1

A proposal to REVIEW the EMERGY METHODOLOGY in

order to make possible a

PROPER ASSESSMENT

of sustainable rural systems

Laboratory of Ecological Engineering, Food Engineering School,

State University of Campinas,Campinas, SP, Brazil

Enrique Ortega, Fabio Takahashi,

José Maria Gusman,Luis Alberto Ambrosio

Support:

2

PROBLEM

In the Northern Hemisphere, the agriculture was transformed into a very simple system due to the intensive use of industrial chemicals and machinery in substitution of biological processes and local labor.

Because of that, the emergy assessment of rural systems lost its inherent complexity.

For the correct assessment of ecological farming the excluded factors must be considered.

PROPOSAL

3

INTRODUCTION

The research at the Laboratory of Ecological Engineering deals with the emergy diagnosis of Food Production and Consumption Systems and the design of new models for rural systems.

At the beginning of activities in 1994, the emergy methodology was applied to conventional chemical farming systems.

In 1998, the research focus shifted to soybean farming, the most important agricultural system in Brazil. Soybean is produced in many types of farms, some of them are ecological farms.

4

During the data collection it was discovered that:

• In family managed ecological farms, an important objective was the maintenance of local labor;

• The native vegetation is preserved because it supplies materials and services to the peasant’s family;

• Regional feedback inputs can be renewable or partly renewable;

• Ecological farms produce environmental services.

• Chemical farms produce deleterious externalities.

5

It was concluded that there were two main soybean production models, both with two variants:

(a) Biological model - agro-ecological farming- organic farming

(b) Chemical model - inputs intensive farming- biotechnological farming

It was necessary to work with farm typology, a novelty in emergy analysis. In this presentation the farming models studied will be described.

6

The emergy methodology needs to be actualized, it demands always to be improved!

The suggestion of considering the inputs specific renewability was presented at the 4th International Workshop Advances in Energy Studies, in 2002.

In the 4th Emergy Conference, which took place in 2006, it was presented the idea that information is the key input for Brazilian soybean system and a form to calculate it.

In this meeting, the main contribution is that farm diagnosis should consider impact absorption area using concepts of ecological footprint method and global warming mitigation.

7

The first reference to agriculture emergy analysis was a chapter of the book Energy in Agriculture (Odum, 1984).

After that, in Emergy Folio #4, Brandt-Williams & Odum (2002) presented a very similar systems diagram.

METHODOLOGY HISTORY

Figure 1 shows the diagram used for the emergy analysis of the Agriculture of Florida.

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Environ-ment

Fuel Goods & Services

Farm production

Soil

Labor PotashElec-tricity

LimePesti-cides

Phos-phate

Nitro-gen

Evapotranspiration

Evaluated product

Figure 2. A systems diagram with 11 inputs and 1 product was applied to 22 crops (Emergy Folio 4. Agriculture of Florida)

9

In 1997, Brandt-Williams and Odum wrote a paper to explain the procedure to make the emergy assessment of agriculture. This work became a chapter of the book Ecological Engineering and Sustainable Agriculture that was published in Portuguese on the internet.

The following diagrams belong to this book.

http://www.fea.unicamp.br/docentes/ortega/livro/index.htmwww.fea.unicamp.br/docentes/ortega/livro/C03-SherryOdum.pdf

10Figure 1a. Energy flows diagram of an Agriculture system.

Rain

Wind

SunVegetable cultivation

Soil & nutrients

Farm assets

Run-off

Lime Fertilizers FuelsHuman labor

Goods & services

Market

Evapo-transpiration

Solar energy

Albedo

Low intensity dispersed energy

Production

Pesticides

Sales

Agriculture system

11

Figure 1b. Nomenclature of aggregated flows.

Vegetable cultivation

Soil & nutrients

Farm assets

RRenewable

natural resources

Dispersed energy

Production

Agricultural system

NNon-renewable

natural resources

MMaterials and Fuel

SLabor and Services

F=M+SEconomy Feedback

I=R+NNature input

Y=I+FTotal Emergy

EProduct Energy

12

Figure 1c. Soil as non-renewable resource.

Environmental work

Dispersed energy

N

Agricultural system

MMaterials and Fuel

SLabor and Services

F=M+SEconomy Feedback

I=R+NNature input

Y=I+FTotal emergy

EProduct Energy

RRenewable resources

NNon-renewable natural assets

Economic useR

M SVery slow production

Very rapid consumption

13

Figure 1d. Resumed diagram showing aggregated flows of inputs and one output.

NY=I+FEconomic use of the

ecosystem space

R

M S

14

These two approaches didn’t consider:

• The environmental services provided by farm’s preserved forest and wetlands;

• Biologically fixed nitrogen and soil minerals mobilized by micro-biota;

• That part of production destined to local population; • Recycling; • The possibility of co-products, as for example,

second crops; • Waste, emissions, rural exodus, toxic substances,

deaths by intoxication, biodiversity loss, human culture degradation and other outputs.

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Ortega et al. (2002a, 2002b), concerned with the distortion between reality and emergy indices, proposed the use of input’s renewability for emergy flows calculation and also new indices.

This perspective is described in the next figures.

The feedback could have a renewable part (FR) and non-renewable part (FN):

F = FR + FN = (MR + SR ) + (MN + SN)

MR = MiR = (Reni) (Mi)

MN =MiN =(1-Reni) (Mi)

M = MR + MN

Each Material and Service has its own renewability:

S = SR + SN

16Figure 3a. A broad vision of agricultural systems.

Environmental work

Degraded energy

Agricultural system

M

S

F=M+SEconomy Feedback

I=R+NNature inputs

Y=I+F

Products Energy

R1

Local renewable resources

NCNature assets

R

M RVery slow production

Very slow consumption

R

Services including external labor and information

Materials and fuel

R3

Atmosphere & soil minerals renewable resources

QFarm

Assets HHuman Assets

R2

Regional renewable resources

$Money

$ in

$ out

LLocal labor

S

Environmental services

Direct environmental forces

Very slow production

Total emergy used

Output

Low values

Ecological Agriculture

Biological model: Agro-ecological farming.

17Figure 3b. A broad vision of agriculture systems.

Environmental work

Degraded energy

N

Agricultural system

M

S

F=M+SEconomy Feedback

I=R+NNature inputs

Y=I+F

Products Energy

R1

Local renewable resources

NCNature assets

Agriculture as economic use of

geographic spaceR

M RVery slow production

Very rapid consumption

Very slow consumption

R

Services including external labor and information

Materials and fuel

R3

Atmosphere & soil minerals renewable resources

QFarm

Assets HHuman Assets

R2

Regional renewable resources

$Money

$ in

$ out

LLocal labor

S

Destruction

Emissions, efluents and residues energy

Environmental services

Direct environmental forces

N

Very slow production

Biodiversity lossSoil erosion

Toxic substancesRural exodusCultural loss

Total emergy used

Output

Transition to chemical farming.

18Figure 3c. A broad vision of agriculture systems.

Environmental work

Degraded energy

N

Agricultural system

M

S

F=M+SEconomy Feedback

I=R+NNature inputs

Y=I+F

Products Energy

R1

Local renewable resources

NCNature assets

Agriculture as economic use of

geographic spaceR

MVery rapid consumption

Services including external labor and information

Materials and fuel

QFarm

Assets

R2

Regional renewable resources

$Money

$ in

$ out

S

Destruction

Emissions, efluents and residues energy

Direct environmental forces

N

Biodiversity lossSoil erosion

Toxic substancesRural exodusCultural loss

Total emergy used

Output

X

X

Chemical model: inputs intensive farming.

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Figure 3d. Aggregated flows diagram. Products Energy

Economic use of geographic space as chemical agriculture

M R S

Emissions, efluents and residues energy

N

R

Very rapid consumption

R

Very slow production

interactionR

N FNFR

interactionR

N FNFR

interactionR

N FNFR

Reni

Mi

Reni

Ri

Reni

Si

F = FR + FN

Biodiversity lossCO2, Rural exodusToxic substances

Cultural lossSoil erosion

OutputDestruction N

Environmental servicesVery slow production

20Figure 4. A new diagram proposed to study agricultural systems (Ortega et al., 2002a, 2002b)

Environmental work

Agriculture system

I=R+NNature inputs

R1

Local renewable resources

BNature assets

Very slow production

Very slow consumption

R3

Atmosphere & soil minerals renewable resources

R2

Regional renewable resources

Products Energy

M LL S

Emissions, efluents and residues energy

Environmental servicesVery slow production

Biodiversity lossCO2, Rural exodusToxic substances

Human culture lossSoil erosion

Output

N

R

Very rapid consumption

R

interactionR

N FNFR

Reni

Mi

Reni

Reni

Si

M

S

F=M+SFeedback from Economy

Services including external labor and information

Materials and fuel

QFarm

Assets HHuman Assets

$Money

$ in

$ out

LLocal labor

DestructionN

Economic use of geographic space as agriculture

interactionR

N FNFR

Direct use

Our first idea for a General Model(It includes biological & chemical systems).

21Figure 5. Proposal of a more complete systems diagram measuring INFO, GW, WT and LR (Ortega, 2006).

Water and mineral

resourcesfrom soil

(M&S)R

Renewable energy

Nitrogen from

atmosphere

People

(M&S)N

Soil

Local processing

Environmental Services

Negative externalities

Products

Plantation

Forest reserve

Regional biodiversity

Local population

Materials and Services

ProductsSun, Moonand Earth´s internal heat

Albedo

Residues

InfoN

Local resources

CO2 in excess

captured

Acid deposition due to NOx

and SOx liberation

Local and global climate change

Not filtered UV radiation

InfoR

Waste treatment

Loss Recovery

Additional services

Info

WT

LR

GW

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Rural space biocapacity

Rural production unit(s)

Earth deep heat

Moon-Earth gravity force

Sun energy

Nitrogen biológically

fixed

Soil mineralsbiolocally mobilized

Industrial urban centers

Environmental services for external use

Industrial products and services

Residues & emissions

Local population

Environmental services locally used

Residues & emissions

Local resources used above

recovering rate

Crop lands & grazing lands

Wetlands, prairies, swamps

Poly-culture

Native vegetation

(productive)

Past eras ecosystems

Bio-mass

External consumption

Biological diversity

Raw materials without added value

Infra-structure

Industrial products obtained with non-

renewable resources

Animal husbandry

PeopleProcessed

products

Local consumption

Treatment & recycling

Crops, cattle and forestry products

Negative externalities (receptor damage)

$

$

Infra-structure

Money

Culture

CultureInformation

External inputs Recycled

residues

Human labor

Geophysical, thermo-chemical processes

Biocapacity of areas without human control

Emissions and industrial wastes with global impact

Petroleum, gas, coal

Recycling

Extraction, Power plants, Petrochemical and Pharmaceutical industries, Metalurgy, etc.

Global resources used above

reovering rate

Minerals, wood

Net yield of energy and materials

Feed-back

Biological diversity

“non productive” biomas of present era

Greenhouse gases,

acid aerosols

CO2Soil, wood

Solid wastes, effluents and emissions

Transfer controls

Figure 6. An even more complete systems diagram for an agricultural system.

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Rural space biocapacity

Rural production unit(s)

Earth deep heat

Moon-Earth gravity force

Sun energy

Nitrogen biológically

fixed

Soil mineralsbiolocally mobilized

Crop lands & grazing lands

Wetlands, prairies, swamps

Poly-culture

Native vegetation

(productive)

Biological diversity

Animal husbandry

External inputs Recycled

residues

Human labor

Greenhouse gases,

acid aerosols

Residues & emissions

Local population

Environmental services locally used

Local resources used above

recovering rate

Infra-structure

PeopleProcessed

products

Local consumption

Treatment & recycling

Crops, cattle and forestry products

$Money

CultureInformation

Recycling

Solid wastes, effluents and emissions

Soil, wood

Raw materials without added value

Environmental services for external use

Negative externalities (receptor damage)

Net yield of energy and materials

Step by step building-up of the complex diagram

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Rural space biocapacity

Rural production unit(s)

Earth deep heat

Moon-Earth gravity force

Sun energy

Nitrogen biológically

fixed

Soil mineralsbiolocally mobilized

Environmental services for external use

Residues & emissions

Local population

Environmental services locally used

Local resources used above

recovering rate

Crop lands & grazing lands

Wetlands, prairies, swamps

Poly-culture

Native vegetation

(productive)

Biological diversity

Raw materials without added value

Infra-structure

Animal husbandry

PeopleProcessed

products

Local consumption

Treatment & recycling

Crops, cattle and forestry products

Negative externalities (receptor damage)

$Money

CultureInformation

External inputs Recycled

residues

Human labor

Recycling

Net yield of energy and materials

Greenhouse gases,

acid aerosols

Solid wastes, effluents and emissions

Soil, wood

Industrial urban centers

Residues & emissions

External consumption

$

Infra-structure

Culture

Transfer controls

Past eras ecosystems

Bio-mass

Industrial products obtained with non-

renewable resources

Geophysical, thermo-chemical processes

Petroleum, gas, coal Extraction, Power plants, Petrochemical and

Pharmaceutical industries, Metalurgy, etc.

Global resources used above

reovering rate

Minerals, wood CO2

Biological diversity

“non productive” biomas of present era

Biocapacity of areas without human controlIndustrial products and services

Emissions and industrial wastes with global impact

Feed-back

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OUR SUGGESTIONS

(a) To use the renewability of each input in the Emergy Flows and Emergy Indices calculations;

(b) To consider as additional renewable inputs those flows that are produced by biodiversity, such as soil minerals obtained by deep roots and micro-biota and chemicals produced by symbiotic biota;

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• The real productivity without the consideration of top soil erosion and fossil fuel use as positive fact (instead of EYR = (R/F) + (N/F) +1 use R/F instead of ESI =EYR/ELR use B/C=R/N);

(c) To develop indicators that measure:

• Renewable and non-renewable capital;

• Internal flows (local consumption, material recycling, internal services);

• Human labor quality;

• Environmental services loss;

• Negative externalities;

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(d) To consider Natural Capital, Environmental services, Infra-structure, Financial and Social Resources, Emissions and Waste as new items in the Inputs-Output balance.

(e) To consider the value of Information as input, stock and output;

(f) To discuss the contradiction of using Transformity Tr = (R+N+F)/E as indicator of viability, because low productivity (E) and high erosion farms (N) could have the biggest values!

(g) To consider impact absorption area.

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APLC

ESLC

LL

Ex

ES

Local consumption

Residues, effluents, emissions

F

Preserved ecosystems

AgricultureProduction

Local labor

APLP

AP

CL

APT

WT

WL

WE

R

EST

Transfor-mation

Greenhouse gases

and Acids

Heat

Cold

F´ F´´

AP

Environmental services

Locally processedagricultural products

Waste and losses from destroyed internal structure

Negative externalities

Human economy feedback: materials & services

Directrenewable resources

Exportedagricultural products

NLNon- renewable local resources

Nitrogen & minerals mobilized by biota

R’

R’’

Other ecosystems resources

Ex

Figure 7. First part of a proposal for a generic diagram.

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R Global ecosystems

Treatment & recovering systems

Impact absorption: heat, negative externalities, internal structure losses, waste, effluents, emissions

ES

Forested lands of Clean Development Mechanism

F´´´

Cold environment

Negative externalities

Additional feedback from human economy: materials & services

Ex

Environmental services: clear air, clean water, healthy soil,preserved species,stabilized climate.

Area

Area

Area

The second part of the generic diagram: impact absorption area

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The complete system diagram

APLC

ESLC

LL

Ex

ES

Local consumption

Residues, effluents, emissions

F

Preserved ecosystems

AgricultureProduction

Local labor

APLP

AP

CL

APT

WT

WL

WE

R

EST

Transfor-mation

Greenhouse gases

and Acids

Heat

Cold

F´ F´´

AP

Environmental services

Locally processedagricultural products

Waste and losses from destroyed internal structure

Negative externalities

Human economy feedback: materials & services

Directrenewable resources

Exportedagricultural products

NL

Nitrogen & minerals mobilized by biota

R’

R’’

Other ecosystems resources

R

Global ecosystems

Treatment & recovering systems

ESForested lands of Clean Development Mechanism

F´´´

Cold environment

Greenhouse gases (CO2, CH4, N2O) Heat, Acids, Organic matter, Losses from system internal structure, Toxic substances.

Additional feedback from human economy: materials & services

Clear air and water, healthy soil,preserved species,stabilized climate.Area

AreaArea

Environmental services:

The impact production must fit the impact absorption capacity

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APLC

ESLC

LL

Ex

ES

F

LA & P

APLP

AP

CL

APT

WA

WL

WE

R

R

GE

GT ES

EST

CDM

TP

GHG

H

F´ F´´´F´´

C

AP

CL

WLT

A’’

Production Area

Impact Absortion Area

A’’

NLC

NLT

NCE

NC

PNL

Ex

The complete system can be represented in a compact form.

It can be seen as a fractal.

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APLC

ESLC

LL

Ex

ES

F

APLP

AP

CL

APT

WA

WL

WE

R

R

GE

GT ES

EST

CDM

GHG

F´ F´´´F´´

AP

CL

WT

A’’

Production Area

Impact Absortion Area

A’’

APLC

ESLC

LL

Ex

ES

F

APLP

AP

CL

APT

WA

WL

WE

R

R

GE

GT ES

EST

CDM

GHG

F´ F´´´F´´

AP

CL

WT

A’’

Production Area

Impact Absortion Area

A’’

APLC

ESLC

LL

Ex

ES

F

APLP

AP

CL

APT

WA

WL

WE

R

R

GE

GT ES

EST

CDM

GHG

F´ F´´´F´´

AP

CL

WT

A’’

Production Area

Impact Absortion Area

A’’

Chemical Inputs

Agriculture production

Urban consumption

Interconnected fractals

The question is that until today the production-consumption systems have not been planned correctly!

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R

GE

TRSES

CDM

F´´´

CE

A

AA

Ex

R

GE

TRSES

CDM

F´´´

CE

A

AA

Ex

R

GE

TRSES

CDM

F´´´

CE

A

AA

Ex

APLC

ESLC

LL

Ex

ES

F

Ll

APLP

AP

CL

APT

WT

WL

WE

R

EST

Tr

GHG

Heat

Cold

F´ F´´

AP

NL

R’

R’’

APLC

ESLC

LL

Ex

ES

F

Ll

APLP

AP

CL

APT

WT

WL

WE

R

EST

Tr

GHG

Heat

Cold

F´ F´´

AP

NL

R’

R’’

APLC

ESLC

LL

Ex

ES

F

Ll

APLP

AP

CL

APT

WT

WL

WE

R

EST

Tr

GHG

Heat

Cold

F´ F´´

AP

NL

R’

R’’

Chemical Inputs

Agriculture production Urban

consumption

Area deficit

Area deficit

Area deficit

All the human systems have been built without impact absorption area!

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APLC

ESLC

LL

Ex

ES

F

Ll

APLP

AP

CL

APT

WT

WL

WE

R

EST

Tr

GHG

Heat

Cold

F´ F´´

AP

NL

R’

R’’

Overshoot possibility!

0

5

10

15

20

25

30

35

40

0 1 2 3 4 5 6 7 8

EIR

Fo

rest

are

a /

fa

rmin

g a

rea

SANPP

SAR

R

GE

TRSES

CDM

F´´´

CE

A

AA

Ex

There is an area deficit!

(Agostinho et al., 2008)

It is up to 6 to 13 times bigger than the crop area!

What is the size of the impact absorption area in agriculture?

Brazilian watershed

(Siche et al., 2007)

(Ulgiati et al., 2001)

Other countries

(Brown et al., 2002)

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The farm productivity should be compared in a proper basis: as a whole system, including complementary area.

The agro-ecological farm already includes its impact absorption area as preserved natural area that also produces environmental services.

The chemical farm should include the complementary area needed to absorb environmental impact and to produce the environmental services that are lost due to its full conversion to crop land.

Productivity = --------------------------------------------------------Production (kg/year)

Crop area + Impact absorption area (ha)

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An example of whole system comparison:

Corn production in an agro-ecological farm:

Corn production in a chemical farm:

Productivity = ----------------------------------------------- = ---------------2000 kg/year

Crop area (1 ha) + absorption area (1 ha)

1000 kg/year

ha

Productivity = ----------------------------------------------- = ---------------6000 kg/year

Crop area (1 ha) + absorption area (11 ha)

500 kg/year

ha

This concept helps to explain the so called “Scale Economy” that really works in the opposite sense!

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Table 1. Classification of Emergy flows

Inputs and services Description

I: Nature contribution R + N

R = R1 + R2 +R3

Renewable resources from nature

Rain;Materials and Services from preserved areas; Nutrients from soil minerals and air.

N: Nature non-renewable inputs Soil and diversity loss (including people).

F: Economy Feedback F = M + S

M: Materials M = MR + MN

MR: Renewable Materials Renewable materials from natural origin.

MN: Non-renewable Materials Minerals, Chemicals, Steel, Fuel, etc.

S: Services (total) S = SR + SN + SA

SR: Labor Services (partially renewable) Labor (family, local and external): SR = SRF + SRL + SRE

SN: Other Services (non-renewable) Taxes, money costs, insurance, etc.

SA: Additional Services (non-renewable) Externalities: effluents, medical and job costs,

Y: Total Emergy Y = I + F

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Table 2a. Proposals for Emergy Indices

Modified Emergy Indices Formula Concept

Renewability* R* = (R + MR + SR) / Y Renewable/Total

Environmental Loading ratio* ELR* = (N+MN+SN) / (R+MR+SR) Non-renewable/renewable

New Emergy Indices Formula Concept

Labor Services Ratio LSR = SR / S Labor/Services

Labor Empower Ratio LER = SR / Y Labor/Empower

Family farming LWR = SRF / (SRL+SNE) Family labor/Others

Externalities Empower Ratio ExER = SA / Y Externalities/Empower

Cycling ratio CR = C / F Cycling / Feedback

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Table 2b. Proposals for Emergy Indices

New Emergy Indices Formula Concept

Natural Capital/Economy NC / (IE + FN) Natural Capital / Feedback

Renewable mobilization Benefit =R/F Renewable/Feedback

Non-renewable mobilization Cost =N/F Nonrenewable / Feedback

Systemic Benefit/Cost BC=R/N Renewables /Non-renewables

External resources dependence ED= F/R Feedback/Renewables

Natural Capital rate CN / Time Natural capital change with time

Anthropic rate (IE + FN) / Time Human assets change with time

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RESULTS & DISCUSSIONAgro-forestry (10 years)

Conventional extensive low productivity

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The End of Oil Actual and Projected Oil Production

Increasing:N/F, ELR, EIR, Tr, EER

Increasing: %Ren, R/F

Decreasing: %Ren, R/F Decreasing:N/F, ELR, EIR,Tr, EER

CO2 Reduction Actual and Projected CO2 Production

Individualism, capitalismcompetition & exclusion

Community solutions

Support a social & ecological perspective for

42

CONCLUSIONS OR RECOMMENDATIONS

1. If the suggestions proposed here are pertinent, then it is necessary to organize a group to discuss these issues in deep;

2. Give this group a reasonable time (4-6 months) to discuss on the best procedures for this kind of emergy calculation;

3. Disseminate the preliminary results among the emergy researchers to obtain feedback;

4. Write a new folio on Agriculture (General Scope)

43

ACKNOWLEDGEMENTS

• Adriana Pires for egg production system research

• Teldes Albuquerque for Agro-forestry systems research

• Mileine Zanghetin for helping in preparation of PowerPoint presentation

• Feni Agostinho for discussion and graph preparation of forested area needed to absorb the impact of non-renewable feedback from economy

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