THE GREENHOUSE EFFECT

Stephen E. Schwartz

Atmospheric Sciences Division

CSSP Lecture

July 30, 2002

http://www.ecd.bnl.gov/steve/schwartz.html

370360350340330320310

20001990198019701960

C. D. Keeling

Year

CO

2 co

ncen

trat

ion

(ppm

)

180

200

220

240

260

280

300

320

340

360

380

800 1000 1200 1400 1600 1800 2000

Law Dome Adelie LandSipleSouth Pole

Mauna Loa Hawaii

ATMOSPHERIC CARBON DIOXIDE IS INCREASING

Global carbon dioxide concentration over the last thousand years

Polar ice cores

Mann et al., Geophysical Research Letters, 1999

Northern Hemisphere temperature trend (1000-1998), fromtree-ring, coral, and ice-core proxy records As calibrated byinstrumental measurements.

1000 1200 1400 1600 1800 2000YEAR

-1.0

-0.5

0.0

0.5

1.0T

EM

PE

RA

TU

RE

AN

OM

ALY

(o C

)

Reconstruction (AD 1000-1980)Instrumental data (AD 1902-1998)Calibration period (AD 1902-1980) meanReconstruction (40 year smoothed)Linear trend (AD 1000-1850)

1998

THE TEMPERATURE'S RISING

ATMOSPHERICRADIATION

Energy per area pertime

Power per area

Unit:Watt per square meterW m-2

GLOBAL ENERGY BALANCEGlobal and annual average energy fluxes in watts per square meter

343

237

237≈ 254K

390≈288K

106 68

169

327 9016

Rayleigh

Aerosol

α = 31%

69% = 1 -α

1/4 S0 1/4 S0 =(1-α ) σT4

Shortwave Longwave

H2O, CO2, CH4...

Atmosphere

LS

Schwartz, 1996, modified from Ramanathan, 1987

RADIATIVE FORCING

A change in a component of the Earth’s radiationbudget.

GLOBAL CARBON DIOXIDE OVER THE INDUSTRIAL PERIOD

360

340

320

300

280

CO

2 M

ixin

g R

atio

, µm

ol/m

ol(a

ir) [p

pm]

200019501900185018001750

0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

Forcing, W

m-2

370

360

350

340

330

320

31020001990198019701960

C. D. Keeling

ICE CORESSIPLE STATION ANTARCTICA

← MAUNA LOA HAWAII →

GREENHOUSE GAS MIXING RATIOS OVER THE INDUSTRIAL PERIOD

280

300

320

340

360

ppm

CO2

ice core

in situ↓ ← →

800

1200

1600

ppb

CH4

ice core insitu

Antarctica

Greenland↓ ↑

↑

↓

280

300

320

ppb

N2O

ice core in situ↓

↑

1850 1875 1900 1925 1950 1975 2000 0

200

400

600

CFC-11CFC-12other trace gas forcingpp

t

CFCs

converted to CFC-11 amount

Hansen et al., PNAS. 1998

GREENHOUSE GAS FORCINGS OVER THE INDUSTRIAL PERIOD2.5

2.0

1.5

1.0

0.5

0.0

For

cing

rel

ativ

e to

185

0, W

m-2

2000197519501925190018751850

Year

Total

CO2

CH4

N2OCFC-12CFC-11

Other

Data: GISS

NORTHERN HEMISPHERE TEMPERATURE TREND (1000-1998)From tree-ring, coral, and ice-core proxy records

As calibrated by instrumental measurements

1000 1200 1400 1600 1800 2000YEAR

-1.0

-0.5

0.0

0.5

1.0

TE

MP

ER

AT

UR

E A

NO

MA

LY (

o C)

Reconstruction (AD 1000-1980)Instrumental data (AD 1902-1998)Calibration period (AD 1902-1980) meanReconstruction (40 year smoothed)Linear trend (AD 1000-1850)

1998

Mann et al., GRL, 1999

WHERE IS ALLTHIS CO

COMING FROM?2

WHO IS RESPONSIBLE?

HOW MUCH CARBONIS IN A GALLON

OF GASOLINE?

? ??

? ?

1 lb? 2 lbs?3 lbs!? 5 lbs!?!

?

All of this carbon goes into the atmosphere as carbon dioxide whenyou burn the gasoline in your car.

? ?

THE MOST EFFECTIVE WAY TO DOUBLE THE FUEL ECONOMY OF A CAR . . .

IS TO PUT TWO PEOPLE IN IT!

YOUR FAMILY’S CONTRIBUTION TO THEGREENHOUSE EFFECT

0.8

0.6

0.4

0.2

0.0CO

2 em

issi

ons,

Pou

nds

(C)

per

KW

H

Coal Oil Natural gas Nuclear

CARBON DIOXIDE EMISSIONS FROMELECTRIC ENERGY PRODUCTION

(1990's Technology)

Suffolk County 2001Legislation

How much does your household contribute?

A typical household using 1000 kilowatt hours of electricityper month is responsible for emission of 3 tons of carbona year in the form of carbon dioxide.

YOUR CONTRIBUTION TO THE GREENHOUSE EFFECT

0.49 lbs Carbon per KWH

At half a pound of carbon per KWH, the average household is responsible for emission of 500 pounds of carbon a month.

Breath of Fresh AirGaffney signs bill to limit greenhouse gas emissions

July 25, 2001By Emi Endo

Suffolk County ExecutiveRobert Gaffney yesterdaysigned into law a bill aimed atlimiting greenhouse gasemissions locally, althoughcritics questioned how much itwould actually reduce theemissions.

Beginning in March, for every100 megawatts of newgeneration added in thecounty, the emissions ratemust be reduced by 1 percent,

until a 20-percent reduction isachieved. Power plants thatexceed the standard would facefines.

During negotiations, Fisherraised the emissions limit fromless than 1,500 pounds to1,800 pounds of carbondioxide per megawatt hour andcut the penalties from $5 foreach ton of carbon dioxideemissions exceeding the limitto $2.

Suffolk County Limits CO Emissions2

0.49 lbs Carbon per KWH

WHERE DOES YOUR ELECTRIC ENERGYCOME FROM?

50

40

30

20

10

0

Per

cent

of T

otal

Coal Natural Gas Oil Hydro Geothermal Solar Wind Biomass Nuclear

SOURCES OF ELECTRIC ENERGYIN THE UNITED STATES

- - - FOSSIL FUEL - - -

- - - Less than 1 % each - - -

- - - - - Renewable - - - - -

Annual Total 3.71 Trillion KWH

On Long Island most electric energy derives from combustion of oil.

WHAT COUNTRY USES THE MOSTELECTRIC POWER?

WHAT COUNTRY USES THE MOSTELECTRIC POWER?

30

20

10

0

Per

cent

of T

otal

US China Russia Japan Germany

ANNUAL ENERGY CONSUMPTIONTotal Global Consumption 382 Quadrillion BTU

Selected Countries

No surprise. It's the United States.

WHAT COUNTRY USES THE MOSTELECTRIC POWER PER CAPITA?

WHAT COUNTRY USES THE MOSTELECTRIC POWER PER CAPITA?

No surprise. It's the United States again.

400

300

200

100

0Mill

ion

BT

U p

er p

erso

n pe

r ye

ar

US China Russia Japan Germany

PER CAPITA ENERGY CONSUMPTIONSelected Countries

THE “BIBLE” OF CLIMATE CHANGE RESEARCH

Cambridge University Press, 2001