This document summarizes the key climate forcings that have caused changes in the Earth's climate, both in the past and present. It finds that: 1) During the last ice age 20,000 years ago, negative climate forcings from factors like reduced greenhouse gases and dust caused temperatures to be 5°C colder. 2) Recent positive climate forcings, mainly from increased greenhouse gases like CO2 and methane, have increased total forcing by around 1.7 W/m2 since pre-industrial times. 3) However, the oceans' slow response means we have only seen a global temperature increase of around 0.7°C to date, with more warming still to come from gases

1. 1
CHIEF COUN4SEL OFFICEPAE
83/20/2001 15:05 3012861713
Ae200yesagrlaiet
2 Fgr1.Climate forcing during theI
Ice Age Climate Forcrngs (W/m ) 2
of -6 .6 *1.5 W/m and the 5'C
the current interglacial period. This forcing 2
of O.75 0 C per 1 W/m .
-0.5± 1 cooli. of the Ice Age imply a climate sensitivity
re=g- 6. 6 +LSK/WM
4 CeWn
-2.6±0.5
-3.5*±1
Climate Forcings
I
2
I0,7+0,Z to
W~~~
0.4±0.2dAt-0 0Is
iG
W,±.3 V~aI
0.35.0.05
.9±0.4~~-030.
Meal~~~~~~~~~~~~~~~CTU ~ tdLona~
0 -0 I
-0.2r0.
2 2 ,drc vi ~
1
-0.1+0 1 rnosbeLGO
Troposphcfl; Acro6pI.i
~ ~ ~ ~ ~ ~ I Otbet Anthr ...... iCFotilng% ----- ) 4aci )~cnt5-j
G'.C0'4'C
forctngs between LLS and 2000.
Figure 2. Estimated change of climate
C~w L1.7 KW
Tot/ag: 3T r wau,56KY ± 0. 7 Wli 2~ uoaxUxy inkbatzao
Climate Forcings
2
due
Figure 3. Clmt forcmgs inthe past 50 year
~~~~~~~~~~~~torltv
six mnechanisms, o15-Tefrtfv
C
fordongs am based mainly on observationls, with
4.1~~~~~~~ due to
stratiospheri 1120 jBcuding only the source
-GHGs * gaies. itnecludesth 03llmandH0.Th
~
so2a wroo
trradpheiace CH, oxidation. 010inlSetewl-xd n 40 h
-2 soratser iCrfl)S'IS *rehuegss
~. t xlds0
-.ozone troposphedec aerosol forchig;I~s uncertain in both its
H20
- .stratospheric
i
magnitude and time dependence-
ti siti3ersl
1950 1960 1970 190
1980~~~~~9 2000

2. PAGE 13
CHIEF COUNSEL OFFICE
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.
Greenhouse Gas Mixing Ratdos
(ppm) ~. H(ppb>.
192a -
IS92z -*
10 - tro
350 ice core
O 100 T 'Ictv
NZOWb)
in svellarionario
4. -1
c cr
!c- instu
~ ~ 0
300~ ~ I-
[PC 9
201 -ta-H-nd300
S2aseasfrC
320se
scenarioC sis Ful
owe
4.2 CpC4--
4,
300
-0C1
0
insiu
-'--othe alo
2050 1~~50 19752000 ZS05
2025
1975 2000
O.CH n 2 0[P
1900ceaisfo 199250 i~taedfrcmasn
20001
Hanseneta]-
ro felwoK ndssiodns from] Felsmt ox~c yN.Mlo3
eisio
Figre8.C0
Uiveri Y
Rockfellr 2

3. CHIEF COUNSEL OFFICE PAGE 12
09/20/2001 15:0E 30122e1713
0 4]
(a) Stratospheric Temperature ( C) [MSU Channel
2.0
-1.5 ~ Bsns-SUtl
Ocean, Wini)
(c) Planetary Energy Imbalance (Heat Storage in
FigureS5. Simulated
temperatures and
Planetary energy
for the six
~~~~~~~~~~~~~~~~~~~~~~~im
1'0
forcings in Figure 3 for
1950-1999 with two
scenarios for 2000-2050,
.0 ~~~~~~~~~~~~~~~~~~~~with
businesl-aM-u9ual
(1% CO 2 year, 2.9 Wtjn)
.5
~~~~~~~~~~~~~~~~~~~~~~~~a
the alternative
scenario (Figure 7,
W/n 2 ).
~~~~~~~~~~~~~~~~~~~~~1.1I
1.0
1990 2db203 20.50
1950 1970
Alternative ScenariO
Business-As-Usual Scenario
3W Gasotes 1
C02 Other
GasesGae
1050 in a "business-as-usual" scenario and the "alternative"
Figure 6. Added climate forcings between 2000 and
scenlario.

4. qn~~~~~ CHIEF ~~~~~PAGE
COUNSEL OFFICE 11
CIFCUSLOFC
@3/20/2001 15:06 3012861713
simulated and Observed0 Climate (Change
Channel 4]
(a) Stratospheric Temper~tr ( C)[MStI
-.5 Base Perid 1984-90
-10(b) Tropospheric Temprn rC(oC) (MS'U Channel 23
-. 2~
.6
-.01
Coeri(d:
OceanBIce
(e)
4~~~~~~~~~~~~~~6~~~~~~
lnc (Heat t198g 19n
OcenWI
lntayEnry6m0
1950
I'0~~~~~~~~~~~~~st~l~a~ih05
hnefr15.00 hs
Figre . imuatd adosre lmt f iue3
si heoen Ciaefrcnsae hs
clmt odlepoyepnalmxn a

5. 4
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The Forcing Agent Ud yngClimate Change
Group
Briefing for:0 iba Clmten DChag Working
Max~ 29, 2001
lanes B.Linsen, Head
Studies
NASA Goddard Inhtitute for Space
climate chanlge. I am director of the NASA.
Tankyouforti-s oporlinty to discuss
Goamonin- C olumia
of Goddard Space Fligh Cetr oatda
Goddard hnstitute for Space Studies a division h at'&ciate -thowpbit
University in New York, We specialize in the stud ofpaethseill icntattes publaic
varies, and why it varies. One of our prime 0 beolstopoiesintfcifra not our job tosuggest polce.,n 31
help wake i5L policies- It is
and their representatives canuet qI aRtitati'v adas clear as the data permit.
infrmatin thtseas from year to Year
is toprovie
tnor&stio thmarie as few aiconet. The Earth's climate fluctuates
itopermvitde socane
from day to day. It is a. chaotic system, responds to
and century to century, just as the weath~t filuctae in magnitude. The climate also
change aelitd
occot. without any forcing, te sn chaotic
but the
art beoms warmer- if a large volcand spews
bighen, anatra focin, te
faring. I ol
wyadteBrhtnst
aerosols into the stratosphere. these small particl~rfetsnih l h ua-ae
Fieape
There ate also hurman-made forcings. squarentt Cwim) o xmlaltehmnmd
We measure forcings in watts per miniature
. 2W/rn. It is as if we have placed twoincreasing the
as ocn fmr
greenos gae2o meeoof h Earth's surface That is equivalent to
C nhoutmS ga lbs cuever squrein
ge nov
u otrlal
teErhsciaei oafrig
brightness of the sun by about 1 percent. sensiieteErhsciaei oafrig u otrlal
We understand reasonably well how can compare the current warm period, which has
the Earth.
measure comes from the history of ic gaout 20,000 years ago- We
know the
previous
existed several thousand Years, to the were trapped as the ice sheets
the ice ag rmbubbles of air that
composition of the atmosphere during less carbon dioxide (GO2 ) and less
frmsofl.Teewas
on Greenland and Antarctica built up with ice sheets covering Canada
(CH 4 , but more dust in the arTesuAfacc was different then, sea level
methane even the coast-lines differed, because
and parts of Europe, differenit distributos fVejetatiofl, a negative climate forcing of
as Summarie6d in Figure 1, caused
was 300 feet lower. These changes, than today. This empirical
a plant that was 5 C colder
about 61½ W&n. That forcing maintained /4urVC watt of forcing- Climate models
per
have the
informatiOn implies that climate sensitivity is a the complex
agreement between the real world and
sane sensitivity, which shows an encouraginghoclmt may change in the future.
predict
computer models that we are using -to h climate cannot respond immediately
to a
There is another important concept to undesad to achieve just half of
to wan the ocean. It takes a few decades only 75-90 percent
forcing, because of the long tint needed respofise may be
a forcing. Een in10yerth
the equilibrium climate response to o oiymkr. It means that we
can put
complete. This long response time complicates th rbe children and grandclhildtren.
will only ermergeduigtelvsoor
into the pipeline climate change that n so that the most appropriate
and undersdand cliaecag al
Therefore we must be alert to detect
policies can be adopted. summasrized in Figure 2. The greenhouse
gases.
With that preamble, let',s discuss the climate forcings has the largest forcing, but
woujl tend to cause warming- C0O,
on the left, have a positive forcing, which a forcing half as large as that of CO~.
effect on other gases, causes
methane, when you include its indirect are not negligible-
inth future, but the other forcings
CO 2 is likely to be increasinlgly dominaml particles in the air. Some of these, such as sulfate,
Aerosols, in the middle of the figureaefn oil burning, are white, so they scatter sunlight and cause
in coal aid
which comes from the sulfur released especially of diesel fuel
a cooling. Black carbon, which is soot, is a prddut of incomplete combustion,

6. PAGE 05
CHIEF COUNSEL OFFICE
15:O8 3012851713
03/20/2001
increaseffeth s humbergof
th plntoArslstn toe
and coal. Soot a~bsorbs sunlight and thus warms a#d longer-lived. Alloftearslfecshvlrg
brighter
coddoplets, in turn making the clouds urncerstainties, is wolmtd.cnld
t
are, inadqae n
uncertainty bars, because our measurements fC Beganth~ e wrrrubrd concludeth,
If we accepted these estimates at face value, desieterlag ro as nsm
by 13 W asnethIdsra eoui~lbgn[h warming from a
clmt forcing has increased ntentfrigo Wi]-The equilibrium
cliate n ctvyedauneant we would expect
a u2-.3c.ri Hoevr beaue of the ocean' s long response time,
fasein ofu1.7ctive, yis remiglos, wittatrmuch
yimaac ofC0.7 W/nothe
a global warming to date of only about 3/400. AA This moans there istohr120gobal' warming'
than going out-
more energy com-ing into the planet siio remispefixdatl tday'sth values5
- it will occur even if atmospercaom yeaescilydrnthpst2
already in the pipeline more, Pleciseliy for the past 50
We Jcnow these climate forcings axe shown in Figure 3. The history
Of the
yeas o
saellte neaureefts. Our best estimates tis vr
Of postv n eaIves dorcings
tropsphricaerosol forcing', Which involves Partil cancellation whichaelrgfoinsdigtis
forcings,
uncrtan.However, the GHU adsrtpbfcerosol 1= oe ocluaeth lmt hne ssoni
sSoni
period. are known accurately. aclt h lmt hne
a global claemdlt
When we use these forcings in EWe make five model runs, because of the
chaos in
Figure 4, the results are consistent with observati ts. black dots are observations-I The
is the average of the five runs. The
the climate system. The red curve increase, but it warms after volcanic
of ozone dep letion and C02
Earth's stratosphere cools as a result the predominantly positive forcing
by
exnptions. The troposphere and the surface warminbecatQtC of with observations.
reasonably good agreement
iticreases of greenhouse gases, in that the simulated planet has au
increasing energy
in Figure 4 is important. It Khows is energy
The fourth panel the planet, from the sun, than there
imbalance with spate. There is more energy coxrirg intit implies that
imbalance today is about 0.7
Wi . This, as mentioned above,
going out- The calculated even if the atnosphefic
warming al ready in the pipeline,
there is about 0-5CC additional global confirmationl of this energy imbalaiice
has occurred
coniposition does not change frh.Aniprtartf study, by Syd Levitfls of NOAA. shows
the deep ocean isIwanng. That t~he past 50 years, which is.reasonably
recently~vith the discovery that
average rate of 63 W/nt during as
that the ocean took up heat at an global sea ice cover has also decreased
from climate models. Observed
consistent with the predictions
the models predict scenlarios
into the future for two climate forcing
We extend these climate model simulations scenario, which the newspapers
love, the
illustrated in Figure 5. In the popular "busirie5~ss-ti-sual" years. Ttis leads to additional global warming
3 W/n? in tile next 50
climate forcing increases by almost the "alternative scentario fossil
fuels continue to
and several degrees by '100 In growth
of about 1.5CC by 2050 CO 2 emissions, but there is no farther The
be used at about today's rate, with a slow trend toaward less any worse that it is today.
air pollut~iou is iot allowed to get
of the other forcmg.s. In simple termis, scenario is just over 1 W/11? in the next 50 years-
added climate forcing in the alternative scenario. is about ¾/ 00, much
the next 50b years in the alternative declines in the
additional global warming in
The
the business45s-sual scenario.
In addition, the rate of stratosphefle cooling planetary
less than for begins to recover. The
stop entirely if ~aop~l ozone scenario, but by almost 1 Wlm? in
alternative scenario, and it way only about ¼/Wni the alrernative
energy imbalance increases by
the busine5ssas-usflal scenarid. the alternative scenario. First, we
must kceep thethe
is
Figure 6 adde C07foringsat emphasizing the two arts of of C02 increase in the next 50 years to be about
a cartoon W&.Thisrequres rate
in the C02 growtb
the sceflafio has a slow decline
recent decades. More precisely, the second half
same as it has been in further decrease growth rates in
rat& during this 50 years, which would make~ractical to
it that means
is assumed to cease. Principally
of the century. Second. the growth of other cliia~te forcings specific trace gas scenarios used in the
and black carbon aerosols, [The
methane. tropospheric ozone, in Figure 7-1
GCM simulations are shown rate from exceeding that of today?
Figure 8
,C~abonDiwde.Is it realistic to keep theC02 growth than 4%
increased exponentially at mote
helps us to think about this. After World War Ci emnissions %
2

7. CHIEF COUNSEL OFFICEPAE0
15:06 3012861713
09/20/2001
PericeaI
ta e ol%
by fossil fael6energy Sinc 0ther peortya-
per year, as economries anudwealth eXpanded rapidlydriven was
raehsbenjs oe1veeya.btt19si weohav bas nothear short perios
shock in the 19705, the growth a ea lk
slightly negative. efisDoty ard from having
the past three years it has been syta the wrld
emissions- H-owever, tisfrto nryefcec n eeal
with negative rate of CO2CC
growth of
. This suggests that incr~e mhsso
flat emission emission rates and declining emission
the difference between ibrasn C 2
eergysucscnwk However. I do want to make
~ ~ ge no djCYo seiicplcies.
rates.~ gtit doayo pcfcPl
-ndont want to inappropriately basis of actions that make
is a practical Scenario. it is doable on the or renewable energy can
clea ttteatraiesnario, u stinig that energy efficiency a larger
goodar onornthe andtstatiegi
s~ens."'mnt will continue to increase, as
Shortae. ELMoblts BIg trical power needs Indeed, this is helpful for the sake of
aloeone olve curndsrtepowe use is electrical.
alne slarer puroet poweofour andte wrorld's ee- cras neg
to reduce air pollbutinadin
achieving the alternative scenario, It is more praltcS aruhaing-ma
local sources of fossil fuel should al~so be awar itia
effilenY ata mdempower station than at I pote that policy-makers, scenario if aging nuclear
aruet,
Atiiec ris mofdlterigmman meain ngrgume
ath sms~ions in the alternative
the lutein slowl
t~ciV y lmt
plants.ieaing
bedfiut improved effiienc cleaos-oal
by coal-tfired plants. evwusing bullet' for teproeo nnm7il lmt
powet plants are replaced power is close to being a silver
Other issues a"ide, nuclear contrast the: merits of these
policY-malbag rersentatives should carefully If clean-cOal tecbnology
forcitigs. Thtpflblic and their are each develoed to their modern Potentials-
different energy sources as they
hnaheeet of the alternative scenario way
for coal in Power geeain C2 Cpueof CO2 at power
plants
leads to an increasing role of some of the coaile- te to be
require capture and sequeStratiOfl methods of sequestraItion an the uLtimate effects of sequestrfttidflneed
way in fact be practical, but scenario, in
understood better. for achieving the alternative
~~~~~2~ns The other requiremenit of nion-C0z forcng.rncpl. and
of C0'2, [is to stop the growth (03)
addition to flattening the emissions rate the growtb of black carbon (soot), tropospheric ozone
better reverse dilute amouflts methane is
that means to halt, or even a-s air pollution, although in
methane (CE1 ). 'These can loosely be descrbd carbon, nitrates and sulfates, and txdpospheflc
carbon, with adsore orsanic
4
not harmful to health, Black in air po1 ilib 1 very
ozone are the principal ingredients
1
case of exhaust puffs from
carbon acrosOliexcept~il the extreme
Black carbon (soot). Black tiny 5ponges that soajc up toxic
are invisibly small i~articles. They aie like small that they
dirty diesel tracks or buses, product of fossil fuel combustion. The aerosols are so
ogncmaterial that is also a into the lug.Iti:lt
i oluinhsbe
penetrat human tissue deeply when they are breathed A recent study in Europe [Kunzil. 20001
respiratory and cardiac problems.25,000 new cases of chronic bronchitis,
increasingly implicated in
caused arnuallY 40k00 deaths, Switzerland and
estimated that air pollution 500,000 asthma attacks in France, of therO?
20000 episodes of bronchitis in children, and~ percent olto
from the human health impacts equal to 1.6 carbon in the
Austria alone, with a net cost level- Primary sources of black
the U5S. are at a comrparable
levels and health effects in In h eeoigwrdaesagdl.Asuyrcnl
West are coal burning and diesel fuels. pollutioni h eeoigwrdaepagrn.Asuyrcnl
air
The human~ costs of particulate that about
Sciences [Smirh. 2000] concluded
of the National Academoy of infections arising from
published in the Proceedings per year from acute respiratory nfiin
the age of fie- uyb o eprtr
270,000 Indianpollution. under case the: air pollto scue ~
children
In This of cooking and
pariculate air ad coal within households for
I the purpose
burnngo fied co dun, biwa
reidu, use isthlagtsore
bad, but there residential coal
heating. pollution levels in China are compa~rbly
[Streets. 2001V. black
followed by residential biofii4 cause cooling, in addition to
note that ibeiej are several aerosols thnt eimssiofls or reduce
pReferring back to Figure 2. oso h growth of sullijt
Ifot
There are Ongoii scenario for climate
carbon that causes warm~ing. of reduinacdrn.I our
alternative
emissionis absolutely, for the purpose
3

8. Il
CONLOFIEPt
15:05 3012881713CHE
03/20/2001
cleaner mOrf
cenrmeefincintdieusel motorsand eri placetof
heating. Principal opportunities in the West are o Lie developing world ofpnldeue
io
Opporunmities in
efficient coal buturnin at utilities. eventually use atelectrical energy produced at centralpoeplns
solidfuej forhoushold use, and ourganicf
ethae alozonetfributi)n arevoatil
Ozone (Os). Chemical emissions that lead to anopo cntrbete. PBecausores foei o h
anpetaeolo
compounds and nitrogen oxides (carbon monoXidJ plants and industrialprcse.Baueoneith
power
cemcal ar tansportatiofl Vehicles,
thee leemissi onsei
Sloaltrbem, eig.,
ospheric ozone is a
can have a lifetime of weeks, trop cozon
ofd
free troposphere quality in the United S ates ihlevelsh
Asia are projected to have a significanit effect on air health andero
s
Of the impacts an theUanie
helthandecoystemn effects. Annual costs billion per year i'teUie
hav aders Order Lt $10
ttsaoe
be on the
harodctvetrsaeheacth adecstiatd to to stop further -growthof polltarnt
ths
Our alternative scenario assumes that it will bepsil downwind of reginuhas Western
ozone d ti easing
Recent evidence suggests that tropospheric nowonrle but increasing downwind Of EasAia
are
Europe, where nitrogen Oxide esnissiofls combusintcnlg oaheea
There is aclear potential for cleaner energy source and improved dcyo raiiatrudr
ozone reduction.mehnismcba smcoildcyo rai ae ne
Methane (CR4-. The primary natural soarce b ehn as the natural
AnthropogeIic sore, hc in sum may be twice as great leakage
anoxic conditions in wetlands. rumin ts, baceildecay in landfills
and sewage,
sourc, include rice cultivation, domestic from naD a gas pipelines, and biomiass burning.
during the wining of fossil fuels, leakage wil bposible to stop further growth of methane VithinL 1-2
that it
our alternative scenario assumes are economic benefits to reduction
and bring about a small reduction in mtae by 2050- There and waste
decades to methane Ca-pture from landfills
of methane lass from pipelines and during miiAand clean fuel. There is also an incentive and methods
can be usdas a.
management lagoans, as the methane as their goalsartopduem tilanpwr
available for farmers to reduce methane production~ and fiber flora the fields, not methane. However,
to produce food
fromn the animals, not methane, and automaticaly. The large climate
benefits are not so great that the¶ are: likely to happen gas.
these economic more attention being paid to this
forcing by methane, which is half as large as that yc~,wrat are important
focnbtseveral other forcings
Su~marn- CO, causes the single largest clat the sum of these forchigs. Figure, 2 emphasizes
ems rdce Indeed&
(Figure 2). To reduce global warmuing troposphlic03.o~ and CE4 are important climoate forcings.
carbon,
that, in addition to CO~. black that fossil fuel burning will
of C0 2 . Although it can be assumed
their forcing, in sum, exceeds that (alternative to business-as--Usual)
we suggest aul alternative scenario of a
Continue in the foreseeable future, 50 years and allow the possibility
that would result in relatively moderate climate th ngeh the next possibility of stronger remedies in
later in the Cetu, as well as the
,,soft landing", for climate change a necessity.
onclmtLhfg indicates such is only I W/m .-
t
decades ahead if empirical evidence climate forcing in the next 50 years energy
theade
Alternative scenario. In this scenario sA!s which could be achieved via improved
Thi rquresony dwnten i CO e
.sal
The other requiieifltft in
from no3tfossil fuel sources of energy. conceited attack on air
efficiency and increased contributions clmt forcings, which implies a
this scenario is stop the growth Of non1-C02
pollution. forcing scenario,
- benefits- There are multipl
benefits of the alternative climate
opportunities world, increased
States and especially in the developing
jncluding improved public health in the United for business and technology. Indeed,
the
energy independence for the United States, and opportunities hum-an health and agricultural productivity.
benefits via improved
alternative scenario leads to i6conormic putting the United States in a positive leadership role in a strategy
of
This, scenario also has the advantage wo rld, as well as the developed world- the alternative scenario
that should be welcomed by the developing MO
limat chage. Te increase of climate forcing in
Soft andinfor
the case with business-as-USal.
energy imaac"tan would be
results in a much smaller "planetary a much lower chance of dramatic
climate
Thus we will be willing to our children andgrncidn be feasible to
with C0 2 emissiof! elnn slowly toward 2050, it should
problems. In this scenario, In the worst4
opsto ae nte etury with advanced energy technologies.
stabilize atopeL

9. CHIEF COUNSEL OFFICE
15:05 3012851713
09/20/2001
energy
we fail to have developed non-fossil
cas, i clmat
cang aceleats unacceptably ad should and setluester it, as a Ilarger and larger
CO2 at p wer station
sores,ifbteshould epactic~alto cpture power stations.
gescnb
po IDof energy generation Will occur at cetral progrsban be2
scenaopoidsennfakagntwhh n aamnrhtoieUiedSae g eloblC
M'easurabk Progress. The alternative
demonstrated. Ini the 1990s Idespite extensive gloa aretwel
beusaCOopenisiohc)
fossil fuel us ad
emissions increased, as did global air pollution, mrvn-thus ethseereail years wien th reodsta
af air Pollutionpolluti[onr levels during tenx eea er ihteted
level
tabulated and measurements and air vr teNS
will allow comparison of ernissionlE
that occurred in the recent Past.
ond'efo~c~ the
eie-Hwv' NASA
has no to seen :oel mind oel ntetpc
Disclaimer.Danielspecilic discussion
this
Goldin, has encouraged mtosek
my
Administrator,
century; an alternativC
, .Sto. Watecd- A- Lacis and
V. Oinas, Global warming in the twenty-first
Rdy, Sc, 91. 9875-9880, 2000-
Hansn
scnajlo,Sato . foughtoli. Lfl. Meira
ClmtcCag 992, edited by J.T-
IntgOeD~~nProlane o Cimt ChangeS(DCC) 1992 . ubou61x
resS -. york.,
geN ew
Filha. B -. caliander and
A S.K. Varney, Cambhridge O. Fi - Sommry,M Hora20c, '..Publnic-helt
M-, Chanel. 0Idilier a]dSmmr - 00,~ulc.c~
N.,YKaisor,RB-, Medinla, S. studnicka, B... ver gnau& J.C.
I
Kunzli, VQenel.p., chneidr I, Seetbalor : a European assessment'. The Lancet 35679-01
Texie.
air pollution
Teiepc f o. utdnctr and, tafc-related Ridge, TN, .19798. 8-323
ork Nallt-oab, POcak
aidg
Marlarnd, G. and T. Hoden, co, Information Cenec ssi. i Chin-a29,
97
disease in India fro idoarpllin.Pc.NtAcd
Smith., K R-, National burden of msinnCia
7C odadB iuBakcro
Stretts, D-G-, S. Gupta, S1-TwaidhoffM.Q. Wan~g,
Atrns. Environ-, in press, 2001.
5-

10. B9/20/2001 15:0IB 3012861713 CHIEF COUNSEL OFFICEPAL ,
Summary: CliaeForcings
1. Climate is being forced by' human actions
2. It takes a long time for foirings to have their full effect
3. Reducing the net forcing is clearly desirable
4. CH!, black carbon, and oospheric 03 are almnost as
4
important as CO 2 over tile next 50 years
5. Aggressively targeting the non-CO,2 forcings wvill lead
to slower growth in the net forcing than just 'thckling
CO 2 would, while also leading to other benefits,
especially for human he~lth
6. CO2 remains important, especially on longer time
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