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 CO 2 Emissions/GDP for Technology, then ‘Impact’ simplifies to total CO 2 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, CO 2 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 km 2 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

e iz el B 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 2 Global 1 km IGBP Land-Cover Dataset Country

Belize Nicaragua Honduras Guatemala Costa Rica El Salvador

Population (1996)

224,000 4,351,000 5,751,000 11,241,000 3,466,000 5,935,000

El Salvador Costa Rica DMSP-OLS ‘Earth at Night’ dataset Eco-Value/Night Light

261,306 184,308 97,093 62,085 24,959 9,896

Local Rank

6 5 4 3 2 1

Sustainability Scores According to the Eco-Value / Night Light Energy Index

Very High Color Code to Sustainability according to Eco-Value / Night Light ESI 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 Eco Deficit of Wackernagel is not significant (R 2 = 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

Scatterplots with Regressions of the three ESIs discussed here 50 40 30 20 10 0 0

Statistically Significant 2 R = 0.59

UK US SZ JA NL GM KS IS GR SF JO VE MX TH TU RP CH BG CS MY CI ID AS CO BR NZ CA ET NO NI IN PK SW FI AU PO DA PL SP HU EG EZ FR 10 20 30 40

Rank of Eco-Deficit

50 Key for labeling of Nations in Scatterplots

High GDP/Capita Countries GDP/Cap >$20,000

Australia Austria Belgium Canada Denmark Finland France Germany Japan Netherlands Norway Singapore Sweden Switzerland United Kingdom United States

Fips Code

AS AU BE CA DA FI FR GM JA NL NO SN SW SZ UK US

Medium GDP/Capita Countries $20K>GDP/Cap >$3K

Argentina Brazil Chile Czech Republic Greece Hungary Ireland Israel Malaysia Mexico New Zealand Portugal South Africa Spain Venezuela

Fips Code

AR BR CI EZ GR HU EI IS MY MX NZ PO SF SP VE

Low GDP/Capita Countries GDP/Cap<$3,000

Bangladesh China Colombia Costa Rica Egypt Ethiopia India Indonesia Jordan Nigeria Pakistan Peru Phillipines Poland South Korea Thailand Turkey

Fips Code

BG CH CO CS EG ET IN ID JO NI PK PE RP PL KS TH TU

2 Note #1: R reported are derived from ranked or non-parametric regression Note #2: Higher ranks in all cases suggest higher sustainability

Problems & Future Research

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 Eco Value 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