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CO2 GREENHOUSE UPDATE 1985
o Lamont-Doherty Research

. CRSL Research

+ Contribution to DOE State of the Art Report

* Oceanic effects on transient climate change
o Budget Status, Proposal
o DOE and other reports
o Recent research developments

October 4, 1985
New York City
B. P. Flannery

 rt

LAMONT-DOHERTY PROGRAM 1985 PROGRESS REPORT
SEASONAL STUDY OF THE CO2 AND TRACER DISTRIBUTIONS IN
THE HIGH LATITUDE ATLANTIC, W. Broecker and T. Takahashi

.

Goal: gain better understanding of the air-sea exchange
of CO2 in high latitude surface waters

.

First systematic study of seasonal CO2 chemistry in North Atlantic

o Field studies complete March 1985

.

Related studies
+ North Pacific (DOE support)
+ South Pacific (EXXON, DOE)

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SAMPLING POSITIONS IN THE NORTH ATLANTIC

. Transport Freight Limited ships, Greenland stations
EXXON/IFL N()BIH RILRNIIC PNOJECI

 LARGE SEASONAL VARTATTON rN P(CO2)
r9

MAMJ
E

o

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AI

83

t984

-

----*7t"*-----14
EFFECT OF
CIIANGE IN

o
o

oBs€RV

TETllP CORR€CTED

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ar

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--+I----+-- 

4-r---i-::--------n-

€FFECT OF
CHANGE IN

ESERVE0 6B.N

Previously only summer data available, low values
assumed to persist all year

 PRINCIPAL FINDINGS, CONCLUSIONS

. Large, unexpected seasonal variation in P(CO2) in high latitude
surface waters

.

Standard thermodynamic models for CO2 variation
cannot explain observations
+ Biology and mixing required

. lmplication for CO2 uptake by ocean two sided

+ Lower exchange from air to surface ocean
+ Higher exchange from surface to deep water

. Results need to be assessed in quantitative
oceanic carbon cycle

models of

 AVATLABLE COMPTLATTON OF OCEANTC p(CO2)

.

GEOSECS data (Atlantic 72, Pacific 73, lndian 78)

ff

ffi

60

80s

. No information

on seasonal variation

. Much additional data acquired, but not compiled

 "

LAMONT PROPOSAL 1986: SEASONAL AND GEOGRAPHICAL
MAP OF P(CO2) tN SURFACE WATERS
o Compilation

of seasonal P(CO2)map

+ All available data
+ 10 x 10 degree grid

* February, August
.

Objectives
+ Differentiate regional behavior, important effects
+ Develop a seasonal modelto explain variation
+ Re-examine oceanic carbon cycle

 DOE STATE-OF-THE-ART REPORT
MODEL PROJECTIONS OF TIME DEPENDENT RESPONSE
TO INCREASING CARBON DIOXIDE
MJ. HOFFRERT (NYU) and B.P. FLANNERY

.

Observational data for modern climate (1850-1980)

.

Elements of transient climate models

.

Disagreement among results for steady state models

.

Hindcasting for model verification

e Forecasting of future change, first effects

r Conclusions and Recommendations

 HISTORICAL DATA FOR TRANSIENT MODEL VERIFICATION
VARIATION OF GLOBAL MEAN TEMPERATURE 1880.1980

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..--.- 5r.rn.l.ltB2l
r/'tnnltr n.l-

ltsol

-{r3

1880 r89s r0t0 t025 r0a0
rg55 r0ro

r0E5

YEAR

.
.

Temperature change +0.5 C (1980-1880)

Factors besides CO2 must operate
* volcanoes, solar variability, oceanic upwelling

o Other archived data exist, Sea lce, Regional Temperature,

+ Less reliably predicted by models
+ Display more variability, as measured

...

 ELEMENTS OF STEADY STATE AND TRANSIENT MODELS

ATMOSPHERE

fa.ra3l.r!l
Sadranon

Haor t{t, o!, corr

orr

atc.

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H€ar

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w,nd

Str€ss gtot ASS

Armosph.r€.Oc€lnCoupt,

Ch.ngos ol L.^d Fs.lv.es.
Oro!'.phy. Veg€r.r'on.
Ch.nges ot Oc.an aas'n
Shap.. Saln'lt. alc

Steady State response CO2 addition
lR decreases, temperature rises
+ Additionalfeedbacks
- Atmospheric water vapor
- Snow/ice cover
- Cloudiness amounts, types

*

r Transient evolution, timescales
+Land, 1 week
+Atmosphere, 1 month
+Ocean mixed layer, 8 yrs
+Deep ocean,(1 -.10) thousand yrs

 GENERAL CIRCULATION MODELS DISAGREE ON
STEADY STATE RESPONSE 2xCO2
DOUBLED CO2

-----.-.-.
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. Basic results

+ Global mean temperature rise 1.5-4.S C

* Warming greater at poles
. Major disagreement

between models

. Sources of disagreement

+ Treatment of oceanic transport

* Treatment of cloudiness feedback

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=

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. Recent models show 4-5 C Global warming
+ lnclude other trace gasses

 HTNDCASTTNG RESULTS/ VER F CAT ON
Nod.l
Obla.vationt

Modsl

F.

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Obaorvetion.

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Modal: aun + CO2 + volcrno.r

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!+,

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a

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(r980)

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a
GILLILAND (I982)

a

aa
-0.5

a

1880

1900

1920

1940

YEAR

r

Models claim to detect CO2 effect, but required
other types of forcing
volcanoes, solar variation, (oceanic upwelling)

*

o Spurious agreement in conclusions

+ Treatment of forcing differs

* Observational data differs

o Consensus view CO2 warming not yet confirmed by observation

1960

1980

 FORECASTING RESULTS/ PREDICTION AND FIRST EFFECTS

. Requires forecast of future CO2 emissions
.

Ocean delays CO2 warming
+ As yet unrealized warming could be substantial

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v%1////t
o Results from General Circulation Model still unavailable

+ lnclusion oceanic transport challenging task

 coNcLUS roNS/RECOMMENDATTONS
o Modern climate is forced by factors other than CO2

.
.

Oceanic response delays warming by at least 10 years
Consensus prediction 1 C warming (1860-200 O), 2-5 C (2100)

o To date models do not provide unique forecasts

. Model development:
+

*

+

GCM results display substantial discrepancies
Research requires a hierarchy of climate models
Reliable GCM results are at least 10 years away

o Must develop improved understanding of oceanic transport
o Must develop observationally based strategies for model verification

 CR RESEARCH 1984-85

.

Continuing role in the environmental impact assessment
of the Natuna Gas Project

.

Preparation of the "Transient Climate Models" chapter
of the DOE State of the Art Report on CO2 Research

. Role of oceanic effects on climate change

+ Collaborative development of a sophisticated
+

Balance Climate model (Livermore, NYU)
Studies of thermal lag from oceanic effects

Energy

 EMERGING DILEMMA FOR CLIMATE MODELS:
WHY HASN'T WARMING BEEN OBSERVED?

.

Recent GCM models predict greater sensitivity
warming 2xCO2 (1 850-1 980)
2-3
0.8 C marginally detectable
4-5
1.6 C readily detectable

C
C

. Proposed solution, delay from oceanic thermal buffering
much greater than found in previous studies

.

Requires strong thermal coupling between surface

and deep ocean

 MODELS INCLUDING ENERGY TRANSFER TO DEEP OCEAN
PREDICT LONG DELAYS FOR ATMOSPHERIC WARMING

. Purely Diffusive (PD) Model (Hansen 1984)

5

Response to lnslant Ooubling ol COz
(squrlibllum sensalivlty : 4 zoo)

4
65

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mrr.d loy.r hlot copocily
mrrad loycr + lhcrrnochna

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15

35

20

Yeors

o Pattern of global response
Average lag time 125 years

*

90

60
50

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::::::'

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-60

0

Lonqrlirde (degrees)

60

 THE UPWELLING DIFFUSION MODEL FOR HEAT TRANSFER
INTO THE MIXED LAYER AND DEEP OCEAN

.

Schematic of model (Hoffert, Callegari, Hseih 1gg0)

l-.4D.

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. Timescales

+ Mixed layer heat exchange,
+ Diffussion time 5000 years
+ Upwelling time 1000 years

10 years (heat capacity)

b
ta@o

 uPWzulNG DlFFusloN (uD) nxo punEr-v orrrusrvE (pD)
M.DELS
o

Orrent climate, average surface temperature 15 C

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Fa,

Doptb (mobrs)

e lvlodels with 3 C

strface warming
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F

Dopth (mcton)

 COMPARISON OF STEADY STATE SOLUTIONS
UPWzuING DIFFUSION (UD) AND PUREr-V Orr_rUSrVE(PD) MODELS

o Curent climate, average surface temperature 15 C

U:
)
o9

K= 3000

A
E

Dopth (m€tors)

o Temperature change vs depth for
3 C surface warrning
+ PD models require maximum heating

o
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llDlns

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Deptb (motors)

 TRANSIENT EVOLUTION, COMPARISON WITH HANSEN
o Addition of upwelling decreases response time

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Tlmc (:rccrr)

. Recalibrate

Diffusion coefficient using UD model
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. Lag time decades

o

t

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a,

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llmc

(ycars)

 HISTORICAL AND FORECAST CO2 INCREASE 1850-2100

o CO2 record and forecasts

from Weubbles (SOA Report)

E

A
A
a
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()

Hi&

o Corresponding change in equilibrium temperature

+AT=AT(2xCO2)xln(CO2 ppm/540 ppm)

u
F

Lor

Datc

 TEMPERATURE CHANGE WITH UD MODEL
W=4
K= 3000
AT(2xCor)= 2.5

. Surface temperature variation

+ Lag time 30 years in 1983
but increases with time
(poorly defined concept)

O
ol

CO,

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a
6

L
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A
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ql

F

IJ
(,

. Profile of ocean warming (year 2100)

Nominal

U
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()

lY= 4
K= 3000

AT(2xCor)= 2.5

Nominal CO"
Year 21OO '

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a
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L

a,

A
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0,

F

Depth (meters)

 TEMPERATURE CHANGE FOR VARIOUS CO2 FORECASTS

. Surface temperature variation
+ (1850-1985) 0.52 C

+

1 C warming (2007, 2018,2033)

. Lag time decades, not hundreds of years

W=4
K= 3000

AT(2xCO.)= 2.5

 CONCLUSIONS FROM 1D OCEAN MODEL

.

Purely diffusive models overestimate response time
lmproper steady state solution
+ Overestimate diffusion coefficient

.

Lag time poorly defined concept to express
delay in warming caused by oceans

*

.

Response delayed by decades, 30 years, not centuries

.

Simple models can contribute to understanding of oceanic effects

 CR PROGRAM 1986

. Present results Transient Climate models
Ocean modelling conference Woods Hole late 1985
Manuscript in preparation

0 Continuing development of Coupled atmosphere ocean EBM

. Menitor research and reports (80A)

I
I

CO2 GREENHOI.JSE BUDGET, PROPOSAL
Projected
CR EFFOFf,

Professional time

Consultants/R.rchased Research
Travel
Other

TotalCR
Lamont-Doherty

Total

1985
K$

Proposed
1986
K$

132

'140

14
7

35

4

10
5

157

190

93

60

250

250