Black carbon sources & climate impacts Black carbon sources & climate impacts Tami C. Bond Tami C. Bond Department of Civil & Environmental Engineering Department of Civil & Environmental Engineering University of Illinois at Urbana- -Champaign Champaign University of Illinois at Urbana yark@illinois.edu yark@illinois.edu Black Carbon, Climate, and Air Quality Lunch Briefing Washington, DC April 29, 2010 Photo: NASA 1 1
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Black carbon is an unusual particle. Black carbon is an unusual particle. Light is reflected away from Earth-- COOLING Scattering particle Almost everything that is not BC e.g. Absorbing sulfates & particle organic carbon It looks like this under a very strong Light is absorbed and microscope turned into heat – WARMING Li et al, J. Geophys. Res.-Atmos., 108(D13), 8484, 10.1029/2002jd002310, 2004. 3 3
Black carbon � powerful, immediate warming Black carbon � powerful, immediate warming CO2 � long, slow warming CO2 � long, slow warming 1 W 1 5 0 0 W n o l l a g 3 / 1 1 g BC ( 1 / 25 oz or ½ dime ) = space heater for 1 week 7 pounds CO 2 = 1 small bulb for 100 years Both come from an old diesel truck driving 2 miles 4 4
Climate impact = mix of emitted pollutants Climate impact = mix of emitted pollutants Black Reflecting carbon particles Some sources of black carbon may produce net cooling. Cooling clouds usually increase when particles are added (but not always) 5 5
~ 8800 Global sources of black carbon Global sources of black carbon (short) tons/yr 6 6 Year 2000 estimates (Bond et al., GBC 2007 + van der Werf, 2006 + updates for IPCC AR5)
(short) tons/yr 7 7 ~ 460 United States: 5% of global United States: 5% of global
Black carbon sources by latitude Black carbon sources by latitude All longitudes, BC 90 80 North of 40º N 70 May travel 60 directly to Arctic 50 40 30 20 Latitude 10 0 Power -10 Industry -20 Res fossil fuel -30 S of 40º N -40 Res biofuel Affects -50 Transportation -60 atmospheric Crop waste -70 warming -80 Open burning -90 0 200 400 600 800 1000 1200 1400 BC emissions (Gg/year) 8 8 Photo credits: guardian.co.uk (above), V. Ramanathan (below)
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Black carbon’s impacts are complex Black carbon’s impacts are complex Also Main change Where? Warms Atmosphere Alters rainfall atmosphere, cools (“direct”) ground Suppresses More or fewer Clouds vertical motion, cloud droplets, increases clouds more clouds (indirect) Exposes surface, Snow/ice Melts snow accelerates melt 10 10
Global average impact Global average impact Looks small, but has triple whammy with melting Lifetime: Days Some BC sources also emit sulfate, but major sulfate sources emit little BC Accumulating, All methane other growing in magnitude Lifetime: Years Clouds have been apportioned by mass of aerosol emissions, a very crude approximation that is not sanctioned by IPCC. 11 11 Source: IPCC AR4 – gases, sulfate, and cloud total; BC + cloud apportionment – own analysis
Both emission and impact have “hot spots” Both emission and impact have “hot spots” Black carbon emission, year 2000 Includes energy-related & open Bond et al., Glob Biogeochem Cyc, 21, GB2018 Units: ng/m 3 /sec Black carbon distribution Koch et al., Atmos Chem Phys, 9, 9026 12 12 Units: ng/m3
Mitigation potential Mitigation potential Reduce Some rgns Feasible Implemen- atmos. deposit to alternatives? tation? warming? Arctic?* Diesel STRONG HIGH YES SOME Res. wood HIGH IN PIPELINE STRONG-MOD NEED PUSH Res. coal IN PIPELINE MAYBE NEED PUSH OPEN QNS Industry PROBABLE OPEN QNS MANY NEED PUSH Agri. Burn HIGH OPEN QNS CHALLENGING YES Open Burn HIGH QUESTIONABLE OPEN QNS 13 13 * Confidence applies to some emitting regions; other emissions may not transport
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