GJJ1999 THE GREENHOUSE EFFECT AND CLIMATE CHANGE

THE GREENHOUSE EFFECT AND CLIMATE CHANGE

A briefing from the Hadley Centre

Version 1: April 1999

• the greenhouse effect and greenhouse gases

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GJJ99 1Hadley Centre for Climate Prediction and Research

• the greenhouse effect and greenhouse gases

• modelling climate change

• predictions of climate change

• sea level rise and ocean currents

• uncertainties

• the attribution of recent change

THE GREENHOUSE EFFECT

Visible energy from the sun passes through the glass and heats the ground

Infra-red heat energy from the ground is partly

reflected by the glass, and some is trapped inside the

greenhouse

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THE GREENHOUSE EFFECT

SUNSome solar radiation isreflected by the earth’s

surface and the atmosphere

Some of the infraredradiation is absorbedand re-emitted by thegreenhouse gases.

The effect of this is towarm the surface

and the loweratmosphere

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ATMOSPHERE

Solar radiationpasses through theclear atmosphere

EARTHMost solar radiation is absorbedby the surface, which warms

Infrared radiationis emitted from theEarth’s surface

THE LONDON, EDINBURGH AND DUBLIN

PHILOSOPHICAL MAGAZINEAND JOURNAL OF SCIENCE

[FIFTH SERIES APRIL 1896]

XXXI. On the Influence of Carbonic Acid in the Air upon the Temperatureof the Ground. By Prof. SVANTE ARRHENIUS*.

1. Introduction: Observations of Langley on Atmospherical Absorption.

A GREAT deal has been written on the influence of the absorption of the atmosphere upon the climate. Tyndall † in particular has pointed out the enormous importance of this

question. To him it was chiefly the diurnal and annual variations of temperature that were lessened by this circumstance. Another side of the question, that has long attracted the

attention of physicists, is this: Is the mean temperature of the ground in any way

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lessened by this circumstance. Another side of the question, that has long attracted the attention of physicists, is this: Is the mean temperature of the ground in any way influenced by the presence of heat-absorbing gases in the atmosphere? Fourier ‡

maintained that the atmosphere acts like the glass in a hot house, because it lets through the light rays of the sun but retains the dark rays from the ground. This idea was

elaborated by Pouillet §; and Langley was by some of his researches led to the view, that ‘the temperature of the earth under direct sunshine, even though our atmosphere were present as now, would probably fall to – 200 °C., if that atmosphere did not possess the

* Extract from a paper presented to the Royal Swedish Academy of Sciences,11th December 1895. Communicated by the Author.

† “Heat a mode of motion,” 2nd ed. p.405 (Lond.,1865).‡ Mem. de l’Ac. R. d. Sci. de l’Inst. de France, t. vii. 1827.

§ Compress rendus, t. vii. p41 (1838).

Phil. Mag. S. 5. Vol. 41. No. 251. April 1896 S

ATMOSPHERE5.51.5

22

NATURAL AND HUMAN-MADE CYCLE OF CARBON

Annual transfers in GtC natural and human-made

3

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OCEANLAND

90 9060 60

22

Source: IPCC

THE EFFECT OF AEROSOL ON CLIMATE

Solar radiationscattered back =cooling influenceon climate

Aerosol in the

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Sulphur dioxideemissions

Aerosol in theboundary layer

THE INDIRECT EFFECT OF AEROSOL

Somesunlightreflected

More sunlightreflected –

cooling effect

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Brighter clouds‘Normal clouds’

Relatively cleanlower atmosphere

Pollutedlower atmosphere

ATMOSPHERIC CONSTITUENTS sources, lifetimes

Carbon dioxide Fossil fuels, land use changes 100 yea rs

Methane Agriculture, natural gas 10 years

Nitrous oxide Combustion 150 years

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Chlorofluorocarbons Production 100 years

Ground-level ozone Transport, industry 3 months

Aerosol Power generation, transport 2 weeks

RISING GREENHOUSE GAS CONCENTRATIONS

Carbon dioxide: 33% rise Methane: 100% rise

Mauna LoaObservatory

Flasks

340

360

380

1400

1600

1800

conc

entr

atio

n/pp

m

Met

hane

con

cent

ratio

n/pp

b

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Source: IPCC


Ice cores

Ice cores

1700 1800 1900 2000Year

1700 1800 1900 2000Year

260

280

300

320

340

600

800

1000

1200

1400

CO

2co

ncen

trat

ion/

ppm

Met

hane

con

cent

ratio

n/pp

b

CONCENTRATIONS OF CO2

conc

entr

atio

n (p

pm)

750

650

550Constant 1990

emissions

Best estimate(IS92a)

CO2 concentration dueto three emission scenarios

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CO

2co

ncen

trat

ion

(ppm

)

450

350

2501990 2010 2030 2050 2070 2090

Year

Pre-industrial

50% 1990emissions

Source: IPCC

GREENHOUSE WARMING POTENTIALof some greenhouse gases, 100 year horizon

carbon dioxide 1methane 21nitrous oxide 310

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Source: IPCC


nitrous oxide 310CFC12 8 100HCFC22 1 500HFC134a 420sulphur hexafluoride 34 900

RELATIVE WARMING OF GREENHOUSE GASES current emissions, over next 100 years

Methane24%

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Source: IPCC


Tropospheric ozone

not included

24%Carbondioxide

63%Nitrous

oxide 10%

Others3%

PREDICTING CLIMATE CHANGE

CONCENTRATIONSCO2, methane, etc.

HEATING EFFECT

Scenarios frompopulation, energy,economics models

Carbon cycle andchemistry models

EMISSIONS

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HEATING EFFECT‘Climate Forcing’.

IMPACTSFlooding, food supply, etc.

Gas properties

Coupled climatemodels

Impacts models

CLIMATE CHANGETemp, rain, sea-level, etc.

CONCENTRATIONSCO2, methane, etc.

HEATING EFFECT

Scenarios frompopulation, energy,economics models

Carbon cycle andchemistry models

Feedbacks

EMISSIONS

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PREDICTING CLIMATE CHANGE


HEATING EFFECT‘Climate Forcing’.

IMPACTSFlooding, food supply, etc.

Gas properties

Coupled climatemodels

Impacts models

CLIMATE CHANGETemp, rain, sea-level, etc.

Feedbacks

THE CLIMATE SYSTEM

Clouds

Solar

Terrestrialradiation

Greenhouse gases and aerosol

ATMOSPHERE

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OCEAN

PrecipitationSea-ice

LAND

Ice- sheetssnow

Biomass

Solarradiation

Atmosphere Atmosphere Atmosphere Atmosphere Atmosphere A tmosphere

Land surfaceLand surfaceLand surfaceLand surfaceLand surface

Ocean & sea-ice Ocean & sea-ice Ocean & sea-ice Ocean & sea-ice

Sulphateaerosol

Sulphateaerosol

Sulphateaerosol

Non-sulphateaerosol

Non-sulphateaerosol

Carbon cycle Carbon cycle

1975 1985 1992 1997

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HADLEY CENTRE EARTH SYSTEM MODEL


Atmosphericchemistry

Ocean & sea-icemodel

Sulphurcycle model

Non-sulphateaerosols

Carboncycle model

Land carboncycle model

Ocean carboncycle model



Off-linemodeldevelopment

Strengthening coloursdenote improvementsin models

HADLEY CENTRECoupled Ocean Atmosphere Climate Model

• ocean model: 1.25°x 1.25°grid • 20 vertical levels: T, S

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• atmosphere model • 2.5°lat x 3.75°long•19 vertical levels•T, q, q c, v, p*

HADLEY CENTRE CLIMATE MODELFORTRAN programme code

CALL SUBROUTINE LSP_FOCWWIL! Purpose: Calculate from temperature the Fraction Of Cloud Water Which! Is Liquid. Operates within range 0 to -9 deg.C based upon! MRF observational analysis.

*CALL C_0_DG_CREAL& TSTART ! Temperature at which ROCWWIL reaches 1.&,TRANGE ! Temperature range over which 0 < ROCWWIL < 1.PARAMETER(TSTART=TM, TRANGE=9.0)DO I = 1, POINTS

TFOC = T(I)

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TFOC = T(I)! Calculate fraction cloud water which is liquid (FL)as in eq. P26.50.

IF (TFOC .LE. (TSTART - TRANGE)) THEN! Low temperatures, cloud water all frozen------------------------

ROCWWIL(I) = 0.0ELSE IF (TFOC .LT. TSTART) THEN

! Intermediate temperatures---------------------------------------ROCWWIL(I) = (TFOC - TSTART + TRANGE) / TRANGE

ELSE! High temperatures, cloud water all liquid-----------------------

ROCWWIL(I) = 1.0END IF

END DO ! Loop over points RETURNEND

*ENDIF

The third Hadley Centrecoupled climate model

• ocean resolution 1.25 o x 1.25o, plus improved ocean parametrisations

• improved parametrisation of radiation,

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• improved parametrisation of radiation, land surface, mountains, clouds

• obviates the need for flux corrections

• interactive sulphur cycle model

• better validation against ocean data

70°N

60°N

50°N

40°N

30°N

90°W 10°E10°W30°W50°W70°W

0 4 8 12 16 20

SIMULATION OF

THE GULF

STREAM

improves

at higher ocean

resolution

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70°N

60°N

50°N

40°N

30°N

90°W 10°E10°W30°W50°W70°W

Above: Currents at 50m

with 1.25 x 1.25°ocean

(HadCM3)

Below: Currents at 50m

with 2.5 x 3.75°ocean

(HadCM3L)

resolution

IMPACTS OF CLIMATE CHANGEassessments using Hadley Centre scenarios

• Hadley model data is supplied freely for impacts assessments, via the LINK/DDC project at UEA

• Data have been used by over 100 groups worldwide, for assessments including:

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for assessments including:

– African climate change (World Bank)

– Forest fires (WWF, USDA)

– Global water scarcity (ODA - DfID)

• Scenarios based on Hadley data used by national impacts assessments: UKCIP, US Programme, EC

GLOBAL TEMPERATURE RISEdue to “business-as-usual” greenhouse gas emissions

Tem

pera

ture

ris

e / d

egre

es C

Had

CM

3 G

HG

and

con

trol

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Tem

pera

ture

ris

e / d

egre

es C

Had

CM

3 G

HG

and

con

trol

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Changes in land, sea, and global mean surface tempe raturedue to ‘business-as-usual’ greenhouse gas emissions .

HadC

M3 G

HG

CHANGE in TEMPERATUREby the 2050s, relative to present day, northern win ter

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90N

0

45N


Degrees C

Had

CM

3GH

G

90S

0

45S

180 18090W 90E0

-2 0 1 2 4 6 8

CHANGE in PRECIPITATIONby the 2050s, relative to present day, northern win ter

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90N

0

45N


Mm/day

Had

CM

3GH

G

90S

0

45S

180 18090W 90E0

-4 42-2 0

CHANGES IN UK CLIMATE by the 2050srelative to the present day

0

20

10

5

2

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Annual meantemperature change (deg C)

Summertime (JJA)rainfall change (%)

-2

-5

-10

-20

HadCM2GHGx4UEANORWICH

Rel

ativ

e fr

eque

ncy

of o

ccur

renc

e

DAILY NIGHT MINIMUM TEMPERATURES

HadCM2 GHGSE England

Summer (JJA)

control

2070-99

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Rel

ativ

e fr

eque

ncy

of o

ccur

renc

e

Temperature / degree C

UK RAINFALL PROBABILITYPre-industrial 2050s

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Summer Winter

Pro

babi

lity

(%)

Pro

babi

lity

(%)


Daily rainfall (mm) Daily rainfall (mm)

Pro

babi

lity

(%)

Pro

babi

lity

(%)

CHANGE IN UK WINTER PRECIPITATIONfrom the Global Model and the Regional Model

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GLOBAL MODEL EUROPEAN MODELmm/day

-1 0.5 0.2 0 0.5 1 1.5 -1 0.5 0.2 0 0.5 1 1.5

TEMPERATURE

RISE OVER

NORTHERN

ENGLANDWinter (DJF)

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6

4

2

0

-2

-4

-6

6

Tem

pera

ture

(oC

)


Simulated by the

Hadley Centre

climate model,

relative to 1961-90H

adC

M3G

HG

Summer (JJA)

4

2

0

-2

-4

-6

Tem

pera

ture

(oC

)

1900 1950 2000 2050 2100Year

PREDICTIONS OF TEMPERATURE CHANGE

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HadC

M3

CHANGE IN SUMMER

RAINFALL OVER EUROPE

2030-2049(mm/day)

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top: when greenhouse gases only are increased

bottom: when the effect of changes in sulphate aerosol are also included

SEA LEVEL RISE and its components

0.8

0.6

0.4

TotalThermal expansionGlaciersGreenland

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HadC

M2 G

HG

1

0.4

0.2

0.01950 2000 2050 2100Year 1900

Sea-level rise 1860 –2100

PATTERNS OF SEA LEVEL RISEchange by 2090 from present day (mm)

90°N

45°N

0°

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HadC

M2 G

HG

1

45°S

90°S180 90°W 0 90°E 180

100 200 300 400 500 600 700Mean = 520 mm

CHANGE IN STORM SURGE FREQUENCY

Ret

urn

heig

ht/m

etre

s

Harwich (data from POL)

Current 100-yearreturn period water level

31 cm sea-level rise by 2050s

5.5

6.0

6.5

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Ret

urn

heig

ht/m

etre

s

by 2050s

Return periodin 2050s=20 years

1 10 100 10004.5

5.0

Return period/years

TEMPERATURE PROFILE IN THE OCEANchange by 2080s from pre-industrial

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HadC

M3 G

HG

SEA LEVEL RISE COMMITTMENTThermal expansion and land ice melt after an initial 1% increase in CO2 for 70 years


GLOBAL OCEAN CIRCULATIONCOOLING

WARM

SURFACE

CURRENT

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INTERMEDIATE

WATERS

WARM AND LESS SALINE ANTARCTIC CIRCUMPOLAR CURRENT

CHANGES TO OCEAN CIRCULATION

UnperturbedIPCC ‘business-as-usual’2% pa rise in concentrations

–30

–25

–20

Circ

ulat

ion

stre

ngth

(S

verd

rups

)

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HadC

M3 G

HG

–20

–15

–101900 1950 2000 2050 2100

Year

Circ

ulat

ion

stre

ngth

(S

verd

rups

)

N ATLANTIC SEA TEMPERATURESchange by 2090 from present day (C)

75°N

60°N

45°N

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HadC

M3 G

HG

1

30°N

15°N90°W 60°W 30°W 0

–4.5 –3 – 1.5 0 1.5 3 4.5

UNCERTAINTIES IN CLIMATE CHANGE PREDICTIONS

• projections of future emissions• initial climate conditions• natural and human climate factors• realism of the climate model

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• realism of the climate model– feedbacks– resolution– extremes of climate

• surprises• estimating uncertainty• climate variability over the next decade

IPCC SRES99 CO2 EMISSIONS(Fossil fuels, GtC per year)

20

25

30

A1

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0

5

10

15

1990 2020 2050 2100

A2B1B2

4

2

3

4Te

mpe

ratu

re r

ise

/ deg

C

GLOBAL TEMPERATURE RISE due to the IPCC SRES99 emissions scenarios

Hadley EBM climate sensitivity=2.5KA1A2B1B2


0

1

2

Tem

pera

ture

ris

e / d

eg C

2000 2020 2040 2060 2080 2100

GLOBAL TEMPERATURES UNDER KYOTO PROTOCOLdue to IPCC ‘business-as-usual’ and three post-Kyot o scenarios

IS92a

Only Kyoto

B constant

B-1% p.a.

Tem

pera

ture

ris

e/

°C

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4.0

3.0


2100208020602040202020000.0

1.0

2.0

Tem

pera

ture

ris

e/

UNCERTAINTY DUE TO INITIAL CONDITIONSAn ensemble of projections of warming due to 1% per year increase in CO 2

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HadC

M2 G

HG

GLOBAL-MEAN RADIATIVE FORCING(pre-industrial to 1992)

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Source: IPCC


CLOUDS AND CLIMATE

Low clouds reflect sunlight but trap little infra-red radiation;

They act to cool climate

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High clouds reflect sunlight but also trap infra-red radiation;

They act to warm climate

Global warming may change the characteristics of clouds, and thus alter their current net cooling effect; th is could

exert a powerful feedback on climate change .

The Met.Office C-130 RESEARCH AIRCRAFT

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SIMULATED WINTER PRECIPITATION

300kmGlobal Model

50kmRegional Model

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Mm/day


25kmRegional Model

Observed

WINTER

SEA SURFACE

TEMPERATURES

in the

NORTH

ATLANTIC

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ATLANTIC

1945 - 1999

HadISST3.0

Florida Distance along track (x 1000km) Scotla nd

Sea Surface Temperature anomaly (K)

GLOBAL MEAN SURFACE TEMPERATURE1860-1998

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Global surface temperaturesrelative to average for 1961-90

0.4

0.5

0.6

Cha

nge

(deg

rees

C)

1

23

4

5

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0

0.1

0.2

0.3

80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98

Cha

nge

(deg

rees

C)

10

5

67 89

GLOBAL TEMPERATURE RISEobserved from three independent sources

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0.6

0.4

0.2

0.0

Diff

eren

ces,

oC


0.0

-0.2

-0.4

-0.6

-0.8

Diff

eren

ces,

Sea surface

Night marine air

Land surface

1860 1880 1900 1920 1940 1960 1980 2000

THE EL NINO OF 1997/98Sea surface temperature anomalies in November 1997

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EL NINO AND LA NINA, 1870-1998GJJ1999


Changes in sea-surface temperature for the eastern tropical Pacific off Peru.

Tem

pera

ture

cha

nge

deg

rees

C

OBSERVATIONS OF TEMPERATURE CHANGEat the surface and in the atmosphere

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1.5

Atmosphere

Surface


Tem

pera

ture

cha

nge

deg

rees

C

1.0

0.5

0.01970 1975 1980 1985 1990 1995 2000

Causes of recent climate change

• Has climate changed? - monitoring

• Is the change unusual? - detection

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• Is the change unusual? - detection

• What are its causes? - attribution

CLIMATE CHANGE DUE TO CHANGES IN EARTH’S ORBIT

Temperature changes deduced from Antarctic ice cores (Russian-French Vostok analysis)

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Source: IPPCC


1374

1372

Sol

ar r

adia

tion

/ W

m–2

CHANGES IN SOLAR ACTIVITY

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1370

1368

1850 1900 1950 2000

Sol

ar r

adia

tion

/ W

m

0.15

Rel

ativ

e ab

sorp

tion

of s

unlig

ht

CHANGES IN VOLCANIC AEROSOL

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Source: Sato


0.10

0.05

0.00

1850 1900 1950

Rel

ativ

e ab

sorp

tion

of s

unlig

ht

2000

0.3

0.4

0.5

Atm

osph

eric

sul

phur

/ T

g

340

360

380

CO

2 co

ncen

trat

ion

/ ppm

Mauna LoaObservatory

Carbon dioxide Sulphateaerosol

CHANGES IN HUMAN FACTORSGJJ1999


20001900180017000.0

0.1

0.2

Year

Atm

osph

eric

sul

phur

/ T

g

2000195019001850180017501700260

280

300

320

CO

2 co

ncen

trat

ion

/ ppm

ice cores

NATURAL VARIABILITY OF CLIMATE

0.2

0.4

0.6

0.8

1.0Model controlObserved

Tem

pera

ture

var

iatio

n (

°C)

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–0.4

–0.2

0.0

0.2

Tem

pera

ture

var

iatio

n (

2000 2200 2400 2600 2800

Year

HadC

M2 G

HG

GLOBAL MEAN SURFACE TEMPERATUREsimulated and observed

2.0

1.5

1.0

Greenhouse gases onlyAll anthropogenic factorsObserved

Tem

pera

ture

diff

eren

ce (

°C)

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HadC

M3

0.5

0.0

–0.51860 1880 1900 1920 1940 1960 1980 2000

Year

Tem

pera

ture

diff

eren

ce (

SURFACE AIR TEMPERATURE

change from 1880-1920 to 1975-95

Observed–1 –0.5 0 0.5 1 1.5 2

90°W 0° 90°E

90°N

45°N

45°S

90°S180°

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Simulated

HadC

M2

90°W

–1

0° 90°E

–0.5 0 0.5 1 1.5 2

90°N

45°N

45°S

90°S180°

TEMPERATURE TRENDS IN THE ATMOSPHERE1961 - 1996

1520

90°N

Hei

ght (

km)

0

5

10

1520

45°N 0° 45°S 90°SObserved

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Hei

ght (

km)

0

5

10

15

°C / year

90°N 45°N 0° 45°S 90°S

–0.08 –0.06 –0.04 –0.02 0 0.02 0.04

HadC

M2 G

HG

Simulated

ATTRIBUTION OF RECENT CLIMATE CHANGE

• Comparison of model simulated patterns of change (“fingerprints”) with those observed

• changes in time and space and by season ; discriminates against eg solar and volcanic

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discriminates against eg solar and volcanic

• gives low weight to areas of high natural variabili ty

• indicates human-made activities are largely responsible for changes since 1945

• NB: assumes patterns of change and natural variability are adequately simulated by model

GJJ1999 THE GREENHOUSE EFFECT AND CLIMATE CHANGE

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Transcript of GJJ1999 THE GREENHOUSE EFFECT AND CLIMATE CHANGE