J

a=-

i
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-.-d

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bfrA-( J//qJ

PROPRII'TARY I{TORMATION
Fq Authorlzrd ConrPrnY tll. O.tU
RESEARCH AND EIUGINEERING COMPANY
P.O. BOX 1O1, FLORHAM PARK, NEW JERSEY 07932

EXXON ENGINEERING PETROLEUM DEPATTMENT

Planning Engineerrng Oivision

Coble: ENGREXXON. N.Y.

R. L. MASTRACCHIO
Manager

L. E. Hill

October L6,

Senior Eng. Assoc.

L979

Controlling Aturospheric

CO,

79PE 554

Dr. R. L. Ilirsch:
The attached memorandum presents the results of a study on the
potential impact of fossil fuel combustion on the CO, concentration in the
a's.rmer employee i-n
atmosphere. this study was made by St".t" Kt$,
Division.
Plaruring Engineering
The study considers the changes in future energy sources which
would be necessary to control the atrnospheric CO, concentration at differenr leve1s. The principle assumption for the COi balance is that 50% of
the CO. generated by fossil fuels remains in the-atmosphere. This corresponds
to thezrecent daLa on the increasing COI concentration in the atoosphere compared to the quantity of fossil fuel cofibusted.

Present cllmatic models predict that the present Erend of fossil
fuel use will lead to dramatic clfunatic changes wl-thln the next 75 years.
However, it is not obvi-ous whether these changes would be all bad or all good.
The major conclusion from thls report ls that, should it be deemed necessary
to maintaln atmospheric CO,, levels to prevent significant clinnatic changes,
dramatic changes in patterfis of energy use would be required. llorld fossil
fuel resources other than oil and gas could never be used to an appreciable
extent

yet

neans of recovering and disposing of CO, emissions has
been developed and the above conclusion assumes thaE recov6ry will not
No

practical

be feasible.

It must be realized that there is great uncertainty in the existing climatic models because of a poor understanding of Ehe atmospheric/
teirestriaUoceanic CO. balance. Ifuch more study and research in this area
is required before roaj6r changes in energy type usage could be reconm.ended.

IILF: ceg

Attachment

 'I

-2J. F. Black
J. l{. llerrmann
L. E. Hill
E. D. IIooPer
F. J. Kalser
R. L. Mastracchio
I{. H. Mueller
H. Shaw
G. O. $lLlheln

 PR0PRIiTi,l'r

::

;

:'iRi",lATl0N

Exxon
For Authorized ComPanY Ulc OnV
Engineering
7

EXXON

RESEABCH

AND

,

gPE 554

ENGINEERING

CONTR0LLING TI{E COZ CONCENTMTION

IN TIIE

Petroleum Department
ocrober L6,

-

L979

COMPANY

ATMOSPITERE

The C02 concentration in the atnosphere has increased since the
beginning of the world induetrialization. It is now l5Z greater than it lras
in 1850 and the rate of C02 release fron anthropogenic sourcee appears to
be doubling every 15 years. The most widely held theory is thac:

r The increase is due to fogeil fuel conbustion
o Increasing coz concentration will cause a warming of the earthts
o

surface
The present trend of foseil fuel consuoption
envirorunental effects before the year 2050.

vill

cause dramatic

However, the quantitative effect is very speculative because the data
base support ing it ia weak. The CO2 balance betueen the atEosphere, the
biosphere and the oceans is very ill-defined. Also, the overall effect of
increasing atmospheric CO2 concentration on the world environmen! is not
well understood, Finally, the relative effec! of other inpacts on the
earthrs climate, such as solar activity, volcanic action, etc. Bay be as
great as that of CO2.

Nevertheless, recognizing the uncertainty, there is a possibility
that an atmospheric CO2 buildup will cause adveree environnent al effects
in enough areas of the sorld to coneider limiting the future use of fossil
fuels as major energy sourcea. This report illustrates the possible future
lirnits on fossil fuel use by exanining different energy scenarios nith
varying rates of CO2 emissions. Comparison of the different energy
scenarios shoh' the uragnitude of the switch fron fossil fuels to non-foseil
fuels that night be necesaary in the future. Non-fossil fuels include
fission/fusion, geothernal, biomass, hydroelectric and solar power. Itre
possible environmental changes associated with each scenario are al.eo
d

iscus sed

.

CONCLUSIONS

As 6tated previously, predictions of the precise consequencea
of uncontrolled fossil fuel use cannot be made due to all of the uncertainties associated with the future energy denand and the global CO2
balance. On the basis that C02 emissione must be controlled, this study
examined the possible future fuel consunptions to achieve various degrees of
control. Following are some observations and the principle conclusions froq
the s tudy:

o

of fossil fuel combustion with a coal euphas is
will lead to dranatic world clinate changes within the next 75 years,
according to Eany present clinatic nodels.

The present trends

 .id..'

f

c1798

-2buildup in the atmosPhere is a worldwide problen. U-S.
efforts to restrict CO2 enrission would delay for a short tirne but
solve the problem.

Ttre CO2

not

Warming trends rihich would move Ehe temperate climate northward may be
beneficial for aome netions (i.e., the USSR' see Figure 1) and deUrimental for others. Ttrerefore, global cooperation may be difficult to

achieve.

Removal of CO2 from flue gases does not apPear practicat due to
economics and lack of reasonable disposal meLhode-

If it

becomes necessary

to linit future

CO2

eniseions without practical

removal/dispoeal roethode, coal and possibly other foesil fuel resources
could not be utilized to an appreciable extent.

with dramatic changee in current energy resource uaer it appears
unlikely that an increase of 502 over the Pre-industrial CO2 level
can be avoided in the next century. Ttris ttould be likely to cause a
slight increase in global ternperatures but not, a significant change in
cl.imate, oceen neter leveL or other serious environmental efforts.

Even

potential problem is great and urgent. Too little is knonn at
najor U.S. or worldwide change in energy type usage
thie tine to rffia
but it is very clear that ionediate research is necesgary to better modeL
the atmoephere/terrestrial/oceanic CO2 balance. Only with a beEter
understanding of the balance will we know if a problem truly exists.
Ttre

Existing Data and Present

Models

industrialization, the atmospheric carbon
dioxide concentration has increased from approxinately 290 ppm in 1860 to

336 pp'n today. Atmospheric CO2 concentrations have been recorded on a
monthly basis by C. D. Keeling since 1958 at Mauna Loa Observatory in Hawaii
(see Figure 2). Seasonal variatione are cl-early shorm with the CO2
concentrations lowest during the North American and Euraeian sunmers, due to
increased photosynthetic activities. Over the laet ten years, the atmoapheric concenEration has been increasing at an average rate of about 1.2
pp'n/year.
Ttre present consumption of fossil fuels releases more than 5
billion tons of carbon as CO2 into the atmosphere each year. Data to date
indicate that of the aount released approximately one-half ie absorbed by
the oceans. the other half remaine in the atmosphere. There is some
question as to whether the terrestrial biosphere is a sink, absorbing
atmospheric CO2r or a source of CO2 enissions, due to manrs land clearing activities. Current opinion att,ributes the atmospheric CO2 increase
to fossil fuels and considers the biosphere input to be negligible.

t

 c1798

-3Figure 3 shows the carbon cycle with the ocean and the biosphere as sinks
for approximately 502 of the fogsil fuel emissions. Most models show the
ocean !o be a major eink while the biosPhere aPPears to be a much smaller
sink if it absorbe any CO2 at all. It is clear frorn Figure 3 that the net
atmospheric increase in Co2 is quite srual l comPared to the quantities of
COZ exchanged betlreen the atmosphere and the earth. This nakes it very
difficult to analyze the fossil fuel inpact on the overall carbon cyc1e.

fossil fuel resource is very large conpared to the quantity of
carbon in the atmosphere. Therefore, if one half of the C02 released by
cornbust ion of fossil fuels remains in the atnosphere, only about 202 of the
recovetable fossil fuel could be used before doubling the atnosPheric CO2
The

conEent.

the increasing CO2 levels arises because of the
radiative properties of the gas in the atnosPhere. CO2 does not affect
the inconing short-lrave (solar) radiation to the earth but it does absorb
long-wave energy reradiated from the earth. The absorption of long-wave
energy by CO2 leads to a warming of the atmosPhere. This warrning phenorBenom is known as the "greer*rouse effect.r'
The concern over

A vast amount of speculation has been made on how increased Co2
levels will affect atmospheric temperatures. Many rnodels today Predict that
doubling the 1850 atmospheric CO2 concentration will cause a lo to 5oC
global iemperature increase (see Figure 4). ExtraPolation of Present fossil
fuel trends would predict this doubling of the CO2 concentration to occur
about 2050. A tenperature difference of 5oC is equal- to the difference
betrreen a glacial and an interglacial period. The temPerature increases
will also tend to vary with location being rnuch higher in the polar region
(see Figure 5). These ternperature predictions may turn out too high or 1ow
by several fold as a result of many feedback nechanisms that nay arise due
to increased temperatures and have not been properly accounted for in

present rnodels.

These nechanisrns include:

and ice coverage.

albedo (reflecE ivity)

This is a

pos

it ive

would result in a decrease of the earth
rft ich would produce an added warming effect.

I

s

Cloud Cover. This is considered Ehe most important feedback mechanism
io=E-?i.oir, t ea for in present Bodels. A change of a few percent in
cloud cover could cause larger temperature changes than Ehose caused by
COZ. Increased atmoepheric temperafure could cause increased evaporation from the oceans and increased cloud cover.

the CO2 level is increased
and the ambient temperature rises, the ocean may lose some of its
capacity to absorb CO2 resulting in a positive feedback. However,
increased C02 leveLs could increase photosynthetic activities r.tr ich
would then be a negative feedback mechanism.
Ocean and Biosphere Responses. As

 !tlj- r

c1798

,li

t

-4As evidenced by the balance shown in Figure 3, the atmospheric
carbon exchange with the terrestrial biosphere and the oceans is so large
that srnall changes due Eo these feedback mechanisrns could drastically offset,
or add to the impacE of fossil fuel combustion on Ehe earthrs temperature.
Appendix A gives one, but not unanimous' viewpoint. of how the
environment night change if the feedback mechanisms are ignored. Ttre
contribution that will ultimately be made by these feedback mechanisms is
unknorrn aE Present.

Energy Scenarios

'';'

:# 'i+'l,'.S.
$'
't;
{

for Various

COc LimiEs

Using the CO2 atnospheric concentration data recorded to date,
of these data with fossiL fuel consumption and the proposed
correlation
the
Itgreenhouse effecttt models, thie study reviews various world energy consumption
scenarios to liuit CO2 atmospheric buildup. Ttre concentration of CO2 in
the atmosphere is controlled in these studies by regulaEing the quantity of
each type of fossil fuel used and by using non-fossil energy sources when
required. Ttre quantity of CO2 enitted by various fuels is shown in Table
1. Ttrese factors were cal.culat,ed based on the combustion energy/carbon
contenr ratio of the fuel and the thernal efficiency of the overall conversion
process nrhere applicable. They show the high Co./energy raEio for coal and
shale and the very higlr ratios for synthetic fuefs from these base fossil
fuels r*rich are proposed as fuels of the future.
The total world energy demand used in these scenarios is based
the predictions in the Exxon Fal.l 1977 Wotld Et".gy Ottlook for the
no
high oil trice case for the years 1976 to lgffiat
period
be
made
of
energy
could
during
this
of
supply
the
sources
in
changes
CO2
restrictions
on
emissions,
has
no
follows
the
of time. Case A, which
2000.
price
predictiona
until
high oi1
upon

Petroleum production and consumption is the same in each scenario.
high oil price case predictions are followed until 2000. After 2000
petroleum production continues to increase until a reserve to production
ratio (R/P) equals ten to one. Production peaks at this point and then
continues at a ten to one R/P ratio until supplies run out.

The

The consumption of coat, natural gas and non-fossil fuels (fission/
fusion, geothermal, biomass, hydroelectric and solar power) vary with each
scenario. Shale oiL makes small contributions past the year 2000. It is
not predicted to be a major future energy source due to environmentat damage
associated with the mining of shale oil, and also due to rather large
amounts of CO2 enitted per unit energy generaEed (see Table 1). If more
shale oil were used, it would have the same effect on CO2 emissions as the
use of more coal. Ttre fossil fuel resources assumed to be recoverable are
tabulated in Appendix B.

I
I

 cl7

98

-5A.

No

Lini! on Co2 Emissions

In this ecenario no limitations are placed upon future fossil fuel
uae. The uee of coal is ernphasized for the rest of this century
and continues on into the next century, The developrnent and u8e of
non-fossil fuels continue to grote but without added enphasis.
Natural gas production continues at a slowly increasing rate until
an R/P ratio of 7/l is reached around 2030. Production after 2030
continuec at a 7lL ratio until leserves run ouE. Figure 6 shows
the future energy deBand for this scenario.
Figure 7 shows that the CO2 buildup frosr this energy strategy
is quite rapid. Ttr e yearly atrnospheric CO2 increase rises from
1.3 ppo in 1975 to 4.5 ppn in 2040. Noticeable EeoPerarure changes
soutd- occur around 2010 aa the concentration reaches 400 ppn'
Significant clinatic changes occur around 2035 when the concentration approaches 500 ppur. A doubling of the pre-industrial concentration occurs around 2050. The doubling would bring abouE draBatic changes in the world's environment (see Appendix A). Continued use of coal as a roajor energy source Past lhe year 2050
would furEher increase the atnospheric C02 level resulting in
increased global temperatures and environmental uPsets.
B.

coz Increase Linited to 510

pplq

This energy scenario is linited to a 752 increase over the preindustrial concentration of 290 ppm. No liuitations are placed on
petroleum production. Natural gas producEion is encouraged beginning in 1990 to ruinimize coal combustion until non-fossil fuels are
developed. Production of natural gas would increase unlil 2010
when an R/P ratio of 7/l would be reached. Production would then
continue at a R/P of 7/l until supplies ran out. Ttre developdent
and use of nonfossil fuels are erophas ized beginning the 1990rs.
Non-fossil fuels start to be substituted for coal in I990's.
Figure 8 shows the future energy deroand by fuel for this scenario.
Figure 9 sholrs the atnospheric CO2 concentration trends for this
scenario. The lower graph shows che maximum yearly atmospheric
CO2 increase allowable for the 510 ppm limit.
The yearly CO2
increase peaks in 2005 when it amounts to 2.3 ppro and then steadily
decreases reaching 0.2 ppu in 2100. A 0.2 ppn increnent is equivalent to the direct conbustion of 5.1billion B.O.E. of coal . This
would be approxiarately 2 to 3% of the total world energy denanded
in 2100. (For uore detail on the construction of Figure 9, see

Appendix C. )

A conparison of the Exxon year 2000 predictions and this scenario's
year 2000 requirenents 6hows the nagnitude of possible future
energy source changes, The Exxon predictions call for nonfoseil
fuels to account for 18 billion B.O,E. in 2000. This scenario
requires that 20 billion 8.0.E. be supplied by non-fossil fuels by

 iI"

1p
i,
:+

br798

+

?

-62000. Ttris dif ference of 2 billion B.O.E. is equivalenE to

Ehe

power supplied by 214-1000 MI{ nuclear Poner plants oPerating at
607. of capacity. If it were supplied by methane produced from
biomass, it would be equivalent to 801000 square miles of biomass
at a yield of 50 ton/acre, heat value of 6500 Btu/dry pound and a
352 ctnversion efficiency to methane. Therefore even a 2O7 itcrease in non-fossil fuel use is a gigantic undertaking.

of the change to non-fossil fuels as major energy
sources is more aPParent lthen scenarios A and B are comPared in the
year zoz5. scenario B requires an 85 billion B.o.E. input from
non-fossil fuels in ?025. This ie almost double the 45 billion
B.O.E. inpur predicted in scenario A. Ttris 35 billion B.o.E.
differenc" i" "pp.oximately equal to the t'otal energy consumption
for the entire world in 1970-

Ttre magnitude

with Ehis scenario wouldn't be
as severe as if the CO2 concentration were allowed to double as
in scenario A. Noticeable temPerature changes would occur around
20I0 wtren the CO2 concentration reaches 400 pprn. Significant
climate changes would occur as the atmospheric concentration nears
500 ppn around 2080. Even though changes in the environment due
to increased atmospheric CO concentrations are uncertain, an
increase to 500 ppm would probably bring about undesirable clinatic
changes to many parts of the earth although other areas may be
beneiitted by the changes. (See Appendix A, Part l)-

Ttre environmental changes associated

c.

COr Increase

Limited to 440 pPm

Ttris scenario lisrits future atmospheric CO2 increases to a 502
increase over the pre-industrial concentration of 290 pprn. As in
the previous case, no timitations are placed on petroleum production and increased natural gas production is encouraged. Much
emphasis is placed on Ehe developrrent and use of non-fossil fue1s.
Non-fossil fuels are substituted for coal beginning in the 1990rs.
By 2010 they will have to account for 5O7" of the energy supplied
worldwide. Thie would be an extremely difficult and costly effort
if possible. In this scenario coal or shale will never become a
major energy source. Figure I0 shows the future world energy
demand by fuel for Ehis scenario.
The atmospheric CO2 concentration trends for this scenario are
To satisfy the lirnits of this scenario
shown in Figure ll.
the yearly COZ emissions would have to peak in 1995 aE 2.0 pprn,

 b1798

-7and Ehen rapidly decrease reaching a value of 0.04 ppm in 2100. A
0.04 ppm naximum allowable increase means that unless removal/disposal methods for CO2 emissions are available only one billion
B.O.E. of coal may be directly combusted in 2100 (or 1.4 billion
Barrels of Oil). Ttris would be less than lZ of the lotal energy
demanded by the world in 2100

To adhere to the 440 ppur linit, non-fossil fuels will have to
account for 28 billion B.O.E. in 2000 as compared to 20 billion
B.O.E. in scenario B and 18 billion B.O.E. in scenario A. Ttris
difference between scenarios A and C of l0 billion B.O.E. is
equivalent to over 1000, 1000 MW nuclear power plants oPerating at
60ll ot capicity. Ten billion B.O.E. is also approximately equivalent to 4001000 square miles of biomass at 357" conversion efficiency lo methane. Ttris is equivalent to almost one-half the total
U.S. forest land.

By 2O25 the 110 billion B.o.E. input from non-fossil fuels called
for in this scenario is more than twice as much as the 45 billion
B.O.E. input predicted in scenario A. This difference of 65
billion is approxinately equal to the amount of energy the entire
world will consume in 1980. In tetms of power plants, 65 billion
B.O.E. is equivalenE to almost 7000, lO00 MW nuclear power plants
operating at 6O7. ot capacity.
An atmospheric CO2 concentration of 440 ppm is assumed to
be a relatively safe level for the environment. A slight global
warming trend should be noticeable but not so extreme a8 to cauee
rnajor changes. Slight changes in precipitation night also be
noticeable as the atmospheric CO2 concentration nears 400 ppn.

S.

KNISELY

 a1798

-8REFERENCES

Corporate Plannlng DeparEment, Exxon Corp. (Fal1r

L977). I{orld

Energv

Outlook, 1977-1990.

Flower, A. R. (1978). t'I'lorld O11 Production,rl ScientlfLc Amerlcan 238 (3) '

pp. 42-49.

Griffirh, E. D. and Clarke, A- W- (1979).
tlflc Amerlcan 24O (l)' PP. 38-47.
McCornlckl W. T.' R. B- Kallsch, aad T. J'
Assesses World Natural
13, 1978, PP. 103-106.

ItWorld Coal Productionr" Sclen-

Wander (1978). rrAGA Study
Gas SuppJ-yrrr The O11 and Gas Journal. February

peterson, E. K. (1969). "Carbon Dloxlde Affects Gtobal Ecologyr'r Envlronmental Sclence and Technologv 3 (11)' pp' 1162-1169'

Rotty, R. M. (1979). Uncertainties Associated wlth Global Effscts of
Atroospherlc Carbon Dloxide' ORAV/IEA-79-6 (0)'
rrPredlctlng Future Atmospheric
SLegenthaler, U. and Oeschger, H. (f978).
Carbon Dloxide Levels," Scierce 199' PP. 388-395.
Shaw, Henry (1978). Attached Appendlx
Jr. on December 7, 1978.

(B) of Letter to Dr. E. E. David'

SteLabergr. M., A. S. Albanese and Vl-duong Dang (f978). 'rEnvlronmental
Control Technology for Carbon DLoxlderrr presented at Tlst Annual AICIIE
MeetLng, November L2-I6, L978, !li-aml, Florida

Stuiver, ll. (1978). "Atmospherlc Carbon Dloxide and Carbon ResenroLr
Changesr" Science 199,

Terra, Stan (1978) .
1978' pp. 22-27.

PP

-

263-258.

"CO2 and Spaceshlp Earthrrl EPRI

Journal July/August,

!{illiams, J. (f97S). "Global Energy Strategles' the Inpllcatlons of
Futures, August, 1978, PP' 293-302.

CO2r"

 b1798

Table I
@e

EMISSIONS

Z
Fuel

froo

of

Present
CO. Out,puE

0.35

0

a32

0

0.38

0

II2 frm Coal Gasif icat ion

0.38

0

Shale Oil

o.23

0

SNG

Coal

Coal Liquids
Methenol

frm

Goal

Bituminous Coal

.2L

382

Petroleum

.15

492

Natural

.11

r3z

Gas

triesion/Fusion

0

0

Biomass

0

0

SoIar

0

0

* Includes converaion losses t*rere applicabLe.

 c1798
APPENDIX A
ECOLOGTCAL CONSEQUENCES OF
INCREASED CO. LEVELS

From:

Peterson, E.K., ttCarbon Dioxide Af fects Global Ecology,r' Environmental
Science and Technology 3 (1f), 1162-1169 (Nov '69).

1. Environmental effects of increasing Ehe
times 1860 level)

CO2

levels to 500 pprn, (f.Z

o A global temperature increase of 3oF which is the equivalent of
a 1o-4o southerly shift in latitude. A 40 shift is equal to
the north to south height of the staBe of Oregon.
hotter, probably by nore than

.

The souEhlrest states would be
and drier.

o

Ttre flow of the Colorado River would dirninish and
nater shortage would become much more acut.e.

the

3oF,

southwest

Ehe glaciers in the North Cascades and Glacier National
Park would be melted. There would be less of a winter snow pack
in the Cascades, Sierras, and Rockies, necessitating a major
increase in storage reservoirs.

. l'lost of

. llarine life would

be markedly changed. Maintaining runs of

sal-mon and steelhead and other subarctic species
River sysEem would becosre increasingly difficult.

.

in the Colurnbia

The rate of plant growth in the Pacific NorthwesE would increase
102 due to the added CO2, and another l0Z due to increased
temperatures.

2. Effects of a doubling of the

1850 CO2 concenrrarion. (580 ppn)

. Global temperatures would be 9oF above

1950 levels.

o Most areas would get more rainfall, and snow would be rare in
the contiguous states, excepE on higher mountains.
.

Ocean

.

The melE ing

o

The

levels would rise four feet.

of the polar ice caps could cause tremendous redietribution of weight and pressure exerEed on the earEhrs crust. Ttris
could trigger major increases in earthquakeg and volcanic activity resulting in even more atmospheric co2 and violent storrs.

Arctic ocean would be ice free for at leasE six months each
year, causing major shifts in weather patterns in the northern

hemisphere.

 .

troplcs rtould be hotter, more hurnld, and less habltable, but the preaent teaperature latltude would be warmer and
rcre habltable.

The present

 b1798
APPENDIX

FOSSIL FUEL

RESOURCES

barrels of oil potentially recoverable
as of 1975 (agsuming the future recovery rate to be 402r.
ltre ninimun allowable Reserve to Production (R/P) ratio is
ten one

Oil

Shale

B

Assume

Oil

Natural Gas

coal

t.6 trillion

Potential of 3.0 trillion B.O.E. but aesuming 1977 technology only 20O billion B.O.E. actuaLly recoverableApproximately 1.6 trillion B.O.E. potentially recoverable.
Minimun allowable R/P = 7.1.

:::iil::":;:;:"::::Jil":"::":::::.i::'ffi'::::L::"1ity.

 b1798
APPENDIX

C

CONSTRUCTION OF SCENARIOS

(scena
l.

Scenario

B AND C

ncrol

)

B

the

concenEration
by the folLowing equation
CO2

vs. year curve in Figure 9 was generated

afEer 1970 (t = 0), then
xC

=

292 ppm

+

2L9 ppr^/[l + 5.37 exp.

Gt/Z4 years)l

where C = concenEration

in

PPm

the lower section of Figure 9, atmospheric co2
generated
by finding the difference in the concentrais
years,
increase vs.
This
years.
curve gives the maximum yearly increases
tions of successive
placed on this scenario. The amount of
the
lirnits
within
allowable to stay
any given year can then be. calculated by
in
be
consumed
fossil fuel that may
For
examPle:
the lower curve.
The curve on

In

2100 the maximum allorrable CO2 increase equals

0.2

ppm'

This is equivalent to:
2PPrn

3.1 x tOl2 tU

x $$!:lJ
CO2

x +ftl!- x

$ffi

=3.rxrol2

nay be released by the combustion of:

forcoar_, @

+x

1990=Pt9- ';zTTffio2 '1B'o'E'
5--8-T-ro6 rtu

= 2.5 billion B.O.E. of coal
This scenario is based on Ehe assumption that 507', of CO2 rewill always be absorbed by the ocean and the rest will
renain in the atmosphere.
leased each year

FDerived Trom an equation presented by U. Siegenthaler and

(1978) (see references).

ll.

Oeschger

lbco2

 aL798

-22. Seenario

C

Ttre equatlon

for the generatton of F!.gure 11 ls derlved

to be,

after
*C

-

292 ppD

+

1970

146

(t -

0)

r

then

ppn/tl + 3.37 exp. (-tlz0 years)I

Thle scenarlo ls the saoe ae Scenarlo B ooly with dlfferent llnlts'

 Figure

1

MOST OF THE USSR'S VAST
AGRICULTURAL LAND BASE
LIES LATITUDINALLY NORTH
OF THE UNITED STATES

#[?h

rc

sovrET AGRrcuLruFAL LANDS

 Flgure

CONCENT RATION OF ATMOSPHERIC CO2 AT MAUNA LOA

OBSERVATORY, HAWAII

c)'\t

529

()

F,*
320

OT}IER"STATIONS

POINT MRROWI AK

316

ANTARCTICA

At'lERlCAl,l SAI€A

r96e 1964 t966 1968 t970 tg72

YEAR

t974

 Ficure

3

The Carbon CYcl e
Current

Fluxes in Gt/a
Pool sizes in Gt

,,-

SpecuLati ve adsorption of
fossi L C02 by oceans or
terrestriSL bi osphe re

Atmosphera

i0?

Photosynthesi s
56
Decompos

ition
25

Fuel
Conbustion

Respi

Gas Exchange
90

90.

ration

3l

5

Surface llater
Dissolved Carbon
580

Dead

l2 ,ooo
(7,300 recoverable)

Livi

0rgan i c

ng

( ltumus

0rgani c

)

I 000-3000

Li ve
Aqua',f c
0rgani c

I

Thern''oci i ne
0l sso'!ved

Ca

rbon

6,600

800
Deep

a

Aquatic
0rganl c

llater

Dissolved Carbon
3l ,800

Fossil Fuels

anC Shale

Terestrial

Biosphere

0ceans

Reac

t'ive

Sedi;r:nts

 Flgure

4

HOW PREDICTEDAT
COMPARES \AJITH RECENT TEfuIPERATURES
()
l-

t3

trj

t2

lrJ

il

g-

z

UI

r
E

o
tr,

to

E,

I

F

7

)

E

tJ
(L

5

F

4

trj

u

3

rr

2

v)

I

tr
f

o
trJ

(9
<.

l:()

0
o

o

o
o

6

s

rd

Eslimoled Polor Regions Temperolure'.oi
o

9

o

Estimoted Globol Meon Temperolure

Or

Approximbte Ronge of
Undislurbed Climote
in Posl Few Cenluries

0bserved
Norlhern
Tempero

o

-l

o
o
o
o
o
o

1850

le50
YEAR

(

ilil1

 I

Flgure

5

TEMPERATURE EF!:ECT OF DOUBLING COZ

d

Y
tr,

t20
tu
v)
IJJ

o
m

F10
I

!,
x
tr,

/\

0

j'

90'

70^

/-r

\*

\^
'\qtil

60' 50' l0
IATITUDE

\'r-

-

30'

---

t--

t-\
-,

20'

 Figure 6
WORLD ENERGY DENNAND BY FUEL
UNLIMITED C02 INCREASE
(COAL EMPHASIS)

140

r20
E
trl

100

ttJ

Im
tn

z
o
=

6
Natural
Gas

15

Petroleum
And
Shale 0il

0

t9B0

L990

2000
YEAR

2010

2A20

2030

 Figure 7

coz IN ATMOSPHERE
RATE 0F C02 BUILDUP
UNLIMITED INCREASE

oo-

500

z,

o
tr

E.

450

ztl.I

c)
z.

o
O

400

ol
o
c)

350

E

5.0

oo-

tl!
a

4.O

lrl

E,
()

=N

3.0

o

c)

9
E
trl

2.O

oa
o

F

1.0

1980

t99A

2000

20].o

YEAR

2020

2030

2040

 :

Figure 8
WORLD ENDERGY DEMAND RT FUEL

LIMITED T0 A 75"h CO2 TNCREASE

E
ttl

100

UJ

o

6
a

80

z,
c)

f

J

6

Petroleum
And
Shale 0il

0

1980

1990

2000
YEAR

2010

2020

2030

 Figure 9

c0

IN ATMOSPHERE

RATE 0F CO2 BUILDUP
LtM TED TO 75"/" INCREASE

500
oo-

z,

o

450

E,

z.
(J
z,
UJ

400

o
C)
C!
o
o 350

E
lrl

2.O

=o
otlt

VI

1.5

lrl

E,
()

=N

o
c)

1.0

()
E,

lJ.l

o-

a
o

0.5

F

0

1980

2000

2020

204A

YEAR

2050

2080

zLO0

 I ..
}
J:iJ
'tr,'.
5:."
I
lul:
\'

i'
\

t'

t,

Figure

'

""-t

11.

CO.' lN ATMOSPHERE
RATE 0F CO2 BUILDUP

45A

=o
oz.

400

F
E
F
=
lrl
()

3so

o

z,

o

C)

sl
o
C)

300

E
lrl

2.4

oo-

F

z,
lrl
l=
rl

1.5

E

C)

z,
N
o
(J
q)

1.0

E,

lrl

oU'

o
F

0.5

0

1980

2000

2020

2040
YEAR

2060

2080

2100