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Black carbon sources & climate impactsBlack carbon sources & climate impacts

Tami C. BondTami C. BondDepartment of Civil & Environmental EngineeringDepartment of Civil & Environmental Engineering

University of Illinois at UrbanaUniversity of Illinois at Urbana--ChampaignChampaignyark@illinois.eduyark@illinois.edu

Photo: NASA

Black Carbon, Climate, and Air Quality Lunch BriefingWashington, DCApril 29, 2010

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Black carbon is an unusual particle.Black carbon is an unusual particle.

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Scattering particle

Light is reflected away from Earth--

COOLING

Absorbingparticle

Light is absorbed and turned into heat –

WARMING

Almost everything that

is not BCe.g.

sulfates &organic carbon

It looks like thisunder a very strong

microscope

Li et al, J. Geophys. Res.-Atmos., 108(D13), 8484, 10.1029/2002jd002310, 2004.

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Black carbon powerful, immediate warmingCO2 long, slow warmingBlack carbon powerful, immediate warmingCO2 long, slow warming

1500 W

1 g BC (1/25 oz or ½ dime ) = space heater for 1 week7 pounds CO2 = 1 small bulb for 100 years

Both come from an old diesel truck driving 2 miles

1/3 gallon

1 W

Climate impact = mix of emitted pollutantsClimate impact = mix of emitted pollutants

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Black carbon

Reflectingparticles

Cooling clouds usually increase when

particles are added(but not always)

Some sources of black carbon may

produce net cooling.

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Global sources of black carbonGlobal sources of black carbon

Year 2000 estimates (Bond et al., GBC 2007 + van der Werf, 2006 + updates for IPCC AR5)

~8800(short) tons/yr

United States: 5% of globalUnited States: 5% of global

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~460(short) tons/yr

Black carbon sources by latitudeBlack carbon sources by latitude

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0 200 400 600 800 1000 1200 1400-90-80-70-60-50-40-30-20-10

0102030405060708090

BC emissions (Gg/year)

Latit

ude

All longitudes, BC

PowerIndustryRes fossil fuelRes biofuelTransportationCrop wasteOpen burning

North of 40ºNMay travel

directly to Arctic

S of 40ºNAffects

atmosphericwarming

Photo credits: guardian.co.uk (above), V. Ramanathan (below)

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Black carbon’s impacts are complexBlack carbon’s impacts are complex

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Atmosphere(“direct”)

Clouds(indirect)

Snow/ice

Warms atmosphere, cools

ground

More or fewer cloud droplets, more clouds

Melts snow

Where? Main change Also

Alters rainfall

Exposes surface, accelerates melt

Suppresses vertical motion, increases clouds

Global average impactGlobal average impact

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methaneAll

otherAccumulating,

growing in magnitude

Clouds have been apportioned by mass of aerosol emissions, a very crude approximation that is not sanctioned by IPCC.

Source: IPCC AR4 – gases, sulfate, and cloud total; BC + cloud apportionment – own analysis

Some BC sources also emit sulfate, but major sulfate

sources emit little BC

Lifetime: Years

Lifetime: Days

Looks small, but has triple whammy with

melting

Both emission and impact have “hot spots”Both emission and impact have “hot spots”

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Black carbon emission, year 2000Includes energy-related & open

Bond et al., Glob Biogeochem Cyc, 21, GB2018Units: ng/m3/sec

Black carbon distributionKoch et al., Atmos Chem Phys, 9, 9026

Units: ng/m3

Mitigation potentialMitigation potential

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Diesel

Res. wood

Res. coal

Industry

Agri. Burn

Open Burn

STRONG

STRONG-MOD

OPEN QNS

OPEN QNS

OPEN QNS

Feasiblealternatives?

YES

QUESTIONABLE

HIGH

Reduce atmos.

warming?

Some rgnsdeposit to Arctic?*

HIGH

PROBABLE

MAYBE

HIGH

OPEN QNS

HIGH IN PIPELINE

IN PIPELINE

SOME

Implemen-tation?

CHALLENGING

NEED PUSH

NEED PUSH

NEED PUSH

* Confidence applies to some emitting regions; other emissions may not transport

MANY

YES