Control Conjunto de los Contaminantes del Aire Urbanos y de los Gases de Efecto Invernadero en la Ciudad de Mexico

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Effect of NOx emission controls on the long-range
transport of ozone air pollution and human
mortality
J. Jason West, Vaishali Naik, Larry W. Horowitz,
Arlene M. Fiore
2
What is the effect of NOx reductions in one
region, on ozone in all other world regions?
Reduce anthropogenic NOx emissions by 10 in each
of 9 world regions, in the MOZART-2 global CTM
(MACCM3 meteorology, EDGAR emissions for 1990s).
Naik et al. (JGR, 2005) used these simulations to
show that NOx reductions in each region increase
net RF.
3
Surface O3 Change from 10 regional NOx
reductions
Change in surface O3 (ppb), averaged over the
3-month period with highest population-weighted
O3 in source region.
4
Effect of 10 regional NOx reductions
Receptor Region
NA EU FSU AF IN EA SA SE AU
NA -512 -63 -46 -44 -44 -8 -11 -10 -3
EU -8 -194 -184 -73 -13 -9 1 -3 1
FSU -14 -55 -401 -16 -16 -27 0 0 0
AF -4 -9 -15 -176 -50 -1 -8 -8 -17
IN -4 0 -2 -6 -482 -16 -2 -32 -1
EA -16 -7 -16 -6 -6 -930 -1 -105 0
SA -6 1 1 -4 -4 1 -252 -5 -34
SE 0 2 1 -2 -15 -38 -9 -265 -11
AU 0 0 0 -1 0 0 -13 -3 -179
Source Region
Change in population-weighted O3 (ppt), averaged
over the 3-month period with highest O3 in the
receptor region.
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Normalized source-receptor matrix
Receptor Region
NA EU FSU AF IN EA SA SE AU
NA 0.64 0.08 0.06 0.06 0.05 0.01 0.01 0.01 0.00
EU 0.02 0.40 0.38 0.15 0.03 0.02 0.00 0.01 0.00
FSU 0.06 0.22 1.62 0.07 0.06 0.11 0.00 0.00 0.00
AF 0.02 0.04 0.07 0.89 0.25 0.00 0.04 0.04 0.08
IN 0.04 0.00 0.02 0.05 4.19 0.14 0.02 0.28 0.01
EA 0.04 0.02 0.04 0.02 0.02 2.33 0.00 0.26 0.00
SA 0.07 -0.02 -0.01 0.05 0.05 -0.01 3.07 0.06 0.41
SE 0.00 -0.02 -0.01 0.04 0.23 0.58 0.13 4.05 0.16
AU -0.01 -0.01 -0.01 0.02 0.02 -0.01 0.34 0.08 4.70
Source Region
Change in 3-month population-weighted average O3
per unit change in NOx emissions (ppb (Tg N
yr-1)-1).
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Example Europe
EU as source
EU as receptor
EU as receptor per Tg N
Change in population-weighted O3, averaged over
the 3-month period with highest O3 in the
receptor region.
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Example North America
NA as source
NA as receptor
NA as receptor per Tg N
Change in population-weighted O3, averaged over
the 3-month period with highest O3 in the
receptor region.
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Monthly O3 changes in each receptor region
Panels for receptor regions, showing effects of
10 NOx reductions in each source region, for
population-weighted monthly average O3.
9
Why greater sensitivity to changes in emissions
in tropics and SH?
Mainly due to decreased O3 production
below 500 mb. Units are Tg O3,
Tg O3 (TgN yr-1)-1, Tg O3
yr-1 (TgN yr-1)-1
dO3 Burden dO3 Burden / dEmis dO3 Production / dEmis Fraction of dO3 Production above 500 mb dO3 Export from source region dO3 Production outside of source region
NA -0.46 -0.58 -18.2 0.16 -3.51 -3.55
EU -0.09 -0.19 -9.9 0.07 -0.73 -1.76
FSU -0.07 -0.28 -14.7 0.04 -0.82 -0.73
AF -0.24 -1.21 -36.9 0.10 -2.16 -0.95
IN -0.19 -1.68 -40.9 0.21 -1.85 -0.93
EA -0.25 -0.62 -18.9 0.11 -2.25 -1.44
SA -0.27 -3.25 -78.5 0.19 -1.92 -1.62
SE -0.30 -4.65 -90.6 0.36 -2.39 -1.19
AU -0.12 -3.14 -66.7 0.09 -0.54 -1.25
Source Region
10
Is ozone exported or NOy?
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Effects on Metropolitan Regions
Receptor
Los Angeles Toronto London Athens Moscow Tehran Delhi Hong Kong Bangkok
NA -411 -572 -123 -49 -39 -82 -71 -28 -14
EU -12 -12 801 -656 -254 -112 -24 -14 -5
FSU -23 -23 0 -87 -393 -323 -38 -10 -1
AF -1 0 -24 -135 -1 -198 -83 -14 -7
IN -8 -1 -8 -2 0 -6 -363 -25 -21
EA -46 -17 -26 -13 -8 -13 -10 -583 -232
SA 0 1 0 1 1 0 -3 0 -3
SE 1 1 -2 1 1 0 -5 -7 -243
AU 1 0 0 1 0 0 0 1 0
Source Region
Change in 3-month population-weighted average O3
(ppt).
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Avoided Mortalities (annual)
Receptor Region
NA EU FSU AF IN EA SA SE AU TOT
NA 251 148 59 162 133 106 11 7 0 876
EU 12 -289 89 250 39 54 0 2 0 158
FSU 12 53 50 67 62 89 0 1 0 333
AF 12 49 36 938 134 58 4 5 5 1238
IN 13 13 10 53 3012 80 1 56 0 3238
EA 38 45 25 34 107 1154 0 124 0 1527
SA 3 -1 0 33 9 -1 203 3 1 251
SE 3 1 1 29 149 100 4 417 0 704
AU -1 -1 0 7 -2 -2 5 7 7 20
TOT 8344
Source Region
Mortality based on Bell et al. (2004) Intra-region
al avoided mortalities 5744 Inter-regional
2600
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Avoided Mortalities (annual) per Tg N yr-1
Receptor Region
NA EU FSU AF IN EA SA SE AU TOT
NA 32 18 7 20 17 13 1 1 0 110
EU 3 -60 18 52 8 11 0 4 0 33
FSU 5 21 20 27 25 36 0 0 0 135
AF 6 25 18 472 68 29 2 0 0 623
IN 12 11 8 46 2621 70 1 3 0 2818
EA 10 11 6 8 27 290 0 49 0 383
SA 4 -1 0 40 12 -1 248 31 1 306
SE 5 2 1 44 227 152 6 637 0 1076
AU -1 -2 -1 18 -6 -4 13 17 19 52
TOT 345
Source Region
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Long-term changes in O3 via CH4
EU as source
EU as receptor
EU as receptor per Tg N
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Long-term changes in O3 via CH4
CH4 and long-term O3 increase per unit NOx
decrease (global annual average surface O3 change)
Tropical and SH regions have much greater effect
on CH4 and long-term O3 per ton NOx reduced
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Conclusions

• Based on 10 regional anthropogenic NOx emission
  reductions
• Inter-continental effects are 10x smaller than
  effects within a region.
• Largest impact is Europe on the Former Soviet
  Union.
• Control costs would need to be 10 of
  within-region cost for overseas reductions to be
  cost-effective.
• Tropical regions cause a greater ?O3 per ton NOx
  reduced, than temperate regions.
• Avoided mortalities are greater outside of NA,
  EU, and FSU than within.
• Long-term changes in O3 (via CH4) roughly cancel
  the short-term O3 reduction for some region pairs.

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Ozone Precursors Affect Both Ozone Air Quality
and Climate Forcing
O3
Free Troposphere
hn
NO
NO2
OH
HO2
Boundary layer (0-3 km)
Direct Intercontinental Transport
NMVOC, CO, CH4
NOx NMVOCs
O3
NOx NMVOCs
O3
CONTINENT 2
CONTINENT 1
OCEAN
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Ozone Precursors Affect Both Ozone Air Quality
and Climate Forcing
20
Surface ozone changes due to 20 anthropogenic
reductions
Effect of global 20 anthropogenic emission
reductions on 8-hr daily maximum surface O3,
averaged over 3 month period with highest O3, at
steady state (MOZART-2).
21
Ozone changesEffects of 20 reductions in
anthropogenic emissions
Tropospheric O3 burden
?O3srf annual average
Short term
Steady state
?O3srf global population-weighted 8hr. 3-month
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Radiative forcingEffects of 20 reductions in
anthropogenic emissions
METHANE
OZONE
CH4 forcing estimated using Ramaswamy et al.
(2001), O3 forcing using GFDL AM2 radiative
transfer model.
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Radiative Forcing and Ozone Air QualityEffects
of 20 reductions in anthropogenic emissions
Radiative Forcing
Ozone air quality
METHANE
OZONE
?O3srf global population- weighted 8hr. 3-month
Reducing methane emissions causes the greatest
reduction in RF per unit improvement in O3 air
quality.
? RFnet / ? O3srf
West et al. (2007) GRL
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Human Health Effects of Ozone and PM

• Time-series studies relate short-term
  (day-to-day) changes in concentration to daily
  mortality rates
• Cohort studies relate community-level exposures
  over multiple years to annual mortality
• Relative Risk (RR) the ratio of the probability
  of health outcome in exposed group vs. unexposed
  group

Mortality effects of PM in long-term cohort
studies
Mortality effects of ozone in short-term
time-series studies
Bell et al., 2004
Pope et al., 2002
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Mitigating Global Ozone Pollution by Reducing
Methane Emissions Global Health Benefits
Change in surface ozone from a 20 reduction in
global anthropogenic methane emissions.

• Motivation
• Methane, the most abundant VOC, contributes to
  the growing global background of tropospheric
  ozone.
• Methane mitigation has been considered for
  climate, but not for air quality.
• GOAL Consider the viability of methane control
  for managing tropospheric ozone, by considering
  the costs of control and benefits for avoided
  human mortality.

• Methane mitigation decreases O3 everywhere (using
  MOZART-2, steady-state relative to 2030 A2).
• ?O3 -1.16 ppbv (glob. Ann. Avg. 8-hr. O3,
  population-weighted).

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Mitigating Global Ozone Pollution by Reducing
Methane Emissions Global Health Benefits

• Conclusions
• Methane emission reductions decrease ozone
  everywhere, while also reducing greenhouse
  warming.
• Monetized health benefits are 240 per ton CH4
  (12 per ton CO2 eq.) - which can justify the 20
  methane reduction.
• Methane abatement can be a cost-effective
  component of international long-term ozone
  management.

Global avoided premature mortalities from a 20
reduction in global anthropogenic methane
emissions.
Prevents 30,000 premature mortalities in 2030
(0.04 of total deaths), and 370,000 from
2010-2030.
West et al. (2006) PNAS
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Ozone Precursors Affect Both Ozone Air Quality
and Climate Forcing
Urban
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Is ozone exported or NOx?
dO3 Burden dO3 Burden / dEmis dO3 Production / dEmis Fraction of dO3 Production above 500 mb dO3 Export from source region dO3 Production outside of source region
NA -0.46 -0.58 -18.2 0.16 -3.51 -3.55
EU -0.09 -0.19 -9.9 0.07 -0.73 -1.76
FSU -0.07 -0.28 -14.7 0.04 -0.82 -0.73
AF -0.24 -1.21 -36.9 0.10 -2.16 -0.95
IN -0.19 -1.68 -40.9 0.21 -1.85 -0.93
EA -0.25 -0.62 -18.9 0.11 -2.25 -1.44
SA -0.27 -3.25 -78.5 0.19 -1.92 -1.62
SE -0.30 -4.65 -90.6 0.36 -2.39 -1.19
AU -0.12 -3.14 -66.7 0.09 -0.54 -1.25
Source Region
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Ozone changesEffects of 20 reductions in
anthropogenic emissions
Tropospheric O3 burden
?O3srf annual average
Short term
Steady state
?O3srf global population-weighted 8hr. 3-month
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Effect of 10 regional NOx reductionsat steady
state
Receptor Region
NA EU FSU AF IN EA SA SE AU
NA -498 -45 -33 -30 -29 3 1 2 9
EU -4 -189 -180 -69 -9 -6 4 1 4
FSU -11 -51 -398 -13 -13 -25 3 2 3
AF 4 2 -7 -167 -41 6 -1 -1 -10
IN 1 6 2 -1 -476 -13 2 -28 2
EA -9 2 -10 1 1 -924 5 -99 5
SA 2 11 8 4 4 7 -245 2 -28
SE 8 12 8 6 -7 -32 -2 -259 -4
AU 4 5 4 3 4 3 -10 0 -176
Source Region
Change in 3-month population-weighted average O3
(ppt)