POTENTIAL CONSEQUENCES OF INCREASING ATMOSPHERIC … 2000 Technology.pdf · 1700 1750 1800 1850...

Technology, Vol. 7S, pp. 189-213,2000Printed in the USA. All rights reserved

1072-9240/00 $2000 + .00Copyright IQ 2000 Cognizant Communication Corporation

POTENTIAL CONSEQUENCESOF INCREASING ATMOSPHERIC

CO2 CONCENTRATION COMPAREDTO OTHER ENVIRONMENTAL PROBLEMS

Indur M. GoklanyVienna, VA

TS 9907-532 M (Received 16 June 1999; accepted 14 April 2000)

This paper examines the validity of the assertion that anthropogenic climate change is the overridingenvironmental concern facing the globe today. Examination of recent trends for some climate-sensitiveindicators (e.g., global food security; U.S. deaths due to storms and floods; global death rates due toinfectious and parasitic diseases; and biomass in the northern forests) shows that matters have improvednotwithstanding any climate change to date. For others (such as global deforestation and sea level rise).recent trends have continued to worsen; but so far the contribution of any anthropogenic climate changeto these impacts seems to have been relatively minor. Next, based largely upon the IntergovernmentalPanel on Climate Change's 1995 Impact Assessment. the paper determines that over the next severaldecades the projected global impacts of climate change upon food security, deforestation, biodiversity,and human health could be an order of magnitude smaller than those due to other stressors such aspopulation growth, poverty, land conversion, or baseline (i.e., non-climate change related) rates ofinfectious and parasitic diseases. Therefore, eliminating anthropogenic climate change, even if feasible,would-for the next several decades-do little to reduce the much larger baseline rates of globaldeforestation, biodiversity loss, and infectious and parasitic diseases. Hence, climate change, while apotentially serious long-term problem. is not today-nor likely to be in the foreseeable future-as urgentas other current environmental and public health problems. The paper then proposes an integratedapproach to deal with today's urgent environmental problems while enhancing the ability to address thelong term-problem of climate change.

INTRODUCTION

Many scientists and, perhaps more importantly,policy makers claim that climate change is theoverriding environmental challenge facing the globetoday (1-4). This assertion is in no small wayresponsible for the emphasis placed upon the Kyotoprotocol on emission reductions (5). This paperexamines whether this claim is supported by theavailable information on the impacts of climate

change that may be occurring now and in the "fore-seeable" future by comparing those impacts with theimpacts of other environmental problems. Such acomparison would help in the development of arational approach to dealing with not only climatechange but other critical environmental and publichealth problems facing the globe over the next few

generations.

189

I. M. Goklany190

The paper will focus on the economic sectors andenvironmental consequences and indicators forwhichlong-term retrospective data and future projections areavailable. These sectors and indicators-agricultureand food security; forests and biodiversity; humanhealth; hurricanes and other extreme weather events;and sea level rise-are also thought to be the mostsensitive to climate change. For brevity, the paperwill refer to these as the climate-sensitive sectors orindicators.

The paper's time horizon is the foreseeable future,which it assumes is the middle of the twenty-firstcentury. Postmortems of several studies (e.g., 6, 7)projecting future use of natural resources and theresulting impacts have shown the difficulty of accu-rately projecting use and associated impacts even oneor two decades-let alone a few generations-ahead;mainly because the projections did not adequatelyaccount for technological progress and adaptationto any adverse social and economic circumstancesarising from the use or impact of the resources(8-11). Also, because the paper limits itself to theforeseeable future, it will not examine potentiallycatastrophic consequences of climate change whichare unlikely to occur, if at all, until a few centurieshave passed. These catastrophic consequences in-clude the rapid collapse of the West Antarctica IceSheet, which could occur after about five to sevencenturies (12, 13), and the shutting down of the"ocean conveyor belt" which warms NorthernEurope and contiguous Asia due to a termination inthe thermohaline circulation (14, 15).

creased 260% from 1.62 billion to 5.85 billion,but cropland increased only 95% from 7.7 Tm2 to15.1 Tm2asindicatedinFig.1 (16, 17). The 165%gapbetween the increases in population and in cropland(equivalent to 12.8 Tm1 is the minimum amount ofhabitat saved from conversion to cropland because ofincreased productivity in the food and agriculturalsector. The 12.8 Tm2 estimate assumes that despitefreezing technology at the 1900 level (16, 18, 19):1. All new cropland would, on average, be as pro-ductive as existing cropland was in 1900. This maybe an optimistic assumption because, arguably, themost productive croplands were probably alreadyunder cultivation in 1900.2. All cropland that was in existence in 1900 wouldmaintain its level of productivity at the 1900 level.3. The penetration of any existing technology wouldexpand only to the extent necessary to ensure thatassumptions 1) and 2) are realized. This impliesthat, at a minimum, inputs would probably increasein proportion to the amount of total cropland.4. Average global food supplies per capita would befrozen at the marginal levels of 1900.Absent the large (12.8 Tm1 reduction in land con-version, deforestation and loss of habitat-the majorglobal causes of the loss of biodiversity-would havebeen worse than they already are (18, 19). Figure 1shows that although the amount of cropland neededto feed the average person has been reduced almostby one half during this century (4,770 m2 per capitain 1900 versus 2,580 in 1995), food is cheaperand, consequently, the average person is better fed.Between 1961-63 and 1994-96, global per capita foodsupplies increased 19%(from2,280t02, 720 kcald-I),and global protein supplies per capita increased 16%(from 62.8 to 72.6 g d-1). Between 1960 and 1996,world food prices (in constant dollars) declined 41 %

(20, 21). Consequently, although global populationincreased 45% between 1969-71 and 1990-92, theabsolute number of people suffering from chronicundernourishment in developing nations decreasedfrom 917 million (or 35% of their population) to839 million (or 21%) (22). These data indicate thatdespite the increase in population, global vulnera-bility to famine and malnourishment has declined.In turn, that helped improve the world's healthstatus by contributing to reduced infant and ma-ternal mortality rates, and higher expected life

spans (23).

CURRENT TRENDS IN THE CLIMATESENSITIVE SECTORS

Analysis of past trends in the impacts of variousclimate-sensitive phenomena and in the ability of theclimate-sensitive sectors to meet human demands canhelp determine whether it is becoming harder to meetthose demands because of, or despite, any warmingthat may have taken place so far. An understandingof these trends can also instruct us as to the factorswhich determine adaptation and vulnerability tovarious climate-related challenges.

Agriculture and food security

Between 1900 and 1997, global population in-

191Poten1ial co~eoces of iocreasing a~ric CO} coocentration

0.66

'CC~0.50...u--0

84!~-UG

~3g:c02G

0.0G

0,1c

~:c

0.5

0.4

'a~

0.3 ;;DJ'a==DJ

0.2 -s:.!!.

0.1

a020001700 1750 1800 1850

Sources: Goklany (16,19); FAD (17).

'1900 1950

Fig. 1. Cropland and cropland productivity, 1700-1997.

Although the amount of cropland per capita hasnever been lower, the fact that the average person isbetter fed today is only possible because globalproductivity in the food and agricultural sector is atan all time high. This is in contrast to the conten-tion that warming may reduce global agriculturalproductivity through a combination of factors in-cluding more frequent floods, droughts and loss ofsoil moisture, and pest and disease outbreaks (24)--especially given Mann et al.'s (25) centuries longreconstruction of temperature trends which suggeststhat the earth today is the warmest it has been in thelast six centuries (26), and Dai et al.'s (27) analysisindicating an increasing trend in the global com-bined areas of severe drought and severe moisturesurplus since the 1970s. So how can one explainthe historical increases in agricultural productivityand improved food security at a time when theclimate is getting worse?

The three possible explanations for this diver-gence are as follows:I. Perhaps the net effects of global warming atcurrent CO2 and temperature levels are not particu-larly detrimental to global agricultural productivityor, more importantly, global food security. In fact,there is some evidence that so far CO2-enhancedwarming may be contributing to increased agricul-

tural productivity. Nicholls (28) estimated that 30-50% of the post-1950 increases in com yields inAustralia may be due to higher minimum tempera-tures. In the far northern latitudes, the active grow-ing season seems to have lengthened by 12:i: 4 daysin the 1980s and plant growth has apparently accel-erated (29). In addition, numerous controlled fieldexperiments show that increasing atmospheric CO2concentrations increases crop yields. The Intergov-ernmental Panel on Climate Change (IPCC) 1995Impact Assessment suggests that yields of C3 crops(i.e., the majority of crops) may increase an averageof 30% due to a doubling of CO2 (30). Wittwerestimates that the increase in CO2 concentrationsover the last two centuries may have increasedproduction by as much as 14% (31). Between 1961and 1996, global cereal yields increased 115% (20),while CO2 concentrations increased only 14% (32),and annual global temperature increased less than0.3 °C. (26). Thus, CO2-enhanced warming is un-likely to explain more than a small portion of theincrease in global agricultural productivity.2. The increased global agricultural productivityand global food security is due to technologicalprogress driven by the mutually-reinforcing, co-evolving forces of economic growth, technologicalchange, and trade (9, 16, 18, 19,33).

M. Goklany192

3. Perhaps the most plausible explanation of all isthat both CO2-enhanced global warming and techno-logical progress have contributed to reduced humanvulnerability to hunger and malnourishment, withthe latter being the major contributor.

much of it at the expense of forests and wood-lands (20).

Mortality and property loss due tc~ storms,floods and other extreme weather events

Forest cover and biodiversity

Through the ages, human demand for land foragriculture and-toamuch lesser extent-settlementsand infrastructure, has been the major reason forthe loss of forest cover and diversion of habitataway from the rest of nature (9, 16, 19,33). Suchdeforestation and habitat conversion, in turn, isresponsible for much of the presumed threat toglobal biodiversity. Between 1980 and 1995, globalpopulation increased 28% (33). To meet the addi-tional food demand, net agricultural land increasedby about 4% or 2.0 Tm2 (including 0.8 Tm2 ofcropland), and net forest cover decreased by about1.7 Tm2 (34). In the developing countries, netforest cover declined about 1.9 Tm2. By contrast,forest cover increased by about 0.2 Tm2 in thedeveloped countries.

There is no evidence that anthropogenic globalwarming has contributed to the loss of forest cover,significantly or otherwise. In fact, for forests asfor agriculture, CO2-enhanced warming may haveincreased productivity, thereby stimulating timbergrowth and forest mass (29, 35-37). The trendsin developing and developed countries (taken asgroups) confirm the importance of economic growthand technological progress in limiting deforestation(34, 38). Forest cover is declining in developingcountries largely because their increases in agricul-tural and forest productivity lag behind the de-mands of their growing populations for food andother products. Meanwhile, developed countriesare being reforested because-despite diversionof land for urbanization and infrastructure projects-productivity in the agricultural and forestry sec-tors is growing faster than the increase in demandsfor food and timber. Without science-based andmarket-driven increases in food and agriculturalproductivity, global deforestation would have beengreater. Thus, between 1980 and 1995, at least anadditional 12.3 Tm2 of agricultural land (including4.0 Tm2 of cropland) would have been needed,

Deaths and death rates: Long-term data onV.S. fatalities due to tornados, floods, lightning, andNorth Atlantic hurricanes and cyclones hitting theV.S. mainland from 1916-97, 1903-97, 1959-96,and 1900-97, respectively, were obtained from var-ious groups within the National Oceanic and Atmo-spheric Administration (NOAA) (39-43).

However, there are several discrepancies betweenthe flood fatalities data from NOAA's HydrologicalInformation Center (HIC) and its National ClimaticData Center (39), and both differ from data in theBureau of the Census' Statistical Abstracts and theHistorical Statistics (44). Since HIC was suppos-edly the original source for the flood data for theother groups as well, it was decided to use its dataset (40). However, in the earlier years, even theHIC data set may be prone to error, possiblyundercounting fatalities (45). For instance, in 1911,that data set shows 0 fatalities; however, the NewYork Times indicates that there were at least 55fatalities that flood year. Similarly, the Times in-dicates at least 244 in 1928 and 42 in 1931 com-pared to 15 and 0, respectively, in the HIC dataset (45, 46). However, the corrected values maythemselves be lower bounds. Notably, the keeperof the HIC's data set expresses greater confidencein the data after the mid-1960s on fatalities andmid-1950s on property losses.

For the most recent nine-year period for the vari-ous data series (1989-97 for tornados, floods, andhurricanes; 1988-96 for lightning), average annualdeaths for these extreme weather events declined86.5,53.5,97.3 and 46.5%, respectively, since theirnine-year averages peaked in 1917-25, 1969-77,1900-08, and 1959-67, respectively (45, 46). Thedeclines in death rates (measured as deaths permillion population) are even more dramatic (45).For the latest nine-year periods, death rates are94.3, 70.9, 99.2 and 60.7% below the 1917-25,1913-21,1900-08, and 1959-67 peaks for tornados,floods, hurricanes, and lightning as indicated inFig. 2 (45,46).

193Potential consequences of increasing atmospheric CO2 concentration

(deatb, per miUioo popolotioo, 9-y..r mo.iqa.erac... 1900-1997)

143.5

12

10

8

6

4

~ 3+~+~2.5~~...i 2~~S 1.5Ii=~

! 1.....a..~O.5 2

ii !~

't I IIi !I'\~'-\i i\!"-..,- ,i ~ I

~,I ,t "" , ,.-.', ,r' I',_.~.-,.,.,-,_,:,_-,-,-,- 00 ." -

1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000

Source: GokIany (45).

Fig. 2. Death rates due to tornados, floods, lightning, and hurricanes.

While a portion of the declines in deaths anddeath rates for hurricanes may be due to a reduc-tion in the number and wind speeds of violentAtlantic hurricanes since the 1940s (47), a portionof the credit is perhaps also due to technology-

based adaptation (46).The declines in deaths (D) [and death rates (DR)

per million population per year] can be fitted usingcurve-fitting models that vary linearly with time (t)for D or log D [or DR or log DR]. (Table 1)

Results of curve fitting analyses for deaths and death rates due to extreme weather events.Table

Equations fitting the data p for the slopeYears, no. of observations(obs), period

rType of Event

0.3670.563

<0.001<0.001

DR = 2.484 -0.0341 1Log DR = 0.395 -0.01541

Tornados 1916-9782 annual obs.t=lt082

0.2690.354

<0.001<0.001

D = 289.3 -3.401tLog D = 2.395 -O.OI00t

DR = 0.859 -0.0219 TLog DR = -0.176. 0.0089T

0.0940.037

>0.1>0.1

Floods 1903-9719 non-overlapping5-yr periods,T = I to 19 0.630

0.613<0.001<0.001

D=148.7-3.541TLog D = 2.180 -0.0136T

0.2810.702

<0.05<0.001

DR = 5.514 -0.5141TLog DR = 0.640 -0.1357 T

Hurricanes 1900-9714 non-overlapping7-yr periods,T = I to 14 <0.05

<0.005D = 456.2 -40.07TLog D = 2.519 -O.0960T

0.2990.549

0.6390.749

<0.001<0.001

DR = 0.686 -0.0137tLog DR = -0.143 -0.0140l

1959-9638 annual obst = 1 to 38

Lightning

0.5070.576

<0.001<0.001

0=127.6-1.981tLogO=2.IIO-O.OO94t

c.=;:~.iCoc.'0~c~n

194 I. M. Goklany

With respect to floods, according to Karl andKnight (48) the intensity of heavy and extremeprecipitation events (defined as daily precipitationevents exceeding 2 inches or 50.8 mm) apparentlyhas increased for the U.S. since 1910 which, all elsebeing equal, ought to increase the frequency andintensity of floods and the risk of fatalities due tofloods. On the other hand, the Lins and Slack (49)analysis of streamflow data from 1914 onward forrelatively undisturbed watersheds shows that whilethere may be an increase in the discharges due tolower and middle streamflow regimes, there seemsto be no general upward trend in the highest flowsdue to hydrological events alone-suggesting thatthe likelihood of floods due to weather or climatemay have actually declined. Regardless of whetherfrequency and intensity of flooding may have in-creased or decreased, what is more important isthat fatalities as well as death rates have declined.(Fig. 2) It is likely that the bulk of these decreases,as well as for other extreme events, is due to in-creased wealth and new technologies which have

enabled people to benefit from adaptation mea-sures such as more reliable forecasts; early warningsystems; elaborate evacuation plans; more robustconstruction of houses and infrastructure; an exten-sive transportation network; and the constant drum-beat of television and radio weathermen once astorm registers on their radar screens.

Property losses: One might expect that while awealthier society may take extra effort to limit lossof life, it may be less concerned about propertylosses. A wealthier society is also likely to havemore property at risk. Moreover, if the interpreta-tion by Karl and Knight of trends related to floodsin the U.S. are more accurate than that of Lins andSlack, the frequency and intensity of floods in theU.S. may have increased. Figure 3 shows that atfirst blush, despite wide year-to-year fluctuations,the overall trend between 1903 and 1997 for prop-erty losses due to U.S. floods (adjusted to realdollars using the construction cost index) seemsupward (45).

20 0.28

15 0.24

~a....--c~=~~.E

~:...

0.2 ~~~

0.16 :~.0...

0.12 ~to~;..

0.08

-10

0.04

-15

1900

0

20001920 1940 1960 1980

.Wealth measured as fixed reproducible tangible assets.

SaIIt:r:: ~y (45).

Fig. 3. Property losses due to floods, 1903-1997.

ing land values) using data from the Bureau ofEconomic Affairs (50) for 1925-1996-a betterindicator of the amount of property at risk-then the

However, if property losses due to floods areestimated as a percent of the nation's wealth mea-sured as fixed tangible reproducible assets (exclud-

10

5

0

-5

Potential co~elx:eS of iocreasing a~ric Caz coocenn-ation 195

overall direction of the trend between 1925 (thefirst year for which such wealth data are available)and 1997 (51) is unclear. (Fig. 3) Curve-fittingmodels utilizing property loss rate (LR) specified

in tenDs of percent of wealth, give poorer fits thanthose utilizing real dollars. (Table 2) In this analy-sis, wealth for 1997 was based upon an extrapola-tion for the previous three years (45).

Table 2. Results of curve fitting analyses for property losses due to floods.

rProperty Loss, in terms of: p fi)f the slopeCurve fitting equationsPeriod,no. of observations

Billions of Real (1997) S LR= 1.183 +0.1732TLog LR = 0.1207 + 0.0257 T

0.2830.240

<0.02<0.05

1903-97nineteen 5-yr periods

Billions of Real (1997) $ LR=17.11+2.900TLog LR = 0.3055 + 0.0423 T

0.3730.358

>0.1>0.1

% of wealth LR = 0.2829 -0.0135 TLog LR = -1.525 -0.0242 T

0.1360.140

>0.3>0.3

1926-97eight 9-yr periods


Similarly, any upward trend in property lossesdue to hurricanes in terms of real dollars between1900-97 is obscured if losses are measured interms of percent of wealth as reflected in Fig. 4and Table 3. (45; see also, 51)

warmer world has been raised as one of the majorconcerns regarding anthropogenic climate change.Some fear that vectors such as the anophelesmosquito--the carrier of malaria--could becomemore widespread with warming since a change inclimate could alter the range and abundance ofspecies (52, 53). However, this has been disputedon the basis that global warming would not neces-sarily expand-nor is it the major determinantof-the range of all vectors (54-57). Today the

Infectious and parasitic diseases, and otherhealth impacts

The potential spread of vector borne diseases in a

0.3540

0.330

0.25 !"'::0.2 :

~0-.

0.15 ~..~~.

0.1

~......-0

;a:EoS

~;~ ....

""

0.05-20

' f' : I i,, ' i, ...i, !of .: i '.'!: ::! :: I ., I I::

" ....'-30 .0 [

1900 1920 1940 1960 1980 2000

.Wealth measured as fIXed reproducible tangible assets

S~e Goklany (45)

Fig. 4. Hurricane property losses, 1900-1997.

20

10

0

-10

M. Goklany196

Table 3 Results of curve fining analyses for property losses due to hurricanes.

rProperty Loss, in terms of: p for the slopeCurve fitting equationsPeriod,no. of observations

Billions of Real (1997) $ LR = -825.0 + 283.37 T

LogLR= 1.916+0.1223T0.6040.826

<0.001<0.001

1903-97fourteen 7-yr periods

Billions of Real (1997) $ LR = -623.9 + 518.39 TLog LR = 2.428 + 0.1415 T

0.5530.716

<0.05<0.01


LR = 0.0087 -0.0011 TLog LR = -2.0389 + 0.0277 T

0.1520.082

>0.3>0.3

% of wealth 1926-97eight 9-yr periods

prevalence of these diseases has less to do with theirpotential ranges than with the public health measurestaken to deal with the vectors and the diseases theyspread. For instance, in the last century, malaria,cholera, and other diarrheal and parasitic diseaseswere prevalent around the world-including theUnited States and Western Europe-but today theyare problems only in countries where the necessarypublic health measures are unaffordable or have beencompromised (58,59). For instance, mainly becauseof cholera, yellow fever, typhoid, and various diar-rhoeal and gastrointestinal diseases, the mean crudedeath rate (CDR) in New Orleans for a 30-yearperiod between 1830 and 1859 was 60,000 permillion (60). By comparison, in 1990-1995, it was44,600 per million for Rwanda-the nation with thehighest CDR-and 8,800 for the U.S. (21). In 1900,the cumulative death rate in the U.S. for typhoid,paratyphoid, various gastrointestinal diseases, andall forms of dysentery was 1,860 per million pop-ulation (9). Today, due to a host of public health

measures, these diseases barely show up in currentstatistics-accounting for a death rate of less than5 per million (61).

Better nutrition, advances in-and increased avail-ability of-medical and public health technology,and greater investments in public health programsand infrastructure helped reduce infectious andparasitic diseases worldwide-particularly amongthe young in developing countries. As a result,crude global death rates dropped from 19.8 per 1000population in 1950-55 to 9.3 in 1990-95, helpingpush global life expectancy at birth from 46.4 to64.7 years (62). These improvements would havebeen unlikely, if not impossible, without: I) thetransfer of scientific information and technologiesgenerated in the richer nations; and 2) the wealthgenerated by economic growth which made thosetechnologies affordable (9, 33). Table 4 shows,for a sampling of countries, how various publicand environmental health indicators improve withwealth (46).

Table 4. Improvement in public and environmental health status with wealth for selected countries

Child mortalityrate, 1995(per 1000)

Access to safewater, 1994

(% of population)

Access to adequatesanitation, 1994(% of population)

Country

3,239

2,755

2,393

2,585

2,443

1,670t

78.2

73.8

66.3

56.5

435

43.5

24,740

3,170

850

430

240

<200

6

17

48

113

207

251

100

96

84

56

57

10

100

71

75

42

20

8

Sweden

Chile

Philippines

Ghana

Guinea-Bissau

Afghanistan

t 1990-92 average.Source: Goklany (46)

Food supplies per Life expectancy at GNP percapita, 1994 birth, 1990-95 capita 1993(Kcal/day) (years) (US $)


uted in death certificates to extreme cold and ex-treme heat, respectively (73). However, it does notnecessarily follow that warming would reduce netmortality. This is because of two competing phe-nomena not captured in the death certificate data(53,69, 70). First, excess deaths (i.e., deaths abovea background level in the absence of an extremeevent, adjusted for the period of the year) due to allcauses (e.g., strokes or heart disease) on average goup more due to extreme heat than due to extremecold events. This is true even if one considers thatthe death rate drops below the background levelafter the extreme event has ended, and that suchdrops (like the increases) are more pronounced forextreme heat events. Overall, there are many moredeaths during the winter months than in the summermonths. A proper evaluation of the net effect ofany warming on mortality ought to consider thesefactors-as well as possible changes in backgrounddeath rates-within a framework which consid-ers adaptation and uses "years of life lost" and"disability-adjusted life years lost" because mortal-ity rates due to both extreme cold and extreme heatevents are higher among the aged and those alreadysusceptible (74). While this is outside the scope ofthis paper, one ought to expect some cancellation ofmortality effects due to more heat waves and fewercold ones because of climate change (53, 69, 70).

Accelerated sea level rise

A major concern related to global warming isthat it could accelerate the rate at which sea levelhas been rising for millennia. Preliminary resultsfrom the TOPEX/POSEIDON satellite observationsfrom 1993-1996 are consistent with the historicaltide gauge record, which shows mean sea levelrising at a rate of about 18 :!: 1 cm (about 8 inches)over the last 100 years (75, 76). While it is notknown what fraction, if any, of that might be dueto any anthropogenic warming, it is worth notingthat the IPCC's Science Assessment notes thatthere is no detectable acceleration of sea level riseover the last century (76). Suffice it to say, so farany accelerated sea level rise due to man-madewarming is unlikely to have caused anything otherthan a minor impact on human or natural systemscompared to other environmental stressors such asdevelopment of coastlines, conversion of lands for

Despite these improvements, poor sanitation, un-availability of safe water, and indoor air pollutionare still among the major causes of higher mor-talities and lower life expectancies in developingcountries. An estimated 2.9 billion people lackadequate sanitation and 1.1 billion have no access tosafe water in developing countries. These deficien-cies are largely responsible for about 2.5 milliondeaths due to diarrhoeal diseases (in 1996). Ac-cording to the World Health Organization, another3 million premature deaths-mainly in developingcountries-were caused by air pollution globally,of which 2.8 million deaths were due to indoor airpollution (63). In addition, malaria caused anestimated 1.5-2.7 million deaths in 1996, almostexclusively in the developing countries. It has beensuggested that climate change may be a factor in therecent resurgences in vector-borne diseases (52,53).Resurgences include malaria in Henan Province(China); malaria and dengue in the Americas; andcholera in Peru and Rwanda. However, increases indrug resistance; increased urbanization which canlead to unsanitary conditions and facilitates thespread of infectious diseases; premature discon-tinuation of control measures such as indoor spray-ing and use of impregnated mosquito nets; andfaltering mosquito control and public health mea-sures (e.g., reduction in DDT usage and chlorina-tion) aggravated by poor nutrition seem to be morelikely causes (57, 64-68).

Finally, although extreme temperatures pose less-er public health problems than infectious and para-sitic diseases, they are known to cause deaths (52,53,69,70). Gaffen and Ross (71) have reported thatbetween 1949 and 1995 the frequency of "extremeheat stress events" has increased for the U.S. Theysuggest that continuation of this trend could posepublic health problems in the future. However,analysis by Goklany and Straja (72) of death certifi-cate data from the Centers for Disease Control andPrevention (73), shows no upward trends in U.S.CDRs due to excessive heat and excessive coldbetween 1979 and 1997, despite the aging of thepopulation which, if all else is equal, ought to haveincreased risks of death due to either.

Notably, deaths and death rates in the U.S. duringthe 1979-1997 period due to extreme cold exceedthose due to extreme heat. During that period therewere cumulatively 13,319 and 6,693 deaths attrib-~

198 M. Goklany

aquaculture, drainage for other human land uses,sediment diversion due to dam construction up-river, construction of seawalls, and subsidenceowing to water, oil and gas extraction (77).

FUTURE IMPACTS OF WARMING RELATIVETO THE BASELINE

Moreover, net global impacts are also uncertainbecause they are an aggregation of the variouslocation-specific impacts, although there may besome cancellation of errors. Nonetheless, the un-certainties are large enough that one cannot beconfident either of the magnitude or, in many cases,even the direction of impacts, i.e., whether the netimpacts are positive or negative. This is true notonly at any specific geographic location, but also atthe global scale.

Beyond these uncertainties, there are majorsources of systematic upward biases. These studiesdo not fully or adequately account for technologicalprogress and adaptation (8-11, 79-81) which notonly overestimates the potential negative impactsbut also underestimates the potential gains fromharnessing positive aspects of global warming.Figures 1 and 2, as well as the virtual elimination ofmalaria, cholera, and other infectious and parasiticdiseases in the richer countries, for instance, showthat while adaptations may be difficult-if notimpossible--to model in advance of their occur-rence, they are, nonetheless, real and quite substan-tial. The above-noted trends also show that forthese climate-sensitive sectors and indicators overthe last century (or so), adaptations have so far morethan offset any increases in negative impacts due toany climate change. While failure to fully accountfor adaptations significantly simplifies the mechan-ics of estimating "impacts," it also inflates purportedimpacts. At best, that could provide misleadinginformation to policymakers; or, at worst, that couldskew societal priorities, unless users of such impactsanalyses are fully aware not only of their shortcom-ings, but also their implications. Yet another reasonfor a bias toward overestimation of climate changeimpacts is that the climate change scenarios used inthe studies relied upon by the IPCC 1995 Assess-ment, are sometimes more extreme than the IPCC's"best estimate" scenarios.

Despite all these shortcomings, it is assumed inthe following that the IPCC's 1995 assessmentprovides robust impact estimates.

Agriculture

There are numerous reasons to be skeptical of thestudies reported in the IPCC's 1995 assessment ofthe impacts of climate change (78). This is becauseprojections of future impacts are based on a series ofmodel calculations with each succeeding modelusing, as its inputs, increasingly uncertain outputs ofthe previous model (8, 78, 79). First, future emis-sions of greenhouse gases (GHGs) have to bemodeled using uncertain projections of futurepopulation, economic conditions, energy usage, landuse, and land cover. These emissions are them-selves sensitive to climatic conditions and atmo-spheric concentrations. Next, these emissions haveto be converted into each GHG's atmosphericconcentration. These concentrations then have tobe used to determine future radiation forcing whichis used (ideally) by coupled atmospheric-oceanmodels to project climatic changes (such as changesin seasonal temperatures and precipitation; seasonalhighs and lows; and changes in diurnal variability).Moreover, these climatic changes should be esti-mated at relatively fine geographical scales be-cause the impacts of climate change are location-specific (8), but the finer the geographic scale, themore uncertain the results.

These uncertain climatic changes then serve asinputs to simplified and often inadequate modelswhich project location-specific biophysical changes(e.g., crop or timber yields). Next, depending on thehuman or natural system under consideration, theoutputs of these biophysical models may have tobe fed into additional models to calculate impactson those systems. For example, estimates of cropyields at various locations should serve as inputs fornational and global models of the agriculturalsystem in order to estimate overall impact on food

security.Thus, estimates of the impacts of global warming

in any specific location at any particular time areprobably even more uncertain than estimates of theglobally-averaged temperature and/or precipitation.

Rosenzweig and Parry (82), an important sourceof the IPCC' s 1995 Impacts Assessment chapter onagriculture (30), estimated that the baseline global

199Potential consequences of increasing annOSpheric CO2 concentration

7.3 billion to 10.7 billion with 8.9 billion being the"most likely" estimate (85).

Clearly, at least till the middle of the next century,the effects of climate change upon food security willbe relatively minor compared to population andeconomic growth. If the world's population in 2060cannot be adequately fed, it will not be because ofclimate change, but because of a larger population,insufficient economic growth, technological change,and trade. Moreover, if the quest for food securityleads to massive land conversion and consequenthabitat and biodiversity losses, that too will bedue to insufficient technological progress during aperiod of high population growth, rather than CO2-enhanced warming (8, 33).

Forests and biodiversity

cereal production, i.e., production in the absence ofclimate change, would rise 83% between 1990 and2060. The baseline assumed a 2060 population of10.3 billion and a 330% economic growth between1980 and 2060. With climate change (but no miti-gation policies, i.e., "business-as-usual" or BAU),some production would shift from developing todeveloped nations, thus increasing the former's foodimports and vulnerability to chronic malnutritionand hunger. However, assuming some adaptations,the net change in global production would be rela-tively modest: the baseline production level wouldbe perturbed by -2.4% to + 1.1 % in 2060 due to an"equivalent doubling of CO2 concentrations."

The climate change scenarios utilized byRosenzweig and Parry effectively assumed a globalwarming of 4.0°-5.2 °C, and a CO2 concentration of555 ppm (/lL/L) in 2060. By comparison, the IPCCestimated a temperature range ofO. 7-1. 7°C (with abest estimate of 1.1-1.2°C) in 2060, and 0.8-4.5°Cin 2100 (with a best estimate of2.0°C) (82:40). Itwould be a mistake to assume that although thismay overestimate the impacts in 2060, Rosenzweigand Parry's estimates would nonetheless be areasonable upper bound of negative impacts for2100 (or shortly thereafter) under BAU. First, bythe year 2100, the BAU CO2 concentrations wouldbe closer to 700 ppm (/lL/L), not 555 ppm (/lL/L)(84). Thus, the beneficial direct CO2 effects wouldbe underestimated for 21 00, while the more negativetemperature- and evaporation-related effects wouldnot. This is a major problem with estimating im-pacts using the equilibrium climate based uponequivalent CO2 doubling (8). Another reason whythe estimates of Rosenzweig and Parry would notbe valid for 2100 is that the capacity to adapt willbe greater in 2100 than in 2060 because of thesecular upward trend in technological change andadaptability which, moreover, could be furtherboosted by economic growth (8, 18, 19,33).

Nevertheless, despite the tendency for theRosenzweig and Parry approach to overestimatenegative impacts, the agricultural impacts due toclimate change (-2.4% to +1.l%)-and their foodsecurity consequences-will be lost in the "noise"due to uncertainties in future levels of populationand economic output, either of which could be offby :1::20% (or so) by 2060. For instance, the U.N.'s1998 population projection for 2050 ranges from~

The IPCC's Impact Assessment notes that onecomputer model (BlOME) estimates that in theabsence of any additional human demand for land,climate change alone (but excluding the largelybeneficial direct effects of CO2 on plant growth)could, by 2050, actually increase global forest areaby + 1 to +9% over 1990 levels (86). Another model(IMAGE) which essentially combines BlOME withmodels that can account for human land use changesand direct CO2 effects estimates that global forestcover would decline by 25%, including a 47%decline in tropical forests and a 10% increase inboreal forests (86). Thus, even if global warmingwere to be completely halted-and the notion thatwarming could increase net global forest area wastotally discounted-then according to the modelsused in the studies relied upon by the IPCC, massiveloss of forests should still be expected. Not sur-prisingly, the IPCC assessment states that land usechange is obviously the greatest threat to speciesdiversity of tropical forests (87). Once again, overthe next few decades, the impacts of climate changeare likely to be small compared to other non-clima-tic factors-namely, conversion of forests to rela-tively low yield agricultural uses in developingnations due to increasing food demand, and rever-sion of agricultural lands to forests in the richernations due to increasing agricultural productivity

(33,34).Climate change will also affect the rate of for-

est growth. CO2-enhanced warming may in fact

M. Goklany200

accelerate wood production (e.g., 29, 35, 88, 89),though some have suggested that much of theincreased growth could fall prey to pests, diseases,and fires (86). Nevertheless, in more carefully-managed forests, it ought to be possible to harnesstechnology to take advantage of the positive featuresof CO2-enhanced wanning, while minimizing anynegative effects (33). For instance, King et al. (88)estimate that due to equivalent CO2 doubling,vegetative carbon could increase 12-16% owing toclimate change alone, and 31-37% if CO2 fertiliza-tion is also considered. Recent evidence indicatesthat the Northern latitudes may already have be-come more productive (29). Goklany, based upona population estimate of 9.6 billion in 2050, hasestimated that 8.15 Tm2 of plantations and agro-forestry enterprises could meet the global demandfor wood in 2050 (33). Thus, even a 12% increasein sustainable yield could reduce the amount offorest land needed to meet human needs for forestproducts in 2050 by 1.0 Tm2

Extreme weather events

The IPCC's 1995 Science Assessment noted thatit was unable to state whether the frequencies orintensities of extreme events such as hurricanes andcyclones would change due to any anthropogenicwarming (83). As noted, empirical data suggeststhat the number and intensity of hurricanes touch-ing the United States may have declined since the1940s. Gray (90) has suggested that we may beentering a period of heightened hurricane activity,but bases his claim not upon any global warmingbut on the Atlantic Ocean thermohaline circula-tion. A recent post-IPCC assessment concludedthat while thermodynamic calculations predict a10-20% increase in the maximum potential inten-sity due to a doubled CO2 climate, the knownomissions in these calculations all act to reduce

these increases (91, 92).

Infectious and parasitic diseases, and other

health impacts

health specialists point out that such prognostica-tions disregard historical fact that disease incidencedepends more upon public health measures (or lackthereot) which is determined by a nation's economicstatus and state-of-the-knowledge regarding thedisease, rather than the potential range or by clima-tic factors (55-57). This is exactly why the currentgeographical distribution of incidences of a numberof infectious and parasitic diseases no longer corre-sponds to their historic potential ranges. The studiesunderlying the IPCC report also assume essentiallyno medical progress against these diseases over thenext 100 years, which seems quite unlikely, giventhe experience of the past 100 years and the acceler-ating rate of the creation and spread of new knowl-edge and technology in the fields of medicine andits supporting disciplines. Nevertheless, this studyrelies on the 10-16% estimate, which translates intoabout 50-80 million potential additional cases in2100, compared to a baseline of 500 million inthe absence of climate change. Assuming that theadditional cases due to climate change (expressed asfractions of baseline cases) increase exponentiallywith time, that implies a 5-8% increase by 2060.Further, assuming a similar increase in all infectiousand parasitic diseases, the public health impact nodoubt would be significant since currently, globally17 million people-including 1.5-2.7 million due tomalaria-die prematurely from such diseases eachyear, with over 99% occurring in the developingworld (63). Nevertheless, until at least the middleof the 2151 century, such an increase would be lessthan one-tenth of the global base rate in the absenceof climate change.

The potential impacts of extreme heat and coldbecause of anthropogenic climate change are rela-tively modest by comparison with the potentialimpacts of infectious and parasitic diseases. More-over, globally there may be at least a partial cancel-lation of adverse effects due to increased incidencesof heat stress in some locations, e.g., North Amer-ica, and reduced incidences of cold stress in others,

e.g., Europe (52, 53, 93-96).Finally, the recent IPCC assessment of the re-

gional vulnerabilities to the impacts of climatechange, which essentially employed similar meth-odologies and GCM inputs as those used by the1995 Impacts Assessment, observes that in 2100--compared with the total burden of ill health-the

The IPCC suggests that malaria cases may in-crease 10-16% by 2100, based upon studies whichhave focused upon changes in the potential rangesof anopheles mosquitos (52,53). Skeptical public

Potential comequences of increasing aunospheric CO2 concentration 201

public health problems due to climate changethrough increases in heat-stress mortality, tropicalvector-borne diseases, urban air pollution prob-lems, and decreases in cold-related illnesses areunlikely to be large (97).

Accelerated sea level rise

According to the IPCC, between 1990 and 2100,sea level may rise between 13 and 94 cm (5 to37 inches) due to anthropogenic climate change,with a best estimate of 49 cm (19 inches) by2100, with only about half that occurring by 2060(76). Notably, the IPCC furnishes a global esti-mate of about $1 billion per year to protect againsta sea level rise of 50 cm by 2100 (98) whichtranslates into less than 0.005% of the world'seconomic product (45).

DISCUSSION

productivity is probably due to CO2-induced climatechange, most of these improvements in climate-sensitive indicators of human well-being are dueto technological progress driven by market- andscience-based economic growth, technology, andtrade. Such progress has also reduced the vulnera-bility of the human enterprise to climate change(8, 16, 19). As a result, technological progress hashad a greater impact upon the climate-sensitivesectors than has climate change itself.

With respect to the future, the foregoing analysisof the IPCC's 1995 Impacts Assessment (summa-rized in Table 5) shows that at least until the mid-21 51

century, the effect of climate change upon the mostcritical climate-sensitive indicators will probably besmall compared to those due to other stressors suchas population growth, poverty, land conversion,habitat losses, and infectious and parasitic diseases(82, 30, 87, 86, 52, 76). By 2100, only the impact ofsea level rise (as estimated by the IPCC's 1995Assessment) may verge on becoming significant.Thus, over the next several decades, other environ-mental and public health problems plaguing theworld will probably be substantially larger-andmore critical-than climate change.

This conclusion is relatively robust unless theestimates of the impacts reported in the IPCC aresubstantially underestimated. But that seems un-likely for several reasons:1. The studies underlying the IPCC's Impact As-sessment generally do not adequately account fortechnological change and human adaptability.2. Recent analyses of agricultural and sea levelimpacts of climate change indicate that they couldbe less adverse than reported by the IPCC (80, 81,100, 101). Recent studies of mortality due to orassociated with extreme heat and cold continue tosuggest at least partial cancellation of effects glob-

ally (93-96).3. For some sectors, the IPCC's underlying impactstudies assumed, as noted, a greater climatic changethan that estimated by the IPCC's Science Assess-

ment, e.g., agriculture (45, 102).4. Empirical data on CO2 concentrations suggestthat carbon fertilization is real and probably alreadytaking place which, by itself, ought to moderate CO2growth rates, at least for a while (e.g., 29, 35);increase timber production, at least in managedforests; and help reduce loss of forest cover (16).

Over the last century or more, according to theIPCC, the globe has warmed 0.3-0.6 °C, perhapsdue to man's influence (e.g., 83). The foregoinganalysis of historical trends indicates that duringthat period, certain climate-sensitive biophysicalindicators-forest cover, biodiversity and sea level-have continued to deteriorate. But anthropo-genic warming has had very little to do with that.Current threats to forest cover and biodiversity arethe result of increased human demands for food,clothing, and shelter from a larger and richer pop-ulation, while sea level has risen mainly due tonatural warming. On the other hand, for otherclimate-sensitive indicators, matters have improvedsubstantially. Land is more productive (Fig. 1); theaverage person is better fed; infectious and parasiticdiseases have been reduced if not eliminated inmany areas; infant and child mortality are down;life expectancies are up (21); and while propertylosses (relative to wealth) due to various extremeweather-related conditions mayor may not beincreasing (Fig. 3 and 4), more significantly, deathsand death rates due to such phenomena have de-clined (Fig. 2). Hence, although the world mayhave warmed, by virtually any measure of humanwell-being, the average person's welfare has im-

proved markedly (99).Although some credit for increasing agricultural

202 M. Goklany

Table 5. Projected climate change impact V5. impacts of baseline (ie., other environmental) problem~

Impact/EffectClimate-SensitiveSector/Indicator Projection for Year Baseline, includes impacts of

environmental problems other thanclimate change

Impacts of climate change, on top of thebaseline

Agricultural Production must increase 83% over 1990 levels2060 for baseline;

>2100 for climate change (see text)

Global Forest Area 2050

2060

2100

2060

2100

decrease 25 to 30 (+) % relative to 1990

500 million

500 million

varies by location

varies by location

net global production would change-24% to + 1.1 %; but could substantiallyredistribute production from developing

to developed countries

reduced loss of global forest area

25 to 40 million additional cases

50 to 80 million additional cases

less than 25 cm (or 10 inches)

less than 50 cm (or 20 inches)

Malaria Incidence

Sea Level Rise

Sources: Rosenzweig and Parry (82); Reilly et aI. (30); Kirschbaum et aI (87); Solomon et al. (86); McMichael et al. (52); Warrick et al. (76)

5. Empirical data indicate that the atmosphericmethane growth rate, which had been increasingsince 1945, seems to have peaked in the early1980s and may stabilize in the next decade (103).Dlugokencky et al. (104) estimate that between 1984and 1996, the growth in atmospheric concentrationsof methane had slowed down by about 75%.6. Recent calculations of radiative forcing due togreenhouse gases suggest that the forcing used bythe IPCC's climate change projections may havebeen overestimated by a net 10% because an under-estimate of the forcing due to chlorofluorocarbonswas more than compensated by an overestimate ofthe CO2 forcing (105).7. Recent data indicates that the world's populationis growing less rapidly, which ought to somewhatreduce estimates of future impacts of cl imate changeand deforsetation. For instance, the InternationalInstitute for Applied Systems Analysis' 1996 centralestimate for the population in 2100 was 10.4 billion(106), against the 11.3 billion central estimate as-sumed in many of the IPCC's projections (78).

Thus, based on both historical trends and futureprojections of impacts, it seems that anthropogenicclimate change is not now or in the foreseeablefuture as urgent as other global environmental orpublic health problems. However, it may be arguedthat climate change on top of all the other environ-mental problems may be the straw which breaks thecamel's back-particularly with respect to forests,

ecosystems, and biodiversity. Thus, goes thisargument: immediate action must be taken to cur-tail GHG emissions.

There are two approaches to dealing with theproblem of the last straw, and neither has to bemutually-exclusive (46, 99). The first, more com-mon approach is to concentrate only on reducing oreliminating the size of the last straw. Anotherapproach would be to lighten the entire burdenbefore the last straw descends (46, 99). Withrespect to malaria, for instance, under the firstapproach-focusing on the last straw--one wouldattempt to eliminate the 50-80 million new cases in2100 by totally eliminating climate change; underthe second approach, one could try to reduce thetotal number of cases-whether it is 500 millionthis year or 550-580 million in 2100. This secondapproach is more comprehensive since it wouldreduce cumulative adverse impacts rather thanmerely a portion, and that, too, merely a small por-tion (Table 5). It would effectively strengthen theability of human and natural systems to adapt andcope with climate change as well as other currently,more urgent environmental stressors.

There are numerous advantages to the second

approach, i.e., enhancing adaptability by reducingvulnerability:1. Even a small reduction in the baseline (i.e., non-climate change-related) rate could provide great-er aggregate public health benefits than a large

Potential consequences of increasing aunospheric CO2 concentration 203

these sectors include agricultural production, foodsecurity, forest cover, ecosystems, and biodiversity.

Reconciling regional losers with regionalwinners

Another criticism of the conclusion that climatechange is not the globe's most urgent environmentalproblem is that its underlying rationale overempha-sizes net global impacts while ignoring the possibil-ity of severe dislocations that may occur in specificareas because of climate change. For instance,currently most developing nations have food defi-cits. These deficits may worsen in the future anddeteriorate even further if climate changes.

Today, developing countries import food fromdeveloped countries to make up their deficits. Ex-pansion of this trade would help developing countriescope with any additional shortfalls (whether due toclimate change or not). In fact, international tradecan help alleviate any geographically non-uniformeffect, regardless of its cause. But such trade is onlypossible if developing countries' economies produceand sell other goods which then can generate therevenues to purchase food grown elsewhere (16).Moreover, as noted below, bolstering economicgrowth will have many other benefits.

Increasing the resiliency of developingcountries

It is generally recognized that developing coun-tries are most vulnerable to climate change (8, 78,110). The fundamental reason for this is not thatclimate change will be greater in developing coun-tries, but poverty. Being poorer, developing coun-tries are less able to develop, acquire, and imple-ment technologies to adapt to or cope with anyhardship or misfortune (8, 16, 19).

Thus, poorer countries have lower crop yields(Fig. 5) and lower available food per capita (Fig. 6),which leads to higher rates of malnutrition andgreater susceptibility to infectious and parasiticdiseases (98). Hence, poorer countries have higherinfant mortality rates and lower life expectancies(Figs. 7 and 8). Moreover, because their land use isless efficient (Fig. 5), their forest cover continues todecline; whereas, by contrast, developed countriesare being reforested (34, 45). Lack of econom-ic growth also maintains conditions that are not

reduction in the additional number of cases due toclimate change. Assuming exponential growth inthe relative number of additional malaria cases dueto climate change, reducing the number of baselinemalaria cases an additional 0.2% per year betweennow and 2100 would more than compensate forany increases due to climate change.2. Resources employed to reduce the base ratewould provide substantial benefits to humanity de-cades before any significant benefits are realizedfrom limiting climate change.3. Given the uncertainties noted previously regard-ing impacts assessments, the benefits of reducingthe base rate are much more certain than thoserelated to limiting climate change.4. The lessons learned, technologies developed, andpublic health measures implemented to reduce thebase rate would themselves serve to limit additionalcases due to climate change when, and if, they occur.5. Reducing the base rate would serve as an insur-ance policy against adverse impacts of climatechange whether that change is due to anthropogenicor natural causes, or if it comes more rapidly than theIPCC's "best estimates." In effect, by reducing thebase rate today, one would also be helping to solvethe cumulative malaria problem of tomorrow, what-ever its cause.6. Because of the inertia of the climate system, it isunrealistic to think that future climate change couldbe completely eliminated even ifGHG emisions wereto be frozen immediately at today's level. Given theprogress in reducing GHG emissions in response tothe Kyoto protocol, such a freeze is most unlikely.Moreover, full adherence to the protocol wouldreduce projected temperature increase for 2100 byless than 10% (107-109). Thus, the first approachcan, at best, only be partially successful, and that too,for only a small portion of the malaria problem.7. The stated objective of the Framework Conven-tion on Climate Change is to prevent anthropogenicclimate change from becoming dangerous. But,however "dangerous" may be defined, it dependsupon societal and environmental adaptability. En-hancing adaptation would, therefore, increase thelevel at which GHG concentrations become danger-ous," potentially resulting in substantial savings inthe cost of controls (8).

Similar logic applies to the other climate-sensitivesectors where the problems are dominated by non-climate change-related factors. As Table 5 indicates,~

204 I. M. Goklany

resource sectors (i.e., agriculture and forestry). In1996, for instance, 55% of the developing world'spopulation was engaged in agriculture, compared to22% in the transition countries, and 5% in the rest ofthe developed world (20). Thus, economic growthought to reduce a country's economic vulnerability toclimate change (8, 19).

conducive to reducing population growth rates

voluntarily (Fig. 9) (16,19,46). Furthennore, pov-erty reduces the ability of nations to afford technolo-gies to limit climate change, such as more efficientpower plants-particularly those which entail ahigher initial cost (8, 19). Finally, poorer countriesare more dependent on their climate-sensitive natural

8,000

-ca

:E 6.000C)

.¥.-"C'i)

~4.000

~ 2,000<

0

21,000 28,0007,000 14,000

GDP/capitaa

Sources: Goklany (99) based on WRI (21).

Fig. 5. Cereal yields (CY), 1995.

4.53.3 3.6 3.9

Log (GDP/capita)4.22.7 3


Fig. 6. Daily food supplies (FS) per capita, 1995

Potential comequences of ilx:reasing aanospheric C~ coocenttation205

2.5

2

0.5

0

2.6 3 3.4 3.8

Log (GDP/capita)4.2 4.6


Fig. 7 Infantmortality(IM),1990-1995.

90-U)...IVQ)

:?;:;.c't::c-IV>-t)CIV-t)Q)Co)(Q)

Q)-:J

0

2.6 3 3.4 3.8

Log (GDP/capita)4.2 4.6


Fig. 8. Life expectancy, 1990-1995.

80

70

60

50

40

30

20

10

I. M. Goklany206

8 I I i

3.6LogW

4.1 4.62.6 3.1


Fig. 9. Total fertility rate (TFR) 1990-1995

Therefore, developing better institutions to fostereconomic growth, particularly in the poorer nations,will increase their resiliency and boost their abilityto cope with adversity in general, including thosedue to climate change. These institutions, whichalso undergird civil societies, include free markets,freer trade, secure property rights, and honest andpredictable bureaucracies and governments. Theseare, by and large, the very same institutions that alsostimulate technological change (8, 19).

Longer term perspective

pursuant to specified targets and final compliance,humanity can wait a couple of decades untilinitiation of control efforts without the impacts ofclimate change becoming excessive in comparisonwith those of other existing environmental andpublic health stressors. In the meantime, one mayargue, the cumulative benefit obtained from re-ducing overall vulnerability (i.e., vulnerability notonly to climate change but also to other environmen-tal stressors) through bolstering economic growth,technological change, and trade ought to be greater(Figs. 5-8; and Table 4) than any controls designedto address only climate change.

Moreover, one cannot get to the long-term with-out getting through the short- and medium-termssuccessfully. Consider the interrelated problemsof agriculture, food security, forest cover, andbiodiversity. Even if climate change were haltedcompletely, by 2050 more than 25% of the World'sforest area would be lost (Table 5). Not only wouldthis affect biodiversity, it would add to CO2 emis-sions by reducing carbon stores and removing sinks.In fact, the world would be undergoing the verysame catastrophe that the control of climate changehopes to avoid. The issue, therefore, is how to deal

It might also be argued that although climatechange may not be an urgent problem in the short-to medium-term, because of the inertia of the cli-mate and energy systems it may be too late to affectit by the time it becomes urgent. Therefore-runsthis argument-from a longer term perspective,climate change is a critical problem even today;thus, we must act now (111-114).

However, in light of the information presented inTable 5, various analyses on the timing of GHGcontrols (114-116) suggest that even with a 50-yearlag between initiation of climate change controls


with the critical problems of today and tomorrowwithout compromising-and, if possible, magnify-ing-our ability to deal with the important problemsof the day after.

With respect to deforestation and loss of bio-diversity, this issue can be addressed by attackingtheir major causes, namely, the conversion of landand water to satisfy the demands of a larger andwealthier population for food, fibre, and timber(8, 16, 18, 19,33). Some analysts contend that it is,therefore, necessary to decrease demand by reducingpopulations and/or modifying dietary and consump-tion habits (117). However, this is much easier saidthan done. In a democratic society where familiesare free to choose their own sizes and individualstheir diets and consumption patterns (as constrainedby the market), it is doubtful whether such recom-mendations can have a significant impact becausethey ignore human nature (16,33). An alternativeapproach-one, arguably, more likely to succeedbecause it accepts human nature for what itis-would be to increase in an environmentally-sound manner the productivity of land and water toproduce more food, timber, and other products per

acre of land or gallon of water diverted to humanuse. This would limit conversion of these naturalresources to human use while meeting humandemands adequately.

Figure 10 indicates for a hypothetical food de-mand case in 2050, how much additional land wouldhave to be converted to cropland between 1993 and2050 as a function of increases in the productivity ofthe food and agricultural sector (46). It assumes:that the global population will be 9.6 billion, consis-tent with the World Bank's 1994 "medium" projec-tion; that food supplies per capita would increase atthe historical 1969-71 to 1989-91 rate; and thatnew cropland will, on average, be just as productiveas cropland in 1993 (an optimistic assumption).Figure 10 also shows that if productivity does notincrease, cropland would have to increase by17.5 Tm2. Much of this would necessarily have tocome from forested areas (46). On the other hand,a 1 % per year increase in productivity would reduceadditional (net) cropland requirements to 3.7 Tm2,while a productivity increase of 1.5% per yearwould result in a net conversion of 0.8 Tm2 ofcropland to forests or other uses.

-aGO 0

0 0.2 0.4 0.8 0.1 1 1.2 1.4

Annual Productivity Incr9aSe (0/0)1.8

1..

z

Sourcc: Gokllny (16).

Fig. 10. Trade-off between productivity growth and habitat loss net conversion of land to cropland from 1993 to 2050.

Such increases in productivity are plausible giventhe numerous existing-but-unused opportunities toenhance productivity in an environmentally sound

manner, and that technological change has yet to runits course (33, 46). However, to capitalize on theseopportunities and to increase productivity, it is

208 M. GokIany

modified to grow faster in poor soils or adverseclimatic conditions; developing technologies tomore fully utilize felled trees and extend the usefullife of timber and wood products; improving exten-sion services to transfer technology; and researchingmethods to increase growth rates, and combat pestsand diseases without undue environmental effectsthrough broader, but more careful and targeted, useof various inputs (8, 33, 68, 99).

CONCLUSION: DEALING WITH THE URGENTWITHOUT IGNORING THE SERIOUS

essential to have economic growth in order togenerate the investments needed for: 1) research-ing, developing, acquiring, and operating moreproductive technologies; and 2) any additionalinfrastructure necessary for the efficient functioningof the food and agricultural sector. By 2050, anestimated $250 billion may have to be investedannually in developing countries' food and agricul-tural sectors (33).

One approach toward increasing productivity is toenhance efforts to develop crops and agriculturalpractices for adverse conditions that exist today butwould either persist or become more prevalentbecause of climate change. Thus, research anddevelopment (R&D) could emphasize developingand improving seeds and crops for dry and salineconditions; methods to mitigate soil erosion; andtechnologies to reduce pre- and post-harvest and enduse wastage and spoilage. Obviously, bioengineeredcrops can play an important, beneficial role inmeeting global food demands whether or not cli-mate changes (68). Similarly, developing institu-tions and economic instruments to use or reusewater more efficiently would help deal with currentand future water supply problems (16).

The resulting decrease in forest conversion due toenhanced food productivity would also reduce CO2emissions, and limit habitat loss and fragmentationwhich would otherwise add to the substantial exist-ing barriers to "natural" adaptation (via migrationand dispersion) of species if climate changes.Notably, Article II of the Framework Convention onClimate Change refers to allowing ecosystems toadapt naturally to climate change. Finally, in-creased agricultural productivity would lower thedemand for cropland which would reduce landprices, thereby decreasing the costs of purchasing orreserving land for conservation, carbon sequestra-tion, or both (33, 46).

Similar logic also applies to other spheres ofhuman activity that rely on land and water, such asforestry, habitation, and irrigation. For example,sustainably increasing the usable amount of forestproducts produced per acre of intensively-managedplantation forests would likewise reduce the amountof forestlands diverted to human use, and reducepressures on habitat, biodiversity, and carbon stocksand reservoirs. Measures which would increaseforest productivity regardless of any climate changeinclude boosting R & D on tree species genetically-

Global warming may be a serious problem in thelong run, but if the IPCC's impact assessment iseven qualitatively credible, it is not now-nor is itlikely to be in the next several decades-among theworld's list of critical environmental or healthproblems. In the unlikely event that further climatechange can be halted, that would do little or nothingin the foreseeable future to alleviate the very prob-lems which are proffered as reasons for controllingGHGs. Specifically, mortality and morbidity due toinfectious and parasitic diseases would be virtuallyunchanged; conversion of land and water to humanuses-the major, imminent threat to global forests,ecosystems, biodiversity, and loss of carbon sinksand stores-would continue almost unabated; andfood security will not be markedly advanced, if at all.

Yet, it is possible to deal with urgent short- andmedium-term public health and environmentalproblems, while also addressing the potentiallyserious longer-term problem of climate change.This can be done, for instance, by bolstering theinstitutions underpinning the mutually-reinforcingforces of economic growth, technological change,and trade. Strengthening them would:I. Address the root cause of the vulnerability of thepoorer nations to climate change as well as to other-and, at present, more critical-sources of adver-sity such as hunger, malnutrition, and infectious andparasitic diseases.2. Increase the productivity of land and waterdiverted to meet human needs for food, clothing,shelter, paper, and other material goods, whichwould reduce the loss of forests, habitat, bio-diversity, and carbon sinks and stores, whether ornot there is any climate change.3. Increase the voluntary movement of food andother goods to move from surplus to deficit areas, in

Potential consequeoces of increasing atmospheric CO2 concentration 209

8.

Goklany, I. M. Adaptation and climate change. Pre-sented at 1992 annual meeting of the American Associa-tion for the Advancement of Science, Chicago, February6-11; 1992. Available from Washington, DC: Depart-ment of the Interior; 1992.

order to alleviate shifts in competitive advantagewhether due to warming, or another factor.4. Increase the ability of developing nations toafford mitigation and adaptation technologies.

Adaptation can also be enhanced by developingand implementing technologies to address thoseenvironmental and societal problems which wouldbe further aggravated by climate change. Thiswould require, for instance, putting resources nowinto reducing malaria and increasing agriculturaland forest productivity in hot and dry conditions.This would bring greater and faster returns tohumanity, particularly in developing countries, thanwould focusing scarce resources on limiting climatechange. Successful adaptation will also raise thethresholds at which GHG concentrations couldbecome dangerous, which would reduce the cost ofcontrols worldwide. Therefore, although adapta-tion is not cost-free, there can be no optimalstrategy for addressing climate change which doesnot give adaptation its due.

9. Goklany, I. M. Factors affecting environmental impacts:The effects of technology on long term trends in cropland,air pollution and water-related diseases. Arnbio 25:497-503; 1996.

10. Frederick, K. M.; Goklany, I. M.; Rosenberg, N. J.Conclusions, remaining issues, and next steps. ClimaticChange 28:209-219; 1994.

11 Rogers, P. Assessing the socioeconomic consequences ofclimate change on water resources. Climatic Change28:179-208; 1994.

12. Oppenheimer, M. Global warming and the stability of theWest Antarctic ice sheet. Nature 393:325-332; 1998.

13, Kerr, R. A. Signs of past collapse beneath the Antarcticice. Science 281:17-19; 1998.

14. Rahmstorf, S. Risk of sea-change in the Atlantic. Nature388:825-826; 1997.

REFERENCES15. Stocker, T. F; Schmittner, A. Influence of CO2 emission

rates on the stability of the thermohaline circulation.Nature 388:862-865 ; 1997.Clinton, W. J. State of the Union Address, January 27,

1998. Available at http://www.pub.whitehouse.gov/uri-res/l2R?pdi://oma.eop.gov.us/1998/01/27/ll.text.l. 16. Goklany, I. M. Meeting global food needs: The environ-

mental trade-offs between increasing land conversion andland productivity. Technology 6:107-130; 1999.2. Clinton, W. J. State of the Union Address, January 20,

1999. Available at http://www.pub.whitehouse.gov/uri-res/I2R?pdi://oma.eop.gov.us/I999/1/20/1.text.l. 17. FAO (Food and Agricultural Organization). FAOSTAT

database, 1999. Available at http://apps.fao.org/.3. Woodwell, G. M. Exaggeration or underestimate. Nature

390:547; 1997. 18. Goklany, I. M.; Sprague, M. W. An alternative approachto sustainable development. Conserving forests, habitatand biological diversity by increasing the efficiency andproductivity of land utilization. Washington, DC: U.S.Department of the Interior; 1991.

4 Greenwire. Worldview-<:limate change II: Scientistsfear warming, February 5, 1998. Available throughsearch engine at http://nationaljournal.com/pubs/greenwire/extra/search.htm.

19. Goklany, I. M. Strategies to enhance adaptability:Technological change, sustainable growth and free trade.Climatic Change 30:427-449; 1995.

UNFCCC (United Nations Framework Convention onClimate Change). The Kyoto protocol to the UnitedNations framework convention on climate change, 1999.Available at http://www.unfccc.de/resource/docs/convkp/

kpeng.html.

5

20. FAO (Food and Agricultural Organization). FAOSTATdatabase, 1998. Available at http://apps.fao.org/.

Meadows, D. H. et al. The limits to growth: A report forthe Club of Rome's project on the predicament of man-kind. Second ed. New York: Universe Books; 1974.

WRI (World Resources Institute). World resources 1998-99 database. Washington, DC: WRI; 1998.

6. 21

22. FAO (Food and Agricultural Organization). The state offood and agriculture 9. Rome: FAO; 1996.7. CEQ (Council on Environmental Quality). The global

2000 report to the President: Entering the twenty-firstcentury. Washington, DC: U.S. Government PrintingOffice; 1980.

23. WHO (World Health Organization). World health report1999. Geneva: WHO; 1999.

210 M. Gok.lany

24. Kendall, H. W.; Pimentel, D. Constraints on the expan-sion of the global food supply. Ambio 23:198-205;1998.

39. NCDC (National Climatic Data Center). 1996 Annualsummaries. Asheville, NC: National Climatic DataCenter; 1997.

25. Mann, M. E.; Bradley, R. S.; Hughes, M. K. Global-scaletemperature patterns and climate forcing over the past sixcenturies. Nature 392:779-787; 1998.

40. HIC (Hydrologic Information Center). Flood losses:Compilation of flood loss statistics, 1998. Available at

http://www.nws.noaa.gov/oh/hic/flood_stats/Flood_loss_time_series.htm.

26. Jones, P. D.; Parker, D. E.; Osborn, T. J.; Briffa, K. R.Global and hemispheric temperature anomalies-land andmarine instrumental records. In: Trends: A compendiumof data on global change. Oak Ridge, TN: Carbon Diox-ide Information Analysis Center, Oak Ridge NationalLaboratory; 1998.

41 SPC (Stonn Prediction Center). 1997 Tornado deathsby state, 1998. Available at http://www.spc.noaa.gov/archive/tornadoesldead97.gif.

42. Hebert, P. J.; Jarrell, J. D.; Mayfield, M. The deadliest,costliest, and most intense United States hurricanes of thiscentury (and other frequently requested hurricane facts).NOAA Technical Memorandum NWS TPC-]. Miami,FI: National Weather Service; 1997.

27. Oai, A.; Trenberth, K. E.; Karl, T. R. Global variationsin droughts and wet spells. Geophysical Research Letters25:3367-3370; 1998.

28. Nicholls, N. Increased Australian wheat yield due torecent climate trends. Nature 387:484-485; 1997.

43. NHC (National Hurricane Center). The 1997 Atlantichurricane season, preliminary reports, 1998. Available athnp://www.nhc.noaa.gov/1997text.html.29. Myneni, R. B. et al. Increased plant growth in the

northern high latitudes. Nature 386:698-702; 1997. 44. Bureau of Commerce. Historical statistics of the UnitedStates, colonial times to 1970. Washington, DC: Govern-ment Printing Office; 1975.30. Reilly, J. et aI. Agriculture in a changing climate:

Impacts and adaptations. In: Watson, R. et al., eds.Climate change 1995: Impacts, adaptations and mitiga-tion of climate change. Cambridge: Cambridge Univer-sity Press; 427-467; 1996.

45. Goklany, I. M. The importance of climate change com-pared to other global changes. Proc. of the secondinternational specialty conference: Global climate change:Science, policy, and mitigation/adaptation strategies,Crystal City, VA, October 13-16,1998. Sewickley, fA:Air & Waste Management Association; 1024-1041; 1998.

31 Wittwer, S. H. Food, climate and carbon dioxide: Theglobal environment and world food production. BocaRaton, FL: Lewis Publishers; 56-57; 1995.

46. Goklany, I. M. Richer is more resilient: Dealing withclimate change and more urgent environmental problems.In: Bailey, R., ed. Earth report 2000: The true state ofthe planet revisited. New York: McGraw-Hili; 1999.

32 Keeling, C.D.; Whorf, T.P. Atmospheric CO2 concentra-tions (ppmv) derived from in situ air samples collected atMauna Loa Observatory, Hawaii, 1998. Available athttp://cdiac.esd.oml.gov/ftp/ndpOO1r7/ndpOOlr7.dat.

47. Landsea, C. W. et al. Downward trends in the frequencyof intense Atlantic hurricanes during the past five de-cades. Geophysical Research Letters 23: 1697-1700;1996.

33. Goklany, I. M. Saving habitat and conserving bio-diversity on a crowded planet. BioScience 48:94 I -953:1998.

FAO (Food and Agricultural Organization). The state ofthe world's forests 1997. Rome: FAO; 1997.

34.48. Karl, T. R.; Knight, R. W. Secular trends ofprecipitation

amount, frequency, and intensity in the United States.Bulletin of the American Meteorological Society 79:231-241; 1998.

35. Tans, P. P.; White, J. W. C. The global carbon cycle: Inbalance, with a little help from the plants. Science281:183-184; 1998.

Lins, H. F.; Slack, J. R. Streamflow trends in the UnitedStates. Geophysical Research Letters 26:227-230; 1999.

49.Fan, S. et aI. A large terrestrial carbon sink in NorthAmerica implied by atmospheric and oceanic carbondioxide data and models. Science 282:442-446; 1998.

36.

50. BEA (Bureau of Economic Affairs). 15 Tangible wealthtables from the September 1997 "Survey of CurrentBusiness," 1998. Available at http://www.edstats.gov/findex20.html.

37. Tian, H. et al. Effect of interannual climate variabilityon carbon storage in amazonian ecosystems. Nature396:664-667; 1998.

51 Pielke, Jr., R. A.; Landsea, C. W. Normalized hurricanedamage in the United States: 1925-1995. Weather andForecasting 13:621-631; 1998.

38. Vincent. J. R.; Panayotou, T.276:55-57; 1997.

or distraction. Science

Potential consequences of increasing atmospheric CO2 concentration 211

52. McMichael, A. J. et al. Human population health. In:Watson, R. et al., eds. Climate change 1995: Impacts,adaptations and mitigation of climate change. Cam-bridge: Cambridge University Press; 561-584; 1996.

~8. Goklany, I. M. Applying the precautionary principle toDOT, global warming, and genetically modified crops.In: Morris, J., ed. Risk and the precautionary principle.Oxford, UK: Butterworth-Heinemann; 2000.

53. McMichael, A. J. et al., eds. Climate change and humanhealth. Geneva: World Health Organization; 1996.

69. Kilbourne, E. M. Cold environments. In: Noji, E. K., ed.The public health consequences of disasters. New York:Oxford University Press; 270-286; 1997.

54. ACSH (American Council on Science and Health).Global climate change and human health. New York:ACSH; 1997.

70. Kilbourne, E. M. Heat waves and hot environments. In:Noji, E. K., ed. The public health consequences ofdisasters. New York: Oxford University Press; 245-269;1997.

55. Reiter, P. Global wanning and mosquito-borne disease inUSA. Lancet 348:622; 1996.

71 Gaffen, D. J.; Ross, R. J. Increased summertime heatstress in the U.S. Nature 396: 529-530; 1998.

56. Bryan, J. H.; Foley, D. H.; Sutherst, R. W. Malariatransmission and climate change in Australia. Med. J.Aust. 164:345-347; 1996.

72. Goklany, I. M.; Straja, S. R. U.S. trends in crude deathrates due to extreme heat in cold ascribed to weather,1979-1997. Technology 7 (suppl.):165-173; 2000.

57. Taubes, G. Global wanning: Apocalypse not. Science278:1004-1006; 1997.

73.58. CDC (Centers for Disease Control and Prevention).WONDER database, 1999. Available at http://wonder.cdc.gov.

Porter, R., ed. The Cambridge illustrated history ofmedicine. New York: Cambridge University Press; 1996.

59. Howard, L. O. Economic loss to the people of the UnitedStates through insects that carry disease. NationalGeographic 20:735-749; 1909.

74, Murray, C. J. L.; Lopez, A. D. The global burden ofdisease. Geneva: World Health Organization; 1996.

60. Smillie, W. G. The period of great epidemics in theUnited States (1800-1875). In: Top, R. H., ed. Thehistory of american epidemiology. St. Louis, MO: C. V.Mosby; 52-73; 1952.

75 Nerem, R. S. Global mean sea level change: Correction.Science 275:1049-1053; 1997.

76. Warrick, R. A. et al. Changes in sea level. In: Houghton,J. T. et al., eds. Climate change 1995: The science ofclimate change. Cambridge: Cambridge University Press;359-405; 1996.

61 Rosenberg, H. M. et aI. Births and deaths: United States,1995. Monthly vital statistics report 45(3, supp. 2):31;1996.

77. McNeely, J. A. et al. Human influences in biodiversity.In: Heywood, V. H. et al., eds. Global biodiversityassessment. Cambridge: Cambridge University Press;755-757; 1995.

62 WRI (World Resources Institute). World resources1996-97. New York, NY: Oxford University Press; 1996.

63 WHO (World Health Organization). World health report1997. Geneva: WHO; 1997. 78. Watson, R. et al., eds. Climate Change 1995: Impacts,

Adaptations and Mitigation of Climate Change. Cam-bridge: Cambridge University Press; 1996.

64 Pinheiro, F. P.; Chuit, R. Emergence of dengue hemor-rhagic fever in the Americas. Infections in Medicine15(4):244-251; 1998.

79. IPCC (Intergovernmental Panel on Climate Change).Climate change: The IPCC impacts assessment. Can-berra: Australian Government Publishing Services; 1991.

Sleigh, A. C.; Liu, X. -L.; Jackson, S.; Li, P.; Shang,L. -Y. Resurgence of vivax malaria in Henan Province,China. Bulletin of the World Health Organization 76;1998.

65.

80. Mendelsohn, R. Climate-change damages. In: Nordhaus,W. D., ed. Economics and policy issues in climatechange. Washington, DC: Resources for the Future; 219-236; 1998.

66. Roberts, D. R. et al. DOT, global strategies, and amalaria control crisis in South America. EmergingInfectious Diseases 3:295-301; 1997.

81 Cantor, R.; Yohe, G. Economic analysis. In: Rayner, S.;Malone, E. L., eds. Human choices & climate change,vol. 3: Tools for policy analysis. Columbus, OH:Battelle Press; 1-103; 1998.

67. Besser, R. E. et al. Prevention of cholera transmission:rapid evaluation of the quality of municipal water inTrujillo. Peru. Bol Oficina San it Panam 119(3): 189-94;1995.

212 M. Goklany

82. Rosenzweig, C.; Parry, M. L. Potential impacts ofclimate change on world food supply. Nature 367:133-138; 1994.

later changes associated with respiratory mortality aftercold weather in South East England. J. Epidemiol.Comm. Health 51 :643-648, 1997.

83. Houghton, J. T. et al., eds., Climate change 1995: Thescience of climate change. Cambridge: CambridgeUniversity Press; 40; 1996.

95. Donaldson, G. C.; Keatinge, W. R. Mortality related tocold weather in elderly people in Southeast England,1979-94. Brit. Med. J. 315:1055-1056; 1997.

84. Schimel, D. et al. Radiative forcing of climate change.In: Houghton, J. T. et al., eds. Climate change 1995:The science of climate change. Cambridge: CambridgeUniversity Press; 83-85; 1996.

96. Donaldson, G. C. et al. Winter mortality and cold stressin Yekaterinburg, Russia: Interview survey. Brit. Med.J. 316:514-518; 1998.

97. Watson, R. et al. Summary for policymakers-theregional impacts of climate change: An Assessment ofVulnerability. New York, NY: Cambridge UniversityPress; 5; 1997.

85. UNPD (United Nations Population Division). Revisionof the world population estimates and projections, 1998.Available at http://www.popin.orgipopI998/.

86. Solomon, A. F. et al. Wood production under changingclimate and land use. In: Watson, R. et al., eds. Climatechange 1995: Impacts, adaptations and mitigation ofclimate change. Cambridge: Cambridge University Press;492-496; 1996.

98.

Pearce, D. W. et al. The social costs of climate change:Greenhouse damage and the benefits of control. In:Bruce, J. P. et aI., eds. Climate change 1995: Economicand social dimensions of climate change. New York, NY:Cambridge University Press; 191; 1996.

87. Kirschbaum, M. U. F. et al. Climate change impacts onforests. In: Watson, R. et al., eds. Climate change 1995:Impacts, adaptations and mitigation of climate change.Cambridge: Cambridge University Press; 95-129; 1996.

99. Goklany, I. M. The future of industrial society. Pre-sented at the international conference on industrialecology and sustainability, University of Technology ofTroyes, Troyes, France, September 22-25, 1999. Avail-able from Washington, DC: Department of the Interior;1999.

88. King, A .W.; Post, W. M.; Wullschleger, S. D. Thepotential response of terrestrial carbon storage to changesin climate and atmospheric CO2, Climatic Change35:199-227; 1997. 100. Schimmelpfennig, D. et al. Agricultural adaptation to

climate change: Issues of longrun sustainability. Wash-ington, DC: Economic Research Service, U.S. Depart-ment of Agriculture; 1996.

89 Cao, M.; Woodward, F. I. Dynamic responses ofterres-trial ecosystem carbon cycling to global climate change.Nature 393:249-252: 1998.

101. Titus, J. G.; Narayanan, V. The risk of sea level rise.Climatic Change 31:151-212; 1996.90. Gray, W. Past and future trends in U.S. hurricanes

and their destruction. Presented at Air & Waste Man-agement Association, 2"" international specialty con-ference, global climate change: Science, policy andmitigation/adaptation strategies, October 13-15, 1998.Sewick1ey, PA: Air & Waste Management Association;61-66; 1998.

102. Smith. J. B. Standardized estimates of climate changedamages for the United States. Climatic Change 32:313-326; 1996.

103. Etheridge, D. M. et al. Atmospheric methane between1000 A.D. and present: Evidence of anthropogenicemissions and climatic variability. J. Geophys. Res.103:15979-15993; 1998.

91 Henderson-Sellers, A. et al. Tropical cyclones and globalclimate change: A post-IPCC assessment. Bulletin of theAmerican Meteorological Society 79:19-38; 1998.

104. Dlugokencky, E. J. et al. Continuing decline in thegrowth rate of the atmospheric methane burden. Nature393:447-450; 1998.

92. Henderson-Sellers, A. Climate whispers: Media commu-nication about climate change. Climatic Change 40:421-456; 1998

105. Myhre, G.; Highwood, E. J.; Shine, K. P.; Stordal, F.New estimates of radiative forcing due to well mixedgreenhouse gases. Geophysical Research Letters 25 :2715-2718; 1998.

Kalkstein, L. S.; Greene, J. S. An evaluation of cli-mate/mortality relationships in large U.S. cities and thepossible impacts of climate change. EnvironmentalHealth Perspectives 105:84-93; 1997.

93.

106. Lutz, W., ed. IIASA Population Projection Results, 1998.Available at http://www.iiasa.ac.at'Research/POP/docs/

Population- Projections_Results.html.

94.

Donaldson, G. C.; Keatinge, W. R. Early increases inischaemic heart disease mortality dissociated from and


107. Wigley, T. M. L. The Kyoto protocol: COb CH4 and

climate implications. Geophysical Research Letters

25:2285-2288; 1998.

112. Azar, C.; Rodhe, H. Targets for stabilization of atmo-spheric CO2. Science 276:1818-1819; 1997.

113. Ramakrishna, K. The great debate on CO2 emissions.Nature 39:227-228; 1997.108. Masood, E. Kyoto agreement creates new agenda for

climate research. Nature 390:649-650; 1997. 114. Ha-Ouong, M.; Grubb, M. J.; Hourcade, J. -C. Influenceof socioeconomic inertia and uncertainty on optimal (sic)CO2-emission abatement. Nature 390:270-273; 1997.109. Malakoff, D. Thirty Kyotos needed to control warming.

Science 278:2048; 1997.115. Wigley, T. M. L. Implications of recent CO2 emission-

limitation proposals for stabilization of atmosphericconcentrations. Nature 390:267-270; 1997.

liD. IPCC (Intergovernmental Panel on Climate Change).Chapter 6: Resource use and management. In: Climatechange: The IPCC response strategies. Washington, DC:Island Press; 1991.

116. Wigley, T. M. L. et al. Economic and environmentalchoices in the stabilization of atmospheric CO2 concentra-tions. Nature 379:240-243; 1996.

Hoffert, M. I. et aI. Energy implications of future stabili-zation of atmospheric CO2. content. Nature 395:881-884; 1998.

III

117. Myers,N. Consumption: Challengetosustainabledevel-opment. Science 276:53-55: 1997.

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