Corrigendum to: “Present and potential future contributions of sulfate, black and organic carbon aerosols from China to global air quality, premature mortality and radiative forcing” [Atmos. Environ. 43 (2009) 2814–2822]

2010 ◽  
Vol 44 (35) ◽  
pp. 4528
Author(s):  
Eri Saikawa ◽  
Vaishali Naik ◽  
Larry W. Horowitz ◽  
Junfeng Liu ◽  
Denise L. Mauzerall
2013 ◽  
Vol 13 (23) ◽  
pp. 12059-12071 ◽  
Author(s):  
A. I. Partanen ◽  
A. Laakso ◽  
A. Schmidt ◽  
H. Kokkola ◽  
T. Kuokkanen ◽  
...  

Abstract. Aerosol particles from shipping emissions both cool the climate and cause adverse health effects. The cooling effect is, however, declining because of shipping emission controls aiming to improve air quality. We used an aerosol-climate model ECHAM-HAMMOZ to test whether by altering ship fuel sulfur content, the present-day aerosol-induced cooling effect from shipping could be preserved, while at the same time reducing premature mortality rates related to shipping emissions. We compared the climate and health effects of a present-day shipping emission scenario (ship fuel sulfur content of 2.7%) with (1) a simulation with strict emission controls in the coastal waters (ship fuel sulfur content of 0.1%) and twofold the present-day fuel sulfur content (i.e. 5.4%) elsewhere; and (2) a scenario with global strict shipping emission controls (ship fuel sulfur content of 0.1% in coastal waters and 0.5% elsewhere) roughly corresponding to international agreements to be enforced by the year 2020. Scenario 1 had a slightly stronger aerosol-induced effective radiative forcing (ERF) from shipping than the present-day scenario (−0.43 W m−2 vs. −0.39 W m−2) while reducing premature mortality from shipping by 69% (globally 34 900 deaths avoided per year). Scenario 2 decreased the ERF to −0.06 W m−2 and annual deaths by 96% (globally 48 200 deaths avoided per year) compared to present-day. Our results show that the cooling effect of present-day emissions could be retained with simultaneous notable improvements in air quality, even though the shipping emissions from the open ocean clearly have a significant effect on continental air quality. However, increasing ship fuel sulfur content in the open ocean would violate existing international treaties, could cause detrimental side-effects, and could be classified as geoengineering.


2016 ◽  
Author(s):  
Nicolas Bellouin ◽  
Laura Baker ◽  
Øivind Hodnebrog ◽  
Dirk Olivié ◽  
Ribu Cherian ◽  
...  

Abstract. Dedicated model simulations by four general circulation and chemistry-transport models are used to establish a matrix of specific radiative forcing, defined as the radiative forcing per unit change in mass emitted, as a function of the near-term climate forcer emitted, its source region, and the season of emission. Emissions of eight near-term climate forcers are reduced: sulphur dioxide, the precursor to sulphate aerosols; black carbon aerosols; organic carbon aerosols; ammonia, a precursor to nitrate aerosols; methane; and nitrogen oxides, carbon monoxide, and volatile organic compounds, the precursors to ozone and to secondary organic aerosols. The focus is on two source regions, Europe and East Asia, but the shipping sector and global averages are also included. Emission reductions are applied over two time periods: May–Oct and Nov–Apr. Models generally agree on the sign and ranking of specific radiative forcing for different emitted species, but disagree quantitatively. Black carbon aerosols, methane, and carbon monoxide exert positive specific radiative forcings. Black carbon exerts the strongest specific radiative forcing, even after accounting for rapid adjustments from the semi-direct effect, and is most efficient in local summer. However, although methane and carbon monoxide are less efficient in a specific sense, the potential for decreasing the mass emitted is larger. Organic carbon aerosols, sulphur dioxide, ammonia, and emissions by the shipping sector exert negative specific radiative forcings, with local summer emission changes being again more efficient. Ammonia is notable for its weak specific radiative forcing. For aerosols, specific radiative forcing exerted by European emissions is stronger than for East Asia, because the European baseline is less polluted. Radiative forcing of European and East Asian emission reductions is mainly exerted in the mid-latitudes of the Northern Hemisphere, but atmospheric transport yields sizeable radiative forcings in neighbouring regions, such as the Arctic. Models disagree on the sign of the net radiative forcing exerted by reductions in the emissions of nitrogen oxides and volatile organic compounds, because those reductions trigger complex changes in the oxidising capacity of the atmosphere, translating into radiative forcings by aerosols, methane, and ozone of different signs. The response of nitrate aerosols to nitrogen oxide reductions is particularly important in determining the sign of the corresponding radiative forcing. Model diversity comes from different modelled lifetimes, different unperturbed baselines, and different numbers of species and radiative forcing mechanisms represented. The strength of the aerosol-chemistry coupling is also diverse, translating into aerosol responses to perturbations of ozone precursors of different magnitudes.


2011 ◽  
Vol 116 (D15) ◽  
Author(s):  
L. K. Sahu ◽  
Y. Kondo ◽  
Y. Miyazaki ◽  
Prapat Pongkiatkul ◽  
N. T. Kim Oanh

2018 ◽  
Author(s):  
Steven Turnock ◽  
Oliver Wild ◽  
Frank Dentener ◽  
Yanko Davila ◽  
Louisa Emmons ◽  
...  

Abstract. This study quantifies future changes in tropospheric ozone (O3) using a simple parameterisation of source-receptor relationships based on simulations from a range of models participating in the Task Force on Hemispheric Transport of Air Pollutants (TF-HTAP) experiments. Surface and tropospheric O3 changes are calculated globally and across 16 regions from perturbations in precursor emissions (NOx, CO, VOCs) and methane (CH4) abundance. A source attribution is provided for each source region along with an estimate of uncertainty based on the spread of the results from the models. Tests against model simulations using HadGEM2-ES confirm that the approaches used within the parameterisation are valid. The O3 response to changes in CH4 abundance is slightly larger in TF-HTAP Phase 2 than in the TF-HTAP Phase 1 assessment (2010) and provides further evidence that controlling CH4 is important for limiting future O3 concentrations. Different treatments of chemistry and meteorology in models remains one of the largest uncertainties in calculating the O3 response to perturbations in CH4 abundance and precursor emissions, particularly over the Middle East and South Asian regions. Emission changes for the future ECLIPSE scenarios and a subset of preliminary Shared Socio-economic Pathways (SSPs) indicate that surface O3 concentrations will increase by 1 to 8 ppbv in 2050 across different regions. Source attribution analysis highlights the growing importance of CH4 in the future under current legislation. A global tropospheric O3 radiative forcing of +0.07 W m−2 from 2010 to 2050 is predicted using the ECLIPSE scenarios and SSPs, based solely on changes in CH4 abundance and tropospheric O3 precursor emissions and neglecting any influence of climate change. Current legislation is shown to be inadequate in limiting the future degradation of surface ozone air quality and enhancement of near-term climate warming. More stringent future emission controls provide a large reduction in both surface O3 concentrations and O3 radiative forcing. The parameterisation provides a simple tool to highlight the different impacts and associated uncertainties of local and hemispheric emission control strategies on both surface air quality and the near-term climate forcing by tropospheric O3.


2014 ◽  
Vol 119 (6) ◽  
pp. 3476-3485 ◽  
Author(s):  
Elena N. Kirillova ◽  
August Andersson ◽  
Suresh Tiwari ◽  
Atul Kumar Srivastava ◽  
Deewan Singh Bisht ◽  
...  

2015 ◽  
Vol 15 (21) ◽  
pp. 31385-31432
Author(s):  
Y. H. Lee ◽  
D. T. Shindell ◽  
G. Faluvegi ◽  
R. W. Pinder

Abstract. We have investigated how future air quality and climate change are influenced by the US air quality regulations that existed or were proposed in 2013 and a hypothetical climate mitigation policy that reduces 2050 CO2 emissions to be 50 % below 2005 emissions. Using NASA GISS ModelE2, we look at the impacts in year 2030 and 2055. The US energy-sector emissions are from the GLIMPSE project (GEOS-Chem LIDORT Integrated with MARKAL for the Purpose of Scenario Exploration), and other US emissions and the rest of the world emissions are based on the RCP4.5 scenario. The US air quality regulations are projected to have a strong beneficial impact on US air quality and public health in the future but result in positive radiative forcing. Surface PM2.5 is reduced by ~ 2 μg m−3 on average over the US, and surface ozone by ~ 8 ppbv. The improved air quality prevents about 91 400 premature deaths in the US, mainly due to the PM2.5 reduction (~ 74 200 lives saved). The air quality regulations reduces the light-reflecting aerosols (i.e., sulfate and organic matter) more than the light-absorbing species (i.e., black carbon and ozone), leading a strong positive radiative forcing (RF) by both aerosols direct and indirect forcing: total RF is ~ 0.04 W m−2 over the globe; ~ 0.8 W m−2 over the US. Under the hypothetical climate policy, future US energy relies less on coal and thus SO2 emissions are noticeably reduced. This provides air quality co-benefits, but it leads to climate dis-benefits over the US. In 2055, the US mean total RF is +0.22 W m−2 due to positive aerosol direct and indirect forcing, while the global mean total RF is −0.06 W m−2 due to the dominant negative CO2 RF (instantaneous RF). To achieve a regional-scale climate benefit via a climate policy, it is critical (1) to have multi-national efforts to reduce GHGs emissions and (2) to target emission reduction of light-absorbing species (e.g., BC and O3) on top of long-lived species. The latter is very desirable as the resulting climate benefit occurs faster and provides co-benefits to air quality and public health.


Elem Sci Anth ◽  
2019 ◽  
Vol 7 ◽  
Author(s):  
Benjamin de Foy ◽  
James J. Schauer

The San Joaquin Valley in California suffers from poor air quality due to a combination of local emissions and weak ventilation. Over the course of decades, there has been a concerted effort to control emissions from vehicles as well as from residential wood burning. A multiple linear regression model was used to evaluate the trends in air pollution over multiple time scales: by year, by season, by day of the week and by time of day. The model was applied to 18 years of measurements in Fresno including hourly mole fractions of NOx and concentrations of PM2.5; and daily measurements of speciated components of PM2.5. The analysis shows that there have been reductions in NOx, elemental carbon and ammonium nitrate of 4 to 6%/year. On weekends, NOx mole fractions are reduced by 15 to 30% due to fewer vehicle miles traveled and a smaller fraction of diesel traffic. These weekend reductions in NOx have not been accompanied by weekend reductions in PM2.5 however. In particular, elemental and organic carbon concentrations are higher on winter weekends. Analysis of diurnal profiles suggests that this is because of increased PM2.5 on Saturday and holiday evenings which are likely due to residential wood combustion. Furthermore, while organic carbon concentrations have decreased in the winter months, they have been variable but without a net decline in the summer, most likely as a result of forest fires offsetting other improvements in air quality. Fog was found to greatly enhance ammonium nitrate formation and was therefore associated with higher PM2.5 in the winter months. Overall the analysis shows that air quality controls have been effective at reducing NOx all year and PM2.5 in the winter, that continued reductions in emissions will further reduce pollutant concentrations, but that winter residential wood combustion and summer forest fires could offset some of the gains obtained.


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