The Ecologic al Footpr int

2. 83/2. 813

T.G. Gutowski

Feb 8, 2006

Re ad ing Assig nme nts

• Homework (reviewed 2/14)• 2/14 Sustainability?

•

• a) Diamond, J., “Easter Island’s End” Discover Magazine, 1995. (6 pages)

• http://www.hartford-hwp.com/archives/24/042.html

•

• b) Broswimmer, “The Chaco Anasazi….,” p 45-48 (handout)

•

• c) Hardin, G., “Tragedy of the Commons,” Science, 162, 1968, p 1243-1248.

• http://dieoff.org/

•

• d) Wilson, E.O., “The Bottleneck” pp 22 – 41, Ch 2 in The Future of Life, 2001 (handout)

•

• e) Lomborg, B., “Biodiversity” in The Skeptical Environmentalist: Measuring the Real State of the World, 2001, p 251-257. (handout)

U nf i nished Business

• IPAT equation example

• Systems Framework (3X3) Matrix

(see handouts)

IPAT Equation Examples

Impact population service provided technology

“I” “P” car “T”

“A”

mile

gasoline

car

driven miles cars ofnumber gasoline ××=

1.What are the factors that influence the

amount of gasoline we burn in automobiles?

2. Energy used to make pig iron

iron pig

energy producediron pigEnergy

iron pig

energy

factory

iron pigfactories ofnumber Energy

×=

××=

Again the energy used per ton pig iron produced

depends upon the technology used.

GWP grew at 5% in 2005

GWP per capital grew at 3. 8% in 2004

We must improve our environmental performance of

our goods and services by 5%/year just to stay even!

05%-4%1%

improve to0

=+

≤∆

+∆

+∆

=∆

T

T

A

A

P

P

I

I

s imple versio n of IPAT

Carbon = GWP X (Carbon/GWP)

Impact = “Affluence” X “Technology”

T

T

GWP

GWP

C

C ∆+

∆=

∆

T

T

GWP

GWP

C

C ∆+

∆=

∆

World carbon emissions = C

The underlyi ng truth

From Smil

Ple ase Do Your

Ecologic al Footpr int

http://www.rprogress.org/

“Overhead”

W acker nag el’s paper and

worksheet

http://www.pnas.org/cgi/content/full/99/14/9266

http://www.pnas.org/content/vol0/issue2002/imag

es/data/142033699/DC1/0336DataSet.xls

Table 1. Summary of equivalence factors,

humanity's area demands, and earth's biological

capacity in 1999 (per capita)

Average global area demand (per

capita)

Existing global biocapacity

(per capita)

Area

Equivalence

factor, gha/ha Total demand,

ha (per capita)

Equivalent total,

gha (per capita)

World area,

ha (per

capita)

Equivalent total,

gha (per capita)

Growing crops 2.1 0.25 0.53 0.25 0.53

Grazing animals 0.5 0.21 0.10 0.58 0.27

Harvesting timber 1.3 0.22 0.29 0.65 0.87

Fishing 0.4 0.40 0.14 0.39 0.14

Accommodating infrastructure 2.2 0.05 0.10 0.05 0.10

Fossil fuel and nuclear energy 1.3 0.86 1.16 0.00 0.00

Total 2.33 1.91 1.91

To make aggregation reflect differences in bioproductivity, areas are expressed in standardized global hectares (gha), which

correspond to hectares with world average bioproductivity.

Wackernagel’s Results

Copyright ©2002 by the National Academy of Sciences

Wackernagel, Mathis et al. (2002) Proc. Natl. Acad. Sci. USA 99, 9266-9271

No Caption Found

Copyright ©2002 by the National Academy of Sciences

Wackernagel, Mathis et al. (2002) Proc. Natl. Acad. Sci. USA 99, 9266-9271

No Caption Found

Outl ine

• How much land is there?

• What do we do with this land?

• The production of biomass, NPP

• The sequestration of carbon, NEP

• Lifestyle and Product footprints

• National accounts

2R

R ≈ 6370 km

Surface area =

4πR2 = 510 X 106 km2

71% Oceans

29% Land = 148 Mkm2 = 14.8Gha

(one hectare = 100mX100m

one hectare = 2.47 acres)

There are 13.1 Gha not covered

by water or ice.

13.1/6.5 = 2 ha per person

on earth

(5 acres per person)

How much room is there?

Is there anybody else here

on earth besides us?

Wh at do we do with th is l and?

deserts crops

wetlandsforests

gr ass l and and cows

wilderness and built-up

Albers Projection (equal area)

showing croplands and cities

in Pimm, 2001

Net Pr im ary Product iv ity

NPP = GPP – Ra

GPP = Gross Primary Productivity

(Photosynthesis)

Ra = autotrophic respiration

2612622 666 OOHCOHCO +→+

2612622 666 OOHCOHCO +←+

The Carbo n Cycle

CO2 co nce ntr at io n in the atm

How do you me asure NPP?

• buckets in the woods

• students with clippers

• satellites, see e.g.

http://asnerlab.stanford.edu/index.shtml

1kg/m2

dry mass

after Pimm

Are a, b iom ass, product iv ity

from John Harte

est imate of NPP

from John Harte

Note, Pimm’s crude estimate would give

(1kg/m2 =0.45kgC/m2=4.5tC/ha) x 13.1Gha = 59 GtC

Earth Land Accounts (excluding Antartica)

Ref. Pimm 2004Note: Pimm uses (2.2:1) dry mass to carbon

this gives NPP = 52 Gt(C)

52115131Totals

.922004Other

1.94.220021“too dry”

--8“too cold”

1.22.613002Wet lands

5.712.550025Grass lands

11.625.5170015Corp lands

2044100044Other forests

10.924200012Rain forests

NPP

Gt C

NPP

Gt (dry mass)

Productivity

ton (dry mass)/km2

Area

106

km2

Land Classiciation

(after Olson)

C arbon sequestr at io n

NPP – Rh

Rh = heterotrophic respiration

– see websites at Oak Ridge National Labs

• http://csite.ornl.gov/

• http://cdiac.ornl.gov/home.html

World carbon emissions = C

Wackernagel’s Energy Area

Note:

there are some small differences in worksheet Vs paper

Anthropogenic carbon = 6.3 GtC (1999)

Nuclear (7% of world) add 0.5GtC

Carbon sequestration/yr Giga – “global” hectares

∴

GhaGhaha

tClandtoGtC 6.634.19.4

95.0

69.08.6 =×=×

W acker nag el’s result

Table 1. Summary of equivalence factors,

humanity's area demands, and earth's biological

capacity in 1999 (per capita)

Average global area demand (per

capita)

Existing global biocapacity

(per capita)

Area

Equivalence

factor, gha/ha Total demand,

ha (per capita)

Equivalent total,

gha (per capita)

World area,

ha (per

capita)

Equivalent total,

gha (per capita)

Growing crops 2.1 0.25 0.53 0.25 0.53

Grazing animals 0.5 0.21 0.10 0.58 0.27

Harvesting timber 1.3 0.22 0.29 0.65 0.87

Fishing 0.4 0.40 0.14 0.39 0.14

Accommodating infrastructure 2.2 0.05 0.10 0.05 0.10

Fossil fuel and nuclear energy 1.3 0.86 1.16 0.00 0.00

Total 2.33 1.91 1.91

To make aggregation reflect differences in bioproductivity, areas are expressed in standardized global hectares (gha), which

correspond to hectares with world average bioproductivity.

Wackernagel’s Results

Alter nat ive Diets

• According to Pimm, the biomass from

cropland for human food is about ½ of

what is used for animals. Furthermore the

average diet calories come 5/6 from crops

and 1/5 from animal. Since animals also

use grazing land this makes meat about 3

times more land intensive in terms of

global hectares (even more so for actual

hectares).

Land to

Sequester C

We use 27%,

But are only

5% of

population

U.S. Energy

World Energy EJJGpeopleperson

GJ5.357105.3575.655 18

=×=×

EJGpeopleperson

GJ5.973.0325 =×

∴

%5 5.6

3.0 %;27

5.357

5.97⇒⇒

ha/person 6 0.3Gpeople

1.8Gha

hectares) (global 1.8Gha0.276.6Gha

=

=×

Footprint for An Auto

Sequestion Area

Octane

C8H18

Assume

yrgalgalmile

yrmile/480

/25

/000,12=

368.0cm

g

gasoline

=ρ )(235.168.03785480

3785785.31

3

3

3

metrictcm

g

gal

cmgal

cmlitresgal

=××

==

gasoline

carbon842.0

114

96

18128

128==

+×

×

ture)infrastrucnor mfg. includenot does(

93.03.165.01.1/95.0

842.0235.1hahatc

hatc

t=××⇒

×

Energy used to heat home using

800 gallons of fuel oil/year

hectares global 1.23.16.1

95.0

65.3.2

3.2856.0

9.037858003

3

haha

ha

tC

tC

tCgOIL

gC

cm

g

gal

cmgal

=×⇒×

=×××

Who gets wh at

Natomo Family in Mali, March 27, 2003

MATERIAL WORLD, Peter Menzel

The Skeen Family, Pearland TX,

August 1993

MATERIAL WORLD, Peter Menzel

Crit ic ism of the EF

• Bjorn Lomborg / The Economist

• Journal of Ecological Economics

• E. O. Wilson

Re ad ing Assig nme nts

• Homework (reviewed 2/14)• 2/14 Sustainability?

•

• a) Diamond, J., “Easter Island’s End” Discover Magazine, 1995. (6 pages)

• http://www.hartford-hwp.com/archives/24/042.html

•

• b) Broswimmer, “The Chaco Anasazi….,” p 45-48 (handout)

•

• c) Hardin, G., “Tragedy of the Commons,” Science, 162, 1968, p 1243-1248.

• http://dieoff.org/

•

• d) Wilson, E.O., “The Bottleneck” pp 22 – 41, Ch 2 in The Future of Life, 2001 (handout)

•

• e) Lomborg, B., “Biodiversity” in The Skeptical Environmentalist: Measuring the Real State of the World, 2001, p 251-257. (handout)