ecological aspects of large-scale bioenergy with ccs...

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


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


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


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


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


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)


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


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


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


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


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.


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.


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,

ecological aspects of large-scale bioenergy with ccs...

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