Download 1072-9240/00 $2000 + .00 Technology, Vol. 7S, pp. 189-213,2000

1072-9240/00$2000 + .00
Technology,Vol. 7S,pp. 189-213,2000
Printed in the USA. All rights reserved
Copyright IQ 2000 Cognizant Communication Corporation
POTENTIAL CONSEQUENCES
OF INCREASING ATMOSPHERIC
CO2 CONCENTRATION
COMPARED
TO OTHER ENVIRONMENTAL
PROBLEMS
Indur M. Goklany
Vienna, VA
TS 9907-532M (Received16 June 1999;accepted14 April 2000)
This paper examinesthe validity of the assertionthat anthropogenicclimate changeis the overriding
environmentalconcernfacing the globe today. Examinationof recenttrends for someclimate-sensitive
indicators (e.g., global food security; U.S. deathsdue to storms and floods; global deathrates due to
infectiousand parasitic diseases;andbiomassin the northernforests)shows thatmattershaveimproved
notwithstandingany climate changeto date. For others (suchas global deforestationand sealevel rise).
recenttrends havecontinuedto worsen; but so far the contribution of any anthropogenicclimate change
to theseimpactsseemsto have beenrelatively minor. Next, basedlargely uponthe Intergovernmental
Panelon Climate Change's 1995ImpactAssessment.the paperdeterminesthat over the next several
decadesthe projected global impactsof climate changeuponfood security, deforestation,biodiversity,
and human health could be an order of magnitude smaller than those due to other stressorssuch as
population growth, poverty, land conversion, or baseline (i.e., non-climate change related)rates of
infectiousand parasiticdiseases. Therefore,eliminatinganthropogenicclimate change,evenif feasible,
would-for the next several decades-do little to reduce the much larger baseline rates of global
deforestation,biodiversity loss, and infectiousand parasitic diseases. Hence,climate change,while a
potentiallyserious long-termproblem. is nottoday-nor likely to be in the foreseeablefuture-as urgent
as other current environmentaland public healthproblems. The paper then proposesan integrated
approachto deal with today's urgentenvironmentalproblemswhile enhancingthe ability to addressthe
long term-problem of climate change.
INTRODUCTION
Many scientists and, perhaps more importantly,
policy makers claim that climate change is the
overriding environmental challenge facing the globe
today (1-4). This assertion is in no small way
responsible for the emphasis placed upon the Kyoto
protocol on emission reductions (5). This paper
examines whether this claim is supported by the
available information on the impacts of climate
change that may be occurring now and in the "foreseeable" future by comparing those impacts with the
impacts of other environmental problems. Such a
comparison would help in the development of a
rational approach to dealing with not only climate
change but other critical environmental and public
health problems facing the globe over the next few
generations.
189
I. M. Goklany
190
The paper will focus on the economic sectors and
environmentalconsequencesand indicators forwhich
long-termretrospective dataand future projections are
available. These sectors and indicators-agriculture
and food security; forests and biodiversity; human
health; hurricanes and other extreme weatherevents;
and sea level rise-are also thought to be the most
sensitive to climate change. For brevity, the paper
will refer to these as the climate-sensitive sectors or
indicators.
The paper's time horizon is the foreseeablefuture,
which it assumes is the middle of the twenty-first
century. Postmortems of several studies (e.g., 6, 7)
projecting future use of natural resources and the
resulting impacts have shown the difficulty of accurately projecting use and associatedimpacts evenone
or two decades-let alone a few generations-ahead;
mainly because the projections did not adequately
account for technological progress and adaptation
to any adverse social and economic circumstances
arising from the use or impact of the resources
(8-11). Also, because the paper limits itself to the
foreseeable future, it will not examine potentially
catastrophic consequencesof climate change which
are unlikely to occur, if at all, until a few centuries
have passed. These catastrophic consequencesinclude the rapid collapse of the West Antarctica Ice
Sheet, which could occur after about five to seven
centuries (12, 13), and the shutting down of the
"ocean conveyor belt" which warms Northern
Europe and contiguous Asia due to a termination in
the thermohaline circulation (14, 15).
CURRENT TRENDS IN THE CLIMATE
SENSITIVE SECTORS
Analysis of past trends in the impacts of various
climate-sensitive phenomena and in the ability of the
climate-sensitive sectorsto meethuman demandscan
help determine whether it is becoming harder to meet
those demands because of, or despite, any warming
that may have taken place so far. An understanding
of thesetrends can also instruct us as to the factors
which determine adaptation and vulnerability to
various climate-related challenges.
Agriculture and food security
Between 1900 and 1997, global population in-
creased 260% from 1.62 billion to 5.85 billion,
but cropland increased only 95% from 7.7 Tm2 to
15.1Tm2asindicatedinFig.1 (16, 17). The 165%gap
between the increases in population and in cropland
(equivalent to 12.8 Tm1 is the minimum amount of
habitat savedfrom conversion to cropland becauseof
increased productivity in the food and agricultural
sector. The 12.8 Tm2 estimate assumesthat despite
freezing technology at the 1900 level (16, 18, 19):
1. All new cropland would, on average, be as productive as existing cropland was in 1900. This may
be an optimistic assumption because, arguably, the
most productive croplands were probably already
under cultivation in 1900.
2. All cropland that was in existence in 1900 would
maintain its level of productivity at the 1900 level.
3. The penetration of any existing technology would
expand only to the extent necessary to ensure that
assumptions 1) and 2) are realized. This implies
that, at a minimum, inputs would probably increase
in proportion to the amount of total cropland.
4. Average global food supplies per capita would be
frozen at the marginal levels of 1900.
Absent the large (12.8 Tm1 reduction in land conversion, deforestation and loss of habitat-the major
global causesof the loss of biodiversity-would have
been worse than they already are (18, 19). Figure 1
shows that although the amount of cropland needed
to feed the average person has been reduced almost
by one half during this century (4,770 m2 per capita
in 1900 versus 2,580 in 1995), food is cheaper
and, consequently, the average person is better fed.
Between 1961-63and 1994-96, global per capita food
supplies increased19%(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 population
increased 45% between 1969-71 and 1990-92, the
absolute number of people suffering from chronic
undernourishment in developing nations decreased
from 917 million (or 35% of their population) to
839 million (or 21%) (22). These data indicate that
despite the increase in population, global vulnerability to famine and malnourishment has declined.
In turn, that helped improve the world's health
status by contributing to reduced infant and maternal mortality rates, and higher expected life
spans (23).
Poten1ialco~eoces
of iocreasinga~ric
191
CO} coocentration
6
0.6
0.5
0
...
u
0.5
84
0.4
'C
C
~
--0
!
~
'a
U
G
0.3
~3
g
~
;;
DJ
'a
==
:c
02
DJ
0.2 -s:
.!!.
G
0.
0
G
0.1
0,1
c
~
:c
a
0
1700
1750
1800
1850
'1900
1950
2000
Sources:Goklany(16,19); FAD (17).
Fig. 1. Cropland and croplandproductivity, 1700-1997.
Although the amount of cropland per capita has
never been lower, the fact that the average person is
better fed today is only possible because global
productivity in the food and agricultural sector is at
an all time high. This is in contrast to the contention that warming may reduce global agricultural
productivity through a combination of factors including more frequent floods, droughts and loss of
soil moisture, and pest and disease outbreaks (24)
--especially given Mann et al.'s (25) centuries long
reconstruction of temperature trends which suggests
that the earth today is the warmest it has been in the
last six centuries (26), and Dai et al.'s (27) analysis
indicating an increasing trend in the global combined areas of severe drought and severe moisture
surplus since the 1970s. So how can one explain
the historical increases in agricultural productivity
and improved food security at a time when the
climate is getting worse?
The three possible explanations for this divergence are as follows:
I. Perhaps the net effects of global warming at
current CO2 and temperature levels are not particularly detrimental to global agricultural productivity
or, more importantly, global food security. In fact,
there is some evidence that so far CO2-enhanced
warming may be contributing to increased agricul-
tural productivity. Nicholls (28) estimatedthat 3050% of the post-1950increasesin com yields in
Australia maybe due to higher minimum temperatures. In the far northernlatitudes,the active growing seasonseemsto havelengthenedby 12:i: 4 days
in the 1980sand plant growth has apparentlyaccelerated(29). In addition, numerouscontrolled field
experimentsshowthat increasingatmosphericCO2
concentrationsincreasescrop yields. The IntergovernmentalPanelon Climate Change (IPCC) 1995
ImpactAssessment
suggeststhat yields of C3crops
(i.e., the majority of crops) mayincreasean average
of 30% due to a doubling of CO2 (30). Wittwer
estimatesthat the increase in CO2concentrations
over the last two centuries may have increased
productionby as muchas 14%(31). Between1961
and 1996,globalcerealyields increased115%(20),
while CO2concentrationsincreasedonly 14%(32),
and annualglobal temperatureincreasedless than
0.3°C. (26). Thus, CO2-enhancedwarming is unlikely to explain more than a small portion of the
increasein global agricultural productivity.
2. The increasedglobal agricultural productivity
and global food security is due to technological
progress driven by the mutually-reinforcing, coevolving forces of economicgrowth, technological
change,andtrade(9, 16, 18, 19,33).
192
M. Goklany
3. Perhaps the most plausible explanation of all is
that both CO2-enhancedglobal warming and technological progress have contributed to reduced human
vulnerability to hunger and malnourishment, with
the latter being the major contributor.
much of it at the expenseof forests and woodlands(20).
Forest cover and biodiversity
Deaths and death rates: Long-term data on
V.S. fatalitiesdueto tornados,floods, lightning, and
North Atlantic hurricanesand cyclones hitting the
V.S. mainland from 1916-97, 1903-97, 1959-96,
and 1900-97,respectively,were obtainedfrom various groupswithin the National Oceanicand AtmosphericAdministration (NOAA) (39-43).
However,thereareseveraldiscrepanciesbetween
the flood fatalities datafrom NOAA's Hydrological
InformationCenter(HIC) and its National Climatic
Data Center(39), and both differ from data in the
Bureauof the Census' StatisticalAbstractsand the
Historical Statistics(44). Since HIC was supposedly the original source for the flood data for the
other groupsas well, it was decidedto use its data
set (40). However, in the earlier years, even the
HIC data set may be prone to error, possibly
undercountingfatalities (45). For instance,in 1911,
that data set shows0 fatalities; however,the New
York Timesindicates that there were at least 55
fatalities that flood year. Similarly, the Timesindicates at least 244 in 1928 and 42 in 1931 compared to 15 and 0, respectively, in the HIC data
set (45, 46). However, the corrected values may
themselvesbe lower bounds. Notably, the keeper
of the HIC's data setexpressesgreaterconfidence
in the data after the mid-1960s on fatalities and
mid-1950son property losses.
For the most recentnine-yearperiod for the various data series(1989-97 for tornados,floods, and
hurricanes;1988-96for lightning), averageannual
deaths for these extreme weatherevents declined
86.5,53.5,97.3and 46.5%,respectively,since their
Through the ages, human demand for land for
agriculture and-toamuch lesserextent-settlements
and infrastructure, has been the major reason for
the loss of forest cover and diversion of habitat
away from the rest of nature (9, 16, 19,33). Such
deforestation and habitat conversion, in turn, is
responsible for much of the presumed threat to
global biodiversity. Between 1980 and 1995, global
population increased 28% (33). To meet the additional food demand, net agricultural land increased
by about 4% or 2.0 Tm2 (including 0.8 Tm2 of
cropland), and net forest cover decreased by about
1.7 Tm2 (34). In the developing countries, net
forest cover declined about 1.9 Tm2. By contrast,
forest cover increased by about 0.2 Tm2 in the
developed countries.
There is no evidence that anthropogenic global
warming has contributed to the loss of forest cover,
significantly or otherwise. In fact, for forests as
for agriculture, CO2-enhanced warming may have
increased productivity, thereby stimulating timber
growth and forest mass (29, 35-37). The trends
in developing and developed countries (taken as
groups) confirm the importance of economic growth
and technological progress in limiting deforestation
(34, 38). Forest cover is declining in developing
countries largely because their increases in agricultural and forest productivity lag behind the demands of their growing populations for food and
other products. Meanwhile, developed countries
are being reforested because-despite diversion
of land for urbanization and infrastructure projects
-productivity
in the agricultural and forestry sectors is growing faster than the increase in demands
for food and timber. Without science-based and
market-driven increases in food and agricultural
productivity, global deforestation would have been
greater. Thus, between 1980 and 1995, at least an
additional 12.3 Tm2 of agricultural land (including
4.0 Tm2 of cropland) would have been needed,
Mortality and property loss due tc~storms,
floods and other extreme weather events
nine-year averages peaked in 1917-25, 1969-77,
1900-08,and 1959-67,respectively(45, 46). The
declines in death rates (measured as deaths per
million population) are even more dramatic (45).
For the latest nine-year periods, death rates are
94.3, 70.9, 99.2 and 60.7% below the 1917-25,
1913-21,1900-08,
and 1959-67peaksfor tornados,
floods, hurricanes, and lightning as indicated in
Fig. 2 (45,46).
193
Potential consequencesof increasing atmospheric CO2 concentration
(deatb,permiUioopopolotioo,
9-y..r mo.iqa.erac... 1900-1997)
3.5
14
3
12
~
+
+
10
~2.5
.
~
.
i
..i 2
8
~
~
.
Co
c
'0
6
S 1.5
~
c
~
Ii
=
~
...
=
;:
~
~
!
.
c
~
n
4
1
...
.a
i
i
~O.5
!
~
'
t
i
!I'\~'-\i
0
I
~,I
2
II
i\!"-..,,t
""
,i
, ,.-.',
."r'
~
I
,
I',_.~.-,.,.,-,_,:,_-,-,-,- - 0
1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000
Source: GokIany (45).
Fig. 2. Deathratesdueto tornados,floods, lightning, andhurricanes.
While a portion of the declines in deathsand
deathrates for hurricanes may be due to a reduction in the number and wind speedsof violent
Atlantic hurricanessince the 1940s(47), a portion
of the credit is perhaps also due to technologyTable
Type of Event
Tornados
Resultsof curve fitting analysesfor deathsand deathratesdue to extremeweatherevents.
Years,no. of observations
(obs), period
Equationsfitting the data
r
1916-97
DR = 2.484 -0.0341 1
Log DR = 0.395 -0.01541
0.563
82 annualobs.
t=lt082
Floods
1903-97
19 non-overlapping
5-yr periods,
T = I to 19
Hurricanes
Lightning
basedadaptation(46).
The declinesin deaths(D) [and deathrates (DR)
per million populationper year] canbe fitted using
curve-fitting modelsthat vary linearly with time (t)
for D or log D [or DR or log DR]. (Table 1)
1900-97
14 non-overlapping
7-yr periods,
T = I to 14
1959-96
38 annualobs
0.367
D = 289.3 -3.401t
Log D = 2.395 -O.OI00t
0.269
DR = 0.859 -0.0219 T
Log DR = -0.176. 0.0089T
0.094
0.354
0.037
0.630
p for the slope
<0.001
<0.001
<0.001
<0.001
>0.1
>0.1
D=148.7-3.541T
Log D = 2.180 -0.0136T
0.613
<0.001
<0.001
DR = 5.514 -0.5141T
Log DR = 0.640 -0.1357 T
0.281
0.702
<0.05
<0.001
D = 456.2 -40.07T
Log D = 2.519 -O.0960T
0.299
0.549
<0.05
<0.005
DR = 0.686 -0.0137t
Log DR = -0.143 -0.0140l
0.639
0.749
<0.001
<0.001
0=127.6-1.981t
LogO=2.IIO-O.OO94t
0.507
0.576
<0.001
<0.001
t = 1 to 38
-10
194
I. M. Goklany
With respectto floods, according to Karl and
Knight (48) the intensity of heavy and extreme
precipitation events(defined as daily precipitation
eventsexceeding2 inches or 50.8 mm) apparently
hasincreasedfor the U.S. since1910which, all else
being equal, ought to increasethe frequencyand
intensity of floods and the risk of fatalities due to
floods. On the otherhand,the Lins and Slack(49)
analysisof streamflowdatafrom 1914onward for
relatively undisturbedwatershedsshowsthatwhile
there may be an increasein the dischargesdue to
lower and middle streamflowregimes,there seems
to be no generalupwardtrend in the highestflows
due to hydrological eventsalone-suggesting that
the likelihood of floods due to weatheror climate
mayhave actuallydeclined. Regardlessof whether
frequencyand intensity of flooding may have increasedor decreased,what is more important is
that fatalities as well as deathrateshave declined.
(Fig. 2) It is likely that the bulk of thesedecreases,
as well as for other extremeevents, is due to increasedwealth and new technologieswhich have
~
enabled people to benefit from adaptation measuressuchasmorereliable forecasts;early warning
systems;elaborate evacuationplans; more robust
constructionof housesand infrastructure;an extensive transportationnetwork; andthe constantdrumbeat of television and radio weathermenonce a
stormregisterson their radar screens.
Property losses: One might expectthat while a
wealthier societymaytake extra effort to limit loss
of life, it may be less concerned about property
losses. A wealthier society is also likely to have
more property at risk. Moreover, if the interpretation by Karl and Knight of trends relatedto floods
in the U.S. are more accuratethan that of Lins and
Slack, the frequencyand intensity of floods in the
U.S. may have increased. Figure 3 shows that at
first blush, despitewide year-to-yearfluctuations,
the overall trend between1903and 1997 for property losses due to U.S. floods (adjusted to real
dollars using the construction cost index) seems
upward(45).
20
0.28
15
0.24
10
0.2
a
..
..
--c
~
=
~
~
~
.~
5
0.16 :
0
0.12 to~
~
...
0
~
.E
.
~
~
:
...
;.
0.08
-5
0.04
0
-15
1900
1920
.Wealth
1940
1960
1980
2000
measured as fixed reproducible tangible assets.
SaIIt:r::~y
(45).
Fig. 3. Propertylossesdueto floods, 1903-1997.
However, if property lossesdue to floods are
estimatedas a percentof the nation's wealth measuredas fixed tangible reproducibleassets(exclud-
ing land values) using data from the Bureau of
Economic Affairs (50) for 1925-1996-a better
indicator of the amount of property at risk-then the
Potentialco~elx:eS
of iocreasinga~ric
Caz coocenn-ation
195
overall direction of the trend between 1925 (the
first year for which suchwealth dataare available)
and 1997 (51) is unclear. (Fig. 3) Curve-fitting
modelsutilizing property loss rate (LR) specified
in tenDsof percentof wealth, give poorerfits than
thoseutilizing real dollars. (Table 2) In this analysis, wealth for 1997was basedupon an extrapolation for the previousthreeyears(45).
Table2. Resultsof curve fitting analysesfor propertylossesdueto floods.
r
Curve fitting equations
Period,
Property Loss, in terms of:
p fi)f the slope
no. of observations
LR= 1.183+0.1732T
Log LR = 0.1207+ 0.0257 T
0.283
nineteen5-yr periods
1903-97
0.240
<0.02
<0.05
Billions of Real (1997) $
1926-97
eight9-yr periods
LR=17.11+2.900T
Log LR = 0.3055+ 0.0423T
0.373
0.358
>0.1
>0.1
% of wealth
1926-97
eight 9-yr periods
LR = 0.2829 -0.0135 T
Log LR = -1.525 -0.0242 T
0.136
0.140
>0.3
>0.3
Billions of Real (1997) S
warmerworld has beenraised as one of the major
concernsregardinganthropogenicclimate change.
Some fear that vectors such as the anopheles
mosquito--the carrier of malaria--could become
more widespreadwith warming since a changein
climate could alter the range and abundanceof
species(52, 53). However, this has beendisputed
on the basisthat global warming would not necessarily expand-nor is it the major determinant
of-the range of all vectors (54-57). Today the
Similarly, any upward trend in property losses
due to hurricanes in terms of real dollars between
1900-97 is obscured if losses are measured in
terms of percent of wealth as reflected in Fig. 4
and Table 3. (45; seealso, 51)
Infectious and parasitic diseases,
health impacts
and other
The potentialspreadof vectorbornediseasesin a
40
0.35
30
0.3
0.25
~
.. 20
:
:
- 10
..
..
0.2 :
0
;
a
:E
!"'
~
-.
0
0.15
0
oS
~
; -10
'
~
'f
:I
,,
,!of
,
!:
-20
::!
::
I
I
1900
1920
.
.0
1940
1960
1980
.Wealth measuredas fIXed reproducible tangible assets
S~e
0.05
I::
"
...'
-30
0.1
"
"
.,
Goklany(45)
Fig. 4. Hurricane property losses, 1900-1997.
.
~
...
i
' i
.:...i i '.'
~
..
~
[
2000
M. Goklany
196
Table 3 Resultsof curve fining analysesfor property lossesdue to hurricanes.
Property Loss, in terms of:
r
p for the slope
LR = -825.0 + 283.37T
LogLR= 1.916+0.1223T
0.604
0.826
<0.001
<0.001
LR = -623.9 + 518.39T
Log LR = 2.428+ 0.1415T
0.553
<0.05
0.716
<0.01
LR = 0.0087 -0.0011 T
Log LR = -2.0389 + 0.0277 T
0.152
0.082
>0.3
>0.3
Period,
no. of observations
Curve fitting equations
1903-97
Billions of Real (1997) $
fourteen7-yr periods
1926-97
Billions of Real (1997) $
eight 9-yr periods
% of wealth
1926-97
eight 9-yr periods
prevalence of these diseaseshas less to do with their
potential rangesthan with the public health measures
taken to deal with the vectors and the diseasesthey
spread. For instance, in the last century, malaria,
cholera, and other diarrheal and parasitic diseases
were prevalent around the world-including
the
United States and Western Europe-but today they
are problems only in countries where the necessary
public health measuresare unaffordable or have been
compromised (58,59). For instance, mainly because
of cholera, yellow fever, typhoid, and various diarrhoeal and gastrointestinal diseases,the mean crude
death rate (CDR) in New Orleans for a 30-year
period between 1830 and 1859 was 60,000 per
million (60). By comparison, in 1990-1995, it was
44,600 per million for Rwanda-the nation with the
highest 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, and
all forms of dysentery was 1,860 per million population (9). Today, due to a host of public health
measures,these diseases barely show up in current
statistics-accounting for a death rate of less than
5 per million (61).
Better nutrition, advancesin-and increasedavailability of-medical and public health technology,
and greater investments in public health programs
and infrastructure helped reduce infectious and
parasitic diseases worldwide-particularly
among
the young in developing countries. As a result,
crude global deathrates dropped from 19.8 per 1000
population in 1950-55 to 9.3 in 1990-95, helping
push global life expectancy at birth from 46.4 to
64.7 years (62). These improvements would have
been unlikely, if not impossible, without: I) the
transfer of scientific information and technologies
generated in the richer nations; and 2) the wealth
generated by economic growth which made those
technologies affordable (9, 33). Table 4 shows,
for a sampling of countries, how various public
and environmental health indicators improve with
wealth (46).
Table 4. Improvement in public and environmental health status with wealth for selected countries
Child mortality
Country
rate, 1995
(per 1000)
Accessto safe
water, 1994
(% of population)
Accessto adequate
sanitation,1994
(% of population)
Foodsuppliesper Life expectancyat GNP per
capita, 1994
birth, 1990-95
capita 1993
(Kcal/day)
(years)
(US $)
Sweden
6
100
100
3,239
78.2
24,740
Chile
17
96
71
2,755
73.8
3,170
66.3
850
Philippines
48
84
75
2,393
Ghana
113
56
42
2,585
56.5
430
240
<200
Guinea-Bissau
207
57
20
2,443
435
Afghanistan
251
10
8
1,670t
43.5
t 1990-92average.
Source: Goklany (46)
197
Potentialconsequences
of increasingatmosphericCO2concentration
Despitetheseimprovements,poorsanitation,unavailability of safe water, and indoor air pollution
are still among the major causesof higher mortalities and lower life expectanciesin developing
countries. An estimated2.9 billion people lack
adequatesanitationand1.1 billion haveno accessto
safewater in developingcountries.Thesedeficiencies are largely responsiblefor about 2.5 million
deathsdue to diarrhoealdiseases(in 1996). According to the World HealthOrganization,another
3 million prematuredeaths-mainly in developing
countries-were causedby air pollution globally,
of which 2.8 million deathswere due to indoor air
pollution (63). In addition, malaria caused an
estimated 1.5-2.7 million deaths in 1996, almost
exclusively in the developingcountries. It hasbeen
suggestedthat climatechangemaybe a factor in the
recentresurgencesin vector-bornediseases(52,53).
Resurgencesinclude malaria in Henan Province
(China); malaria and denguein the Americas; and
cholerain PeruandRwanda.However,increasesin
drug resistance;increasedurbanizationwhich can
lead to unsanitary conditions and facilitates the
spread of infectious diseases;premature discontinuation of control measuressuchas indoor spraying and use of impregnatedmosquito nets; and
faltering mosquito control and public health measures(e.g., reduction in DDT usageand chlorination) aggravatedby poor nutrition seemto be more
likely causes(57, 64-68).
Finally, althoughextremetemperaturesposelesser public healthproblemsthan infectious and parasitic diseases,they are knownto causedeaths(52,
53,69,70). GaffenandRoss(71) havereportedthat
between1949and 1995the frequencyof "extreme
heatstressevents" hasincreasedfor the U.S. They
suggestthat continuationof this trend could pose
public health problems in the future. However,
analysisby Goklanyand Straja(72) of deathcertificatedata from the Centersfor DiseaseControl and
Prevention(73), shows no upward trends in U.S.
CDRs due to excessive heat and excessivecold
between1979 and 1997, despitethe aging of the
populationwhich, if all else is equal, oughtto have
increasedrisks of deathdue to either.
Notably, deathsand deathratesin the U.S. during
the 1979-1997period due to extremecold exceed
thosedue to extremeheat. During that period there
were cumulatively 13,319and 6,693 deathsattrib-~
uted in deathcertificates to extreme cold and extremeheat,respectively(73). However, it doesnot
necessarilyfollow that warming would reduce net
mortality. This is becauseof two competingphenomenanot captured in the death certificate data
(53,69, 70). First, excessdeaths(i.e., deathsabove
a background level in the absenceof an extreme
event,adjustedfor the period of the year) due to all
causes(e.g.,strokesor heartdisease)on averagego
up more due to extreme heat than due to extreme
cold events. This is true even if one considersthat
the deathrate drops below the background level
after the extreme event has ended, and that such
drops (like the increases)are more pronouncedfor
extremeheatevents. Overall, there are manymore
deathsduringthe winter monthsthan in the summer
months. A proper evaluation of the net effect of
any warming on mortality ought to considerthese
factors-as well as possiblechangesin background
death rates-within a framework which considers adaptationand uses "years of life lost" and
"disability-adjustedlife yearslost" becausemortality ratesdueto both extremecold and extremeheat
eventsarehigher amongthe agedandthose already
susceptible(74). While this is outsidethe scopeof
this paper,one oughtto expectsomecancellationof
mortality effectsdue to more heatwavesand fewer
cold onesbecauseof climate change(53, 69, 70).
Accelerated
sea level rise
A major concern related to global warming is
that it could accelerate the rate at which sea level
has been rising for millennia. Preliminary results
from the TOPEX/POSEIDON satellite observations
from 1993-1996 are consistent with the historical
tide gauge record, which shows mean sea level
rising at a rate of about 18 :!: 1 cm (about 8 inches)
over the last 100 years (75, 76). While it is not
known what fraction, if any, of that might be due
to any anthropogenic warming, it is worth noting
that the IPCC's Science Assessment notes that
there is no detectable acceleration of sea level rise
over the last century (76). Suffice it to say, so far
any accelerated sea level rise due to man-made
warming is unlikely to have caused anything other
than a minor impact on human or natural systems
compared to other environmental stressors such as
development of coastlines, conversion of lands for
198
aquaculture,drainage for other humanland uses,
sedimentdiversion due to dam constructionupriver, construction of seawalls, and subsidence
owing to water, oil and gas extraction(77).
FUTURE IMPACTS OF WARMING RELATIVE
TO THE BASELINE
There are numerous reasons to be skeptical of the
studies reported in the IPCC's 1995 assessmentof
the impacts of climate change (78). This is because
projections of future impacts are basedon a series of
model calculations with each succeeding model
using, as its inputs, increasingly uncertain outputs of
the previous model (8, 78, 79). First, future emissions of greenhouse gases (GHGs) have to be
modeled using uncertain projections of future
population, economic conditions, energyusage,land
use, and land cover. These emissions are themselves sensitive to climatic conditions and atmospheric concentrations. Next, these emissions have
to be converted into each GHG's atmospheric
concentration. These concentrations then have to
be used to determine future radiation forcing which
is used (ideally) by coupled atmospheric-ocean
models to project climatic changes (such as changes
in seasonaltemperatures and precipitation; seasonal
highs and lows; and changes in diurnal variability).
Moreover, these climatic changes should be estimated at relatively fine geographical scales because the impacts of climate change are locationspecific (8), but the finer the geographic scale, the
more uncertain the results.
These uncertain climatic changes then serve as
inputs to simplified and often inadequate models
which project location-specific biophysical changes
(e.g., crop or timber yields). Next, depending on the
human or natural system under consideration, the
outputs of these biophysical models may have to
be fed into additional models to calculate impacts
on those systems. For example, estimates of crop
yields at various locations should serve as inputs for
national and global models of the agricultural
system 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 are
probably even more uncertain than estimates of the
globally-averaged temperature and/or precipitation.
M. Goklany
Moreover, net global impacts are also uncertain
because they are an aggregation of the various
location-specific impacts, although there may be
some cancellation of errors. Nonetheless, the uncertainties are large enough that one cannot be
confident either of the magnitude or, in many cases,
even the direction of impacts, i.e., whether the net
impacts are positive or negative. This is true not
only at any specific geographic location, but also at
the global scale.
Beyond these uncertainties, there are major
sources of systematic upward biases. These studies
do not fully or adequately account for technological
progress and adaptation (8-11, 79-81) which not
only overestimates the potential negative impacts
but also underestimates the potential gains from
harnessing positive aspects of global warming.
Figures 1 and 2, as well as the virtual elimination of
malaria, cholera, and other infectious and parasitic
diseases in the richer countries, for instance, show
that while adaptations may be difficult-if
not
impossible--to model in advance of their occurrence, they are, nonetheless, real and quite substantial. The above-noted trends also show that for
these climate-sensitive sectors and indicators over
the last century (or so), adaptations have so far more
than offset any increases in negative impacts due to
any climate change. While failure to fully account
for adaptations significantly simplifies the mechanics of estimating "impacts," it also inflates purported
impacts. At best, that could provide misleading
information to policymakers; or, at worst, that could
skew societal priorities, unless users of such impacts
analyses are fully aware not only of their shortcomings, but also their implications. Yet another reason
for a bias toward overestimation of climate change
impacts is that the climate change scenarios used in
the studies relied upon by the IPCC 1995 Assessment, are sometimes more extreme than the IPCC's
"best estimate" scenarios.
Despite all these shortcomings, it is assumed in
the following that the IPCC's 1995 assessment
provides robust impact estimates.
Agriculture
Rosenzweigand Parry(82), an importantsource
of the IPCC's 1995ImpactsAssessmentchapteron
agriculture (30), estimatedthat the baselineglobal
199
Potentialconsequences
of increasingannOSpheric
CO2concentration
cereal production, i.e., production in the absence of
climate change, would rise 83% between 1990 and
2060. The baseline assumed a 2060 population of
10.3 billion and a 330% economic growth between
1980 and 2060. With climate change (but no mitigation policies, i.e., "business-as-usual" or BAU),
some production would shift from developing to
developed nations, thus increasingthe former's food
imports and vulnerability to chronic malnutrition
and hunger. However, assuming some adaptations,
the net change in global production would be relatively modest: the baseline production level would
be perturbed by -2.4% to + 1.1% in 2060 due to an
"equivalent doubling of CO2 concentrations."
The climate change scenarios utilized by
Rosenzweig and Parry effectively assumeda global
warming of 4.0°-5.2 °C, and a CO2concentration of
555 ppm (/lL/L) in 2060. By comparison, the IPCC
estimated a temperature range ofO. 7-1.7°C (with a
best estimate of 1.1-1.2°C) in 2060, and 0.8-4.5°C
in 2100 (with a best estimate of2.0°C) (82:40). It
would be a mistake to assume that although this
may overestimate the impacts in 2060, Rosenzweig
and Parry's estimates would nonetheless be a
reasonable upper bound of negative impacts for
2100 (or shortly thereafter) under BAU. First, by
the year 2100, the BAU CO2 concentrations would
be closer to 700 ppm (/lL/L), not 555 ppm (/lL/L)
(84). Thus, the beneficial direct CO2 effects would
be underestimated for 21 00, while the more negative
temperature- and evaporation-related effects would
not. This is a major problem with estimating impacts using the equilibrium climate based upon
equivalent CO2 doubling (8). Another reason why
the estimates of Rosenzweig and Parry would not
be valid for 2100 is that the capacity to adapt will
be greater in 2100 than in 2060 because of the
secular upward trend in technological change and
adaptability which, moreover, could be further
boosted by economic growth (8, 18, 19,33).
Nevertheless, despite the tendency for the
Rosenzweig and Parry approach to overestimate
negative impacts, the agricultural impacts due to
climate change (-2.4% to +1.l%)-and
their food
security consequences-will be lost in the "noise"
due to uncertainties in future levels of population
and economic output, either of which could be off
by :1::20%(or so) by 2060. For instance, the U.N.'s
1998 population projection for 2050 ranges from~
7.3 billion to 10.7billion with 8.9 billion beingthe
"most likely" estimate(85).
Clearly, at leasttill the middle of the nextcentury,
theeffectsof climatechangeuponfood securitywill
be relatively minor comparedto population and
economicgrowth. If the world's populationin 2060
cannotbe adequatelyfed, it will not be becauseof
climate change,but becauseof a largerpopulation,
insufficienteconomicgrowth,technologicalchange,
and trade. Moreover, if the questfor food security
leadsto massiveland conversionand consequent
habitat and biodiversity losses, that too will be
due to insufficient technologicalprogressduring a
period of high populationgrowth, ratherthan CO2enhancedwarming (8, 33).
Forests and biodiversity
The IPCC's Impact Assessment notes that one
computer model (BlOME) estimates that in the
absence of any additional human demand for land,
climate change alone (but excluding the largely
beneficial direct effects of CO2 on plant growth)
could, by 2050, actually increase global forest area
by + 1 to +9% over 1990 levels (86). Another model
(IMAGE) which essentially combines BlOME with
models that can account for human land use changes
and direct CO2 effects estimates that global forest
cover would decline by 25%, including a 47%
decline in tropical forests and a 10% increase in
boreal forests (86). Thus, even if global warming
were to be completely halted-and the notion that
warming could increase net global forest area was
totally discounted-then according to the models
used in the studies relied upon by the IPCC, massive
loss of forests should still be expected. Not surprisingly, the IPCC assessmentstates that land use
change is obviously the greatest threat to species
diversity of tropical forests (87). Once again, over
the next few decades,the impacts of climate change
are likely to be small compared to other non-climatic factors-namely, conversion of forests to relatively low yield agricultural uses in developing
nations due to increasing food demand, and reversion of agricultural lands to forests in the richer
nations due to increasing agricultural productivity
(33,34).
Climate change will also affect the rate of forest growth. CO2-enhanced warming may in fact
M. Goklany
200
accelerate wood production (e.g., 29, 35, 88, 89),
though some have suggested that much of the
increased growth could fall prey to pests, diseases,
and fires (86). Nevertheless, in more carefullymanaged forests, it ought to be possible to harness
technology to take advantage of the positive features
of CO2-enhanced wanning, while minimizing any
negative effects (33). For instance, King et al. (88)
estimate that due to equivalent CO2 doubling,
vegetative carbon could increase 12-16% owing to
climate change alone, and 31-37% if CO2fertilization is also considered. Recent evidence indicates
that the Northern latitudes may already have become more productive (29). Goklany, based upon
a population estimate of 9.6 billion in 2050, has
estimated that 8.15 Tm2 of plantations and agroforestry enterprises could meet the global demand
for wood in 2050 (33). Thus, even a 12% increase
in sustainable yield could reduce the amount of
forest land needed to meet human needs for forest
products in 2050 by 1.0 Tm2
Extreme weather
events
The IPCC's 1995 Science Assessmentnoted that
it was unable to state whether the frequencies or
intensities of extreme events such as hurricanes and
cyclones would change due to any anthropogenic
warming (83). As noted, empirical data suggests
that the number and intensity of hurricanes touching the United States may have declined since the
1940s. Gray (90) has suggested that we may be
entering a period of heightened hurricane activity,
but bases his claim not upon any global warming
but on the Atlantic Ocean thermohaline circulation. A recent post-IPCC assessmentconcluded
that while thermodynamic calculations predict a
10-20% increase in the maximum potential intensity due to a doubled CO2 climate, the known
omissions in these calculations all act to reduce
these increases (91, 92).
Infectious and parasitic
health impacts
diseases,
and other
The IPCC suggests that malaria cases may increase 10-16% by 2100, based upon studies which
have focused upon changes in the potential ranges
of anopheles mosquitos (52,53). Skeptical public
health specialists point out that such prognostications disregard historical fact that disease incidence
depends more upon public health measures (or lack
thereot) which is determined by a nation's economic
status and state-of-the-knowledge regarding the
disease, rather than the potential range or by climatic factors (55-57). This is exactly why the current
geographical distribution of incidences of a number
of infectious and parasitic diseases no longer correspondsto their historic potential ranges. The studies
underlying the IPCC report also assume essentially
no medical progress against these diseases over the
next 100 years, which seems quite unlikely, given
the experience of the past 100 years and the accelerating rate of the creation and spread of new knowledge and technology in the fields of medicine and
its supporting disciplines. Nevertheless, this study
relies on the 10-16% estimate, which translates into
about 50-80 million potential additional cases in
2100, compared to a baseline of 500 million in
the absence of climate change. Assuming that the
additional casesdue to climate change (expressed as
fractions of baseline cases) increase exponentially
with time, that implies a 5-8% increase by 2060.
Further, assuminga similar increase in all infectious
and parasitic diseases,the public health impact no
doubt would be significant since currently, globally
17 million people-including 1.5-2.7 million due to
malaria-die prematurely from such diseases each
year, with over 99% occurring in the developing
world (63). Nevertheless, until at least the middle
of the 2151century, such an increase would be less
than one-tenth of the global base rate in the absence
of climate change.
The potential impacts of extreme heat and cold
because of anthropogenic climate change are relatively modest by comparison with the potential
impacts of infectious and parasitic diseases. Moreover, globally there may be at least a partial cancellation of adverse effects due to increased incidences
of heat stress in some locations, e.g., North America, and reduced incidences of cold stress in others,
e.g., Europe (52, 53, 93-96).
Finally, the recent IPCC assessment of the regional vulnerabilities to the impacts of climate
change, which essentially employed similar methodologies and GCM inputs as those used by the
1995 Impacts Assessment, observes that in 2100
--compared with the total burden of ill health-the
Potentialcomequencesof increasingaunosphericCO2concentration
public health problems due to climate change
through increasesin heat-stressmortality, tropical
vector-borne diseases,urban air pollution problems, and decreasesin cold-related illnesses are
unlikely to be large(97).
Accelerated
sea level rise
According to the IPCC, between1990and 2100,
sea level may rise between 13 and 94 cm (5 to
37 inches) due to anthropogenicclimate change,
with a best estimate of 49 cm (19 inches) by
2100, with only abouthalf that occurring by 2060
(76). Notably, the IPCC furnishes a global estimate of about$1 billion peryear to protect against
a sea level rise of 50 cm by 2100 (98) which
translates into less than 0.005% of the world's
economic product (45).
DISCUSSION
Over the last century or more, according to the
IPCC, the globe has warmed 0.3-0.6 °C, perhaps
due to man's influence (e.g., 83). The foregoing
analysis of historical trends indicates that during
that period, certain climate-sensitive biophysical
indicators-forest cover, biodiversity and sea level
-have continued to deteriorate. But anthropogenic warming has had very little to do with that.
Current threats to forest cover and biodiversity are
the result of increased human demands for food,
clothing, and shelter from a larger and richer population, while sea level has risen mainly due to
natural warming. On the other hand, for other
climate-sensitive indicators, matters have improved
substantially. Land is more productive (Fig. 1); the
average person is better fed; infectious and parasitic
diseases have been reduced if not eliminated in
many areas; infant and child mortality are down;
life expectancies are up (21); and while property
losses (relative to wealth) due to various extreme
weather-related conditions mayor may not be
increasing (Fig. 3 and 4), more significantly, deaths
and death rates due to such phenomena have declined (Fig. 2). Hence, although the world may
have warmed, by virtually any measure of human
well-being, the average person's welfare has improved markedly (99).
Although some credit for increasing agricultural
201
productivity is probably due to CO2-induced climate
change, most of these improvements in climatesensitive indicators of human well-being are due
to technological progress driven by market- and
science-based economic growth, technology, and
trade. Such progress has also reduced the vulnerability of the human enterprise to climate change
(8, 16, 19). As a result, technological progress has
had a greater impact upon the climate-sensitive
sectors than has climate change itself.
With respect to the future, the foregoing analysis
of the IPCC's 1995 Impacts Assessment (summarized in Table 5) shows that at least until the mid-21 51
century, the effect of climate change upon the most
critical climate-sensitive indicators will probably be
small compared to those due to other stressors such
as population growth, poverty, land conversion,
habitat losses, and infectious and parasitic diseases
(82, 30, 87, 86, 52, 76). By 2100, only the impact of
sea level rise (as estimated by the IPCC's 1995
Assessment) may verge on becoming significant.
Thus, over the next several decades, other environmental and public health problems plaguing the
world will probably be substantially larger-and
more critical-than climate change.
This conclusion is relatively robust unless the
estimates of the impacts reported in the IPCC are
substantially underestimated. But that seems unlikely for several reasons:
1. The studies underlying the IPCC's Impact Assessmentgenerally do not adequately account for
technological change and human adaptability.
2. Recent analyses of agricultural and sea level
impacts of climate change indicate that they could
be less adverse than reported by the IPCC (80, 81,
100, 101). Recent studies of mortality due to or
associated with extreme heat and cold continue to
suggest at least partial cancellation of effects globally (93-96).
3. For some sectors, the IPCC's underlying impact
studies assumed,as noted, a greater climatic change
than that estimated by the IPCC's Science Assessment, e.g., agriculture (45, 102).
4. Empirical data on CO2 concentrations suggest
that carbon fertilization is real and probably already
taking place which, by itself, ought to moderate CO2
growth rates, at least for a while (e.g., 29, 35);
increase timber production, at least in managed
forests; and help reduce loss of forest cover (16).
202
M. Goklany
Table 5. Projected
climate
change impact
V5. impacts
of baseline
(ie., other environmental)
problem~
Impact/Effect
Climate-Sensitive
Sector/Indicator
Projectionfor Year
Baseline, includes impacts of
environmental problems other than
climate change
Impactsof climate change,on top of the
baseline
Agricultural Production
2060 for baseline;
>2100 for climate change(see text)
must increase83% over 1990levels
net global production would change
-24% to + 1.1%; but could substantially
redistribute production from developing
to developedcountries
Global Forest Area
2050
decrease25 to 30 (+) % relativeto 1990
reducedloss of global forest area
2060
500 million
25 to 40 million additionalcases
2100
500 million
50 to 80 million additionalcases
2060
variesby location
less than 25 cm (or 10 inches)
2100
variesby location
less than 50 cm (or 20 inches)
Malaria Incidence
SeaLevel 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 atmospheric
methane growth rate, which had been increasing
since 1945, seems to have peaked in the early
1980s and may stabilize in the next decade (103).
Dlugokencky et al. (104) estimate that between 1984
and 1996, the growth in atmospheric concentrations
of methane had slowed down by about 75%.
6. Recent calculations of radiative forcing due to
greenhouse gases suggest that the forcing used by
the IPCC's climate change projections may have
beenoverestimated by a net 10% becausean underestimate of the forcing due to chlorofluorocarbons
was more than compensated by an overestimate of
the CO2 forcing (105).
7. Recent data indicates that the world's population
is growing less rapidly, which ought to somewhat
reduce estimates of future impacts of cl imate change
and deforsetation. For instance, the International
Institute for Applied SystemsAnalysis' 1996 central
estimate for the population in 2100 was 10.4 billion
(106), against the 11.3 billion central estimate assumed in many of the IPCC's projections (78).
Thus, based on both historical trends and future
projections of impacts, it seemsthat anthropogenic
climate change is not now or in the foreseeable
future as urgent as other global environmental or
public health problems. However, it may be argued
that climate change on top of all the other environmental problems may be the straw which breaks the
camel's back-particularly with respect to forests,
ecosystems, and biodiversity.
Thus, goes this
argument: immediate action must be taken to curtail GHG emissions.
There are two approaches to dealing with the
problem of the last straw, and neither has to be
mutually-exclusive (46, 99). The first, more common approach is to concentrate only on reducing or
eliminating the size of the last straw. Another
approach would be to lighten the entire burden
before the last straw descends (46, 99). With
respect to malaria, for instance, under the first
approach-focusing on the last straw--one would
attempt to eliminate the 50-80 million new cases in
2100 by totally eliminating climate change; under
the second approach, one could try to reduce the
total number of cases-whether it is 500 million
this year or 550-580 million in 2100. This second
approach is more comprehensive since it would
reduce cumulative adverse impacts rather than
merely a portion, and that, too, merely a small portion (Table 5). It would effectively strengthen the
ability of human and natural systems to adapt and
cope 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 reducing
vulnerability:
1. Even a small reduction in the baseline (i.e., nonclimate change-related) rate could provide greater aggregate public health benefits than a large
Potential consequences of increasing aunospheric CO2 concentration
reduction in the additional number of cases due to
climate change. Assuming exponential growth in
the relative number of additional malaria casesdue
to climate change, reducing the number of baseline
malaria cases an additional 0.2% per year between
now and 2100 would more than compensate for
any increases due to climate change.
2. Resourcesemployed to reduce the base rate
203
these sectors include agricultural production, food
security, forest cover, ecosystems,and biodiversity.
Reconciling
winners
regional
losers
with
regional
Another criticism of the conclusion that climate
change is not the globe's most urgent environmental
problem is that its underlying rationale overemphasizes net global impacts while ignoring the possibility of severe dislocations that may occur in specific
areas because of climate change. For instance,
currently most developing nations have food deficits. These deficits may worsen in the future and
deteriorate even further if climate changes.
Today, developing countries import food from
developed countries to make up their deficits. Expansion of this trade would help developing countries
cope with any additional shortfalls (whether due to
climate change or not). In fact, international trade
can help alleviate any geographically non-uniform
effect, regardless of its cause. But such trade is only
possible if developing countries' economies produce
and sell other goods which then can generate the
revenues to purchase food grown elsewhere (16).
Moreover, as noted below, bolstering economic
growth will have many other benefits.
would provide substantial benefits to humanity decades before any significant benefits are realized
from limiting climate change.
3. Given the uncertainties noted previously regarding impacts assessments,the benefits of reducing
the base rate are much more certain than those
related to limiting climate change.
4. The lessonslearned, technologies developed, and
public health measures implemented to reduce the
base rate would themselves serve to limit additional
casesdue to climate change when, and if, they occur.
5. Reducing the base rate would serve as an insurance policy against adverse impacts of climate
change whether that change is due to anthropogenic
or natural causes, or if it comes more rapidly than the
IPCC's "best estimates." In effect, by reducing the
base rate today, one would also be helping to solve
the cumulative malaria problem of tomorrow, whatever its cause.
6. Because of the inertia of the climate system, it is
unrealistic to think that future climate change could
Increasing the resiliency of developing
be completely eliminated evenifGHG emisions were
countries
to be frozen immediately at today's level. Given the
progress in reducing GHG emissions in responseto
It is generally recognized that developing counthe Kyoto protocol, such a freeze is most unlikely.
tries are most vulnerable to climate change (8, 78,
110). The fundamental reason for this is not that
Moreover, full adherence to the protocol would
reduce projected temperature increase for 2100 by
climate change will be greater in developing counless than 10% (107-109). Thus, the first approach
tries, but poverty. Being poorer, developing countries are less able to develop, acquire, and implecan, at best, only be partially successful, and that too,
for only a small portion of the malaria problem.
ment technologies to adapt to or cope with any
hardship or misfortune (8, 16, 19).
7. The stated objective of the Framework Convention on Climate Change is to prevent anthropogenic
Thus, poorer countries have lower crop yields
(Fig. 5) and lower available food per capita (Fig. 6),
climate change from becoming dangerous. But,
however "dangerous" may be defined, it depends
which leads to higher rates of malnutrition and
greater susceptibility to infectious and parasitic
upon societal and environmental adaptability. Endiseases(98). Hence, poorer countries have higher
hancing adaptation would, therefore, increase the
infant mortality rates and lower life expectancies
level at which GHG concentrations become dangerous," potentially resulting in substantial savings in
(Figs. 7 and 8). Moreover, because their land use is
the cost of controls (8).
less efficient (Fig. 5), their forest cover continues to
Similar logic applies to the other climate-sensitive
decline; whereas, by contrast, developed countries
sectors where the problems are dominated by nonare being reforested (34, 45). Lack of economclimate change-related factors. As Table 5 indicates,~ ic growth also maintains conditions that are not
I. M. Goklany
204
conducive to reducing population growth rates
voluntarily (Fig. 9) (16,19,46). Furthennore, poverty reducesthe ability of nations to afford technologies to limit climate change, such as more efficient
power plants-particularly
those which entail a
higher initial cost (8, 19). Finally, poorer countries
are more dependent on their climate-sensitive natural
resourcesectors(i.e., agriculture and forestry). In
1996, for instance,55% of the developingworld's
populationwas engagedin agriculture,comparedto
22% in the transitioncountries,and 5% in the restof
the developedworld (20). Thus, economicgrowth
oughtto reduceacountry'seconomicvulnerabilityto
climatechange(8, 19).
8,000
-
ca
:E 6.000
C)
.¥.
"C
'i)
~4.000
~ 2,000
<
0
a
21,000
14,000
7,000
28,000
GDP/capita
Sources: Goklany (99) basedon WRI(21).
Fig. 5. Cerealyields (CY), 1995.
2.7
3
Sources: Goklany (99) basedon WRI(21).
3.3
3.6
3.9
Log (GDP/capita)
Fig. 6. Daily food supplies(FS) per capita,1995
4.2
4.5
Potential comequences of ilx:reasing aanospheric C~ coocenttation
205
2.5
2
0.5
0
2.6
3
3.4
Sources: Goklany (99) basedon WRI (21).
Fig. 7
-
3.8
4.2
4.6
Log (GDP/capita)
Infantmortality(IM),1990-1995.
90
U) 80
...
IV
Q)
70
:?;:;
.c
't: 60
-
:c
IV
50
>t)
C
IV
40
t)
Q)
30
)(
Q)
20
Co
-
Q)
:J 10
0
2.6
3
3.4
Sources: Goklany (99) basedon WRI (21).
3.8
Log (GDP/capita)
Fig. 8. Life expectancy,1990-1995.
4.2
4.6
I. M. Goklany
206
8
I
2.6
I
i
3.1
Sources: Goklany(99) basedon WRI (21).
3.6
4.1
4.6
LogW
Fig. 9. Total fertility rate (TFR) 1990-1995
Therefore,developingbetterinstitutionsto foster
economicgrowth, particularlyin the poorernations,
will increasetheir resiliencyand boosttheir ability
to cope with adversity in general, including those
due to climate change. Theseinstitutions, which
alsoundergird civil societies,include free markets,
freer trade, secureproperty rights, and honestand
predictablebureaucraciesand governments.These
are,by and large,the very sameinstitutionsthat also
stimulatetechnologicalchange(8, 19).
Longer term perspective
It might also be argued that although climate
changemay not be an urgentproblem in the shortto medium-term,becauseof the inertia of the climateand energysystemsit maybe too late to affect
it by the time it becomesurgent. Therefore-runs
this 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 informationpresentedin
Table 5, various analyseson the timing of GHG
controls (114-116)suggestthat evenwith a 50-year
lag between initiation of climate changecontrols
pursuant to specified targets and final compliance,
humanity can wait a couple of decades until
initiation of control efforts without the impacts of
climate change becoming excessive in comparison
with those of other existing environmental and
public health stressors. In the meantime, one may
argue, the cumulative benefit obtained from reducing overall vulnerability (i.e., vulnerability not
only to climate change but also to other environmental stressors) through bolstering economic growth,
technological change, and trade ought to be greater
(Figs. 5-8; and Table 4) than any controls designed
to address only climate change.
Moreover, one cannot get to the long-term without getting through the short- and medium-terms
successfully. Consider the interrelated problems
of agriculture, food security, forest cover, and
biodiversity. Even if climate change were halted
completely, by 2050 more than 25% of the World's
forest areawould be lost (Table 5). Not only would
this affect biodiversity, it would add to CO2 emissions by reducing carbon stores and removing sinks.
In fact, the world would be undergoing the very
samecatastrophe that the control of climate change
hopes to avoid. The issue, therefore, is how to deal
1..
Potential consequences of increasing atmospheric CO2 concentration
207
with the critical problems of today and tomorrow
without compromising-and, if possible, magnifying-our ability to deal with the important problems
of the day after.
With respect to deforestation and loss of biodiversity, this issue can be addressed by attacking
their major causes, namely, the conversion of land
and water to satisfy the demands of a larger and
wealthier population for food, fibre, and timber
(8, 16, 18, 19,33). Some analysts contend that it is,
therefore, necessaryto decreasedemand by reducing
populations and/or modifying dietary and consumption habits (117). However, this is much easier said
than done. In a democratic society where families
are free to choose their own sizes and individuals
their diets and consumption patterns (as constrained
by the market), it is doubtful whether such recommendations can have a significant impact because
they ignore human nature (16,33). An alternative
approach-one, arguably, more likely to succeed
because it accepts human nature for what it
is-would be to increase in an environmentallysound manner the productivity of land and water to
produce more food, timber, and other products per
acre of land or gallon of water diverted to human
use. This would limit conversion of these natural
resources to human use while meeting human
demands adequately.
Figure 10 indicates for a hypothetical food demand case in 2050, how much additional land would
have to be converted to cropland between 1993 and
2050 as a function of increases in the productivity of
the food and agricultural sector (46). It assumes:
that the global population will be 9.6 billion, consistent with the World Bank's 1994 "medium" projection; that food supplies per capita would increase at
the historical 1969-71 to 1989-91 rate; and that
new cropland will, on average, be just as productive
as cropland in 1993 (an optimistic assumption).
Figure 10 also shows that if productivity does not
increase, cropland would have to increase by
17.5 Tm2. Much of this would necessarily have to
come from forested areas (46). On the other hand,
a 1 % per year increase in productivity would reduce
additional (net) cropland requirements to 3.7 Tm2,
while a productivity increase of 1.5% per year
would result in a net conversion of 0.8 Tm2 of
cropland to forests or other uses.
-aGO
0
0
0.2
0.4
0.8
0.1
1
Annual Productivity
1.2
1.4
1.8
z
Incr9aSe (0/0)
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 given
the numerous existing-but-unused opportunities to
enhance productivity in an environmentally sound
manner, and that technological change has yet to run
its course (33, 46). However, to capitalize on these
opportunities and to increase productivity, it is
208
essential to have economic growth in order to
generate the investments needed for: 1) researching, developing, acquiring, and operating more
productive technologies; and 2) any additional
infrastructure necessaryfor the efficient functioning
of the food and agricultural sector. By 2050, an
estimated $250 billion may have to be invested
annually in developing countries' food and agricultural sectors (33).
One approach toward increasing productivity is to
enhance efforts to develop crops and agricultural
practices for adverse conditions that exist today but
M. GokIany
modified to grow faster in poor soils or adverse
climatic conditions; developing technologies to
more fully utilize felled treesand extendthe useful
life of timber and wood products; improvingextensionservicesto transfertechnology;andresearching
methodsto increasegrowth rates,and combatpests
and diseaseswithout undue environmentaleffects
throughbroader,but more careful andtargeted,use
of various inputs (8, 33, 68, 99).
CONCLUSION: DEALING WITH THE URGENT
WITHOUT IGNORING THE SERIOUS
would either persist or become more prevalent
because of climate change. Thus, research and
development (R&D) could emphasize developing
and improving seeds and crops for dry and saline
conditions; methods to mitigate soil erosion; and
technologies to reduce pre- and post-harvestand end
use wastage and spoilage. Obviously, bioengineered
crops can play an important, beneficial role in
meeting global food demands whether or not climate changes (68). Similarly, developing institutions and economic instruments to use or reuse
water more efficiently would help deal with current
and future water supply problems (16).
The resulting decrease in forest conversion due to
enhanced food productivity would also reduce CO2
emissions, and limit habitat loss and fragmentation
which would otherwise add to the substantial existing barriers to "natural" adaptation (via migration
and dispersion) of species if climate changes.
Notably, Article II of the Framework Convention on
Climate Change refers to allowing ecosystems to
adapt naturally to climate change. Finally, increased agricultural productivity would lower the
demand for cropland which would reduce land
prices, thereby decreasingthe costs of purchasing or
reserving land for conservation, carbon sequestration, or both (33, 46).
Similar logic also applies to other spheres of
human activity that rely on land and water, such as
forestry, habitation, and irrigation. For example,
sustainably increasing the usable amount of forest
products produced per acre of intensively-managed
plantation forests would likewise reduce the amount
of forestlands diverted to human use, and reduce
pressureson habitat, biodiversity, and carbon stocks
and reservoirs. Measures which would increase
forest productivity regardlessof any climate change
include boosting R & D on tree species genetically-
Global warming may be a serious problem in the
long run, but if the IPCC's impact assessment is
even qualitatively credible, it is not now-nor is it
likely to be in the next several decades-among the
world's list of critical environmental or health
problems. In the unlikely event that further climate
change can be halted, that would do little or nothing
in the foreseeable future to alleviate the very problems which are proffered as reasons for controlling
GHGs. Specifically, mortality and morbidity due to
infectious and parasitic diseaseswould be virtually
unchanged; conversion of land and water to human
uses-the major, imminent threat to global forests,
ecosystems, biodiversity, and loss of carbon sinks
and stores-would continue almost unabated; and
food security will not be markedly advanced, if at all.
Yet, it is possible to deal with urgent short- and
medium-term public health and environmental
problems, while also addressing the potentially
serious longer-term problem of climate change.
This can be done, for instance, by bolstering the
institutions underpinning the mutually-reinforcing
forces of economic growth, technological change,
and trade. Strengthening them would:
I. Address the root cause of the vulnerability of the
poorer nations to climate change as well as to other
-and, at present, more critical-sources of adversity such as hunger, malnutrition, and infectious and
parasitic diseases.
2. Increase the productivity of land and water
diverted to meet human needs for food, clothing,
shelter, paper, and other material goods, which
would reduce the loss of forests, habitat, biodiversity, and carbon sinks and stores, whether or
not there is any climate change.
3. Increase the voluntary movement of food and
other goods to move from surplus to deficit areas, in
8.
Potentialconsequeoces
of increasingatmosphericCO2concentration
209
order to alleviate shifts in competitive advantage
whetherdue to warming, or anotherfactor.
4. Increasethe ability of developing nations to
afford mitigation and adaptationtechnologies.
Adaptation can also be enhancedby developing
and implementing technologies to addressthose 9.
environmentaland societalproblemswhich would
be further aggravated by climate change. This
would require, for instance,putting resourcesnow
into reducing malaria and increasingagricultural 10.
and forest productivity in hot and dry conditions.
This would bring greater and faster returns to
11
humanity,particularly in developingcountries,than
would focusingscarceresourceson limiting climate
change. Successfuladaptationwill also raise the
thresholds at which GHG concentrationscould
12.
becomedangerous,which would reducethe costof
controls worldwide. Therefore, althoughadapta13,
tion is not cost-free, there can be no optimal
strategyfor addressingclimate changewhich does
not give adaptationits due.
14.
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