4e azar indicators

8/8/2019 4e Azar Indicators

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ELSEVIER Ecological Economics 18 (1996) 89-112E C O L O G I C A LE C O N O M I C S

M ethodological and Ideological Op tionsS o c i o - e c o l o g i c a l in d i c a to r s fo r su s t a in a b i l i tyChristian Azar, John Holmberg *, Kristian Lindgren

Institute o f Physical Reso urce Theo~', Chalme rs U niversio, of Techno logy and UniversiO; of GOteborg, S-4 12 96 GOteborg, SwedenReceived 20 February 1995; accepted 12 February 1996

A b s t r a c t

A systematic framework of indicators for sustainability is presented. In our approach there is an emphasis on societalactivities that affect nature and on the internal societal resource use, as opposed to environmental quality indicators. In thisway the indicators may give a warning signal to an unsustainable use of resources early in the chain from causes in societalactivities to environmental effects. The aim is that these s oc i o - eco l og i ca l i nd i ca t or s shall serve as a tool in planning anddecision-making processes at various administrative levels in society. The formulation of the indicators is made with respectto four principles of sustainability, which lead to four complementary sets of indicators. The first deals with the societal useof lithospheric material. The second deals with emissions of compounds produced in society. The third set of indicatorsconcerns societal manipulation of nature and the long-term productivity of ecosystems. Final ly, the fourth set deals with theefficiency of the internal societal resource use, which includes indicators for a just distribution of resources.Keywords: Indicators; Sustainability

1 . I n t r o d u c t i o n

The publication of the Brundlandt report 'O ur Co mmon Fut ure' (WC ED, 1987) and the Rio Declaration(United Nations, 1992a) put the challenge of sustainable development on the agenda for planners, decisionmakers and polit icians at all administ rative and institution al levels of the global society. Since then, m uch efforthas been made to define and operationalise the concept of sustainability.

Many researchers have suggested various types of non-mon etary measures to indicate to what extentenv iron ment al states and fun ctions, material flows, or societal activities can be regarded as sustaina ble (see, e.g.,Vos et al., 1985; Liverman et al., 1988; Kuik and Verbruggen, 1991; Opschoor and Reijnders, 1991; Holmbergand Karlsson, 1992; Adriaanse, 1993; Alfsen and Sa~b, 1993; Bergstrrm, 1993; Gilbert and Feenstra, 1994;Moffatt, 1994; OECD, 1994). Most sets of indicators developed so far have focused on the state of theenv iro nme nt rather than on the relation between society and ecosystems. In the present paper we formulateindicators based on four socio -ecologica l principle s for sustaina bility (Hol mberg et al., 1996). The princ iples

* Corresponding author, e-mail: [email protected]/96/$15.00 Copyright 1996 Elsevier Science B.V. All rights reserved.P H S0921-8009(96)00028-6


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C. Azar et al. / Ecolog ical Econo mics 18 (1996) 89-112Table 1The focus of some indicators for sustainability

9 l

Reference Indicated area Societal activities Environm ental pressure State of the environme ntAdriaanse (1993) The Netherlands x xAlfsen and Sa~b0 (1993) Norw ay xAyres (1995) Mainly US A x xten Brink ( 1991 ) Specific ecosystem xBrown et aL (1994) The world x (x) (x)Carlson (1994) Sweden x xECE (1985) EC E member countries (x) x xEnvironment Canada (1991) Canada x xGilbert and Feenstra (1994) Specific ecosystem (x) xHoldren (1990) The world x (x)Holmberg and Karlsson (1992) Not specific x xMiljoministeriet ( 1991) Denm ark (x) x xNilsson and Bergstr~m (1995) Mu nicipality and comp any x x xOE CD (1994) OE CD countries (x) x (x)Opscho or and Reijnders (1991) No t specific x xSNV (1994) Sweden xHaes et al. (1991) Specific ecosystem xVos et al. (1985) Th e Netherlands x xThis paper The world x xThe symbol 'x' indicates the main focus of the work, while (x) means that such indicators are included, but only play a minor role in thework.

3 .1 . P r i n c i p l e 1 : s u b s t a n c e s e x t r a c t e d f r o m t h e l i th o s p h e r e m u s t n o t s y s t e m a t i c a l l y a c c u m u l a t e i n t h e e c o s p h e r e .E l e m e n t s f r o m t h e li t h o s p h e r e m u s t n o t b e s p r e a d a t a r a te w h i c h w i l l g i v e r i s e t o a s y s t e m a t i c i n c r e a s e i n t h e

e c o s p h e r e . S u c h a n i n c r e a s e w i l l o c c u r i f t h e s u m o f th e a n t h r o p o g e n i c e m i s s i o n s a n d t h e n a t ur a l f l o w s f r o m t h el i th o s p h e r e t o t he e c o s p h e r e ( w e a t h e r i n g p r o c e s s e s a n d v o l c a n i c e r u p t i o n s ) e x c e e d s t h e s e d i m e n t a t i o n r a t e a n dt h e ra te o f f in a l d i s p o s a l i n t h e l i t h o s p h e r e . B e c a u s e o f t h e c o m p l e x i t y a n d d e l a y m e c h a n i s m s o f p r o c e s s e s i n th ee c o s p h e r e , i t i s e x t r e m e l y h a r d t o s a y w h a t l e v e l o f a c c u m u l a t i o n w i l l c a u s e a n e f fe c t . In fa c t , e v e r y s u b s t a n c eh a s a l i m i t ( o f t e n u n k n o w n ) , a b o v e w h i c h d a m a g e o c c u r s in th e e c o s p h e r e . I n c r e a s i n g a m o u n t s o f c a rb o nd i o x i d e i n t h e a t m o s p h e r e , o f s u l p h u r d i o x i d e l e a d i n g t o a c id r a in , o f p h o s p h o r u s i n la k e s a n d o f h e a v y m e t a l s i ns o i l s a n d i n o u r b o d i e s a r e a ll e x a m p l e s o f s u c h a c c u m u l a t i o n . I n p r a c t i c e , t h is p r i n c i p l e i m p l i e s r e s t r ic t i o n s o nt h e e x t ra c t i o n r a t e o f m e t a l s a n d f o s s il f u e ls i n c o m b i n a t i o n w i t h i n c r e a s e d r e c y c l i n g o f m a t e ri a l a n d d e c r e a s e dd i s s i p a t i v e u s e o f s c a r c e e l e m e n t s . I t a l s o i m p l i e s s u b s t i t u t i o n o f a b u n d a n t e l e m e n t s f o r s c a r c e e l e m e n t s .3 .2 . P r i n c i p l e 2 : s o c i e ~ - p r o d u c e d s u b s t a n c e s m u s t n o t s y s t e m a t i c a l l y a c c u m u l a t e i n th e e c o s p h e re .

I n th e t e c h n o s p h e r e , m o l e c u l e s a n d a t o m i c n u c l e i o f d i f f e r e n t k i n d s a r e p r o d u c e d , s o m e o f th e m l o n g - l i v e d ,i n a m o u n t s p r e v i o u s l y u n k n o w n t o th e e c o s p h e r e . I f th e y a r e e m i t t e d f a s te r th a n t h e y a r e d e g r a d e d i n tom o l e c u l e s o r n u c l i d e s t h at c a n b e i n te g r a t e d i n t h e e c o s p h e r i c c y c l e s , a n d / o r f a s t er th a n t h e y a r e r e m o v e d t o th el i th o s p h e r e , s u c h s u b s t a n c e s w i l l a c c u m u l a t e i n t h e e c o s p h e r e . I n o r d e r t o r e d u c e t h e a m o u n t e m i t t e d , o n e c a nd e g r a d e s u b s t a n c e s w i t h i n th e t e c h n o s p h e r e o r d e p o s i t t h e m i n fi n a l d i s p o sa l s . C F C m o l e c u l e s d e s t r o y i n g t h eo z o n e l a y e r, i n c r e a s i n g a m o u n t s o f D D T a n d P C B i n b i o ta , a n d r a d i o a c t i v e i n e rt g a s es i n t h e a tm o s p h e r e a r e al le x a m p l e s o f s u c h a c c u m u l a t i o n . T h e p r i n c i p l e a l s o i m p l i e s th a t p e rs i s t e n c e i s a v e r y im p o r t a n t a s p e c t o fs u b s t a n c e s t h a t a re f o r e i g n t o n a tu r e , a n d t h e r e f o r e t h e r e s h o u l d b e s t r o n g r e s t r i c t io n s o n t h e u s e o f p e r s i s t e n ts u b s t a n c e s f o r e i g n t o n a tu r e .


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C . A z a r e t a l. / E c o l o g i c a l E c o n o m i c s 1 8 ( 1 9 9 6 ) 8 9 - 1 1 2 9 3

If i n a l n * jI deposit[ I X R I ~'~ X T" ' - - ~ [ k ex [ T ech n o sp h ere[I

l ,wLithosphere -~ k s

X EEcosphere

F i g . 1 . A n e l e m e n t i s e x t r a c t e d f r o m t h e l i t h o s p h e r e a n d u s e d i n t h e t e c h n o s p h e r e . E v e n t u a l l y i t w il l b e e m i t t e d t o t h e e c o s p h e r e , w h e r e i tw i l l r e m a i n u n t i l s e d i m e n t a t i o n p r o c e s s e s o n c e a g a i n b u r y i t i n t h e l i t h o s p h e r e . T h e f i g u r e s h o w s t h a t t h e t o t a l c o n t e n t s o f t h e e l e m e n t w i l li n c r e a s e i n t h e e c o s p h e r e i f t h e t o ta l e m i s s i o n s f r o m t h e t e c h n o s p h e r e ( k e rn ) p l u s t h e n a t u r a l f l o w f r o m t h e l i t h o s p h e r e ( k w ) e x c e e d t h e r a t eo f s e d i m e n t a t i o n ( k s ) . T h e d a s h e d l i n e r e p r e s e n t s d i r e c t f l o w s f r o m t h e t e c h n o s p h e r e t o t h e l i t h o s p h e r e f o r f i n a l d e p o s i t i o n i n r e p o s i t o r i e s .A t p r e s e n t , t h i s o p t i o n i s o n l y p l a n n e d f o r r a d i o a c t i v e w a s t e .

d i s s i p a t i v e u s e , ( i ii ) r e t u rn i n g t h e m a t e r i a l t o u n d e rg ro u n d r ep o s i t o r i e s (d as h ed l i n e i n F ig . 1 ) an d ( i v ) i n c reas i n gt h e s ed i m en t a t i o n r a t e ( e . g . , b y g u i d i n g t h e em i s s i o n s f ro m t h e t ech n o s p h ere t o a r eas i n t h e eco s p h e re wh ere t h es ed i m en t a t i o n r a t e i s h i g h ) .

T h ere a r e s ev e ra l r eas o n s fo r p u t t i n g t h e fo cu s ea r l y i n t h e cau s a l ch a i n wh en i n d i ca t i n g Pr i n c i p l e 1 . T h ee l em en t s t h a t a r e ex t r ac t ed d o n o t d i s ap p ea r an d a s l o n g a s we d o n o t h av e c l ev e r s tr a t eg i e s fo r p rev e n t i n gaccu m u l a t i o n i n t h e eco s p h e re , a p l au s i b l e f i r s t ap p ro x i m a t i o n i s t h e re fo re t h a t t h e e l em en t s ex t r ac t ed w i l lev en t u a l l y l eak to t h e eco s p h e re . Fu r t h e rm o re , t h e d i f fu s e em i s s i o n s f ro m t h e co n s u m p t i o n s ec t o r o f t h ee c o n o m y n o w e x c e e d t h e m o r e e a s i l y d e t e c t e d e m i s s i o n s f r o m t h e p r o d u c t i o n s e c t o r f o r m a n y e l e m e n t s .B erg b ~i ck (1 9 9 2 ) h as s h o wn t h a t t hi s i s t h e cas e fo r m an y m e t a l s u s ed i n Sw ed en . T h e r e s i d en t ia l t i m e i s o f tenl o n g e r i n t h e co n s u m p t i o n s ec t o r t h an i n t h e p ro d u c t i o n s ec t o r .4 . 1 . 1 . I n d i c a t o r n o . 1 ,1 : l i t h o s p h e r i c e x t r a c t i o n r a t e s

I f t h e r a te o f ex t r ac t i o n i s h i g h co m p ared t o t h e n a tu ra l s ed i m en t a t i o n p ro ces s , acc u m u l a t i o n w i l l o ccu r i n th et ech n o s p h ere , an d s o o n er o r l a t e r i n t h e eco s p h e re . T h e m a t e r i a l accu m u l a t ed i n t h e t ech n o s p h ere w i l l ev en t u a l l yl eak t o th e eco s p h e re . T h u s , i t is i m p o r t an t t o i n d i ca t e th e ex t r ac t i o n r a t e o f each e l em en t . We d e f i n e t h e f i r s ti n d i ca t o r 1 1, , f o r P r i n c i p l e 1 a s t h e ex t r ac t i o n r a t e d i v i d ed b y t h e r a t e o f n a t u ra l s u p p l y ' f ro m t h e l i t h o s p h e re t ot h e eco s p h e re b y wea t h e r i n g an d v o l can i c e ru p t i o n s , i . e . :

k e x1 1 ' 1 = k - - w - ' ( 4 . 1 )

wh ere we u s e t h e co n v en t i o n t h a t t h e f i r s t d i g i t i n t h e s u b s c r i p t o f I r e f e r s t o t h e p r i n c i p l e an d t h e s eco n d i s ani n d ex fo r t h e d i f f e r en t i n d i ca t o r s w i t h i n t h i s g ro u p . T h i s f i r s t i n d i ca t o r , t h e L i t h o s p h e r i c E x t r a c t i o n I n d i c a t o r( L E D , h as t h e ad v an t ag e t h a t i t i s s t r a i g h t fo rward an d eas y t o u n d e r s t an d , an d t h a t d a t a a r e r e l a t i v e l y eas y t oo b t a i n . T h i s t y p e o f i n d i ca t o r h as b een p ro p o s ed a s a m eas u re o f an t h ro p o g en i c d i s ru p t i o n o f n a t u ra l cy c l e s b yB e n j a m i n a n d H o n e y m a n (1 9 9 2) . I f I1,1 = 1 , t h e p res en t an t h ro p o g en i c ex t r ac t i o n i s eq u a l t o t h e n a t u ra l s u p p l yt o t h e eco s p h e re . T h i s i m p l i e s t h a t an t h ro p o g en i c p e r t u rb a t i o n s o f t h e n a t u ra l b i o g eo ch em i ca l cy c l e s a r eco n s i d e ra b l e an d w e can ex p ec t s i g n i f i can t ch an g es i n t h e co n cen t r a t i o n o f t h e e l em en t i n q u es t i o n i n t h ee c o s p h e r e .

Acco rd i n g t o P r i n c i p l e 1 , s u s t a i n ab i l i t y r eq u i r e s t h a t t h e co n cen t r a t i o n o f each o f t h e e l em en t s m u s t n o ti n c reas e s y s t e m a t i ca l l y i n t h e eco s p h e re . O n e co u l d s ay t h a t an t h ro p o g e n i c p e r t u rb a t i o n s o f t h e n a tu ra l

i T h e n a t u r a l s u p p l y t o t h e e c o s p h e r e i s b a l a n c e d b y t h e n a t u r a l s e d i m e n t a t i o n b a c k t o t h e l i t h o s p h e r e .


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94 c. Azar et al. / Ecological E~ onom ics 18 (1996) 89-112b i o g e o c h e m i c a l c y c l e s m u s t b e s m a l l , w h i c h i m p l i e s v a l u e s o f I ~.~ ( m u c h ) l e s s t h an u n i t y . T h i s s h o u l d b ev i e w e d a s a r u le o f t h u m b , a n d i n s p e c i f i c c a s e s o n e m a y a r g u e f o r m o r e e x a c t a c c e p t a b l e v a l u e s f o r th i si n d i c a t o r. E v e n i f t h e r e i s n o o b v i o u s c r i t ic a l v a l u e f o r th e i n d i c a t o r , o n e c a n m a k e a f ir s t c o m p a r i s o n b y l o o k i n ga t t he o r d e r o f m a g n i t u d e o f t h e i n d i c a t o r fo r d i f f e r e n t e l e m e n t s . I n th i s w a y o n e c a n g e t a n i n d i c a t i o n o f, f o ri n s t a n c e , w h i c h m e t a l s c o u l d p o s s i b l y s u b s t i t u te f o r o t h e rs . I f w e f o c u s o n t h e u s e o f a s p e c i f i c e l e m e n t , t h ei n d i c a t o r s h o u l d b e c a l c u l a t e d f o r a t i m e s e r ie s t o r e v e a l th e t r e n d t o w a r d s o r a w a y f r o m s u s t a i n a b i li t y .4 . 1 .2 . I n d i c a t o r n o . 1 , 2: a c c u m u l a t e d l i th o s p h e r i c e x t r a c t i o n

I t i s a l s o o f i n t e r e s t t o i n d i c a t e th e a c c u m u l a t e d a m o u n t o f a s p e c i f i c e l e m e n t i n t h e t e c h n o s p h e r e i n re l a t i o nt o t h e e c o s p h e r i c c o n t e n t o f t h a t e le m e n t . W e a r e e s p e c i a l l y i n te r e s t e d i n th e t o t a l p r e - in d u s t r i a l c o n t e n t i n th eh u m a n a r e a s o i ls , 2 w h i c h w e d e n o t e b y X ~ a n d w e d e f i n e :

l o x xI~= .. ~ E , f _ k ~ x ( t ) d t = X E ' ' ( 4 . 2 )

w h e r e X A is th e a c c u m u l a t e d e x t r a c t i o n f ro m t h e l i th o s p h e r e . F o r m a n y m e t a l s m o s t o f t h e m i n i n g h a s b e e nc a r r i e d o u t d u r i n g t h i s c e n t u r y a n d m o s t o f t h e e x t r a c t e d a m o u n t s t il l r e m a i n s i n t h e t e c h n o s p h e r e . I n t h i s c a s et h e i n d i c a t o r c a n b e a p p r o x i m a t e l y w r i t t e n I~ . z ~ X T / X ~ , w h e r e X ~ i s t h e a m o u n t i n t h e t e c h n o s p h e r e .

W e r e f e r t o th i s r a t i o a s th e A c c u m u l a t e d E x t r a c t i o n I n d i c a t o r . ~" T h e i n d i c a t o r IL 2 c an b e u s e d a s a n e a r l yw a r n i n g s i g n a l. I f it s v a l u e i s h i g h , t h e n t h e r e a r e r e a s o n s f o r a n a l y s i n g t h e f l o w s o f t h a t e l e m e n t i n m o r e d e t a il( e .g . , b y c o m p a r i n g f l o w s i n n a t u r a l s e d i m e n t a t i o n p r o c e s s e s w i t h th e l e a k a g e f r o m t h e t e c h n o s p h e r e ) a n dp o s s i b l y c o n s i d e r i n g f in a l d e p o s i t o f t h e e l e m e n t . C a d m i u m h a s b e e n d i s c u s s e d i n t h is c o n t e x t b y v a n d e r V o e ta n d K l e i j n ( 1 9 9 2 ).4 . 1 .3 . I n d i c a t o r n o . 1 , 3 : n o n - r e n e w a b l e e n e r g y su p p l. v

S e v e r a l e n v i r o n m e n t a l p r o b l e m s a r e r e l a t e d t o t h e us e o f n o n - r e n e w a b l e e n e r g y . H e n c e , w e h a v e c h o s e n t oi n d i c a t e t h e ra t i o b e t w e e n n o n - r e n e w a b l e e n e r g y a n d t o ta l p r i m a r y e n e r g y s u p p l y .

N o n - r e n e w a b l e p r im a r y e n e r g y s u p p l yI i ,3 = T o t a l p r i m a r y e n e r g y s u p p l y ( 4 . 3 )

I n F i g . 2 , w e p r e s e n t a t i m e s e r i e s f o r t h i s i n d i c a t o r .4 . 1 . 4 . O t h e r in d i c a t o r s

T h e r e a r e a l s o o t h e r i n d i c a t o rs t h at c a n b e f o r m u l a t e d f r o m t h e v a r i a b l e s o f F i g . l , F i g . a n d F i g . , a n d t h a tr e f l e c t i m p o r t a n t a s p e c t s o f s o c i e t a l r e s o u r c e u s e ( e . g . , kem/k w or i n d i c a t o r s f o r e m i s s i o n s t o s p e c i f i c p a r t s o ft h e e c o s p h e r e ) , s u c h a s a n t h r o p o g e n i c e m i s s i o n s o f m e t a l s to t he a t m o s p h e r e , a q u a t i c s y s t e m s a n d s o i l s ( L a n t z ya n d M a c k e n z i e , 1 9 79 ; N r i a g u a n d P a c y n a , 1 9 88 ).

T h e e f f i c i e n c y i n t he u s e o f e l e m e n t s w i t h i n s o c i e t y ( e. g ., t h e d e g r e e o f r e c y c l i n g ) is d e a l t w i th i n c o n n e c t i o nw i t h P r i n c i p l e 4 . A l s o , i n d i c a t o r s f o c u s i n g o n t h e p r o b l e m o f t he l i m i t e d a m o u n t o f l it h o s p h e r i c r e s o u r c e sb e l o n g t o P r i n c i p l e 4 s i n c e t h e y d e a l w i th i n t e r g e n e r a t i o n a l j u s t ic e .

I t h a s b e e n a r g u e d t h a t fo r m o s t e l e m e n t s t h e a s s i m i l a t i o n c a p a c i t y o f th e e c o s p h e r e i s a m o r e r e s t r ic t i v ec o n s t r a i n t o n t h e u s e o f t h e s e e l e m e n t s t h a n t h e a m o u n t o f t he r e s o u r c e s a v a i l a b l e i n th e l i t h o s p h e r e ( s e e , e .g . ,H o l m b e r g e t a l. , 1 9 96 ). A p o s s i b l e e x c e p t i o n m a y b e p h o s p h o r u s , w h i c h i s a n o n - s u b s t i t u ta b l e m a c r o - n u t r i e n t .

2 The h uma n area is the top soil layer (to 0.2 m depth) of la nd used for the technosphere. Vitousek et al. (1986) call this the "hu man area"and a ssign it a va lue of 2 million km 2. It is possible to choo se a different reference are a, but it w ill not affect the com parison betwee ndifferent substances in any significant way.W allgren (1992) has called this ratio the Futu re Contt~mination Index (FC I) when calculating i ts value for some metals used in Sw eden.


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C . A z a r e t a l. / E c o l o g i c a l E c o n o m i c s 1 8 ( 1 9 9 6 ) 8 9 - 1 1 2 95

Global non-renewab le energy inpu t100 [% of total input]80

4 020

0 I I I I I I I

Fig. 2. The ratio between non-renewable energy and total en ergy supply. Data based on B P Statistical Review.4 . 1 . 5 . N u m e r i c a l e x a m p l e s

In T a b l e 2 t h e i n d i c a t o r s I 1. ~ a n d I i , 2 a r e g i v e n f o r s o m e o f t h e e l e m e n t s t h a t a r e e x t ra c t e d f r o m t h el i t h o s p h e re .

I f w e l o o k a t I H , i n T a b l e 2 , w e s e e t h a t f o r m a n y e l e m e n t s t h e a n t h r o p o g e n i c f l o w s d o m i n a t e o v e r th en a t u ra l f l o w s . T h e d i s c u s s i o n o f t h e e n v i r o n m e n t a l i m p l i c a t i o n s f o r m e t a l s s u c h a s P b , H g a n d C d h a s a l r e a d yb e g u n . B u t w e s e e f r o m t h e t a b l e t h a t t h i s d i s c u s s i o n m u s t s o o n i n c l u d e o t h e r e l e m e n t s a s w e l l ( e . g . , C u , w h i c hh a s e v e n h i g h e r v a l u e s f o r t h e i n d i c a t o r I ~.1 ). A p l a u s i b l e r e a s o n w h y t h e u s e o f C u i s n o t y e t d i s c u s s e d c a n b et h a t t h i s m e t a l h a s a l o n g e r r e s i d e n c e t i m e w i t h i n s o c i e t y a n d t h a t w e h a v e t r a d i t i o n a l l y p u t o u r f o c u s o n e f f e c t si n n at u r e . A h i g h d e g r e e o f r e c i rc u l a t i o n o f e l e m e n t s w i t h i n s o c i e t y a n d c a r e f u l h a n d l i n g o f th e e l e m e n t s( n o n - d i s s i p a t i v e u s e ) c a n r e d u c e t h e r i s k s a s s o c i a t e d w i t h h i g h v a l u e s f o r t h e i n d ic a t o r .

N o t e t h a t I~ . j i n d i c a t e s a f l o w w h i l e I i , 2 in d i c a t e s a s ta t e . A h i g h v a l u e o f 11. ~ a n d a l o w v a l u e o f I t , 2 i s aw a r n i n g t h a t a r a p i d a c c u m u l a t i o n i s t a k i n g p l a c e a n d I 1 , 2 w i l l i n c r e a s e . T h e re fo re , I~,~ l i es ear l i e r than l j , 2 int h e c a u s a l c h a i n .

T h e v a l u e s f o r t h e i n d i c a t o r I~ .~ f o r t h e e l e m e n t s C , S a n d P a r e c o n s i d e r a b l y l a r g e r th a n u n i t y (s e e T a b l e 2 ) .T h e e n v i r o n m e n t a l e f f e c ts t h at a re k n o w n f r o m t h e e m i s s io n s o f t h es e e l e m e n t s - - t h e g r e e n h o u s e e f f e ct ,a c i d i f i c a t io n a n d e u t r o p h i c a t i o n - - c l e a r l y s h o w t h a t i n a ll th r e e c a s e s w e h a v e e x c e e d e d a cr i ti c a l v a l u e f o r t h isi n d i c a t o r .4 . 2 . S o c i o -eco l o g i ca l i n d i ca t o r s b a s ed o n P r i n c i p l e 2

A c c o r d i n g t o th e s e c o n d s o c i o - e c o l o g i c a l p r in c i p l e f o r s u s ta i n a b il i ty , s u b s t a n c e s t h a t a r e p r o d u c e d i n s o c i e tym u s t n o t s y s t e m a t i c a l l y a c c u m u l a t e i n t h e e c o s p h e r e . H e r e , w e f o r m u l a t e s o c i o - e c o l o g i c a l i n d i c a t o r s f o rs u b s t a n c e s t h a t a r e n a t u r a l l y e x i s t in g ( S e c t i o n 4 . 2 . 1 ) a n d f o r s u b s t a n c e s t h a t a r e f o r e i g n t o n a tu r e ( S e c t i o n 4 . 2 .2 ) .4 . 2 .1 . I n d i ca t o r s f o r m a n -m a d e s u b s t a n c es t h a t a r e n a t u r a l l y ex i s ti n g

T h e m a i n i d e a b e h i n d t h e t w o f i r s t p r i n c i p l e s f o r a s u s t a i n a b l e s o c i e t y i s t h a t s u s t a i n a b i l i t y r e q u i r e s t h a th u m a n d i s r u p t i o n o f t h e n a tu r a l c y c l e s a n d f l o w s o f s u b s t a n c e s a r e s m a l l e n o u g h t o a v o i d a s y s t e m a t i ca c c u m u l a t i o n .4 . 2 .1 . 1 . I n d i ca t o r n o. 2 , 1 : a n t h r o p o g en i c f l o w s co m p a r ed t o n a t u r a l .f l o w s . A s t h e f i r s t i n d i c a t o r f o r s u b s t a n c e st h a t a r e n a t u r a l l y o c c u r r i n g , w e s u g g e s t t h e r a t i o :

Ea1 2 'L = E - -~ " ( 4 . 4 )


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96 C. Azar et al. / Ecological Economi cs 18 (1996) 89-11 2Table 2Indicators for element s extracted from the lithosphereElem ent Conc. in soils (m g/ kg ) Weat herin g a and volcanic (kton) Mini ng (kton) Fossil fuels ~ (kton) lr ~ c 11._~ dMetalsAI 72000 l 100000 18000 34000 0.048Fe 26 000 390 000 540 000 34 000 1.4K 15000 230000 24000 340 0.11Mg 9 000 140 000 3 100 690 0.028Ti 2 900 44 000 2 500 I 700 0.096Mn 550 8 300 8 600 170 I. 1Zr 230 3 500 880 140 0.3V 80 I 200 32 350 0.32Zn 60 910 7 300 260 8.3Cr 54 830 3 800 34 4.6Cu 25 380 900 0 55 24Li 24 360 9.9 220 0.64Ni 19 300 880 570 4.8Pb 19 290 3 300 85 12Ga 17 260 0.037 24 0.092Nb l 1 170 14 14 0.17U 2.7 41 47 3.4 1.2Sn 1.3 20 210 5.7 I IMo 0.97 15 110 17 8.5Be 0.92 14 0.34 10 0.76Cd 0.35 5.3 20 3.4 3.9Hg 0.09 1.4 5.2 10 6.5Ag 0.05 0.75 15 1.7 22Semi-metalsSi 310 000 4 700 000 4 600 95 000 0.021B 33 500 0.37 250 0.52As 7.2 110 19 18 0.33Ge 1.2 18 0.27 17 0.96Sb 0.66 9.9 54 10 6Non-metalsC 25 000 780000 5 400000 6.4S 1 600 33 000 58 000 100 000 3.7F 950 14000 2 300 240 0.17P 430 6500 21 000 1 700 3.5Se 0.39 5.9 2.1 12 2

0.011

0.010.02

6.92.6

232

19

4.23

17

Weatheri ng mobilization is calculated using average concentration in soils (column 1) and suspended sediment flux of 1.5.1016 g per yearin rivers (Nriagu, 1990).b Data for contents of trace elem ents in crude oil are from USA (Yen, 1975). However, the onl y element s for which flow associated withcrude oil are considera ble compared with the flow associated with coal are V, Ni and Hg. The flows of elements associated with fossil fuelspredominate over the amount that is mined for several elements: e.g., V. Li, Ga, Be, Hg, Si, B, Ge, S, Se and, of course, for C. Surprisingly,this is also true for aluminium.

Indicator I U is calculated as anthropogenic flows from the lithosphere to the ecosphere divided by the natural flows. The anthropogenicflows are mini ng and flows associated with fossil fuels and the natural flows are weathering and volcani c processes. Data from 1990.d Indicator Ii. 2 is calcula ted as the accumul ated mini ng since 1900 divid ed by the amount in the top soil laye r in the human area (see thetext). If flows from fossil fuels had been included, the indicator value would increase substanti ally for a number of elements.Source: BP Stati stical Review, Yen (1975), Valk ovid (1983), Nriagu (1989), Sposito (1989), Crowson (1992), Speight (1992), Wallgren(1992), Wal ker and Kasti ngs (1992), Sig entha ler and Sarmi ento (1993), Holmbe rg et al. (1996) and Karlsson el al. (1994).


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C . A z a r e t a l. / E c o l o g i c a l E c o n o m i c s 1 8 (1 9 9 6 ) 8 9 - 1 1 2 97Table 3Indicators for Principle 2Substance 12. i 12,2CO 2 0.07 1.8 a.t,CH 4 1.4-4.1 2.7 bN2(g) ~ N(active) 1.3-3 -N20 0.5-1 1.5 bNH~ and NH~ 0.02-0. 09 -NO x 1.9-2.6 -SO, 0.7-6C t 0.1 1.1

The value for the second indicator for CO~ gives the atmospheric concentrat ion in the year 2100 divided by the pre-industrialconcentration, given that the present global emissions are kept constant. In order to estimate the long-term atmospheric concentration ofCO,, one has to make assumptions about emissions scenarios and fossil fuels reserves, Maier-Reimer and Hasselman (1987) estimate thatfor a stock of fossil fuels equal to 5000 Gton C, the atmospheric concentration of CO 2 would reach peak concentration as high as 4. 5-6. 4times the pre-industrial level (all depending on the rate at which the stock of fossil fuels is combusted). No net-sink in biomass is assumed.b Values from IPCC (1995).S o u r c e s : Bolin (1979), SiSderlund and Rosswall (1982), IPCC (1990), IPCC (1992), IPCC (1995), Jaffe (1992), Bates et al. (1992), Graedeland Crutzen (1993), UNSCEAR (1993).

H e r e E a is t h e a n t h r o p o g e n i c r a t e o f p r o d u c t i o n o f a g i v e n s u b s t a n c e a n d E n i s t h e n a t u r a l r a t e o f p r o d u c t i o n .T h i s i n d i c a t o r is a n a l o g u e t o i n d i c a t o r Ii, l ( s e e E q . 4 . 1 ) .4.2.1.2 . Indica tor no. 2 ,2: the long- term impl icat ion s of pres ent em iss ions . I t i s n o t c l e a r f r o m t h e v a l u e o fi n d i c a t o r IzA, w h a t th e l o n g - t e r m c o n t e n t w i l l b e i n th e e c o s p h e r e . A n a n a l y s i s o f th e l o n g - t e r m c o n t e n t r e q u i r e ss p e c if i c m o d e l s o f h o w , w h e r e a n d w h e n t h e s u b s t a n c e i s r e l e as e d t o t h e e c o s p h e re . I n s o m e c a s e s , h o w e v e r ,t h i s i s e a s i l y d o n e . F o r s o m e s u b s t a n c e s t h a t a r e r e l e a s e d t o t h e a t m o s p h e r e , a n d w h o s e l i f e - t i m e s a r e l o n ge n o u g h t o g u a r a n t e e a re l a ti v e l y h o m o g e n o u s d i s t ri b u ti o n t h r o u g h o u t t h e a tm o s p h e r e , a s im p l e m o d e l c a n b eu s e d i n o r d e r t o g e t a r o u g h p i c t u r e o f th e t o t a l c o n t e n t M ( t ) o f th e s u b s t a n c e i n t h e a t m o s p h e r e a t t i m e t . T h et i m e d e r i v a t i v e o f M ( t ) i s g i v e n b y :

1 V1 ( t ) - ~ E a q - E , - k M ( t ) , ( 4 . 5 )w h e r e k i s t h e r a te o f d e g r a d a t i o n ( o r r e m o v a l ) f r o m t h e a t m o s p h e r e . W h e n e v e r t h is f o r m u l a i s a p p l i c a b l e , i t i ss t r a i g h t f o r w a r d t o e v a l u a t e t h e l o n g - t e r m s t a t i o n a r y a t m o s p h e r i c c o n t e n t f o r t h e p r e s e n t ra t e o f e m i s s i o n sd i v i d e d b y t h e p r e - i n d u s t r i a l a t m o s p h e r i c content, Mprein~1. T h i s r a t i o i s o u r s e c o n d i n d i c a t o r f o r P r i n c i p l e 2 , a n di t i s g i ve n by :

g a + E n E a12,2 1 + - - . ( 4 . 6 )kMvreind E,I n T a b l e 3 , w e p r e s e n t v a l ue s f o r t he i nd i c a t o r s /2 , ~ a nd 12,2 f o r s o m e c o m m o n s u b s t a n c e s . I f 12. ~ = 1 , t h e n

t h e a n t h r o p o g e n i c f l o w s e q u a l n a t u r a l r a t e s o f p r o d u c t i o n , w h i c h i m p l i e s a c o n s i d e r a b l e d i s r u p t i o n o f th e n a tu r a lc y c l e o f t h a t s u b s t a n c e . T h e i m p l i c a t i o n o f t h e i n d i c a t o r v a l u e 12, ~ = 1 is i n g e n e r a l n o t c l e a r d u e t o u n c e r t a i n t ie sa b o u t t h e d e c a y p r o c e s s e s f o r d i f f e r e n t s u b s t a n c e s . T h i s i s , h o w e v e r , n o t t h e c a s e f o r t h o s e s u b s t a n c e s t h a t c a nb e d e s c r i b e d b y E q . 4 . 5 . F o r t h e s e s u b s t a n c e s , t h e l o n g - t e r m a t m o s p h e r i c c o n c e n t r a t i o n s w i l l i n c r e a s e b y a f a c t o ro f t w o ( w h i c h i s e a s i l y s e e n i n E q . 4 . 6 ) .

I t s h o u l d b e n o t e d t h a t a l s o r a th e r s m a l l v a l u e s f o r t h e i n d i c a t o r I z ,~ c o u l d b e u n s u s t a i n a b l e . C o n s i d e r , f o ri n s t a n c e , e m i s s i o n s o f C O 2 . A n t h r o p o g e n i c e m i s s i o n s a m o u n t t o 7.1 ___ 1 .1 G t o n C / y e a r ( I P C C , 1 9 9 5 ) . B u t a tt h e s a m e t i m e , r e s p i r a t i o n b y b i o t a g i v e s r i se t o a n a n n u a l p r o d u c t i o n o f 1 0 0 G t o n C . T h u s , w e h a v e 12.~ = 0 . 0 7 ,w h i c h m a y a p p e a r r a t h e r s m a l l. B u t s i n c e C O 2 i s a s ta b l e c o m p o u n d , t h e p r e s e n t r a te o f e m i s s i o n w i ll c a u s e a


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98 C. Azar et aL /Ecological Economics 18 (1996) 89-112s y s t e m a t i c i n c r e a s e i n t h e a t m o s p h e r i c c o n c e n t r a t i o n s d e s p i t e t h e f a c t th a t t h e v a l u e f o r t he i n d i c a t o r i s lo w . A tp r e s e n t , t h e a t m o s p h e r i c c o n c e n t r a t i o n o f C O 2 is 2 5 % h i g h e r t h a n i t s p r e - i n d u s t r i a l le v e l , a n d t h e c o n c e n t r a t i o ni s i n c r e a s i n g a t a p p r o x i m a t e l y 0 . 5 % p e r y e a r . T h i s i n c r e a s e i s m a i n l y d u e t o t h e fl o w f r o m t h e l i t h o s p h e r e w h i c hi s r e f l e c t e d i n i n d i c a t o r 1~.~ . H e r e e m i s s i o n s d u e t o d e f o r e s t a t i o n a r e a l s o i n c l u d e d i n t h e i n d i c a t o r v a l u e s .

H o w e v e r , w h e n a n e n v i r o n m e n t a l p r o b l e m i s k n o w n a n d d e t a i l e d m o d e l l i n g s t u d ie s e x i s t r e l a ti n g e m i s s io n st o a t m o s p h e r i c c o n c e n t r a t i o n s , i t c o u l d b e m o r e u s e f u l t o d e v e l o p i n d i c a t o r s t ha t d i r e c t l y m e a s u r e h o w f a r t h ep r e s e n t r a t e o f e m i s s i o n s i s f r o m t h e l e v e l w h i c h d o e s n o t g i v e r i s e t o a n y i n c r e a s e i n t h e e c o s p h e r e . I n t h e c a s eo f C O 2 t h e r e a r e , o f c o u r s e , s e v e r a l s u c h s t u d i e s . I P C C ( 1 9 9 5 ) e s t i m a t e s t h a t i n o r d e r t o s t a b i l i s e a t m o s p h e r i cc o n c e n t r a t i o n s a t 3 5 0 p p m ( s l i g h t l y b e l o w t h e p r e s e n t l e v e l ) b y t h e y e a r 2 1 0 0 , t h e a c c u m u l a t e d e m i s s i o n s f r o m1 9 9 0 t o t h e e n d o f t h e 2 1 s t c e n t u r y m u s t n o t e x c e e d s o m e 3 0 0 - 4 3 0 G t o n C . T h i s i m p l i e s a n a n n u a l a v e r a g e r a teo f c a r b o n e m i s s i o n s e q u a l t o 3 .3 _+ 0 . 6 G t o n C / y e a r . 4 T h i s v a l u e c o u l d b e r e f e r r e d t o a s a s u s t a i n a b l e l e v e l o fC O 2 e m i s s i o n s ( g i v e n t h a t t he c l i m a t i c c h a n g e s a s s o c i a t e d w i t h t h e p r e s e n t a t m o s p h e r i c c o n c e n t r a t i o n o f C O 2a r e a c c e p t a b l e ) a n d a s u s t a i n a b i l i t y in d i c a t o r f o r C O 2 e m i s s i o n s c o u l d b e d e f i n e d a s t h e r a t i o b e t w e e n t h ep r e s e n t a n d t h e s u s t a i n a b l e e m i s s i o n r a t e s . I f th i s r a t io i s e q u a l t o u n i t y , t h e n t h e p r e s e n t e m i s s i o n s a r es u s t a i n a b l e . A t p r e s e n t , w e e s t i m a t e i t t o l i e in t h e r a n g e 1 .5 t o 3. 0 .4.2.2. Indicators fo r su bstances that are fore ign to nature

T h e n u m b e r o f c h e m i c a l s u s e d i n s o c i e t y h a s v i r t u a l l y e x p l o d e d . I n th e p r e s e n t i n d u s t r i a l s o c i e t y t en s o ft h o u s a n d s o f c h e m i c a l s a r e u s e d r e g u l a r l y . T h e r e a r e , f o r e x a m p l e , o v e r 7 0 0 0 0 c h e m i c a l s o n t h e U . S . T S C A( T o x i c S u b s t a n c e s C o n t r o l A c t ) I n v e n t o r y ( C l e m e n t s e t a l. , 1 9 94 ). W e k n o w t h a t t h e l i n k s b e t w e e n e m i s s i o n s ,e c o s p h e r i c c o n c e n t r a t i o n s a n d d a m a g e a r e o f t e n c h a r a c t e r i s e d b y l o n g t i m e l a g s a n d a h i g h d e g r e e o fc o m p l e x i t y .

T h i s m e a n s t h a t i t i s e x t r e m e l y d i f f i c u l t t o p r e d i c t t h e e n v i r o n m e n t a l c o n s e q u e n c e s o f a n e m i s s i o n o f as p e c i f i c s u b s t a n c e t o t h e e c o s p h e r e . B u t h o w s h o u l d w e d e t e r m i n e w h i c h r e s t r i c t i o n s a r e n e e d e d ? A c c o r d i n g t oP r i n c i p l e 2 , w e s h o u l d n o t e m i t s u b s t a n c e s t o n a t u re a t a r a t e t h a t is f a s t e r t h a n t h e y a r e d e g r a d e d i n t o n a t u r a l l ye x i s t i n g s u b s t a n c e s t h a t c a n b e i n c o r p o r a t e d i n t h e c y c l e s o f n a t u r e . 5 T h i s i n t u r n i m p l i e s s t r o n g r e s t r i c t i o n s o nt h e u s e o f p e r s i s t e n t 6 s u b s ta n c e s . S u s t a i n a b i l i t y a l s o i m p l i e s s t r o n g r e s t r i c t i o n s o n t h e u s e o f s u b s t a n c e s t h a th a v e l o n g - t e r m i m p a c t s - - i . e . , s u b s t an c e s t h a t m i g h t d e g r a d e r a p i d l y , b u t h a v e t h e p o t e n t i al t o r e d u c eb i o d i v e r s i t y , t h a t a r e m u t a g e n i c o r t h a t a f f e c t r e p r o d u c t i v e s y s t e m s .

I n o r d e r t o d e v e l o p i n d i c a t o r s t h a t re f l e c t to w h a t e x t e n t t h e p r e s e n t u s e o f a r t i fi c i a l l y p r o d u c e d c h e m i c a l s i ss u s t a i n a b l e o r n o t , w e f i rs t m u s t i d e n t i f y t h e c h e m i c a l s t h a t a r e p e r s i s t e n t ( in c l u d i n g m e t a b o l i t e s ) o r t h a t h a v el o n g - t e r m i m p a c t s , a n d t h e n w e n e e d t o f i n d s ta t i s t ic s on t h e i r e m i s s i o n r a t e s .

I d e a l l y , o n e w o u l d l i k e t o c o m p a r e t h e e m i s s i o n r a t e s w i t h t h e d e g r a d a t i o n r a t e s, b u t t h is i s n o t p o s s i b l e f o rt h e v a s t m a j o r i t y o f c h e m i c a l s s i n c e t he d e c a y p r o c e s s e s a r e v e r y c o m p l e x a n d t h e r a te o f d e g r a d a t i o n d e p e n d so n t h e s p e c i f i c e n v i r o n m e n t . W h e n t h e r e is a l a c k o f e m i s s i o n d a t a , e s t im a t e s c a n b e m a d e u s i n g m a s s - b a l a n c ec a l c u l a t i o n s o f i n d u s t r i a l p r o c e s s e s ( s e e , e , g ., A y r e s e t a l. , 1 9 8 9 a n d A y r e s e t a l . , 1 9 9 5) .4.2.2.1. Indicator no. 2,3: production ~'olumes of persistent chemicals forei gn to nature. H e n c e , w e s u g g e s t t h a tt h e tr e n d i n t h e p r o d u c t i o n v o l u m e o f p e r s is t e n t s u b s t a n c e s s h o u l d b e c o n t i n u o u s l y m o n i t o r e d . T h e U . S .E n v i r o n m e n t a l P r o t e c t io n A g e n c y h a s p r o d u c e d a l i st c o n ta i n i n g 8 0 p e r s i st e n t b i o a c c u m u l a t o r s p r o d u c e d i n th eU . S . i n q u a n t i t ie s o v e r 5 t o n s a n n u a l l y . 7 T h e O E C D h a s p r o d u c e d a R e p r e s e n t a t i v e L i s t o f H i g h P r o d u c t i o n

4 For the 22nd century even stronger reductions are needed in order to avoid a renewed increase of CO 2 in the atmosphere.5 The International Joint Com mission (1994) writes that "persistent toxic substances are too dangerous to the biosphere and humans topermit their release in any quantity."6 Here, persistent substances also include substances that are easily degradeable, but whose m etabolites are persistent.7 A later version of this list (Clem ents et al., 199~-) included only those chem icals that are produced in quantities over 500 to ns/ ye ar.This criterion reduced the num ber of chemicals on the list to 33.


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C. Azar et al. / Ecological Economics 18 (1996) 89-112 99Table 4The production volumes of common persistent bioaccumulators n the OECDCAS-number Chemical n a m e 1 2, 3 = P r o d . v o l .(kton/year)1163 -1 9 -5 Di-pentabromobenzene ther US 10, EU 1, JP 14904-61-4 1,5,9-Cyclododecatriene US 10, EU 105216-25-1 p-Chiorobenzontrichloride US 10, EU 167-72-1 Ethane, hexachloro US 1, EU 177-47-4 Hexachlorocyclopentadiene US 1, EU 179-94-7 Tetrabromo-bisphenol US 10, EU 1, CH 1, JP 195-94-3 Benzene-l,2,4,5-tetrachloro US l, EU 1Source: Smith (1994). Here, EU stands for the European Union, CH for Switzerland and JP for Japan.

Volume Chemicals containing the 1363 most co mmonly used chemicals in the OEC D area. 8 Since all majorindustrialised countries except the Eastern European countries (including the former Soviet Un ion) are membersof the OECD, data from the OEC D c ould be used as a first indication of the trends in the worldw ide produc tionof these chemicals. The c ombi nati on of the OECD list and the EPA list yielded 7 chemicals (Pettersson, 1994).But, even for these common chemicals the OECD had not available any time series over the productionvolumes. Data were only available for a single year and only to an order of magnitude accuracy (see Table 4).

This means that there is an urgent need for compiling data on the global production volumes of persistentsubstances, so that the trend in the use of such chemicals can be established. We have asked three majorintern ationa l organisa tions 9 whether they hav e the overall picture of this trend. But non e of them could answ erthe question positively. Hence, it could be useful to develop an indicator that measures the societal knowledgeof the global production of persistent substances.4.2.2.2. Indic ator no. 2,4: long-term implication o f emissions of substances that are fore ign to nature. Here wepresent an indicator for substances that are foreign to nature, but whose degradation processes can be describedby a simple mathematical equation. For such substances, mainly gases emitted to the atmosphere, we willcompare the production volumes with the rate of decay. Assume, as in Eq. 4.5, that the decay process of aspecific gas can be described by:

/kl(t) = E a - kM (t ). (4.7)This is, for instance, possible for radioactive gases and CFCs. Using this representation, we can define a

sustainability indicator as the ratio between long-term content of the substance for the present rate of emissionsin relation to the present content in the atmosphere. We have:

G 2 , 4 ( 4 . 8 )kMpresentIt should be noted that the indicator 12,4 is norma lised by the present cont ent in the atmosphere, whereas I2, 2

is normalised by the pre-industrial content in the atmosphere. This means that the interpretation of the indicatorvalue is different for the two types of indicators. For 12,2 = 1 the anthro pogenic emis sions are equal to zero. For12,4 = 1 the present anthro pogeni c emiss ions will stabilise the present atmospheric concentra tions. This could be

8 The OECD list contains substances that occur on two or more national high volume lists with a production volume of over a 1000tons/year or on one national list, but with a production volume exceeding 10000 tons/year (Freij, 1994).9 The OECD, the European Commissionand the U.N. Economic Commission or Europe.


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I0 0 C. Azar et al. / Ecological Economics 18 (1996) 89-112Table 5Indicator 12,4 for substances that are foreign to natureSubstance 1_9.5CF C 11 4.4CFC 12 7.5CF C 113 14CF C 114 15CFC 115 39HCFC-22 5.3Methylchloroform 1.4Carbon tetrachloride 14Ha lon- 1211 4.2Halon - 1301 19085Kr 2All com pounds except 85Kr are ozone depleters. For the se substances we hav e used global production data from the year 1985 (GermanBundestag, 1989). Sin ce 1985, aggregate production of C FC s has be en halv ed (Brown et al. , 1994). For the last compound, SSKr, aradioactive gas that is emitted by nuclear fuel reprocessing plants, we hav e used emission data from (UNSC EAR , 1993).

s u s t a i n a b l e , b u t o n l y i f t h e p r e s e n t c o n t e n t i n t h e a t m o s p h e r e i s l o w e n o u g h . T h i s i s , f o r e x a m p l e , n o t t h e c a s ef o r C F C s . T h u s , m u c h e f f o r t i s m a d e t o p h a s e o u t t h e p r o d u c t i o n o f C F C s .

If 12,4 > 1 t h e p r e s e n t r a t e o f e m i s s i o n s w i l l c a u s e t h e a t m o s p h e r i c c o n t e n t t o i n c r e a s e . T h e l o n g - t e r ms t a t i o n a r y s t a t e c o n t e n t o f t h e g a s f o r a s p e c i f i c p r o d u c t i o n r a te i s g i v e n b y t h e v a l u e o f t h e i n d i c a t o r m u l t i p l i e db y t h e p r e s e n t c o n t e n t .

W h e n a t i m e s e r i e s i s b a s e d o n t h is i n d i c a t o r , i t i s p o s s i b l e to f i x t h e n o r m a l i s a t i o n c o e f f i c i e n t , M p r e s e n t, a t as p e c i f i c y e a r , s o t h a t th e t r e n d o f t h e e m i s s i o n s i s r e f l e c t e d b y t h e i n d i c a t o r .

F o r t h e o z o n e - d e p l e t i n g s u b s t a n c e s ( s e e T a b l e 5 ) , w e h a v e u s e d p r o d u c t i o n d a t a . E m i s s i o n d a t a f o r o z o n ed e p l e t e r s a r e m o r e u n c e r t a i n t h a n p r o d u c t i o n d a t a s i n c e e m i s s i o n s a r e d u e to l e a k a g e f r o m t h e t e c h n o s p h e r e .T h i s m e a n s t h a t o u r in d i c a t o r v a l u e i s o n l y v a l i d i f t h e e n t i re p r o d u c t i o n v o l u m e e v e n t u a l l y l e a k s o u t. T h ep r e s e n t g l o b a l d e s t r u c t i o n r a t e o f o z o n e d e p l e t e r s i s n e g l i g i b l e i n c o m p a r i s o n t o p r o d u c t i o n r a t e s, b u t t h i s w i l lh o p e f u l l y c h a n g e i n t h e n e a r f u t u r e .4.2.2.3. S ome other desirable indicators fo r Principle 2. S o f a r w e h a v e m a i n l y d i s c u s s e d s u b s t a n c e s t h a t a r ei n t e n t i o n a l l y p r o d u c e d , b u t s i g n i f i c a n t p r o b l e m s a l s o a r is e f r o m t h e u n i n t e n t i o n a l p r o d u c t i o n o f s u b s t a n c e s t h a ta r e f o r e i g n t o n a t u r e . S u c h p r o d u c t i o n o c c u r s i n c h e m i c a l i n d u s t r i e s , i n i n c i n e r a t o r s , a t w a s t e d e p o s i t s w h e r es u b s t a n c e s m i g h t r e a c t , e t c . S e v e r a l s u c h s u b s t a n c e s h a v e b e e n i d e n t i f i e d a s v e r y p e r si s t e n t , b i o a c c u m u l a t i n ga n d e x t r e m e l y t o x i c ( e .g . , d i o x i n ). H o w e v e r , t h e r e i s a s i g n i f i c a n t l a c k o f d a t a o n t h e p r o d u c t i o n v o l u m e s o fu n i n t e n t io n a l l y p r o d u c e d s u b s t a nc e s a n d m a n y o f t h e m e v e n r e m a i n u n i d e n t if i e d .

I n o r d e r t o m a k e a n y i n d i c a t i o n e a r l y i n th e c a u s a l c h a i n , w e s u g g e s t t h a t f o c u s i s p u t o n p r o c e s s e s t h a t a r ek n o w n t o g i v e r i s e t o u n i n t e n t i o n a l p r o d u c t i o n o f s u b s t a n c e s t h a t a r e f o r e i g n t o n a t u r e .

F i n a l l y , a n i n d i c a t o r f o r th e p r o d u c t i o n o f s u b s t a n c e s t h a t a r e n o t t h e m s e l v e s p e r s i s t e n t , b u t th a t h a v el o n g - t e r m i m p a c t s ( e . g . , t h a t a r e m u t a g e n i c ) , t h a t a f f e c t r e p r o d u c t i v e s y s t e m s o r c a u s e l o s s e s i n b i o d i v e r s i t y ,w o u l d b e d e s i r a b l e .4.3. Indicators fo r Principle 3

T h e g l o b a l p o p u l a t i o n i s e x p e c t e d t o n e a r l y d o u b l e b y t h e y e a r 2 0 5 0 ( U n i t e d N a t i o n s , 1 9 9 2b ) . I n o r d e r t op r o v i d e a s u s t a i n a b l e s u p p l y o f b i o m a s s f o r fo o d , m a t e r i a l a n d e n e r g y f o r t h e g r o w i n g p o p u l a t i o n , w e n e e d t om a i n t a i n t h e s e r v i c e s o f th e e c o s y s t e m s . T h e s e s e r v i c e s i n c lu d e , fo r e x a m p l e , g e n e r a t i o n a n d m a i n t e n a n c e o f


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C. Az,ar et al. / Ecological Economics 18 (1996) 8 9-112 10 1

s o i ls , d i s p o s a l o f w as t e s a n d cy c l i n g o f n u tr i en ts , p es t co n t ro l an d p o l l i n a t i o n (E h r l i ch an d E h r l i ch , 1 99 2 ). T h i sm ean s t h a t t h e p ro d u c t i v i t y o f l an d s an d t h e b i o d i v e r s i t y o f eco s y s t em s m u s t n o t w o r s en . T h i s i s t h e e s s en ce o fPr i n c i p l e 3 .

H u m a n a c t iv i t ie s t h r ea t e n e c o s y s t e m p r o d u c t i v i ty a n d b i o d i v e r si t y in t w o w a y s . T h e e x c h a n g e o f s u b s t a n c e sb e t w een s o c i e t y an d n a t u re i s d ea l t w i t h b y t h e i n d i ca t o r s fo r P r i n c i p l e s 1 an d 2 . I n th i s s ec t io n w e fo cu s o ns o c i e t a l ac t iv i t i e s t h a t b y m a n i p u l a t i o n o r h a rv e s t i n g o f eco s y s t em s m ay t h rea t en s u s t a i n ab i li t y an d , i n p a r ti cu l a r ,b i o d i v e r s it y a n d e c o s y s t e m p r o d u c t iv i t y .4.3.1.1. Ma nipulation and harL, s ting. Pr i n c i p l e 3 d ea l s w i th h a rv es t i n g an d m an i p u l a t i o n o f eco s y s t em s .H a rv es t i n g o f fu n d s i n c l u d es ac t i v i t ie s s u ch a s h u n t i n g w i l d li f e , ca t ch i n g f i s h , h a rv es t i n g t r ee s , g ro u n d w a t e re x t r a c ti o n , e t c. H o l m b e r g a n d K a r l s s o n ( 1 9 9 2 ) d i s c u ss t h r e e w a y s o f m a n i p u l a t io n :

( i ) w e c a n d i s p l a c e n a t u r e ( b y f o r c i n g a w a y o r d i s t u r b i n g e c o l o g i c a l s y s t e m s o r g e o p h y s i c a l s y s t e m s - - e . g . ,b y co n s t ru c t i o n o f c i t i e s , a i rp o r t s , e t c . ) ,

( i i) w e can r e s h ap e t h e s t ru c t u re s o f n a tu re (b y d a m m i n g o f r i v e r s , p l o u g h i n g , r e fo re s t a t i o n , d e fo re s t a ti o n ,e tc . ) ,

( i i i ) w e can g u i d e p ro ces s es an d f l o w s (b y g en e m an i p u l a t i o n , an i m a l an d p l an t b r eed i n g , e t c . ) .S i n ce o u r am b i t i o n i s t o d ev e l o p i n d i ca t o r s t h a t f o cu s o n t h e s o c i e t a l ac t i v i t i e s t h a t g i v e r i s e t o ch an g es i n t h e

s t a t e o f t h e en v i ro n m en t , i n d i ca t o r s fo r P r i n c i p l e 3 s h o u l d fo cu s o n t h o s e a s p ec t s o f s o c i e t a l m an i p u l a t i o n an dh a rv es t i n g o f n a t u re t h a t a r e n o t s u s t a i n ab l e r a t h e r th an fo cu s i n g o n t h e en v i ro n m en t a l co n s eq u en ces o f t h eu n s u s t a i n ab l e m e t h o d s . A l a rg e s e t o f i n d i ca t o r s can b e fo u n d i n t h e w o rk b y V i t o u s ek e t a l . ( 1 9 8 6 ) , i n w h i cht h e a n t h r o p o g e n i c u s e o f b i o m a s s i s c o m p a r e d t o n e t p r i m a r y p r o d u c t io n ( N P P ) i n v a r io u s e c o s y s t e m s . F o rex am p l e , i t i s r ep o r t ed t h a t 4 0 % o f t e r re s t r ia l p o t en t i a l N PP i s u s ed d i r ec t l y , co -o p t ed , o r fo r eg o n e d u e t oa n t h r o p o g e n i c m a n i p u l a t io n o r h a r v e s t in g o f t h e e c o s y s t e m s . B e l o w , w e w i ll p r e s e n t a n u m b e r o f o t h e ri n d i ca t o r s t h a t a r e r e l ev an t fo r P r i n c i p l e 3 .

4.3.2. L arge-scale trans formation o f landsSi n ce t h e b eg i n n i n g o f t h e 1 8t h cen t u ry , h u m an i t y h as ca r r i ed o u t a l a rg e s ca l e t r an s fo rm a t i o n o f th e E a r t h ' s

eco s y s t em s an d p ro d u c t i v e s u r f aces ( s ee F i g . 3 ) . T h e a r ea u s ed fo r c ro p s an d g ra s s l an d s h as i n c reas edd ram a t i ca l l y a t t h e ex p en s e o f h u g e l o s s es o f p r i m ary fo re s t s . I n t h e l o n g ru n t h i s t r en d i s o b v i o u s l y n o t

16141210

6420

r,ops8188tural grasscondary forestsmary forests~er landsexploi table forests

1700 1975F i g , 3 . G l o b a l l a n d u s e . I t i s c l e a r l y s h o w n t h a t c r o p s a n d g r a s s l a n d s h a v e i n c r e a s e d a t t h e e x p e n s e o f p r i m a r y f o r e s t s. Source: B u r i n g h a n dD u d a l ( 1 9 8 7 ) .


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102 c. A zar et al . / Ecological Economics 18 (1996) 89-1 12s u s t a i n a b l e d u e t o l i m i t e d l a n d a r e a . F u r t h e r m o r e , i t v i o l a te s b o t h t h e s e c o n d p r i n c i p l e 10 a n d t h e t h i rd ( e . g .,s y s t e m a t i c l o s s e s o f b i o d i v e r s i t y ) .4 . 3 .2 . 1 . I n d i c a t o r n o . 3 , 1 : t r a n s f o r m a t i o n o f l a n d s . T h i s m e a n s t h a t it i s o f p r i m a r y i n t e r e s t t o f o c u s o n t h ea m o u n t o f l a n d d i v e r t e d t o d i f f e r e n t p u r p o s e s . I t s h o u l d b e s t r e s s e d t ha t s u c h a n i n d i c a t o r i s u se f u l f o r g l o b a l ,r e g i o n a l , n a t i o n a l a s w e l l a s l o c a l p l a n n e r s a n d d e c i s i o n m a k e r s . I t c o u l d b e p r e s e n t e d a s i n F i g . 3 .

T h e p r e s e n t t o t a l a n n u a l l o s s o f c r o p l a n d i s e s t i m a t e d a t m o r e t h a n 1 0 M h a , o f w h i c h s o i l e r o s i o n i sr e s p o n s i b l e f o r 5 - 7 M h a / y e a r , u r b an e x p a n s i o n 2 - 4 M h a / y e a r a n d s a l i ni z a t io n a n d w a t e r l o g g i ng 2 - 3M h a / y e a r ( K e n d a l l a n d P i m e n t e l , 1 9 94 ). T h e r e i s , h o w e v e r , a c o n s i d e r a b l e c ro p l a n d g a i n i n t h e o r d e r o f 1 6M h a / y e a r w h i c h i s a c h i e v e d b y d e f o re s t a ti o n .

B e l o w w e p r e s e n t a fe w e x a m p l e s o f i n d i c a t o r s fo r th e a n t h r o p o g e n i c u s e o f t h e d if f e r e n t t y p e s o fl a n d s - - i . e . , a g r i c u l t u r a l a n d f o r e s t a r e a s , a s w e l l a s o c e a n s a n d l a k e s . T h e s e i n d i c a t o r s s h o u l d f o c u s e a r l y i n t h ec a u s a l c h a i n .4 . 3 .3 . I n d i c a t i n g u s e o f l a n d a r e a s

A g r i c u l t u r e a f f e c t s b o t h t h e p r o d u c t i v i t y o f s o i l s a n d b i o l o g i c a l d i v e r s i t y . L o s s e s i n s o i l p r o d u c t i v i t y o c c u r a sa r e s u l t o f a n u m b e r o f c h a n g e s i n s o i l q u a l i t y : e . g . , s o i l e r o s i o n , n u t r i e n t r u n o f f , w a t e r l o g g i n g , d e s e r t i f i c a t i o n ,c o m p a c t i o n , c r u s t i n g , o r g a n i c m a t t e r l o s s, s a l i n i z a t i o n , n u t r i e n t d e p l e t i o n b y l e a c h i n g , t o x i c a n t a c c u m u l a t i o n a n da c i d i f i c a t i o n . L o s s e s i n b i o d i v e r s i t y c o u l d a l s o a f f e c t t he p r o d u c t i v i t y o f s o i l s, a n d c h a n g e s i n s o i l q u a l i t y c a nh a v e a n e g a t i v e i m p a c t o n b i o d i v e r s i t y .

T o x i c a n t a c c u m u l a t i o n a n d a c i d i f i c a t i o n a r e r e l a t e d to P r i n c i p l e s 1 a n d 2 a n d , t h u s , i n d i c a t o r s e a r l y i n t hec a u s a l c h a i n f o r s u b s t a n c e s c a u s i n g t h e s e p r o b l e m s h a v e a l r e a d y b e e n d i s c u s s e d i n S e c t i o n s 4 .1 a n d 4 .2 ,r e s p e c t i v e l y . H e r e , w e w i l l f o c u s o n a g r i c u l t u r a l p r a c t i c e s t h a t c a u s e s o m e o f t he o t h e r p r o b l e m s l i s t e d a b o v e .4 . 3 . 3 . 1 . I n d i c a t o r n o . 3 , 2 : s o i l c o ~ 'e r . S o i l e r o s i o n i s th e s i n g l e m o s t s e r i o u s c a u s e o f d e g r a d a t i o n o f l a n d( K e n d a l l a n d P i m e n t e l , 1 9 94 ). I t i s c a u s e d b y b o t h w a t e r a n d w i n d . I t is e s t i m a t e d t h a t w a t e r e r o s i o n a f f e c t s 5 6 0M h a o f l a n d s w h e r e a s w i n d e r o s i o n a f f e c t s 2 0 0 M h a ( C r a s w e l l , 1 9 93 ). E r o s i o n e x i s t s n a t u r a l l y , b u t i t c a n b ee n h a n c e d b y a n t h r o p o g e n i c m i s m a n a g e m e n t o f l an d s . A l t h o u g h e r o s i o n i s a c o m p l i c a t e d p r o c e s s, t h e re i s ag e n e r a l c o n s e n s u s t h a t t h e m o s t i m p o r t a n t r e a s o n f o r t h e w i d e s p r e a d e x i s t e n c e o f e r o s i o n i s a g r i c u l t u r a lp r a c t i c e s t h a t l e a v e t he s o i l w i t h o u t c o v e r ( K e n d a l l a n d P i m e n t e l , 1 9 94 ).A n i n d i c a t o r e a r l y in t h e c a u s a l c h a i n f o r s o il e r o s i o n w o u l d t h e n b e t h e ra t i o b e t w e e n c r o p l a n d w h i c h i ss u f f i c i e n t l y c o v e r e d 11 L ~ a n d t h e t o t a l a m o u n t o f c r o p l a n d L v :

L ~ ( 4 . 9 )13'2 = L--~-T h e r e a r e , o f c o u r se , o t h e r m e a s u r e s t h a t c a n b e t a k e n i n o r d e r to p r e v e n t s o i l e r o s i o n , b u t s oi l c o v e r i s t h e

m o s t i m p o r t a n t .S o i l e r o s i o n a l s o c r e a t e s a n u m b e r o f o t h e r p r o b l e m s f u r t h e r d o w n s t r e a m ( e .g . , fl o o d i n g , s i l t i n g o f d a m s a n d

d a m a g e t o c o ra l r e e fs ) . I n d i c a t o r s f o r s u c h p r o b l e m s w i l l n o t b e g i v e n h e r e s i n c e t h e s e p r o b l e m s a r e i n d i c a t e d b ye n v i r o n m e n t a l q u a l i t y i n d i c a t o r s .

O t h e r i n d i c a t o r s e a r l y i n t h e c a u s a l c h a i n t h a t n e e d t o b e d e v e l o p e d f o r t h e u s e o f a g r i c u l t u r a l l a n d s a n da g r i c u l t u r a l p r a c t i c e s a r e i n d i c a t o r s t h a t f o c u s o n i r r i g a t io n ( m a l p r a c t i s e d i r r ig a t i o n g i v e s r i s e to s a l i n i z a t i o n ) ,

10 Deforestation is presently estimated to give rise to net emissions of C O 2 amounting to approximately 1.9 Gton C /y ea r (Sigenthaler andSarmiento, 1993).~ Sufficiently covered is a vagu e concept, but it implies that the degree of cover ensures that the rate o f erosion do es not exceed the rateof soil renewal. This means tha t the degree of cover w ill differ from region to region depending on the natural circumstances.


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104 c. Azar et a l. / Ecological Economics 18 (1996) 89-112S t e w a r d s h i p C o u n c i l ( a n i n t e r n a t i o n a l N G O ) i s d e v e l o p i n g c r i t e r i a a n d p r i n c i p l e s t h a t t a k e t h e s e a s p e c t s i n toa c c o u n t .4.3.4. Indicating use o f marine and lake resources

T h e s t a t us o f m a r i n e r e s o u r c e s i s a f f e c t e d b y p o l l u t i o n a s w e l l a s h a r v e s t r a t e s a n d h a r v e s t m e t h o d s . M e t h o d sf o r i n d i c a t i n g t h e s o u r c e s o f p o l l u t i o n a r e d e v e l o p e d i n S e c t i o n s 4 .1 a n d 4 . 2, r e s p e c t i v e l y .

T h e i n t e n s i t y o f th e u s e o f m a r i n e r e s o u r c e s i s a s e r i o u s p r o b l e m , a n d i n d i c a t o r s f o r t h i s s o c i e t a l a c t i v i t y i sn e e d e d . T h e t o t a l w o r l d f i s h c a t c h h a s i n c r e a s e d f r o m 2 2 m i l l i o n to n s i n 1 9 50 t o a l e v e l o f 1 0 0 m i l l i o n t on s( 1 9 8 8 - 1 9 9 2 ) . I n a l l t h e m a j o r f i s h i n g a r e a s i n th e w o r l d t h i s c a t c h r e l i e s o n a y i e l d th a t i s at o r b e y o n d t h e l i m i tf o r s u s t a i n a b i l i t y ( B r o w n e t a l. , 1 9 9 4) . A g r o w i n g w o r l d p o p u l a t i o n i m p l i e s t h a t t h e c a t c h p e r c a p i t a m u s td e c r e a s e . I n 1 9 88 t h e a n n u a l p e r c a p i t a c a tc h p e a k e d a t 1 9 .4 k g , b u t a c c o r d i n g t o p r e l i m i n a r y d a t a f o r 1 9 9 3, i th a s d e c r e a s e d t o 1 7 . 6 k g .4.3.4.1. Indi cator no. 3,4: har~,esting of fund s. A t y p i c a l i n d i c a t o r f o r h a r v e s t i n g ( e .g . , o f a f i s h p o p u l a t i o n ) i st h e y i e l d d i v i d e d b y t h e g r o w t h :

h/3 .4 = - - , ( 4 . 1 1 )gw h e r e h i s t h e h a r v e s t p e r y e a r a n d g i s t h e a n n u a l g r o w t h .

The maximum sustainable yield ( M S Y ) i s t h e m a x i m a l y i e l d t h a t c a n b e a c h i e v e d b y h a r v e s t i n g a p o p u l a t i o na t th e s a m e t i m e a s a s t a t i o n a r y p o p u l a t i o n s i z e is m a i n t a i n e d . S i n c e t h e M S Y c o n c e p t f o c u s e s o n t h e l o n g - t e r ms u s t a i n a b l e y i e l d fr o m a n e c o s y s t e m , i t c a n s e r v e a s a b a s i s f o r d i s c u s s i o n s o n m a n a g e m e n t o f h a r v e s t i n g ( M a ye t a l ., 1 9 79 ). T h e c o n c e p t h a s b e e n c r i t i c i z e d , t h o u g h , f o r n o t t a k i n g i n t o a c c o u n t t h e s t a b i l i t y o f t h e s y s t e m .R e s u l t s f r o m s t u d y i n g m o d e l s y s t e m s s u g g e s t t h a t w h e n h a r v e s t i n g a t th e M S Y , t h e r e is a ri s k o f o v e r e x p l o i t a -

i l l :i i : i l i l i ; i J Z ; i!:ili!iY ii:iiii!ii!I Serv ice

E . , . . L , i " 4 - , D

N a t u r eFig. 4. A schematic illustration of the physical f low s within the technosphere. Substances extracted from nature (E) and substances recycledwithin in the technosphere (R) are converted into products P and losses L caused by the preconsumption conversion. (Som esubstances--e.g. , the elem ents --m ay be turned into products without conversion.) P delivers services to the human sphere when used inthe consum ption conversion. After consumption, used products P together with L are possibly converted, and thereafter sent into therecirculated fraction R or are discharged to the ecosphere (D ) (Holmberg and Karlsson, 1992).


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c. Azar et al. / Ecological Economics 18 (1996) 89-1 12 105t i o n l e a d i n g t o th e e x t i n c t i o n o f t h e h a r v e s t e d s p e c i e s ( s e e , e .g . , B e d d i n g t o n a n d C o o k e , 1 9 82 ), T h i s i se s p e c i a l l y i m p o r t a n t i f t h e h a r v e s t r a t e i s c o n t r o l l e d b y f i x e d c a t c h q u o t a . U n c e r t a i n t i e s a b o u t t h e f i s h s t o c k sm a y l e a d t o h a r v e s t y i e l d s t h a t d e s t a b i l i z e t h e e c o s y s t e m . I n a r e c e n t s t u d y o f a th r e e - s p e c i e s m o d e l ( A z a r e t a l. ,1 9 9 5) , w e h a v e c o m p a r e d t h e s t a b i l i ty o f t w o h a r v e s t i n g s t r a t e g i e s - - ( i ) c o n s t a n t q u o t a a n d ( i i) c o n s t a n te f f o r t - - s h o w i n g t h a t c on s t a n t c a t c h q u o t a c a n l e a d t o b o th o s c i l l a t i o n s ( a n d c h a o s ) a n d a n i n c r e a s e d r i sk o fo v e r e x p l o i t a t i o n .4 . 4. I n d i c a t o r s f o r P r i n c i p l e 4

P r i n c i p l e s l , 2 a n d 3 c o n s t i tu t e t h e f r a m e w o r k f o r a s u s t a i n a b l e in f l u e n c e o n n a t u r e . P r i n c i p l e 4 s t at e s t h a t i fw e w a n t a p r o s p e r o u s s o c i e t y w i t h i n t h i s f r a m e w o r k , t h e s o c i e t a l m e t a b o l i s m m u s t b e e f f i c i e n t a n d j u s t . T h i sp r i n c i p l e c o v e r s f o u r a s p e c t s : o v e r a l l e f f i c i e n c y , i n t e r - a n d i n t r a g e n e r a t i o n a l e q u i ty , a n d b a s i c h u m a n n e e d s .B e l o w , w e d e v e l o p i n d i c a t o r s f o r s o m e o f th e s e a s p e c t s.4 . 4 . 1 . I n d i c a t o r n o . 4 , 1 : o c e r a l l e f f i c i e n c y

A s i m p l e s c h e m a t i c d e s c r i p t i o n o f t h e s o c i e t a l m e t a b o l i s m i s g i v e n i n F i g . 4. T h e o v e r a l l e f f ic i e n c y i n d i c a t o r sa r e m e a s u r e s o f t h e p r o d u c t i v i t y i n t h e t e c h n o s p h e r e . T h e y i n d i c a t e h o w m u c h s e r v i c e ~3 t h a t i s d e l i v e r e d f o r ac e r t a i n a m o u n t o f r e s o u r c e s e x t r a c t e d f r o m n a t u r e , n o r m a l i z e d w i t h r e s p e c t t o th e s i t u a t io n a c e r t a i n y e a r y :

S e r v i c eE14 . 1 S e r v i C e y " ( 4 . 1 2 )

E yI t i s a l s o p o s s i b l e t o c o m p l e m e n t t h e o v e r a l l e f f i c i e n c y i n d i c a t o r s w i t h s p e c i f i c e f f i c i e n c y i n d i c a t o r s t ha t

f o c u s o n t h e i n t e r n a l c o n v e r s i o n i n t h e t e c h n o s p h e r e - - e . g . , t h e f l o w P p e r u n it o f t o t a l i n p u t E + R , o r t h er e c i r c u l a t i o n R c o m p a r e d t o th e to t a l i n p u t E + R ,

P R~ql = E + R ' r l2 E + R ( 4 . 1 3 )

T h e r e c i r c u l a t i o n f l o w R c a n a l s o b e c o m p a r e d t o t h e t o ta l o u t p u t P * + L :R

713 P * + L " ( 4 . 1 4 )I n a s t a t i o n a r y s t at e P e q u a l s P * a n d E e q u a l s D . I t i s p o s s i b l e t o n o r m a l i z e t h e e f f i c i e n c i e s w i t h

n o r m a l i z a t i o n v a l u e s "qn d e t e r m i n e d a c c o r d i n g t o v a r i o u s p r i n c i p l e s : a n o r m a l i z a t i o n t o th e m a x i m u m p o s s i b l et h e o r e ti c a l v a l ue , t o t he b e s t a v a i l a b l e t e c h n o l o g y ( B A T ) , o r t o a d e s ir a b l e v a lu e . W e g e t c o m p l e m e n t a r ye f f i c i e n c y i n d i c a t o r s :

r/ iI i = - - , ( 4 . 1 5 )rTnw h e r e i = 1 , 2 , 3. I n T a b l e 7 s o m e e x a m p l e s o f o v e r a l l e f f i c i e n c y i n d i c a t o r s a r e s h o w n . W e c a n s e e , f o ri n s t a n c e , t h a t t h e s u p p l y o f f o o d p e r h e c t a r e o f l a n d h a s i n c r e a s e d , w h e r e a s t h e s u p p l y o f f o o d p e r p h o s p h a t ei n p u t h a s d e c r e a s e d s i n c e 1 9 70 .

13 The service flows can be the tem perature of a room , the light from a b ulb, etc. The phy sical flows can be, for instance, energy, exergy,different kinds of materials or products. I t is im portant to note that through increased efficiency it is possible to increase the rate of serviceflow w ithout increasing the exchange with nature (i.e., inputs of energy and m aterials and emissions of w aste).


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106Table 7Overall efficiency indicators

C. Azar e t a l . /Eco lo g i ca l Economics 18 ( 1996) 89 - 11 2

Efficiency indicators 1970 1980 (l 987) 1990F o o dCalories in food/Phosphate input (World) 1 0.67 (0.61)Proteins in food/Phosphate input (World) 1 0.66 (0.60)Fats in food/Phosphate input (World) 1 0.69 (0.67)Calories in food/Area input (World) 1 1.03 (1.08)Proteins in food/Area input (World) 1 1.01 (1.07)Fats in food/Area input (World) 1 1.07 (1.18)EnergyGDP/Primary energy input to the World (USD/J) 1 1.07 1.21GDP/Primary energy input to Sweden (USD/J) 1 1.06 1.12Dwelling area/Primary energy input to the dwelling sector in Sweden(m2/J ) 1 1.11 1.14Personal transport/Primary energy input to personal transport in Sweden (Pers. km/J) 1 0.91 0.99Goods transport/Primary energy input to goods transport in Sweden (ton km/J) 1 1.06 0.93The values are normalized o the year 1970.Sources: Bumb (1989), FAO Food Balance Sheet (FAO, 1991), Schipper et al. (1994) and Brown et al. (1994).

As an example of a complementary specific efficiency indicator we have chosen to indicate the efficiency ofthe use of nutrients in the Swedish agricultural system This indicator is defined as;

Nutrients in provision s from the Swedish agricultural systemr /= (4 .16)The supply of nutrients to the Swedish agricultural systemThe supp ly of the nutrients N, P and K in fertilizers (exclud ing manure), imported cattle feed, deposited

nitrogen and biologically fixed nitrogen are 111, 15 and 23 k g/ ha , respectively (Granstedt and Westberg,1992). The content of nutrients in provisions (vegetable and animal food) harvested in Sweden are 29, 6 and 6kg/ha (Granstedt and Westberg, 1992). The differences between these figures are losses due to leakage,sorption, volatilizati on, etc. The e fficiency indicators for the use of nutri ents in the Swed ish agricultural systemin 1990 are then:

r/N = ~ = 26%rh, = 6 = 40%"qK = 6 = 26%

4 . 4 .2 . I n d i c a t o r no . 4 ,2 : i n t r a g e n e r a t i o n a l j u s t i c eThe intrage neratio nal justic e indicators are measures of an une ven distribution of services and resource use.

These indicators can be defined as the amount of services delivered per capita in a specific region (e.g., acountry) compared to the amount of services delivered per capita in a reference region (e.g., the world):

14 z = Suppl y to region A per capita . (4. 17) Supply to reference region per capita

Obviously this indicator will not reflect unequal distributions of income within the specific region.Table 8 gives some e xamples o f intragene rational justic e indicators, where we have comp ared the use of

energy and food per capita in Sweden with the global per capita use. The global per capita use of primaryenergy approaches the Swedish use, but the Swedish per capita use is still much higher than the global use.


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C . A z a r e t a l. / E c o l o g i c a l E c o n o m i c s 1 8 ( 1 9 9 6 ) 8 9 - 1 1 2 10 7

T a b l e 8I n t r a g e n e r a t i o n a l j u s t i c e i n d i c a t o r sI n t r a g e n e r a t i o n a l j u s t i c e i n d i c a t o r s 1 9 7 0 1 9 8 0 ( 1 9 8 7 ) 1 9 9 0F o o dC a l o r i e s p e r c a p i t a i n S w e d e n / C a l o r i e s p e r c a p i t a i n t h e W o r l d 1 .1 8 1 .1 7 ( 1 . 1 3 )P r o t e i n s p e r c a p i t a i n S w e d e n / P r o t e i n s p e r c a p i t a i n t h e W o r l d 1 .3 5 1 . 4 3 ( 1 . 3 7 )F a t s p e r c a p i t a i n S w e d e n / F a t s p e r c a p i t a i n t h e W o r l d 2 .1 1 2 . 1 4 ( 1 .9 8 )E n e r g y( P r i m a r y e n e r g y p e r c a p i t a i n S w e d e n ) / ( P r i m a r y e n e r g y p e r c a p i t a i n t h e W o r l d ) 7 . 3 5 .8 3 .8S o u r c e s : F A O F o o d B a l a n c e S h e e t ( F A O , 1 9 9 1 ) a n d S c h i p p e r et a l. ( 1 99 4 ) .

4.4.3. Indicator no. 4,3: intergenerational jus ticeT h e s e i n d i c a t o r s s h o u l d c o v e r a s p e c t s r e la t e d t o th e u s e o f n o n - r e n e w a b l e r e s o u r c e s o v e r ti m e . I t i s i m p o r t a n t

t o n o t e t h a t n o n - r e n e w a b l e r e s o u r c e s m u s t n o t n e c e s s a r i l y b e k e p t i n t h e l i t h o s p h e r e , b u t m a y b e e q u a l l y o r e v e nm o r e v a l u a b l e t o f u t u r e g e n e r a t i o n s i f t h e y a re k e p t i n " c l o s e d " c y c l e s w i t h in t h e t e c h n o s p h e r e . O n e r o u g hi n d i c a t o r a l o n g t h e s e l i n e s c o u l d b e :

X L14"3 -~- X R -t.- X ~ ' ( 4 . 1 8 )w h e r e X L i s t h e a n n u a l l o s s o f t h e r e s o u r c e d u e t o d i s s ip a t i v e u s e , a n d X R a n d X T r e p r e s e n t t h e a v a i l a b l ea m o u n t o f t h e r e s o u r c e i n t h e l it h o s p h e r e a n d t h e t e c h n o s p h e r e , r e s p e c t i v e l y ( s e e F i g . 1 ) . T h e i n v e r s e o f 14,3g i v e s t h e t i m e i t w o u l d t a k e b e f o r e t h e r e s o u r c e w o u l d b e e x h a u s t e d ( g i v e n c o n s t a n t a n n u a l l o s s e s a n d n o n e wd i s c o v e r i e s ) . I f X c r e p r e s e n t s t h e a c c u m u l a t e d l o s s , th i s in d i c a t o r w o u l d s h o w h o w m u c h w e h a v e u s e d i nc o m p a r i s o n t o h o w m u c h w e h a v e l e f t .4.4.4. Indicator no. 4,4: basic human needs

T h e h u m a n n e e d s i n d i c a t o r s a i m a t i n d i c a t i n g t o w h a t e x t e n t b a s i c h u m a n n e e d s a r e s a t i s f i e d . S t r e e t e n e t a l .( 1 9 8 1 ) s u g g e s t t h a t o n e c o u l d c h o o s e a f e w b a s i c i n d i c a t o r s t h a t t o g e t h e r r e f l e c t t h e f u l f i l m e n t o f b a s i c n e e d s( s e e T a b l e 9 ) . T h e e x a c t f o r m u l a t i o n o f n e e d s a n d c o r r e s p o n d i n g i n d i c a t o r s s h o u l d b e l e f t t o th e e x p e r t s o f t h ed i f f e r e n t s e c t o r s . M a n y i n d i c a t o r s o f th i s k i n d a r e a l r e a d y c a l c u l a t e d b y t h e U n i t e d N a t i o n s ( e . g ., l i t e r a c y , i n f a n tm o r t a l i t y r a t e , l i f e e x p e c t a n c y , c a l o r i e s u p p l y , e t c . ) .

A p o s s i b l e b a s i c h u m a n n e e d s i n d i c a t o r i s g i v e n b y :/4 .4 = T h e s h a r e o f t h e p o p u l a t i o n t h a t d o e s n o t g e t t h e ir b a s i c n e e d s f u l f il l e d . ( 4 . 1 9 )

T a b l e 9B a s i c n e e d s a n d c o r r e s p o n d i n g t y p i c a l i n d i ca t o r sB a s i c n e e d s T y p i c a l i n d i ca t o rF o o dW a t e r a n d s a n i ta t i o n

H e a l t hE d u c a t i o n

P e r c a p i t a d a i l y c a l o r i e i n t a k e a s a p e r c e n t a g e o f r e q u i r e m e n t sP e r c e n t a g e o f p o p u l a t i o n w i t h a d e q u a t e f o o d i n t a k eP e r c e n t a g e o f p o p u l a t i o n w i t h a c c e s s t o p o t a b l e w a t e rP e r c e n t a g e o f p o p u l a t i o n w i t h a c c e s s t o s a n i t a t io n f a c i l i ti e sI n f a n t m o r t a l i ty p e r t h o u s a n d b i r t h sL i f e e x p e c t a n c y a t b i r t hL i t e r a c yP r i m a r y s c h o o l e n r o l lm e n t a s a p e r c e n t a g e o f t h e p o p u l a t io n a g e d 5 t o 1 4

S o u r c e : B a s e d o n S t r e e t e n e t a l . ( 1 9 8 1 ) .


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108 C . A z a r e t a l. / E c o l o g i c a l E c o n o m i c s 1 8 ( 1 9 9 6 ) 8 9 - 1 1 2

1 0 0 08 0 06 0 04 0 02 0 0

0

N u m b e r o f u n d e r n o u r i s h e dp e o p l e in m i l l i o n s

: i ,1 9 7 0 1 9 7 5 1 9 8 0 1 9 9 03 6 % 3 3 % 2 6 % 2 0 %

y e a r a n d p e r c e n t a g e o f p o p u l a t i o n I nd e v e l o p i n g c o u n t r i e s

Fig. 5. The num ber of peop le in developing countries who are chronically undernourished, using data fro m Uvin et al. (1994). It should benoted tha t undernourishment has de creased since 1 970, in b oth abso lute and relative terms.

A t y p i c a l b a s i c n e e d s i n d i c a t o r is t h e n u m b e r o f c h r o n i c a l l y u n d e r n o u r i s h e d p e o p l e : i .e ., p e o p l e w h o o na v e r a g e d u r i n g t h e c o u r s e o f a y e a r d o n o t c o n s u m e e n o u g h f o o d t o m a i n t ai n t h e i r w e i g h t a n d e n g a g e i n l ig h ta c t i v i t y ( a c c o r d i n g t o F A O ) : s e e F ig . 5 ( U v i n e t a l. , 1 9 9 4 ) .

5 . D i s c u s s i o n a n d c o n c l u s i o n s

T h e m a i n r e s u l t o f t h is p a p e r i s th e m e t h o d f o r d e v e l o p i n g s o c i o - e c o l o g i c a l in d i c a t o r s f o r su s t a in a b i l it y . S u c hi n d i c a t o r s s h o u l d b e ( i) b a s e d o n a f r a m e w o r k f o r s u st a i n a b i li t y ( t h e f o u r s o c i o - e c o l o g i c a l p r in c i p l e s f o rs u s t a i n a b i l i t y ) a n d ( i i ) f o c u s e a r l y i n t h e c a u s a l c h a i n .

P r a c t i c a l e x p e r i e n c e f r o m S w e d i s h c o m p a n i e s a n d l o c a l a u t h o r i t i e s h a s s h o w n t h a t t h e s o c i o - e c o l o g i c a lp r i n c i p l e s t h a t w e h a v e u s e d a s a s y s t e m a t i c f r a m e w o r k , f u n c t i o n w e l l w h e n m a k i n g s t r a t e g i c d e c i s i o n s . T o d a y4 0 S w e d i s h m u n i c i p a l i t i e s a n d 2 0 l a r g e r S w e d i s h c o m p a n i e s u s e t h e s e p r i n c i p l e s i n t h e i r s t r a t e g i c p l a n n i n gp r o c e s s e s ( H o l m b e r g e t al ., 1 9 9 6 ; R o b S r t , 1 9 9 4 ) .

I t i s a l s o o u r e x p e r i e n c e t h a t t h e f o c u s f o r f u tu r e w o r k w i t h e n v i r o n m e n t a l i s s u e s is s h i ft i n g f r o m d i s c u s s i o na n d i n v e s t i g a t i o n s o f e n v i r o n m e n t a l e f f e c t s ( e n v i r o n m e n t a l p a t h o l o g y ) t o s t r a te g i c a l p l a n n i n g o f t h e s o c ie t a lm e t a b o l i s m ( s o c i e t a l p r o p h y l a x i s ) . T h i s i m p l i e s t h a t th e r e i s a n e e d f o r in d i c a t o r s t h a t f o c u s e a r l y i n t h e c a u s a lc h a i n - - i . e . , t h a t p u t f o c u s o n t h e a c ti v i ti e s in s o c i e t y . T h i s d o e s n o t m e a n t h a t t h e s o c i o - e c o l o g i c a l i n d i c a t o r sc a n r e p l a c e t h e t r a d i ti o n a l e n v i r o n m e n t a l q u a l i t y i n d i c a to r s . B u t w e t h i n k t h a t t h e y w i l l m a k e a n e c e s s a r yc o m p l e m e n t t o i n d i c a t o r s t h a t f o c u s l a t e r i n t h e c a u s a l c h a i n .

T h e m a i n r e a s o n f o r f o c u s i n g e a r l y i n t h e c a u s a l c h a i n i s t h a t w e w a n t t o c a p t u r e a l s o s o c i e ta l a c t i v it i e s t h a ta r e p o t e n t i a l l y u n s u s t a i n a b l e . I n c a s e s w h e r e t h e c a u s a l c h a i n a n d t h e e n v i r o n m e n t a l e f f e c t s ar e k n o w n , a n d t h et i m e l a g s a r e s m a l l , t h e r e a s o n f o r f o c u s i n g e a r l y i n t h e c a u s a l c h a i n i s n o t t h a t s tr o n g . I n t h e s e c a s e s i t i sp o s s i b l e t o a g g r e g a t e e m i s s i o n s i n t o a n o v e r a l l i n d e x ( s e e , f o r i n s t a n c e , th e s o - c a l l e d t h e m e i n d i c a t o r s d e v e l o p e db y A d r i a a n s e ( 1 9 9 3 ) f o r c l i m a t e c h a n g e , d e p l e t i o n o f t h e o z o n e l a y e r , a c id i f i c a t i o n a n d e u t r o p h i c a t io n ) .

T h e r e a r e n o e x a c t l i m i t s d e f i n i n g s u s t a i n a b i l i t y . I n s t e a d , t h e b o r d e r b e t w e e n s u s t a i n a b i l i t y a n d u n s u s t a i n a b i l -i t y is n o t s h a r p . T h i s m e a n s t h a t it is n o t p o s s i b l e t o d e t e r m i n e e x a c t r e f e r e n c e v a l u e s f o r s u s t a in a b i l it y .H o w e v e r , m a n y o f th e s o c i e t a l ac t i v it i e s to d a y a r e f a r f r o m s u s t a in a b l e , w h i c h m e a n s t h a t t i m e s e r ie s o f t h ei n d i c a t o r s w o u l d e n a b l e u s t o s a y w h e t h e r s u s t a i n a b i l it y i s a p p r o a c h e d o r n o t .


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C . A z a r e t a l . / E c o l o g i c a l E c o n o m i c s 1 8 ( 1 9 9 6 ) 8 9 - 1 1 2Table I 0Socio-ecological indicators based on socio-ecological principles

10 9

P r i n c i p l e 1 : Substances ex-tracted from the lithospheremust n ot systematically accu-mulate in the ecosphere

P r i n c i p l e 2 : Society-produced sub-stances must not systematically ac-cumulate in the ecosphereP r i n c i p le 3 : T h e physicalconditions for production anddiversity within the eco-sphere must not systemati-cally be deteriorated

P r i n c i p l e 4 : The use of re-sources must be efficient andjust with respect to meetinghuman needs

I u : Lithospheric extraction 12,1: Anthro pogenic flows com-comp ared to natural flows pared to natural flowsIL.2:Accum ulated litho- 12.2: Long-term implication ofspheric extraction emissions of naturally existingsubstancesl l ,~: Non -renewab le energy 12,3: Production volume s of persis-supply tent chemicals12,4: Long -term implication o femissions of substances that areforeign to nature

13.1: Transformation o f lands13,2: Soil cover

I~3: Nutrient balance in soils13 .4: Harvesting of funds

1 4 . 1 : Overall efficiency/4.2: Intragenerational justice

la.~: Intergenerational justice4.4: Basic human needs

W e h a v e s u g g e s t e d s p e c i f i c i n d i c a t o r s f o r e a c h o f th e f o u r p r i n c i p l e s ( s e e T a b l e 1 0 ). T h i s b r o a d a p p r o a c hi m p l i e s t h a t s o m e o f t h e i n d i c a to r s s h o u l d b e c o n s i d e r e d a s p r e l i m i n a r y ( e s p e c i a ll y t h e i n d i c a t o r s fo r P r i n c i p l e s3 a n d 4 ) . S t i ll , o n e a d v a n t a g e i s t h a t it o f f e r s a p o i n t o f d e p a r t u r e f o r f u t u r e w o r k o n i n d i c a t o r s w h i c h t a k e s a ni n t e g r a t e d a p p r o a c h t o s u s t a i n a b i l i t y . I t i s o u r h o p e t h a t o u r f o r m u l a t i o n o f i n d i c a t o r s w i l l i n s p i r e f u t u r e r e s e a r c hi n t h i s a r e a .

I n f u tu r e w o r k w e s h a ll d e v e l o p t h e i n d i c a to r s f u rt h e r. F o r p o l i c y p u r p o s e s i t i s im p o r t a n t th a t t h e n u m b e r o fi n d i c a t o r s i s r e l a ti v e l y s m a l l . T h e r e f o r e , w e w i l l i n v e s t i g a t e t h e p o s s i b i l i t y o f a g g r e g a t i n g s o m e i n d i c a t o r s : e . g .,t h e i n d i c a t o r s f o r li t h o s p h e r i c e x t r a c t i o n f o r e a c h e l e m e n t i n t o a n i n d e x f o r a ll e l e m e n t s o r g r o u p s o f e l e m e n t s . I ti s a l s o o f i m p o r t a n c e t o d i s p l a y t i m e s e r i es o f t h e i n d i c a t o r s .

W e s h a l l a l s o a p p l y s o c i o - e c o l o g i c a l i n d i c a t o r s to r e g i o n a l a n d l o c a l s i t u a t io n s , a n d m a k e t h e m e t h o da c c e s s i b l e t o p l a n n e r s a n d d e c i s i o n m a k e r s a t r e g i o n a l a n d l o c a l a d m i n i s t r a t iv e l e v e l s o f s o c ie t y. I n a n o n g o i n gp r o j e c t w e a r e s t u d y i n g t h e r e s o u r c e u s e o f t h e i s l an d o f G o t l a n d i n S w e d e n . H e r e , s p e c i a l e m p h a s i s i s g i v e n top r o b l e m s r e l a t e d t o t h e r e s p o n s i b i l i ty o f m a t e r i a l fl o w s b e t w e e n r e g i o n s ( C a r l s o n e t a l. , 1 9 95 ) .

A c k n o w l e d g e m e n t sW e e x p r e s s o u r g r a t it u d e t o U l r i k a C a r l s o n f o r d i s c u s s i o n s o n i n d i c a to r s a n d f o r c o n t r i b u t i o n s to t h e

e m p i r i c a l b a c k g r o u n d o n s e v e r a l i n d ic a t o r s . W e a l so t h a n k B j iS rn A n d e r s s o n , C u r t i s C . B o h l e n , H e r m a n D a l y ,K a r l - E r ik E r i k s s o n , S t e n K a r ls s o n , K a r l - H e n r i k R o b e r t, J o h a n S w a h n , S t e fa n W i r s e n i u s a n d a n a n o n y m o u sr e v i e w e r f o r t he i r c r it ic a l r e a d i n g o f th e m a n u s c r i p t . T h i s r e s e ar c h w a s s u p p o r t e d b y t h e S w e d i s h C o u n c i l f o rB u i l d i n g R e s e a r c h .

R e f e r e n c e sAdriaanse, A., 1993. Environmental Policy Performance Indicators. Sdu, Den H aag.Alfsen, K .H. an d S~eb, H.V., 199 3, Environmental quality indicators: background principles and examples from N orway. E nviron.Resource Econ., 3: 415-435.Ayres, R.U., 1995. Statistical Measures of Sustainabili ty. W orking paper 95/ 34 /E PS . 1NSEA D, Fontainebleau.Ayres, R.U ., Norberg-Bohm, V ., Prince, J., S tigliani, W .M. an d Yanow itz, J. , 198 9. Industrial Metabolism, the Environment, andApplication of Materials-Balance Principles for Selected Chemicals. International Institute for Applied Systems Analysis (IIASA),Research Report 89-11.


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1 I0 C. Azar et aL/Ecological Economics 18 (1996) 89-112A y r e s , R . U . , A y r e s , L . W . a n d H a h n , A . , 1 9 9 5 . I n d u s t ri a l M e t a b o l i s m o f S e l e c t e d T o x i c C h e m i c a l s , C e n t r e f o r th e M a n a g e m e n t o f

E n v i r o n m e n t a l R e s o u r c e s o f I N S E A D , F o n t a i n eb l e a u .A z a r , C . , H o l m b e r g , J. a n d L i n d g r e n , K . , 1 9 95 . S t a b i l it y a n a l y s i s o f h a r v e s t i n g i n a p r e d a t o r - p r e y m o d e l . J . T h e o r . B i o l. , 1 7 4 : 1 3 - 1 9 .B a t e s , T , S . , L a m b , B . K . , G u e n t h e r , A . , D i g n o n , J . a n d S t o i b e r , R . E . , 1 9 92 . S u l p h u r e m i s s i o n s t o th e a t m o s p h e r e f r o m n a t u r a l s o u r c e s . J.

A t m o s p h . C h e m . , 1 4: 3 1 4 - 3 3 7 .B e d d i n g t o n , J .R . a n d C o o k e , J .K . 1 9 8 2 . H a r v e s t i n g f ro m a p r e y - p r e d a t o r c o m p l e x . E c o l . M o d e l . , 1 4 : 1 5 5 - 1 7 7 .B e n j a m i n , M . M . a n d H o n e y m a n , B . D . , 1 9 9 2 . T

4e azar indicators

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