /ha/y
80 kg N/ha/y 750 L/m2/y (1400 L/kg C)
20 t biomass /ha/y
Heaton et al 2004b Kszos et al 2000 Arundale et al. 2013
Dominguez-Faus 2009 Hickman et al. 2010
Heaton et al 2004b Mishra et al. 2013
Global Resources Switchgrass Miscanthus Land 3 Mha 1.5 Mha
N Fertilizer 25 Tg N y-1 12 Tg N y-1
Calculations for 1 Gt C/y BECCS with Switchgrass
(1.3 Gt C y-1) / [10 Mt biomass Mha-1 y-1 × .43 g C/g biomass] = 3.3 Mha
(3 Mha Land) × (80 kg N/ha/y) (0.1 unit conv.) = 25 Tg N y-1 Fertilizer
Bioenergy with CCS
Water Switchgrass 160 gallons water per kg switchgrass grown
Afforesta5on ET increase from 50% of mean annualprecipitation to 75% of mean annualprecipitation
Switchgrass
Land 10 t biomass/ha/y
Heaton et al 2004
Nitrogen Fertilizer 80 kg N/ha/y Kszos et al 2000
Arundale et al. 2013
Water 1400 L / kg C
Dominguez-Faus 2009 Hickman et al. 2010
Presenta5on:Tornetal.Ecologicalaspectsoflarge-scalebioenergywithCCS(BECCS),CarbonDioxideRemoval/Nega5veEmissionsTechnologiesWorkshop,BerkeleyCA,Feb8,2017,
Resources consumed for 1 Gt C y-1 sequestration by Temperate Bioenergy-CCS
Land Switchgrass 3.3 Mha 8 × area of US maize 19 × area of US bioethanol 2010
Nitrogen Fertilizer
Switchgrass 25 Tg N y-1 24% of global N fertilizer in 2009
Water Switchgrass 1831 km3 y-1
Smith and Torn, Climatic Change, 2013 updated
Land 1.6 Mha 4 × area of US maize 10 × area of US bioethanol 2010
Miscanthus 12 Tg N y-1 11% of global N fertilizer in 2009
Land 3.3 Mha 8 × area of US maize 19 × area of US bioethanol 2010
Nitrogen Fertilizer
25 Tg N y-1 24% of global N fertilizer in 2009
Water 1,831 km3 y-1 8 × Calif irrigation use
Switchgrass
Miscanthus
Presenta5on:Tornetal.Ecologicalaspectsoflarge-scalebioenergywithCCS(BECCS),CarbonDioxideRemoval/Nega5veEmissionsTechnologiesWorkshop,BerkeleyCA,Feb8,2017,
Per 3.3. Gt C sequestered 720 km3 Smith et al. 2015 Change
Total
Smithetal.2015Per 3.3. Gt C sequestered 720 km3 Smith et al. 2015 6,000 km3 Smith & Torn 2013
Presenta5on:Tornetal.Ecologicalaspectsoflarge-scalebioenergywithCCS(BECCS),CarbonDioxideRemoval/Nega5veEmissionsTechnologiesWorkshop,BerkeleyCA,Feb8,2017,
Growing biomass plus soil carbon sequestration can significant co-benefits
Restore soil carbon to native levels Fertility, soil water, arable land—food, erosion
Expand carbon-neutral biomass Decarbonized energy supply
Maintain ecosystem resilience Presenta5on:Tornetal.Ecologicalaspectsoflarge-scalebioenergywithCCS(BECCS),CarbonDioxideRemoval/Nega5veEmissionsTechnologiesWorkshop,BerkeleyCA,Feb8,2017,
17
Suitable Cropland
12.86 Mha in corn ethanol in 2013 (USDA-NAS, AgMRC).
Modeled average miscanthus productivity on corn-ethanol lands = 14.5 Mg biomass/ha/y
Planting all US corn-ethanol land with Miscanthus
Results:
Miscanthus production = 80 Tg C /y
SOC sequestration = 8.8 Tg C/y
Soil C sequestration is 10% bonus on BECCS
BECCS example w/soil C sequestration
Mishra et al. 2013. GCB-Bioenergy
Miscanthus biomass productivity within U.S. croplands and its potential impact on soil organic carbon.
Presenta5on:Tornetal.Ecologicalaspectsoflarge-scalebioenergywithCCS(BECCS),CarbonDioxideRemoval/Nega5veEmissionsTechnologiesWorkshop,BerkeleyCA,Feb8,2017,
Photosynthesis
Microbial function
Allocation
Systemcontrolpoints
Structure Scale
Soil organic matter Presenta5on:Tornetal.Ecologicalaspectsoflarge-
scalebioenergywithCCS(BECCS),CarbonDioxideRemoval/Nega5veEmissionsTechnologiesWorkshop,BerkeleyCA,Feb8,2017,
Conclusions 1. There are real ecological constraints to terrestrial CDR
at the local project level and at large scale.
2. At large scale, terrestrial CDR could consume a significant fraction of world fertilizer supply
3. Land and water use would have opportunity costs and displace food/fuel/fiber and biodiversity.
The metric of success should be avoiding damage and increasing wellbeing, rather than reducing climate change or atmospheric CO2 per se.
Presenta5on:Tornetal.Ecologicalaspectsoflarge-scalebioenergywithCCS(BECCS),CarbonDioxideRemoval/Nega5veEmissionsTechnologiesWorkshop,BerkeleyCA,Feb8,2017,
Thank you
This work was supported in part by aU.S. DOE and Presidential Early Career
Award for Scientist and EngineersPresenta5on:Tornetal.Ecologicalaspectsoflarge-scalebioenergywithCCS(BECCS),CarbonDioxideRemoval/Nega5veEmissionsTechnologiesWorkshop,BerkeleyCA,Feb8,2017,