scholarly journals Impacts of future climate change and effects of biogenic emissions on surface ozone and particulate matter concentrations in US

2011 ◽  
Vol 11 (1) ◽  
pp. 2183-2231 ◽  
Author(s):  
Y. F. Lam ◽  
J. S. Fu ◽  
S. Wu ◽  
L. J. Mickley

Abstract. Simulations of present and future average regional ozone and PM2.5 concentrations over the United States were performed to investigate the potential impacts of global climate change and emissions on regional air quality using CMAQ. Various emissions and climate conditions with different biogenic emissions and domain resolutions were implemented to study the sensitivity of future air quality trends from the impacts of changing biogenic emissions. A comparison of GEOS-Chem and CMAQ was performed to investigate the effect of downscaling on the prediction of future air quality trends. For ozone, the impacts of global climate change are relatively smaller when compared to the impacts of anticipated future emissions reduction, except for the Northeast area, where increasing biogenic emissions due to climate change have stronger positive effects (increases) to the regional ozone air quality. The combination effect from both climate change and emission reductions leads to approximately a 10% or 5 ppbv decrease of the maximum daily average eight-hour ozone (MDA8) over the Eastern United States. For PM2.5, the impacts of global climate change have shown insignificant effect, where as the impacts of anticipated future emissions reduction account for the majority of overall PM2.5 reductions. The annual average 24-h PM2.5 of the future-year condition was found to be about 40% lower than the one from the present-year condition, of which 60% of its overall reductions are contributed to by the decrease of SO4 and NO3 particulate matters. Changing the biogenic emissions model increases the MDA8 ozone by about 5–10% or 3–5 ppbv in the Northeast area. Conversely, it reduces the annual average PM2.5 by 5% or 1.0 μg/m3 in the Southeast region.

2011 ◽  
Vol 11 (10) ◽  
pp. 4789-4806 ◽  
Author(s):  
Y. F. Lam ◽  
J. S. Fu ◽  
S. Wu ◽  
L. J. Mickley

Abstract. Simulations of present and future average regional ozone and PM2.5 concentrations over the United States were performed to investigate the potential impacts of global climate change and emissions on regional air quality using CMAQ. Various emissions and climate conditions with different biogenic emissions and domain resolutions were implemented to study the sensitivity of future air quality trends from the impacts of changing biogenic emissions. A comparison of GEOS-Chem and CMAQ was performed to investigate the effect of downscaling on the prediction of future air quality trends. For ozone, the impacts of global climate change are relatively smaller when compared to the impacts of anticipated future emissions reduction, except for the Northeast area, where increasing biogenic emissions due to climate change have stronger positive effects (increases) to the regional ozone air quality. The combination effect from both climate change and emission reductions leads to approximately a 10 % or 5 ppbv decrease of the maximum daily average eight-hour ozone (MDA8) over the Eastern United States. For PM2.5, the impacts of global climate change have shown insignificant effect, where as the impacts of anticipated future emissions reduction account for the majority of overall PM2.5 reductions. The annual average 24-h PM2.5 of the future-year condition was found to be about 40 % lower than the one from the present-year condition, of which 60 % of its overall reductions are contributed to by the decrease of SO4 and NO3 particulate matters. Changing the biogenic emissions model increases the MDA8 ozone by about 5–10 % or 3–5 ppbv in the Northeast area. Conversely, it reduces the annual average PM2.5 by 5 % or 1.0 μg m−3 in the Southeast region.


2008 ◽  
Vol 8 (14) ◽  
pp. 3973-3983 ◽  
Author(s):  
E. Tagaris ◽  
K.-J. Liao ◽  
K. Manomaiphiboon ◽  
S. He ◽  
J.-H. Woo ◽  
...  

Abstract. Potential impacts of global climate and emissions changes on regional air quality over southern (western and eastern) Canada and northern Mexico are examined by comparing future summers' (i.e., 2049–2051) average regional O3 and PM2.5 concentrations with historic concentrations (i.e., 2000–2002 summers). Air quality modeling was conducted using CMAQ and meteorology downscaled from the GISS-GCM using MM5. Emissions for North America are found using US EPA, Mexican and Canadian inventories and projected emissions following CAIR and IPCC A1B emissions scenario. Higher temperatures for all sub-regions and regional changes in mixing height, insolation and precipitation are forecast in the 2049-2051 period. Future emissions are calculated to be lower over both Canadian sub-regions, but higher over northern Mexico. Global climate change, alone, is predicted to affect PM2.5 concentrations more than O3 for the projections used in this study: average daily maximum eight (8) hour O3 (M8hO3) concentrations are estimated to be slightly different in all examined sub-regions while average PM2.5 concentrations are estimated to be higher over both Canadian sub-regions (8% over western and 3% over eastern) but 11% lower over northern Mexico. More days are forecast where M8hO3 concentrations are over 75 ppb in all examined sub-regions but the number of days where PM2.5 concentration will be over 15 μg/m3 is projected higher only over western Canada. Climate change combined with the projected emissions lead to greater change in pollutant concentrations: average M8hO3 concentrations are simulated to be 6% lower over western Canada and 8% lower over eastern Canada while average PM2.5 concentrations are simulated to be 5% lower over western Canada and 11% lower over eastern Canada. Although future emissions over northern Mexico are projected higher, pollutant concentrations are simulated to be lower due to US emissions reductions. Global climate change combined with the projected emissions will decrease average M8hO3 4% and PM2.5 17% over northern Mexico. Significant reductions in the number of days where M8hO3 concentrations are over 75 ppb and PM2.5 concentration over 15 μg/m3 are also projected with a significant reduction in peak values.


2008 ◽  
Vol 8 (1) ◽  
pp. 3405-3430
Author(s):  
E. Tagaris ◽  
K.-J. Liao ◽  
K. Manomaiphiboon ◽  
S. He ◽  
J.-H. Woo ◽  
...  

Abstract. Potential impacts of global climate and emissions changes on regional air quality over southern (western and eastern) Canada and northern Mexico are examined by comparing future summers' (i.e., 2049–2051) average regional O3 and PM2.5 concentrations with historic concentrations (i.e., 2000–2002 summers). Air quality modeling was conducted using CMAQ and meteorology downscaled from the GISS-GCM using MM5. Emissions for North America are found using US EPA, Mexican and Canadian inventories and projected emissions following CAIR and IPCC A1B emissions scenario. Higher temperatures for all sub-regions and regional changes in mixing height, insolation and precipitation are forecast in the 2049–2051 period. Future emissions are calculated to be lower over both Canadian sub-regions, but higher over northern Mexico. Global climate change, alone, is predicted to affect PM2.5 concentrations more than O3: M8hO3 concentrations are estimated to be slightly different in all examined sub-regions while PM2.5 concentrations are estimated to be higher over both Canadian sub-regions (8% over western and 3% over eastern) but 11% lower over northern Mexico. Climate change combined with the projected emissions lead to greater change in pollutant concentrations: M8hO3 concentrations are simulated to be 6% lower over western Canada and 8% lower over eastern Canada while PM2.5 concentrations are simulated to be 5% lower over western Canada and 11% lower over eastern Canada. Although future emissions over northern Mexico are projected higher, pollutant concentrations are simulated to be lower due to US emissions reductions. Global climate change combined with the projected emissions will decrease M8hO3 4% and PM2.5 17% over northern Mexico.


Significance The United States has already committed, in an unprecedented deal with China in November 2014, to reducing its emissions to 26-28% below 2005 levels by 2025 (an improvement on its previous 17% goal). China in return pledged that its emissions would peak around 2030. This agreement is a game-changer for combating global climate change, since the two countries are the world's largest sources of carbon emissions, together accounting for 40% of the total, and were not covered under the now-expired Kyoto Protocol. Impacts Washington is poised to reclaim its place, lost after Kyoto, as a leader in global efforts against climate change. US-China climate cooperation initiatives could serve as templates for other developing countries. There are new opportunities for trilateral cooperation involving the EU. Fears that the bilateral agreement makes the UNFCCC obsolete are unwarranted, but it could preclude more ambitious efforts.


2015 ◽  
Vol 93 (1) ◽  
pp. 73-95 ◽  
Author(s):  
Anne Dorothée Slovic ◽  
Maria Aparecida de Oliveira ◽  
João Biehl ◽  
Helena Ribeiro

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