Julian L Simon and Aaron Wildavsky - Assessing the Empirical Basis of the Biodiversity Crisis

7/31/2019 Julian L Simon and Aaron Wildavsky - Assessing the Empirical Basis of the Biodiversity Crisis

1/24

eEl

eEl

eEleEl

eEl

eEl

eEl

el

el

NVRONMNALSUD PROGRAM

EING THE EPIRICL

BI OF THE

"BIODIVERITY CII"

Julan . Simon and Aaron Wildavsky

May 99

COMPTIV NTR NITUT Cnt n NW S Wh DC

() - x: (


2/24

The Competitive Enterprse InstituteThe Competitve Enteprise Insttute (C) is a po-market, publc polcy gropcommitted to advancng the pincpes of ee enterpise and imited government.Fonded in 8 by Fred Smt, Jr., C empaszes te marketng and

impementaton o cassca lbea ideas.

C tiizes a ivepont management appoac t eectng pubic poicy, anaysis,edcaton, coaltion bulding, advocacy and tigaton. ts prpose is to advance thefree-market agenda, beevng mted government and competiton best seve thepubc inteest.

non-proft, taxexempt organation nder Secton 5 (c 3) of te ntena RevenueCode, C reies entrey on donatons rom coporations, foundations and pivate

individas with an nterest n restong ndividua berties and economic freedom. cotbos ae ax dede

For more nformation contact:

mpv p I2 Pyv v 2

Wh D 22/547-


3/24

ASSESSIG THE EMPIRICAL BASISOF THE

"BIODIVERSITY CRISIS

by Julian L Smon an Aaron Wdavsy

EXEClVE UMY

For severa years now, the Wor Wfe Fn an other wfe nterest gropshave een sayng sch thngs as "Whot rng a shot, we ay one-fth of a specesof fe on ths panet wthn the next years One proe wth sch assetons s thatthere s no scentfc jstfcaon for akng the. Base on the ost ptoate pshe

aa conceng speces oss:

Known exncon rates are very ow;

t s posse to estate even approxatey how any nrecorespeces ay have ecoe extnct

We o not know how any speces exst even to wthn an orer ofagnte an therefore have no ass pon whch to asset that we knowwhat percenage s gong extnct;

Reavey few attepts have een ae to rgorosy assess the keyagnte of exncton raes.

Ewar O. Wson he oreos proponent o goa efors to ste the prporeynssanae oss o speces says ha he exncton poe s asotey nenaeWson ctes teay hnes o anecoa reports to spport hs ca Howeve thevery reason for he scentc etho n estang rates s that anecota reports are of tteor no vae, an often sea he pc an pocyakers Inee tha's why expensvecensses an other ata gatherng nstrents ae epoye

Howeve vey te wok has een one n hs e A svey of the exsngevence fns he foowng

The estate extncton ae of known speces s ao oe evey for yeasfo 6 to

The esae rate s ao one a yea o to ;


4/24

Some scientists have "haarded a guess" that the extinction rate may nowhave reached species per year;

In tu, this guessed upper limit has ben used as the basis for projecingthat as many as 4, species will be dying out annually before the year

These numbers have he power to fighten the public in a fashion tha smallernumbers would not; this in tu prompts paticular govement policies tha could not beotherwise justied. Neverheless there is no scientic justiication for such use of numbersThe scare about species extinction has ben manufactured in complete contradiction o thescientic data t is truth that is becoming extinct not species.

The known facts about biodiversity lead to the inevitable conclusions ha:

f something is unknowable at present but knowable in principle then theappopiate thing to do is to ind out;

At present some consevation biologists seem more intent on whipping upconce for species loss than they are in documenting the extent of that lossand analyzing the possible ramications if any;

More reliable information about species loss is necessary to guide futurepolicy decisions;

Future policies to address species loss must include the direct and indirctcosts of such policies including the long-term costs of rduction in economicgrowth to a community's hath

There is now no pima facie case or any expensive speciessafeguarding policywithout more extensive analysis. But the queston deseves deeper thought and more caefuland wideranging analysis than has bn done until now. As children say just saying sodoes not make it so


5/24

FOREWOD

This is the st in a series of CEI pubications that wll examne thedebate over endangered species and biodiversity. Many environmentalistsasser that the planet is experiencing a rapid acceleration in the rate of speciesexinctions Drs Simon and Wildavsky take issue with that asserion Bylooking at the empirica data and contrasting it wth the various caims that a"biodiversiy crisis is upon us, Simon and Wildavsky assess such caimsaccording to the scientic method Their conclusion is that there is nolegitimate scientic basis for making them

They are not alone n a controversial August 199 aice in cienceCharles C Mann pointed out that:

ony four of 22 redictions [of species loss came withsucient expanaton to penit independent examnation Alof the rest provde anecdota suppor-r none at a Evenone promnent conseationist-who demanded anonymityexplainng that 'they kll me for saying thisadmied thatthe ack of data does wor me He then added mabsoutey sure were rght but a gut feeing isnt much backuwhen youre asking peope a over the word to change therives completey

Making the environment in the words of Vice President Gore thecentra organizing pincipe of civiliation would indeed require peope aover the world to change their lives competey The specter of masseinctions must therefore be connected to human sefinterest to justi theEndangered Species Act the Convention on nteational Trade in Endangered Species the Earh Sumits Convention on iological Diversity andother such goveenta poicies

However the "problem says Main Hodgate director genera ofThe Word Conseation Union (IUCN) is that we do not know how muchoss of what knds of organisms is toerabe The need for more infoatiois clear Even a few conseation biologists have begun to concede that heecosystem serices argument eaves much to be desired For eampe inBiiesi a book edited by Harard scientist Edward o Wison avidEhrenfeld acknowedges

the species whose members are fewest in number the arestthe most narowy distributed-in sho the ones most ikeyto become extinct-are obviousy the ones east ikey to beissed by the biosphere Many of these species were nevercoon or ecoogicay inuenia; by no stetch of theimagination can we make them vita cogs in he ecoogicamachine

B Bidvi I


6/24

Even Wson adms hs In wha he cals a raoros dgresson,accordng o News& World Report Wson acnowledges ha mosecosysems probably cold lose a hey acon o her speces and sllncon or Wlson he mos compeng reason o gh or evey scrap obodversy has more o do wh hmanys emoona heah Ths heconce or bodversy generay and speces loss speccaly, apparenly has

a mch o do wh moral qesons as bologcal onesB he nrnsc vae o agven speces-or ha o all speces aen

ogeher-s no wha mon and Wldavsy address n hs mporan sdyRaher, hey se her anaytca sghs on a mch more asceanabe ace ohe bodversy debae-namely how reable s he scenc evdence behndhe bodversy crss and o wha exten does exs

Assessng he Emprca Bass o he Bodversy Crss s aconnaon o mon and Wdavsys wor on he ndamena sse oscenc proo whch rs began n her chaper On peces Loss he

Absence o Daa and Rss o Hmany n Jan L mon and HermanKahns 84 boo e Resourcel Earth: A Response to 'lobal

Ths CEI pbcaon brngs he earer wor o mon and Wldavsyp o dae For exampe The World Conservaon Unons C 2boo ropcalDeorestaton andpeces tncton,eded byT C Whmoreand JA ayer s ced exensvey

Perhaps now or someme n he near re, a more hone andsbsanve debae over speces oss w commence As bodversyapproaches he sas o a hosehod word wl become mpoan o

ndersand wha s beng dscssed A sey o wha s nown abo specesloss s only a rs sep n ha drecon. Ths sdy s nended o be ha sep.

Ie C. ggWalker Fellow

n Enronmental tudes

ssess e Bss e Bdves ss


7/24

ASSESSIG THE EMPIRIAL ASIS

OF THE

IOIERSITY RISIS*

by Jun L Simn nd An Wdvsy**

INTRODUCTION

Species exincn s ey ssue f he envinmen mvemen. is he subjec f mgne sies wih es ie "Pying Dice wih Megdeh wih subhed The dds e gd h we wi exenne hf

he wds species wihn he nex cenu. Speces "ss s s he fcpin f ndising m he pubc. And he Cness s sed gin ndgin f ge sums f pubic mney be used diecy nd indiecy fpgms pec widfe nd wid pces

The cen ssein is h speces e dying e h isunpecedenedy high nd dngeus humny The Wd Wdfe Fundwhch pubczes hs ssue wdey mes he ppsiin s fws Wihu ng sh we my neh f species f ife n his pne n henex 10 yes Rughy dened s speces f ife n his pnebigic dvesy is nmy he hec ubc unde which species ss

is discussedThe ssue cme scienc pminence in 7 wih Nmn Myes

Te Snkng Ak nd hen ws bugh n nein pubc nd n heU S pcy gend by he 180 Global epo o he Peien(efeed heee s GTR These s e he cnnic exts

GTR fecs exdiny sses f species beween 80 nd 2000.xincns f pn nd nm speces wi incese dmicy. Hundesf husns f speces-pehps s mny s 20 pecen f species nehw be ieievby s s hei hbis vnish especiy in pi

fess. (US 80, , p. 3).n 84 we eviewed he d n he bseved es f species

exncn. We fund h he scenic evience ws wiy vnce wh

* Exracted y Ie C. Sugg om "Species Loss Revisied, fohcomng in The Slate ofHumani(e by Jlia Smon) ia L Simon is ofessor o Busness Admnsaon a he Unesy o Maynd CogePrk; Aaron Wldavsky is Cass of ofess of olc ene and l ocy eniversiy o Caioa Bekeey aaos are provded/or detcato uoe o()

ssss Bss Bdvrs Css

orld

ldl Fundss, " thoutring a shot, wemkl onehof al species ofl on this planetin the nt10

years


8/24

should srivefor clear and

unbied anunrstanding

possible of

species loss inorr to ma the

best possiblejudgments about how

much time andmon to spend in

arding them

Pa

the by-then-conventional wisdom and did not provide suppot for the variouspolicies suggested to deal with the pupoted dangers We also remindedreaders that recent scientic and techical advancesespecially seed banksand genetic enneerig and perhaps elecroic mass-testing of new dgshadrenderedmuch less ccial the maintenance ofa paricular species of plantlifeinits natural habitat than would have been the case in earlier years Butthebandwagon of the species extinction issue continues to oll with ever

increasing speed

Now we revise our presentation of the empirical and theoreticalsituations in light of the literature that has appeared in the 1980s We nd thatour earlier conclusions remain sound, and may be considered strenghened bythe absence of new countevailing material coming to light since then

These are the key questions: Are species dened with sucient clarityso that dierent people can arrive at satisfactorily similar estimates? What isthe history of species extinction until now? What are the most reasonableforecasts of ture extinction? What will be the results of extinctions

(including resulting new additions) on species diversity? What will be theeconomic and non-economic impacts of the expected course of speciesdiversity?

Society properly is conceed about possible dangers to speciesIndividual species and perhaps all species taken together constitute avaluable endowment and we should guard their suvival just as we guard ourother physical and social assets But we should strive for as clear and unbiasedan understanding as possible of species loss in order to make the best possibleudgments about how much time and money to spend in guarding them Ina world in which this valuable activity must compete with other valuable

activities including the guarding of human life such an understanding is ofmore than mere academic importance

he importance ofthe topic is clear om the farreaching extent of thepolicies suggested EdwardO Wilson and Paul R. Ehrich actually ask thatgovernments act "to reduce the scale of human activities More specicallythey want us to cease 'developing any more reatively undisturbed landbecause Every new shopping center built in the Califoia chaparral everyhectare of tropical forest cut and ued every swamp converted into a ricepaddy or shrimp farm means ess biodiversity (199 p 761

Assessing the Empircal Bass of he Bodvsi Cisis


9/24

DEFINING SPECIES

Before dscussng rates of etncton, we must touch on an ssue thatcomplcates such estmates-the denton of a speces Referng to the"neverendng arguments about the deniton of the speces category EstMayr nfers that "those who do not work wth speces but wth cells ormolecules may think that the speces s an arbtrary and nsgnicant concept

in bology He argues othese "What then Mayr asks "s boogcaclasscaton? "Unhappy he concludes "no agreement on the answerto ths queston exsts yet among bologsts He then argues that thetaxonomy s based not on the smilaty of the speces but on ther commonancestors.

The nlopeia rianniadenes speces as "groups ofndvduas that resembe one another morethan they resembleany others But what consttutes "resemblance? If weadopt the denton of "who mates wth whom we wlreduce the number of speces; f we gve the more generaldenton that "speces are groups of organsms sharng many

trats or characterstcs n common the cassers have a lotof room to rase or ower the number Ifwe use commonDNA

as a crteron we guess the number of speces would greatlydmnish

SPECIES LOSS ESTIMATES

The basc forecast for loss of speces comes from Thomas E Lovejoy:

What then s a reasonabe estmate of gobal extnctons by2000? Gven the amount of tropcal forest already ost (whchs mportant but oen gnored) the extnctons can be est

mated n the low deforestaton case approxmately 15percent of the planets speces can be expected to be lost Inthe hgh deforestaton case perhaps as much as 0 percent wllbe lost Ths means that of the 3 10 mllon speces nowpresent on the eah at least 500000600000 wll be exngushed durng the net two decades (US 1980 p 331

Ths extract summarizes a table whch shows a range between 437000

and 1875000 extnctons out of a present estmated total of 3 O mllonspeces The table in tu s based ona lnear relatonshprunnng om ero

percent speces extngshed at ero percent tropca orest ceared to about95% extngushed at 100% tropcal forest clearng The man source of

derences n the range o estmated losses s the range of31O monspecesn the overall estmate

The bass of any usel projecton must be some body o experencecolected under some range o condtions that encompass the expected

condtons or that can reasonaby be extrapolated to the expected condtios

Bt none of ovejoy's references contanany scentcallympressve boyof experence The only pubshed source gven or hs ey able(u S 19Tabe 133 0 p 331 s Myers' T Sinkig Ark 979)

ssessing he mpa Basis of he Bidves( iss

ard Wlson

andPaulREhrlich acualk o ceasedeveloping amore laiveundisurbedla

P


10/24

No sources agiven for Mers

estimates

e estimate issimp a conjec

and is noteven a point esti

mate but rather anupper boun

P 6

Mys smmay may b ta as h basc soc

a pmitv h ma pobably himslf capabl ofmiag spcs albt as a a occcFomth ya AD 00 howv h bcam abl thoghadvacg tchology to ov-h amas to cto s a fw yas ad to dspt tsv vioms s asapdly Btw h yas 00 ad 900 ma lmad

aodsvy-v ow spcs almos a of thm mammals ad bdsvitally othg has b stabshd abothow may ptls amphbas shs vtbas adplats dsappad Sc 900 ma has matd aodaoth svyv ow amost al ofhmmammas ad bds wih aythig ow abothowmay oth cas hav fadd om th sc h atom th ya 00 o 1900 oghly o spcs 4 yasad th a dg mos of th pst ospcs p ya a to b compad wth a a possbly op1000 yas dg th gat dyg of th dosas

Sc90 howv wh gowth hma mbs

ad hma aspatos bga to r gat mpac oatal voms vast trtos sval majo gosof th wold hav bcom so modd as o b clad of mchof h ma wldlf h s s hat th xtco at hasctaly soad thogh th dtas mosly ma docmtd I 974 a gahig of sctss cocd wth thpoblm hazadd a gss ha th ova tcto atamog a spcs whth ow o scc o ot coldow hav achd 100 spcs p ya [H Mys fs oScence 197 pp 47]

Y v hs sms low A sgl cologca zo hopcal most s blvd to cota btw2 ad5

mllo spcs. f pst patts of xplotatos psst topcal most fosts mch vg fost s lly to havdsappad by th d of th ctry ad mch of thmad w hav b svly dgadd hs wll cashg mbs of spcs to b wpd ot

Lt s sppos that as a cosqc of ths mahadlgofatal vomts th al oqart of ths ctywtsss th lmato of 1 mllo spcsa f fomlly pospct hs wold wo ot dg th cos of25 yas at a avag xtcto at of 0000 spcs pya o ath ov 100 spcs p day h gatstxplotatopsss wll ot b dctd at topcal foss

ad oth spcsrch boms tl towads th d of thpod hat s to say th 1990s cold s may moaccotd fo tha th pvos sal dcads tth dsrptv pocsss a w dray ad t s otalstc to sppos that ght ow at ast o spcs sdsappagach day y th at 198s w cod b facga stato wh o spcs coms xtct ach ho(1979 pp 5

ssessng he mpl Bss o/he Bodves Css


11/24

We may exract these key ponts om the above summary uotaton

( The estmated extncton rate of known speces s about one eveyfour years om 600 to 900.

(2 The estmated rate s about one a year om 1900 to 99. Nosources are ven for these two estmates ether on the pae om whch the

uote s taken or on paes 3031 of Myers book where these estmates areaan dscussed.

(3 Some scentsts (n Myers words have hazaded a uess thatthe extncton rate coud now have reached 00 speces per year That s,the estmate s smply conecture and s not even a pont estmate but ratheran upper bound The source ven for the some scentsts" statement s astawtten news repor (C. Hoden, 94 t shoud be noted however, that

the subject of ths uess s derent om the subect of the estmates n (I) and(2 They nclude manly or exclusvely brds or mamals whereas (3ncudes all speces Whle ths derence mples that ( and (2 may be too

ow a bass for estmatn the present etncton rate of a speces t alsomplesthat there s even ess statstcal bass for estmatn the extncton ratefor speces other than brds and mammals than t mht otherwse seem

(4 Ths uessed upper mt n (3 s then ncreased and used by Myers,and then by Lovejoy as the bass for the projectons" uoted above n GR

the lanuae has become are kely to lead to the etncton of between 14%and 20% of al speces before he year 2000. (US. 980 I p. 328 So anupper lmt for the present that s pure uesswork has become the bass of aforecast for the ture whch has been publshed n newspapers to be read by

tens or hundreds of mlons of peope and understood as a scentc statement

The two hstorcal rates stated by Myers combned wth the yearlyrates mped by Loveoys estmates are ploted toether n Figure t sclearthat wthout explctly bnn nto consderaton some addtonal foceone could exrapolate almost any rate one chooses for the year 2000 and theLoveoy etrapoaton woud have no better cam to belef than a rate say

Figure 1: yers-Lovejoy estmates of species extinctionand extrapolations o the ear 2000.

40,

extinction

b

2

extincns

p a 80

One extinction eve fur y.

1t

ssss r B o Bodvers rss

One exncion

yea, 1o 180

40

1

7


12/24

A upper limitthat pu guesswork h become

the bis of a foct which hbee

publshed i ewspapers a ad

a scieticstatemet

Pa

one hundedh as age Lookng a he wo hsorca pons aone anyfoecases would be lkely o projec a ae uch close o he pas han oLovejoys on he bass of he coon wsdo ha n he absence ofaddona nforaon he bes s approxaon fo a varabe oorrows s vaue oday and he bes second appoxaon s ha he varable wchange a he sae ae n he ue ha has n he pas The unceanyabou he denon of speces eely adds o hs conson

Pojeced change n he aoun of opcal foess pcy undeleshe deences beween pas and pojeced specesoss aes n Lovejoy sdagra Bu o connec hs eeen ogcay hee us be syseacevdence eang an aoun of opca foes eoved o a ae of speceseducon. We have found no epos of such eprca evdence A ecensuey docuen (Red and Mlle 989 says ha A usel ue of hubs ha f a haba s educed by 90 pecen n aea roughly onehaf of sspeces wl be los (p 35, and efes o a gue and an appendx bu noeprca sudes ae efeed only specuaon The ony eprca obseaon we found s by Lugo fo Pueo Rco whee huan acvy educed heaea of pay foess by 99% bu because of coee shade and secondayfoess foes cove was neve beow 0 o 5% Ths assve foesconveson dd no ead o a corespondngy assve speces exnconceanly nowhee nea he 50% auded o by Myes. ( 989, p 28

A hs ples ha hee s no bass o choose beween a) Lovejoyshuge pojeced aes of exncon and b) odes aes connung abou hesae as n he pas and hs s he deence beeen he bass foecoendng vaous naona poces and no akng any ecoendaons a al. (Agan hs s no o say ha no poecon poces should be

underaken Rahe pes ha ohe sos of daa o esae exnconaes ae needed as he bass fo polcy decsons)

COUNTERVALNG DATA

The dscusson so fa s abou he way ha aes sod when wewroe ou 984 ace on he subjec. n esponse o he uesons ha weand ohes haveased he World onsevaon Unon (N cossoneda book opia Deoeaion an Speie xnion (99 eded byWhoe and Saye o nue no he exen of exncons The esuls ofha pojec us be consdeed ang All he auhos connue o beconceed abou he ae of exncon Neveheless hey agee ha he aeof known exncons has been and connues o be vey low Ths s a sapngof uoaons (wh ephass added o he book, s on he subjec of heesaed aes

ssessng he Empr Bss of he Boders ss


13/24

bir and mammals are known to have become extinctbetween Red 1992 p 55)

ts ommople tht foests of the este Uted Sttesweeedued ove two etures to gmets totlg-2%of the ogl extet d tht dug ths destuto, oythee foest bds wet extthe ol pkeet(Conuropsis carolinensis) the woodpeke

(Campephilus principalis d the psse!epgeo (Ectopistes miatorius) Although defoesttoely otbuted to the dele oflthree spees t wspobbly ot t fo the pgeo o the pkeet Geewy,1967) y then would one predict massive extinctionomsimilar desucion of opical forest? Smbelo 992 p85)

N, togethe wth the Wold oseto Motogete hs mssed lge volumes of dt om spelstsoud the wold eltg to spees dele, d t would seemsesble to ompe these moe empl dt wth the globlexto estmtes ft these d othe dt dte tht

the number of recorded extinctions for both plants andanimals is ve smal Heywood d Stuar, 992 p 93)

Known extinction rates are ve low Resoby good dtexst oy fo mammls d bds d the uret te ofextto s bout oe spees pe e Red d Mlle1989) f othe tax wee to exhbt the sme lblty toexto s mmmls d bds s some uthos suggestlthough othes would dspute ths), the, f the totl umbeof spees the wold s sy 30 mllo the ul te ofextto would be some23 00 spees pe ye Ths s vesgt d dstubg umbe but t s muh less th mostestmtes gve ove the lst dede Heywood d Sturt, p

94)

If we ssume tht todys topl foests oupy olybout80% othe e they dd the1830, it must be assumedthat during this contraction ve large numbers of ecieshave been lost in some areas Yet surisingl there is noclearcut evidence for this. Deste extesve qures wehve bee uble to obt olve evdee to suppot thesuggesto tht mssve exttos hve tke ple eettmes s Myes d othes hve suggested O the otry,wok o pojets suh s Flo MesoAme hs t lest some ses eveled ese bude myspees Blkmoe pes omm 99) A exeptol d

muh quoted stuto s desbed by Gety (986) whoepos the qute dmt level of evoluto stu theetel dge the foothlls of the Eudo Ades wheehe foud tht t lest38 d pobbly s my s 90 spees(0% of the total o of the rdge wee edem to theupepossessg dge Howeve the lst pthes of foestwee leed subsequetto hs lst vst d ts pospetve90ew spees hve ledy pssed to botl hsto o sot ws ssumed Subsequetly Dodso d etry (99)moded ths to sy tht udetermed ume of speest etel e ppetly extt foowg bef vsts to

dy C

In Puerto ico,

"msiveforestconversion did notlead to a coespondingly massive species tinc- "on

9


14/24

"Closer examination of the istingta suppos the

aation thatlitle or no speciestinction hyet

occu

"It is impossibleto estimate even

approximatehow many species

have becometinct

P

oher areas such as Lita where up o of h csprousl consdrd xnc wr rfound and a PozaHonda near La Mana where six were rediscovered Heywoodand Suar, 1992 p 96)

h roup of zoologss could no nd a sngl knownanmal cs whch could b proprl dclard xncin site of he massive reducion in area and agmenaion of

her habitas in he pas decades and centuries of inensivehuman activiy A second lis of over 120 lesser-known anmalsome of whch may aer be included as threaened

no species considered exinct; and he oder Brazilian listofthreatened pans, resently under revision aso indicatedno species as extinct Cavacanti 1981) Brown andBrown992 p 27 ciation in the original)

Closrxnaon of h xsng aon boh wel and ileknown groups, however suppors h armaonha lor no cs xncon has occurrdhough some maybe in vey agile in the Aantic forests ndeedan apreciabe number of species considered extinct 20 years

ago cuding several birds and six buteies, have beenrediscovered more recently Brown and Brown, 1992 128)

And here are some comments from ha volume on he lack of any soidbasis for estimaion

How large is the loss of species likely o be? Alhough hloss of cs m ran among h mos nronmnal problms of our m rlal habn mad o rgorousl assss s l

Reid1992 p 55)

I s mpossbl o sma n approxmal how manm ha bcom xnc Heywood and

Stua p

While better knowledge of exinction raes can clearly improve the design of pubic policies it is equally apparent thasmas of global xncon ras araugh wh mprcson W do no know how man spcs xs n owhn an ordr of maud. Red 992 p 56)

The bes tool available to estimate species extinction rates ishe use of species-area cues Tis approac has formed hebasis for almost all cuent estmates of species extinctionrates Reid 992 p 5)

Tr ar man rons wh rcordd ncons do nomach and rpolaons ha ar frqunl

. eywood and Stuat 992 p 9)

ssessng he Eil ss f he des ss


15/24

ANTOOGENIC IMACTS?

n he cae of pecie exincion a wh many other pubic iuehere i a endencyin boh echnica dicuion and in he preo focuony upon the bad eec and o excude om conideraion poibe ood

eect of human acivie. or exampe Luo noe tha Becaue humanhave faciiaed immiraion of pecie and creaed new environmenexoic pecie have uccey become eabihed in he aibbean iand.Thi ha reued in a enera increae in he toa inventorie of bird and treepecie." (989 p 3 ropica Puerto Rico where human aciviyreduced he area of prmay fore by 99%" a rea a reducion a coud beimained even bird pecie. became exinct aer 5 year of humanpreure . and .. exoic newy reiden] pecie enared he pecie poo.More and bird have been preen on he and in he 98 (9 pecie hanwere preent in pre-oombian ime (6 pecie" (pp. 8 and 9

Perhap coneaion biooi make mention of he exinction buno of he newyreiden pecie becaue there i a cear averion o exoticnewy reiden pecie by preeaionit and biooi (in cae uch apredaoy mamma and pe with ood reaon! " (Luo 989 p 3 Thiaverion o new pecie may invove the idea ha humankind i omehowarticia and not naura." onider he anuae of Myer who ha payeda impoan a roe a any peron in raiin the aam abou pecie extinction[Wherea pat exincion have occurred by vitue of natura proceeoday the viruay excuive caue i man." (989 p 4 however i ipecie diveriy ha i a iue raher than ony preevin pecie a they are

today then new pecie houd count for a much a od one.Mainainin he Amon and oher area in a tate of tabiiy mih

even have counerproductive reu for pecie diveriy accordin to arecen body of reearch Naura diurbance a on a hey are nocatatrophic may ead o diconinuity in environment and o coneuentioation of pecie ha may faciiate everincreain diverence(oinvaux 989 p. 3 oinvaux oe on to uet that the hihetpecie rchne wi be found not where he cimate i abe bu rather whereenvironmena diurbance i euen but no exceive" The ame ine fanayi ead o poibe bene om ineenion by humankind

Duin he 98 there ha been increain reconition hat the raeofpecie o reay i no known. Myer now wite Rerettaby we haveno way of knowin the acua curen rae of extinction in tropica foret nrcanwe even make an accurate ue" nd oinvaux refer to he extincioa incacuabe" (989 p ) One woud hnk hat h tate of aarwoud make anyone eery about eimatin ture extincion evetheeMyer continue But we can make ubtantive aement by ookin atpecie number before deforetation and then appyin he anaytica tech

j Bdv

it is species di

versi that atsue rather thanon psering

species as they atod then newspecies shouldcount for much

old ones.


16/24

Cona rsto the tinctions

"incacabeOne wod thinkthat this state of

aairs wodma anyone ee

abot estimaingt tinctions

niues ofiogeography . According o he heo of island iogeogaphy wecan realisically recon ha when a haia has los 90% of is exen i haslos half of is species." (1989 p 3 Bu his is mere peculaion [seeEndnoe 1]

Comaion of he asence of scienic evdence for rapid speciesexincion is implici in he naure of he evdence cied y for exaple

Edward O Wilson He says ha he exincion prolem" is asoluelyundenale". Bu all he cies are lierally hundreds of anecdoal repors"[ Endnoe 1] he very reason for he scienic mehod in esimaing raesis ha anecdoal repos are of lile or no value and oen mslead he pulicand policymaers has why expensive censuses and oher daa gaheringinsmens are employed

Some consevaionss have ecome raed a heir inailiy odocumen a rapid rae of species exincion ha would usi calls forgoveenregulaion and nding; hey also are annoy a our wriing aouhe acual sae of he evidence. a promnen conseaionis responded o

our aicle documening degree of hea is oen dicul and econoissand ohers who wish o downplay he is of an exincion csis can easilydipue his case or ha case casing dou even on he claim ha 5 percenof he worlds irds are hreaened" Diamond 1989 p 1 Diaondherefore has suggesed looing a he evidenial issue in an enirely dierenfashion one which is uie ou of eeping wh ordinay scienic praciceNormally he wres

species are o e considered exan unil proven exinc [BuFor mos species of he ropics or oher remoe regionshai for mos ofhe worlds species a more appropae asump

ion would e exinc unles proven exan We iologisshould no ear he urden of proof o convince econoissadvocaing unlimied human growh [an inaccurae descipion of one of he auhors of hi uvey ha he exincioncsis is real Insead i should e le o hoe econoiss ond research in he ungles ha would posiively uppo heirimplausile claim of a healhy iological world p 1

This is an ineresing wis a reversal of proof urden" as Wesepus i Wese 989, p 33) implies ha i is enough for a waing o esounded a charge o e made for he comuniy o proceed as if he case haseen proven f soeone says ha he fores oor ha ued o lue cheese

and advocaes ha he goveen hould iediaely egin o pacage andsell he cheee i i he esponiiliy of hoe who uesion his policy odemonsrae ha he lue cheee ransfoaion has no aen place. Thiinellecual sraegy sugges ha he iologi now despair of maing heircase wh he usual oos of scienic inuiy and as inead for uppo onhe asis of nonevidenia faih

To go one ep her he presevaionis preise heir forecas ofrapid species eincion on here eing now and n he ure a rapid rae of

g he pl B h Bd


17/24

defoestation We epeat that even f the ate of defoestation wee indeedapid, thee wod st be itte o no bass fo nfering a ate of specesencton of ovejoys pojected agntde Bt thei ine of argent sendeed even ess beevabe by the fact that the hstoical evdence does notspport thei pojectons of defoestaton Endnote 2]

SOM OTHR SSUS

Pehaps we shold ook backwads and wonde Which speceswee eingshed when the settes cea-ct the Middle West of the UnitedStates? Ae we the pooe now fo the loss? Obviosly we do not know theanswes Bt can we even agine that we wod be enoosly bette owith the pesistence of any hypothetica speces? It does not see likey scasts soe dobt on the econoic vae of speces that ight be lostesewhee.

2 s dclt to have a easoned agent with biolosts on specieseinction One eason s that they eqe an aost egios test offeaty andcedentias befoe they will consde a peson's testiony as elevant heenton of a pesons oigna tainng coes p agan and agan n the ecentsvey vole whch he coedted Weste (1989 p 33) wtes Theiplcatons of an etnction spas ae also debatabe aong both bologistsand non-bologsts And Diaond says O crent conce withencton s soeties pooh-poohed' by nonbioogsts with the one-ineEtncton s the natal fate of speces' (989 p 37 n o view thendestandng of data s not the pivate povnce of any dscpline, and thebackgond of the analyst is not a test of the vadity of the anaysis Bt asong as it s a citerion fo bioogsts the isse cannot be sad to be debatedationally

Anothe dclty is that conservation bologsts' goas with espectto species divesty ae not easy to ndestand Soeties they ephasie thespposed econoic benets of species divesty Fo eape n ts widelydistibted 1990 ndaising ette (fo lettes eceived by the hosehod ofone of the pesent athos) the Wold Widfe Fnd ass Why shold yocae abot the fate of these foests thosands of les away? and answesBecase not only do they povide food and shelte to at least half the wolds

species of wildlfe these topcal foests ae also the wold's lagest phaacetical factothe soe soce of life-savng edcnes lie nne ansost potent weapon against alaa Hndeds of thosands of people owe

thei lives today to these pecios pants shbs and tees What wold wedo wthot the? Daond answes silaly We need the to pode

the oygen we beathe absob the cabon dioide we eale decopose osewage povde o food and antan the fetility of o sol ( 990 p )

ssss Bss o Bdvsy Css

Wlso ss that"the tictio

pblem

"absolute udeiable But all hecites a "literalhue of aecdotal ports

Pa 3


18/24

Nol Dmond rtes,

"speces re to beconsded tnt

unt proven extnct . . [u] mo pproprte

sumpton wouldbe 'extnct untl

pven tnt.

Pa 4

But Quinn and Hastings say tat maximing tota spcis divsityis ay i v t pincipa obctiv o consation statgis tasttic souc psation and cationa vaus a on moimpoant (198 p 99) And Lovoy says most incusivy

Wat I m taking about is at t usiv goa odning tminimum siz [o abitat] ndd to maintain t caactis

tic divsity oan cosystm ov tim n ot wods I tnkt goas oconsation ant simpy to potct t aayo pant and anima spcis on t pant but at aso topotcttm in ti natua associations so tat t ationsps btwn spcis a psd and t voutionay andcoogica pocsss a potctd (quotd in Ik 1982 p29)

Ts vagunss o goas maks it vy dicut to compa t wooa spcissaving actiity against anot vau Wat a t ativ woso maintaining t abitat on Mount Gaam iona o abou 150 dsquis wic coud b kpt aiv as a spcis sw o xamp vsus

using 24 acs o an obsatoy tat woud b at t oont oastonomica scinc? (Ne ork es Mac 8 1990 p A-) T is muc ss basis o a asond udgmnt in tms o costs and bnts tan t is vnwit suc toy issus as cticity om nuca pow vsus tat omcoa o dcisions about suppoing additiona sac on canc vsus using

t nds o ig Socia Scuity paymnts o o dns o vn o owtaxs

Poicymaking is aso mad dicut by psationists assing on tonand tatt pupos opsation is tat it is good o uman xstncand on t ot and tat uman xistnc must b imitd o ducd bcaus

it is bad o t ot spcis T a many aistic ways w can avoidxinctions suc as by psving natua abitats and imiting umanpopuation gow (Diamond 1990 p 59) is a typica statmnt o tatsoby t sam wit wo ugs tat umans soud psv t spcisbcaus umans nd tm o xistnc!

Sti anot dicuty in conducting asond discussion o tsubct wit bioogists is ti attitud towad conomists wos tad it isto assss t conomics o suppoting pubic pogams n ot most notdo consation bioogists Pt Ravn viws conomists as oows: Papst most sious sing acadmic pobm in t wod is t taining o

conomists 1988 p 229 W av pnty o compaints ousvs aboutttaining o conomists but ou compaint is tat t ndamnta tutsabout t subct gt ost in tcica scaations compaint oRavn andot bioogists is mo a-anging y biv tat t ndamntastuctu o tougt o conomics is pd bcaus it ads to unsoundsocia coics by omitting considations t bioogists consid cucia But

t consationists do not nd os considations into a om tat acacuus o coic can da wit in is a ma pobm o t issu atand

sssng h p ass h Bs s


19/24

3 The view that the iteests o has ad o othe species aeopposed eads to hakid eig see i a athe gy light [O specieshas a knack o exteatig othes ad wee ecoe ette kes all the

tie" Diaod 99 p 58) A ecet aice is etited Extictio oslads Ma as a Catastophe" Olso 989 p 5)

t is qite cea that species ae see y ay as havig vale qiteapat o ay oe they play i ha lie a vale that is see as copetitivewth the vale o ha ie Rave wtes Athogh ha eigs aeiologcay oy oe o the ios o species that eist o Eah we cotoa hghly dispopotioate shae o the wods esoces" 988 p 22)sggestig that it is ai that we cotol" oe esoces tha do eaglesosqitoes o the vis

These eies ead to policy ecoedatios towad the ha acewhich hge po vaes aot the woth ohas vess the woth o othespecies Ad et o oe dot that the policies ecoeded ae adica Foexaple Wiso ad Ehich sggest that othig less tha the kid ocotets so ecetly ivested i the Cold Wa cold possily sce toaccopish" the goa o peseig iodivesity 99 p 76 ) a tie oheighteed scal awaeess wold Aeicas actally e willig to ivest

tiios o dollas i a edeavo that ay vey well e waated?

5 t is ot the case a soe have asseted that we wish to dowpaythe isk o a etictio csis" Diaod 989 p 4 ) Rathe we wat toake as cea as possie how geat the isk is We wat to sepaate theavailale acts o the gesswok ad the pposel isstateets i ode

to ipove the plic decisioakig pocess And we wat to coetpo how society ay easoay take ito accot the ecooic ad oecooic woths o species i light o o vales o ha ad ohaaspects o ate ad othe aspects olie o eath Moe geeally we wodlike to ove the discssio i the diectio othikig as we as we ca aot

ths pole that is ideed diclt to thik aot sesily hogh it ispoay ch easie to think aot tha the geehose isse which is chless sect to expeetatio ad oseatioa copaiso ecase theeis oly oe atosphee wheeas thee ae ay sepaated aeas whosedivesity ca e stdied

ssss r Bss of Bodvrs Crss

lson andEhrlih suestthat "nothin lessthan the nd of

ommitments soent investedin the Cold arould possibsue to aomplish the oal ofpreservin

biodiversi

5


20/24

sca aboutspecies icio

h bee maufactud i com

plete coradictioto the scietic

ta

e is o oprima facie casefor a pesive

speciessagudig

pol ithoutmo tesive

aasis

Pa 6

SUMMARY AND CONCLUSION

The scare about species extinction has been manufactured in completecontradition to the scientic data. The highest proven observed rate ofexinction unti now is only onespecies per year. Yet the "ocial forecasthasbeen species dyng out per year in ths century-a miion in a.

is tth that is becoming exinc, not speciesSome argue that because we do not know how many species are being

extinguished, we shoud therefore take steps to protect them Such reasonngis logically indistinguishable om the argument that because we do not knowat what rate the anges dancing on the head of a pin are dying o we shoudundertae vast programs to preserve them And it smacks of the "spectralevidence against "alicted young girs who were condemned to death forwitchcra in Salemharges that the accused could not rebut wth anyconceivable materia evdence

f something is unknowabe at present butknowable n pncplethenthe appropriate thing to do is to nd out. his does not necessarily meanding out by direct obseation ony A soid chain ofempirca evidence canead to a reasonabe conclusion. But there must be some modicum ofreasonabeness, in terms of both ogic and evidence

f something is nknablen pncple at east with contemporarytechnques then there is no warrant for any pubic actions whatsoever oassert otherwise is to open the door to pubic actions and expenditures onbehaf of anyone who can generate an eciting and !ghtening hypotheticascenao.

Some say the numbes do not matter scienticaly he policyimpications woud be the same they say even if the numbers were dierentby severa orders of magnitude But if so, why mention any numbers at all?he answer, quite ceary is that these numbers do matter in one imporantway: they have the power to !ghten the public in a shion that smalernumbers woud not We can nd no scientic justication for such use ofnumbers

Some have said but was not Rache Cason's Slent Spng animporant force fo good even though it eaggeated Maybe so But theaccount is not yet cosed on the indiect and ongun consequences of iIIfounded conces about envioenta danges And it seems to us thatwthout some very specia ustication there is a srong presumption in favorof stating the facts as best we now hem especay in a scientic contexather than in any manipuation of them

ing h irical Ba h Bodir Cri


21/24

A a me when hee appea equen epo on he eaodnapoble of genec enneering (fo eample Anmal leed o Poduce Medcne n Mlk Scen Say Rae Dg Coud be Manufacuedwh Relave Eae" e Whnon Pos Augu 99 p begnnng o eem ludcou o ju eaodna ependue fo poecng an anma lke he ed quewhch may no even be genecay

uniqun he gound ha gene poo w be valuabe fo human lfe nhe ue

Sl he queon e How houd decon be made and oundpoce formuaed wh epec o he dange of pece encon? We dono oe a ll anwe ne canno mply popoe avng all pece a anyco any moe han one can popoe a polcy of avng a human ve a anyco

hen we mu alo y o ge moe elable nfomaon abou henumbe of pece ha migh be lo wh vaou foe change h ofcoue, a vey ough ak oo one ha mgh eece he be facule ofaacan and degne of eperimen ne uggeon: f he populaone of eeced pece coud be meaued n a erie of period along whepemenal o nonepeimenal change n haba eapolaon mgh

each omehng abou condon ha would caue pece o appoach oeach encon

Lay polcy analye conceng pece o mu eplcy evauae he oal co o fo eample ceaon of foeng n an aea nd ucha oa co emae mu nclude he longun ndec co of educon neconomic gowh o a communiy' healh [ Endnoe a well a he

houn co of foegone wood o agiculual ale o gnoe uchndec co becaue hey ae had o emae would be no moe eaonablehan gnong he o of pece ha we have no a ye dened

We ummae he uaon a foow: hee now no pima facecae fo any epenve pece-afeguadng polcy whou moe eenveanay han ha been done heeofoe Bu he queon deeve deepehough and moe cael and wde angng analy han ha been done unlnow A chden ay u ayng o doe no make o

e e e dve C

To igno the indict cot of pe

cie protecionbecae the ahard to eimatewould be no moaonable thanignoring the loof pecie that we

have not a etidentie

It i ruth that ibecoming exinctnot pecie

7


22/24

ENDNOES

. Addiiona ciicsm of he bogeogaphy" heo of extincion raes hasreceny been epoed in cience haes Mann Exincion e

Ecologss ing Woience

6 Ags 99 o. 2 7678) bher discsson s beyond he scope of hs paper

2 See Roger A Sedo and Maron awson Goba Foress" n eReurcefu rth New Yo Bas Blacwe 984)

See Aaron Widasy earching fr afe New Bnswic NJ Transacion Press 988) see aso Raph 1 Keeney Moaliy Raes Indced byEconomic Expendes" Ri Anai 0 December 990) 4748

ABOU HE AUHORS

Jlian 1 Simon is Pofesso of Bsiness Adminsaon a he Uniersiy ofMayand a ollege Pa. Among hs boos ae e Ecnmic fPpuatin Grwth; Ert Opprtuni and Weath and Ppuatin Matter: Pepe eurce Enirnment and Immiratin

Aaon Wildas is lass of 194 Pofesso of Poliica Science and PblcPocy and a membe of he Sey Reseach ene a he Unesy ofalifoa, Beeey mong his wings ae and uture(wih MaryDogas Searchin fr Safe and Speain th t Pwer

eg e Emprc Ba ofh Bde


23/24

REERENCES

Akiso, Ia, Iroducd Aimas ad Exicios," i Conservon for he wenrsCenu Edidby David Ws ad Ma C Par w York, Oford Oord Uivrsiy Prss, 199)

Brow, K S, ad G G Brow, Habia alraio ad spcis oss i Brazilia forss," Whimor, TC, ad Sayr, 1992, pp 119-142

Coivaux, Pau Th Pas ad uur Amo," i Scenc Aercn May 99, pp 102

D Br, R, Brazi, ord ood Revew uy, 1979, pp 339

Diamod, ard, Ovriw of Rc Exicios," i Conservon for he wenrs Cenu, Edidby David Ws ad Mary C Par w York, Oxford Oford Uivrsiy Prss, 199)

Diamod, ard, Playig Dic Wih Mgadah," i Dscover Apri 1990, pp 5559

Ehrich Pau ad , nconNw York Radom Hous 191

Ehrich, P, adEO Wiso, Biodivrsiy Sudis: Scic ad Policy", encevo1253, Augus 16, 1991,pp 75762

Fyf, W S , Th Eviromal Crisis Quaiig Gosphr Iracios," Scence Vo 213, 3 uy,91, pp 1050

Hywood, V H, ad S N Suart, Spcis xticios i ropical forss," i Whimor, T C, ad A

Sayr 1992), pp 91-1Hod, Cosac, Sciiss Talk of h Nd for Cosraio ad a Ehic of Bioic Divrsiy o Slow

Spcis Exticio" Scence, May, 974 pp 64764

kr Sam Islads of if I a Fors Sa" i Mosc Spmbr/Ocobr 92, pp 2429

Isiuo Brasiliro Dsiuol, Brazil, ord ood Revew uy, 90 pp 5657

Lugo, Aril E, Edior, Divrsiy of ropical Spcis," i Boo Ineon Spcial Issu, 199

Muhoo M K Brai" ord ood Revew May, 197 pp 5-53

Myrs Norma Te Snkng Arkw York: Prgamo 1979

Myrs, Norma, A Maor Exicio Spasm Prdicabl ad Iviab i onservon for he wenrsenu Edid by David Ws ad Ma Par N ork Oxford Oxford ivrsitPrss, 199

S i Bi Bidivi i Pa 9


24/24

Olsn Srrs L, Exincin n slands Man as a Caasphe," in Conservaon for he wenrsCenu Edied by David Wese and Mary C Peal (New Yrk, Ord Oxfrd Universiy Pess,989).

Perssn, R , World Fores Resources(Sckhlm Ryal Cllege, 94)

Qinn, James F and lan Hasings, Exincin in Sbdivided Habias," in Conservaon Bolo Vlme, N 3 Ocber 98, pp 98208.

Raven, eer H. he Case and Impac f Defesain," in rh '88Changng Geogaphc erecves988 pp. 2 2229.

Reid, W. V, Hw Many species will hee be," Whime, . C, and J Saye 992), pp 554

Reid, Waler v., and Kenn R Mille, Keepng Opons ve e Scenc Bs for ConservngBodvers (Wrld Resces Insie, Ocbe 989)

Rher La, mazn Basin's Fess Ging Up in Smke," e Whngon os Janay 5, 99, 4

Rsh, G Jn, he Disinegraing Web: he Cases and Cnseqences f Exincin," pp 4 5

Sedj Rger Fres Planains in Bazil and heir Pssible Eecs n Wld Plp Markes" Joualof ores 8, Nvember, 980, 02-04.

Simberl D, D speciesarea cves predic exincin in agmened fes?," in Whime . C andJ Saye, 992, pp 590

Smme, dian, emp a an ssessmen f he Wrld's rpical Mis Fress" Unlva 28, 96,

pp 52.

US CEQ and Depamen f Sae e Global Repor o he resden Vl I, (Washingn GPO,980).

US CEQ and Depamen f Sae, Global Fuure me o c (Washingn: GPO, 98)

Waldp, M Michell, Wd Fel f he Fre?", Scence Febra 2, 98 p 9 4

Wese, David Cnseain Bilgy" in Conseraon for he wenrs enu Edied by DavidWese and May C Peal (New k Oxfd: Oxfrd Universiy Pess, 989)

Whimre, c and J Saye eds, ropcal eforesaon and Speces ncon(Chapman and Hall,992)

Whiaker, R H, and G E ikens, he Bisphee and Man" in H ieh and R H. Whiaker (eds), rmaroducv of he Bohere (New k Spinge 95)

Documents

Julian L Simon and Aaron Wildavsky - Assessing the Empirical Basis of the Biodiversity Crisis