Source sector and region contributions to
concentration and direct radiative forcing
of black carbon in China
Ke Li, Hong Liao*, Yuhao Mao
Institute of Atmospheric Physics, Chinese Academy of Sciences (IAP/CAS)
D. A. Ridley
Department of Civil and Environmental Engineering,
Massachusetts Institute of Technology, Cambridge, MA, USA
IGC7, May 4-7, 2015 @Harvard
Motivations
Bond et al. (JGR, 2013）
Our scientific question is:
To quantify the contributions from the major emission sectors in
China and non-China emissions to concentration and DRF of
BC in China.
BC emission inventories in China
Reference
year
energy
Industry
Residential Transportation
Total
198 (11%)
Biomass
burning
N.A.
Zhang et
al. (2009)
2006
36 (2%)
575 (32%)
1002 (55%)
Wang et al. 2007
(2012)
51 (3%)
646 (33%)
988 (51%)
188 (10%)
78 (4%)
1951
Lu et al.,
2011
2008
19 (1%)
510 (29%)
888 (50%)
259 (15%)
110 (6%)
1786
Qin and
Xie, 2012
2009
11 (1%)
735 (40%)
777 (41%)
241 (13%)
117 (6%)
1881
Lu et al.,
2011
2010
21 (1%)
501 (27%)
936 (51%)
283 (15%)
109 (6%)
1850
HTAP
2010
18 (1%)
550 (30%)
893 (49%)
270 (15%)
109 (6%)*
1840
1811
Unit：Gg C yr-1
HTAP (Janssens-Maenhout et al., 2015, ACPD): the Task Force on Hemispheric Transport
of Air Pollution project http://edgar.jrc.ec.europa.eu/htap_v2/index.php?SECURE=123
(Emissions of HTAP in Asia based on MICS-Asia)
* Biomass burning emissions used here are from Lu et al. (2011)
Simulation experiments
 GEOS-Chem model, v9-01-03, nested over Asia (0.5× 0.667)
 All simulations with GEOS-5 meteorology for year 2010
 RRTMG coupled with GEOS-Chem (Heald and Ridley et al., ACP, 2014)
Experiments
BC emissions
(1) CTRL
The control simulation with all global BC emissions from all sectors
(2) no_IND
Same as CTRL, but BC emissions from industry are set to zero in China
(3) no_ENG
Same as CTRL, but BC emissions from energy are set to zero in China
(4) no_RES
Same as CTRL, but BC emissions from residential are set to zero in China
(5) no_TRAS
Same as CTRL, but BC emissions from transportation are set to zero in China
(6) no_Biob
Same as CTRL, but BC emissions from biomass burning are set to zero in
China
(7) no_China
Same as CTRL, but all BC emissions in China are set to zero
Model evaluation: surface BC concentrations
Annual mean
NMB = – 31%
r = 0.65
Model evaluation: BC absorption AOD
Comparison of simulation AAOD vs. observation

10 sites retrieved BC
absorption AOD are from
AERONET, following the
method of Bond et al. (2013)
Contributions to surface BC concentrations (μg m-3)
DJF
Residential
Industry
Energy
Transportation
Biomass
burning
Non-China
MAM
JJA
SON
Simulated all-sky BC DRF at TOA

Simulated BC DRF over
China is 1.22 W m-2.

Simulated BC DRF shows
large seasonal and spatial
variations.

Over eastern China and
Sichuan Basin, high DRF
reaches 8–10 W m-2 in
winter.
Contributions to BC DRF (W m-2)

TOA BC DRF from
residential, industry, energy,
transportation, biomass
burning, and non-China
emissions are 0.44, 0.27,
0.01, 0.12, 0.04, and 0.30
W m-2, respectively,

The domestic and nonChina emissions contribute
75% and 25% to BC DRF in
China, respectively.

Trans-boundary transport in
spring is the largest
contributor for BC DRF in
China
Contributions to BC DRF over different regions (%)
DJF
MAM
JJA
SON
Summary
 Residential sector has the largest contribution to surface BC, by 5–7 µg
m-3 in winter and by 1–3 µg m-3 in summer; Industry contributes 1–3 µg m3
to BC concentrations;
 BC DRF over China is 1.22 W m-2; domestic and non-China emissions
account for 75% and 25%, respectively.
 These results have important implications for taking reduction measures
to mitigate near-term climate warming and to improve air quality in China.
Atmos. Environ. (under revision)
Percent contributions from non-China emissions
to vertical mass concentrations of BC