Post on 14-Aug-2020
The Ecological Footprint
2.83/2.813
T.G. Gutowski
Outline for 2/12/07
• Old business
– IPAT
– Birth rate and affluence
• New Business
– schedule change; readings, homework,
project posted
• Today
– The Ecological Footprint
Schedule change
• Next time: Scale Flow and CyclesScale Flow and CyclesScale Flow and CyclesScale Flow and Cycles, read Klee and Graedel, Smil 1 & 2
• One week from today; Sustainability?Sustainability?Sustainability?Sustainability?reading assignments, please sign up
February Monday Wednesday 7. Introduction
12. Eco-Footprint 14. Sustainability?
20. Scale, Flow and Cycles** 21. Exergy Accounting
26. Intro to LCA 28. Materials Production
March
5. Cutler Cleveland @ 12 noon 7. Mfg Processes
12. Mfg Processes 14. “Coal” discussion
19. Discussion 21. Quiz 1
26. (Spring Break) 28. (Spring Break)
April 2. LCA 4. Scale and Efficiency
9. Material Recycling 11. Product Recycling
16. (Patriots Day Holiday) 18. Product Reuse
23. Photovoltaics (TB) 25. Nanomfg (JI)
30. Presentations
May 2. Presentations
7. Project Follow-up 9. Field Trip
14. Review 16. Quiz 2
Reading Assignments for Next Monday
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)
Current Homework in Red
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discusssolutionlocationtopic#
IPAT, additional examples
1. Automobiles and gasoline
2. pig iron and energy
3. global carbon
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.
3. Carbon emissions
1.5% 0.25% 1.25% 2% 1% Carbon
∆Carbon
GWP
Energy
Pop
GWPPopulationCarbon
+=−−++=
×××=Energy
Carbon
These are rough averages over the last 3 decades,
data taken or calculated from Pacala & Socolow, Science 2004
An underlying truth
From Smil
Please Do Your
Ecological Footprint
http://www.rprogress.org/
“Overhead”
Wackernagel’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
Outline
• 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?
What do we do with this land?
deserts crops
wetlandsforests
grass land and cows
wilderness and built-up
Albers Projection (equal area)
showing croplands and cities
in Pimm, 2001
Net Primary Productivity
NPP = GPP – Ra
GPP = Gross Primary Productivity
(Photosynthesis)
Ra = autotrophic respiration
2612622 666 OOHCOHCO +→+
2612622 666 OOHCOHCO +←+
The Carbon Cycle
CO2 concentration in the atm
How do you measure NPP?
• buckets in the woods
• students with clippers
• satellites, see e.g.
http://asnerlab.stanford.edu/index.shtml
1kg/m2
dry mass
after Pimm
Area, biomass, productivity
from John Harte
estimate 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 km
2
Land Classiciation
(after Olson)
Carbon sequestration
NPP – Rh
Rh = heterotrophic respiration
– see websites at Oak Ridge National Labs
• http://csite.ornl.gov/
• http://cdiac.ornl.gov/home.html
Details of Canada’s Carbon
Carbon budget of Canada's forests
from 1895 to 1996. Also included is
the record of Canada's green-house
gas carbon emission rate.
Integrated Terrestrial Ecosystem
C-budget model
http://ccrs.nrcan.gc.ca/optic/coarse/beps/nep_e.php
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 =×=×
Wackernagel’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
Alternative 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).
Alternative Diets (using global hectares)
1 Gha (crops) for food + [2 Gha (crops) + 0.6 Gha
(grazing)] to feed animals = 3.6 Gt
average diet affluent diet
85% plants 65% plant
15% animals 35% animals
2250 kcal 3250 kcal
3.6Gha Vs 10Gha
1.2Gha (vegan) Vs 10Ghanote, does not include transportation, nor processing
ref. Pimm 2001, Smil 2006, Wackernagel 2002
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 Automobile
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 uses what
Natomo Family in Mali, March 27, 2003
MATERIAL WORLD, Peter Menzel
The Skeen Family, Pearland TX,
August 1993
MATERIAL WORLD, Peter Menzel
Criticism of the EF
• Bjorn Lomborg / The Economist
• Journal of Ecological Economics
• E. O. Wilson
Details of Canada’s Carbon
Carbon budget of Canada's forests
from 1895 to 1996. Also included is
the record of Canada's green-house
gas carbon emission rate.
Integrated Terrestrial Ecosystem
C-budget model
http://ccrs.nrcan.gc.ca/optic/coarse/beps/nep_e.php
February Monday Wednesday 7. Introduction
12. Eco-Footprint 14. Scale, Flow and Cycles
20. Sustainability?* 21. Intro to LCA
26. Exergy Accounting 28. Materials Production
March
5. Cutler Cleveland @ 12 noon 7. Mfg Processes
12. Mfg Processes 14. “Coal” discussion
19. Discussion 21. Quiz 1
26. (Spring Break) 28. (Spring Break)
April 2. LCA 4. Scale and Efficiency
9. Material Recycling 11. Product Recycling
16. (Patriots Day Holiday) 18. Product Reuse
23. Photovoltaics (TB) 25. Nanomfg (JI)
30. Presentations
May 2. Presentations
7. Project Follow-up 9. Field Trip
14. Review 16. Quiz 2
New ScheduleNew ScheduleNew ScheduleNew Schedule