Transcript An Overview of Methods for Estimating Urban Populations

An Empirical Environmental Sustainability
Index derived solely from Nighttime Satellite
Imagery and Ecosystem Service Valuation
Paul Sutton
[email protected]
Department of Geography
University of Denver
Outline
“What is an Environmental Sustainability Index?”
•
•
•
•
•
Data and Methods used to prepare this index
Results: Maps of Environmental Sustainability?
Other ESIs: Wackernagel’s Eco-Deficit & 2001 ESI
How do these ESIs intercompare?
Future Research directions
Sustainable Development &
Environmental Sustainability
The 1987 Brundtland Report made the idea of Sustainability
famous with the term ‘Sustainable Development’:
“Development
that meets the needs of the present
generation without compromising the ability of the
future generations to meet their own needs.”
Measuring Environmental Sustainability is a piece of this
puzzle. Defining and/or measuring Environmental
Sustainability is subject to great debate. Some methods
have been suggested by the likes of Wackernagel,
Ehrlich, and others.
Holdren & Ehrlich’s I=P*A*T
conception of environmental sustainability
• Human ‘Impact’ must be balanced by the
Environment’s ability to absorb said impact
• Daily & Ehrlich suggest that ‘Impact’ should not
exceed either ‘Maximum Sustainable Use’ (MSU)
or ‘Maximum Sustainable Abuse’ (MSA)
• Absolute measures of ‘sustainability’ are virtually
impossible to make; however, RELATIVE
measures might be reasonably made in order to
compare the environmental sustainability of
nations or regions of the world
Measuring Human ‘Impact’
• What data can be used in the I = P*A*T formulation?
• If you use Population for P, GDP/Capita for Affluence,
and CO2 Emissions/GDP for Technology, then ‘Impact’
simplifies to total CO2 emissions
• Daily & Ehrlich used Energy Consumption per Capita to
capture the A*T
• “Impact” is a function of both population size and
individual consumption levels
• Nighttime Imagery from the DMSP OLS correlates with
Population, Energy Consumption, CO2 emissions, and
GDP and may be the best spatially explicit, single
variable, measure of ‘Impact’
Measuring Maximum Sustainable Use
and Maximum Sustainable Abuse
• The myriad ways in which human’s can impact
the environment and the various ways the
environment either supports or absorbs such
actions are beyond the scope of this index.
• The proxy measure of MSA and MSU chosen was
simply the value of the land’s ecosystem services
as outlined by Costanza et. al. and calculated
using a USGS global land cover data set at 1 km2
resolution
Deriving The Eco-Value / Night Light Energy
Environmental Sustainability Index
National
Index
Value
Value of given Nation’s
Ecosystem Services as estimated
by Costanza and measured by
USGS 1 km2 Global Land Cover Grid
Amount of Light Energy seen in
Nighttime Satellite Imagery from
Defense Meteorological Satellite Program’s
Operational Linescan System (DMSP OLS)
This index is similar to the inverse of population density
e.g. ‘square kilometers of land per person’
However; ‘square kilometers of land’ is adjusted by the
land’s ecosystem service value; and, ‘per person’ is
measured by the nighttime satellite imagery provided by
the DMSP OLS
A representation of the datasets used to calculate
Eco-Value and Impact from around Central America
Belize
Guatemala
Honduras
Nicaragua
Evergreen Needleleaf Forest
Evergreen Broadleaf Forest
Deciduous Needleleaf Forest
Deciduous Broadleaf Forest
Open Shrublands
Closed Shrublands
Woody Savannas
Grasslands
Permanent Wetlands
Croplands
Urban
Cropland / Natural Vegetation
Water
El Salvador
Costa Rica
Global 1 km2 IGBP Land-Cover Dataset
Country
Belize
Nicaragua
Honduras
Guatemala
Costa Rica
El Salvador
DMSP-OLS ‘Earth at Night’ dataset
Population (1996) Eco-Value/Night Light
224,000
261,306
4,351,000
184,308
5,751,000
97,093
11,241,000
62,085
3,466,000
24,959
5,935,000
9,896
Local Rank
6
5
4
3
2
1
Sustainability Scores According to the
Eco-Value / Night Light Energy Index
Color Code to Sustainability according to Eco-Value / Night Light ESI
Very
High
High
Just Above
Average
Average
Low
Very
Low
Other National Measures of
Environmental Sustainability
• The 2001 Environmental Sustainability Index
produced by the Global Leaders of Tomorrow Environment Task
Force of the World Economic Forum, The Yale Center for
Environmental Law and Policy (YCELP), and the Center for
International Earth Science Information Network (CIESIN)
• The ‘Eco-Deficit’ derived by Wackernagel and Rees which
results from their ‘Ecological Footprint’ analysis and is in
essence the difference between ‘Available Ecological Capacity’
and the ‘Ecological Footprint’ of nations.
Ecological Footprint Analysis
• “Ecological Footprint analysis is an accounting tool that enables
us to estimate the resource consumption and waste assimilation
requirements of a defined human population or economy in
terms of corresponding productive land area.”
• The ‘Ecological Footprint’ ESI is also a composite index
involving many variables. However, in contrast to the 2001
ESI these variables focus on the nature and productivity of
land resources, variability of human consumption patterns,
and the energy accounting of each nation’s international trade.
The 2001 Environmental Sustainability Index
• The 2001 ESI attempts to develop a ‘transparent,
interactive process that draws on rigorous statistical,
environmental, and analytic expertise to quantify
environmental sustainability’.
• Key Results are: 1) Environmental Sustainability can be
measured, 2) The Index creates benchmarks of environmental
conditions that can influence decision making, 3) Serious ‘data
gaps’ for many nations of the world should be filled, 4)
Economic conditions affect, but do not determine,
environmental conditions; and, policy regarding these
conditions are separate choices.
• Calculated for 122 nations using 5 ‘Core’ indicators each of
which were derived from 67 other variables.
• Correlates Strongly with GDP per Capita
Comparing the 2001 ESI to the Eco-Deficit
• The Correlation between the 2001 ESI and the EcoDeficit of Wackernagel is not significant (R2 = 0.03)
• The 2001 ESI incorporates more cultural and Institutional
elements of sustainability along the lines of those
described by Courtland Smith in a critique of the
I=P*A*T formulation. And is consequently more of a
‘quality of life’ index than a sustainability index.
• The Eco-Deficit takes into account the separation of
production and consumption in ways not accounted for in
the 2001 ESI and may be a better of the global
sustainability of a local people, nation, etc.
Not Statistically Significant
Not Statistically Significant
Key for labeling of Nations in Scatterplots
Statistically Significant
Rank of Eco-Value / Night Light
Scatterplots
with
Regressions
of the three
ESIs
discussed
here
2
R = 0.59
50
ID
BG
40
RP
CH
TU
VE
SF
30
GR
MX
JOTH
20
UK SZ
US
JA
10
NL
BE
SN
0
0
PL SP
MY
CI
CS
AR
EI
ET
NO
IN
PK
SW
FI
AU DA
PO
HU
FR
GM KS
EG
IS
10
NI
PE
AS
COBR
NZ
CA
20
EZ
30
40
Rank of Eco-Deficit
50
High GDP/Capita
Countries
Fips
Code
GDP/Cap >$20,000
Australia
Austria
Belgium
Canada
Denmark
Finland
France
Germany
Japan
Netherlands
Norway
Singapore
Sweden
Switzerland
United Kingdom
United States
Medium GDP/Capita
Countries
Fips Low GDP/Capita Fips
Code
Countries
Code
$20K>GDP/Cap >$3K
AS
AU
BE
CA
DA
FI
FR
GM
JA
NL
NO
SN
SW
SZ
UK
US
Argentina
Brazil
Chile
Czech Republic
Greece
Hungary
Ireland
Israel
Malaysia
Mexico
New Zealand
Portugal
South Africa
Spain
Venezuela
2
GDP/Cap<$3,000
AR
BR
CI
EZ
GR
HU
EI
IS
MY
MX
NZ
PO
SF
SP
VE
Bangladesh
China
Colombia
Costa Rica
Egypt
Ethiopia
India
Indonesia
Jordan
Nigeria
Pakistan
Peru
Phillipines
Poland
South Korea
Thailand
Turkey
Note #1: R reported are derived from
ranked or non-parametric regression
Note #2: Higher ranks in all cases
suggest higher sustainability
BG
CH
CO
CS
EG
ET
IN
ID
JO
NI
PK
PE
RP
PL
KS
TH
TU
Problems & Future Research
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•
•
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General
Definitions: lack of correlation between 2001 ESI
and Eco-Deficit Index suggests that basic work
on defining environmental sustainability still
needs to be done.
ESIs may be interesting but are they of any use?
Specific to Eco-Value / Night Light Energy Index
Scale problems with measuring Eco-Value
Spatial Context problems with measuring EcoValue e.g. Flood control around resevoirs
Conclusions
• Eco-Value / Night Light Energy Index correlates
strongly with Eco-Deficit but not at all with 2001
ESI
• Consilience as to what is meant by the term
‘Environmental Sustainability’ remains elusive
• The ‘Eco-Value’ / Night Light Energy Index is
simple, relatively objective, measureable at fine
spatial resolution, and updateable on a relatively
frequent basis