scholarly journals The impact of a future H<sub>2</sub>-based road transportation sector on the composition and chemistry of the atmosphere – Part 1: Tropospheric composition and air quality

2012 ◽  
Vol 12 (8) ◽  
pp. 19371-19421 ◽  
Author(s):  
D. Wang ◽  
W. Jia ◽  
S. C. Olsen ◽  
D. J. Wuebbles ◽  
M. K. Dubey ◽  
...  

Abstract. Vehicles burning fossil fuel emit a number of substances that change the composition and chemistry of the atmosphere, and contribute to global air and water pollution and climate change. For example, nitrogen oxides and volatile organic compounds (VOCs) emitted as byproducts of fossil fuel combustion are key precursors to ground-level ozone and aerosol formation. In addition, on-road vehicles are major CO2 emitters. In order to tackle these problems, molecular hydrogen (H2) has been proposed as an energy carrier to substitute for fossil fuel in the future. However, before implementing any such strategy it is crucial to evaluate its potential impacts on air quality and climate. Here we evaluate the impact of a future (2050) H2-based road transportation sector on tropospheric chemistry and air quality for several possible growth and technology adoption scenarios. The growth scenarios are based on the high and low emissions Intergovernmental Panel on Climate Change Special Report on Emissions Scenarios, A1FI and B1, respectively. The technological adoption scenarios include H2 fuel cell and H2 internal combustion engine options. The impacts are evaluated with the Community Atmospheric Model Chemistry global chemistry transport model (CAM-Chem). Higher resolution simulations focusing on the contiguous United States are also carried out with the Community Multiscale Air Quality Modeling System (CMAQ) regional chemistry transport model. For all scenarios future air quality improves with the adoption of a H2-based road transportation sector, however, the magnitude and type of improvement depend on the scenario. Model results show that with the adoption of H2 fuel cells decreases tropospheric burdens of ozone (7%), CO (14%), NOx (16%), soot (17%), sulfate aerosol (4%), and ammonium nitrate aerosol (12%) in the A1FI scenario, and decreases those of ozone (5%), CO (4%), NOx (11%), soot (7%), sulfate aerosol (4%), and ammonium nitrate aerosol (9 %) in the B1 scenario. The adoption of H2 internal combustion engines decreases tropospheric burdens of ozone (1%), CO (18%), soot (17%), and sulfate aerosol (3%) in the A1FI scenario, and decreases those of ozone (1%), CO (7%), soot (7%), and sulfate aerosol (3%) in the B1 scenario. In the future, people residing in the contiguous United States are expected to experience significantly fewer days of elevated levels of pollution if a H2 fuel cell road transportation sector is adopted. Health benefits of transitioning to a H2 economy for citizens in developing nations, like China and India, will be much more dramatic particularly in megacities with severe air-quality problems that are exacerbating.

2013 ◽  
Vol 13 (13) ◽  
pp. 6117-6137 ◽  
Author(s):  
D. Wang ◽  
W. Jia ◽  
S. C. Olsen ◽  
D. J. Wuebbles ◽  
M. K. Dubey ◽  
...  

Abstract. Vehicles burning fossil fuel emit a number of substances that change the composition and chemistry of the atmosphere, and contribute to global air and water pollution and climate change. For example, nitrogen oxides and volatile organic compounds (VOCs) emitted as byproducts of fossil fuel combustion are key precursors to ground-level ozone and aerosol formation. In addition, on-road vehicles are major CO2 emitters. In order to tackle these problems, molecular hydrogen (H2) has been proposed as an energy carrier to substitute for fossil fuels in the future. However, before implementing any such strategy it is crucial to evaluate its potential impacts on air quality and climate. Here, we evaluate the impact of a future (2050) H2-based road transportation sector on tropospheric chemistry and air quality for several possible growth and technology adoption scenarios. The growth scenarios are based on the high and low emissions Intergovernmental Panel on Climate Change Special Report on Emissions Scenarios, A1FI and B1, respectively. The technological adoption scenarios include H2 fuel cell and H2 internal combustion engine options. The impacts are evaluated with the Community Atmospheric Model Chemistry global chemistry transport model (CAM-Chem). Higher resolution simulations focusing on the contiguous United States are also carried out with the Community Multiscale Air Quality Modeling System (CMAQ) regional chemistry transport model. For all scenarios future air quality improves with the adoption of a H2-based road transportation sector; however, the magnitude and type of improvement depend on the scenario. Model results show that the adoption of H2 fuel cells would decrease tropospheric burdens of ozone (7%), CO (14%), NOx (16%), soot (17%), sulfate aerosol (4%), and ammonium nitrate aerosol (12%) in the A1FI scenario, and would decrease those of ozone (5%), CO (4%), NOx (11%), soot (7%), sulfate aerosol (4%), and ammonium nitrate aerosol (9%) in the B1 scenario. The adoption of H2 internal combustion engines would decrease tropospheric burdens of ozone (1%), CO (18%), soot (17%), and sulfate aerosol (3%) in the A1FI scenario, and would decrease those of ozone (1%), CO (7%), soot (7%), and sulfate aerosol (3%) in the B1 scenario. In the future, people residing in the contiguous United States could expect to experience significantly fewer days of elevated levels of pollution if a H2 fuel cell road transportation sector were to be adopted. Health benefits of transitioning to a H2 economy for citizens in developing nations, like China and India, will be much more dramatic, particularly in megacities with severe, intensifying air-quality problems.


2020 ◽  
Author(s):  
Hyeonmmin Kim ◽  
Rokjin Park ◽  
Jaein Jeong ◽  
Saewung Kim ◽  
Daun Jeong ◽  
...  

&lt;p&gt;Nitryl chloride (ClNO&lt;sub&gt;2&lt;/sub&gt;) plays an important role as a night-time reservoir of NO&lt;sub&gt;X&lt;/sub&gt; and the source of Cl radical during the daytime, which consequently affects the ozone photochemistry. Its impacts on regional air quality in East Asia, however, are not fully understood so far. We here use extensive observations during the international KORea-US cooperative Air Quality field study in Korea (KORUS-AQ), which occurred in May-June 2016, with a 3-D chemistry transport model to examine the impacts of ClNO&lt;sub&gt;2&lt;/sub&gt; chemistry on radical species and total nitrate concentrations in East Asia. We first update the model by implementing chlorine chemistry and latest anthropogenic chlorine emissions of China and South Korea. We conduct model simulations for May-June, 2016 and validate the model by comparing against the observations from the KORUS-AQ campaign. We find that the ClNO&lt;sub&gt;2&lt;/sub&gt; chemistry in the model results in an increase of ozone by ~1.4 ppbv (~2.5%), Cl radical by ~ 4.6x10&lt;sup&gt;3&lt;/sup&gt; molec cm&lt;sup&gt;-3&lt;/sup&gt; (~3600%), OH ~8.2x10&lt;sup&gt;4&lt;/sup&gt; molec cm&lt;sup&gt;-3&lt;/sup&gt; (~5.3%), HO&lt;sub&gt;2&lt;/sub&gt; ~6.6 molec cm&lt;sup&gt;-3&lt;/sup&gt; (~3.0%), a decrease of TNO&lt;sub&gt;3&lt;/sub&gt; (HNO&lt;sub&gt;3&lt;/sub&gt; + nitrate aerosol) concentrations by ~2 &amp;#956;g m&lt;sup&gt;-3&lt;/sup&gt; on a daily mean basis during the campaign. Overall, the enhanced conversion of NO to NO&lt;sub&gt;2&lt;/sub&gt; driven by ClNO&lt;sub&gt;2&lt;/sub&gt; chemistry contributes to higher oxidant concentrations in the model. As a result, the updated model shows a better agreement with the observations in Korea during the KORUS-AQ campaign.&lt;/p&gt;


Atmosphere ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 467
Author(s):  
Rocío Baró ◽  
Christian Maurer ◽  
Jerome Brioude ◽  
Delia Arnold ◽  
Marcus Hirtl

This paper demonstrates the environmental impacts of the wildfires occurring at the beginning of April 2020 in and around the highly contaminated Chernobyl Exclusion Zone (CEZ). Due to the critical fire location, concerns arose about secondary radioactive contamination potentially spreading over Europe. The impact of the fire was assessed through the evaluation of fire plume dispersion and re-suspension of the radionuclide Cs-137, whereas, to assess the smoke plume effect, a WRF-Chem simulation was performed and compared to Tropospheric Monitoring Instrument (TROPOMI) satellite columns. The results show agreement of the simulated black carbon and carbon monoxide plumes with the plumes as observed by TROPOMI, where pollutants were also transported to Belarus. From an air quality and health perspective, the wildfires caused extremely bad air quality over Kiev, where the WRF-Chem model simulated mean values of PM2.5 up to 300 µg/m3 (during the first fire outbreak) over CEZ. The re-suspension of Cs-137 was assessed by a Bayesian inverse modelling approach using FLEXPART as the atmospheric transport model and Ukraine observations, yielding a total release of 600 ± 200 GBq. The increase in both smoke and Cs-137 emissions was only well correlated on the 9 April, likely related to a shift of the focus area of the fires. From a radiological point of view even the highest Cs-137 values (average measured or modelled air concentrations and modelled deposition) at the measurement site closest to the Chernobyl Nuclear Power Plant, i.e., Kiev, posed no health risk.


2018 ◽  
Vol 10 (7) ◽  
pp. 2529 ◽  
Author(s):  
Noam Bergman

The fossil fuel divestment movement campaigns for removing investments from fossil fuel companies as a strategy to combat climate change. It is a bottom-up movement, largely based in university student groups, although it has rapidly spread to other institutions. Divestment has been criticised for its naiveté and hard-line stance and dismissed as having little impact on fossil fuel finance. I analyse the impact of divestment through reviewing academic and grey literature, complemented by interviews with activists and financial actors, using a theoretical framework that draws on social movement theory. While the direct impacts of divestment are small, the indirect impacts, in terms of public discourse shift, are significant. Divestment has put questions of finance and climate change on the agenda and played a part in changing discourse around the legitimacy, reputation and viability of the fossil fuel industry. This cultural impact contributed to changes in the finance industry through new demands by shareholders and investors and to changes in political discourse, such as rethinking the notion of ‘fiduciary duty.’ Finally, divestment had significant impact on its participants in terms of empowerment and played a part in the revitalisation of the environmental movement in the UK and elsewhere.


2011 ◽  
Vol 11 (4) ◽  
pp. 1711-1727 ◽  
Author(s):  
E. Real ◽  
K. Sartelet

Abstract. This paper evaluates the impact of photolysis rate calculation on simulated European air composition and air quality. In particular, the impact of the cloud parametrisation and the impact of aerosols on photolysis rates are analysed. Photolysis rates are simulated using the Fast-JX photolysis scheme and gas and aerosol concentrations over Europe are simulated with the regional chemistry-transport model Polair3D of the Polyphemus platform. The photolysis scheme is first used to update the clear-sky tabulation of photolysis rates used in the previous Polair3D version. Important differences in photolysis rates are simulated, mainly due to updated cross-sections and quantum yields in the Fast-JX scheme. In the previous Polair3D version, clouds were taken into account by multiplying the clear-sky photolysis rates by a correction factor. In the new version, clouds are taken into account more accurately by simulating them directly in the photolysis scheme. Differences in photolysis rates inside clouds can be large but outside clouds, and especially at the ground, differences are small. To take into account the impact of aerosols on photolysis rates, Polair3D and Fast-JX are coupled. Photolysis rates are updated every hour. Large impact on photolysis rates is observed at the ground, decreasing with altitude. The aerosol specie that impact the most photolysis rates is dust especially in south Europe. Strong impact is also observed over anthropogenic emission regions (Paris, The Po and the Ruhr Valley) where mainly nitrate and sulphate reduce the incoming radiation. Differences in photolysis rates lead to changes in gas concentrations, with the largest impact simulated on OH and NO concentrations. At the ground, monthly mean concentrations of both species are reduced over Europe by around 10 to 14% and their tropospheric burden by around 10%. The decrease in OH leads to an increase of the life-time of several species such as VOC. NO2 concentrations are not strongly impacted and O3 concentrations are mostly reduced at the ground (−3%). O3 peaks are systematically decreased because of the NO2 photolysis rate coefficient decrease. Not only gas are impacted but also secondary aerosols, due to changes in gas precursors concentrations. However changes in aerosol species concentrations often compensate each other resulting in a low impact on PM10 and PM2.5 concentrations (lower than 2%). The changes in gas concentrations at the ground induced by the modification of photolysis rates (by aerosols and clouds) are compared to changes induced by 29 different model parametrisations in Roustan et al. (2010). Among the 31 model parametrisations, "including aerosols on photolysis rates calculation" has the strongest impact on OH concentrations and on O3 bias in July. In terms of air quality, ground concentrations (NO2, O3, PM10) are compared with measurements. Changes arising from cloud parametrisation are small. Simulation performances are often slightly better when including aerosol in photolysis rates calculation. The systematic O3 peak reduction leads to large differences in the exceedances of the European O3 standard as calculated by the model, in better agreement with measurements. The number of exceedances of the information and the alert threshold is divided by 2 when the aerosol impact on photochemistry is simulated. This shows the importance of taking into account aerosols impact on photolysis rates in air quality studies.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Luyu Chang ◽  
Jianming Xu ◽  
Xuexi Tie ◽  
Wei Gao

AbstractSevere ozone (O3) episodes occur frequently in Shanghai during late-summers. We define geopotential height averaged over the key area region (122.5°E-135°E, 27.5°N -35°N) at 500 hPa as a WPSH_SHO3 index which has high positive correlation with surface O3 concentration in Shanghai. In addition, the index has a significant long-term increasing trend during the recent 60 years. Analysis shows the meteorological conditions under the strong WPSH_SHO3 climate background (compared to the weak background) have several important anomalies: (1) A strong WPSH center occurs over the key area region. (2) The cloud cover is less, resulting in high solar radiation and low humidity, enhancing the photochemical reactions of O3. (3) The near-surface southwesterly winds are more frequent, enhancing the transport of upwind pollutants and O3 precursors from polluted regions to Shanghai and producing higher O3 chemical productions. This study suggests that the global climate change could lead to a stronger WPSH in the key region, enhancing ozone pollution in Shanghai. A global chemical/transport model (MOZART-4) is applied to show that the O3 concentrations can be 30 ppbv higher under a strong WPSH_SHO3 condition than a weak condition, indicating the important effect of the global climate change on local air pollution in Shanghai.


2018 ◽  
Vol 7 (4.35) ◽  
pp. 823 ◽  
Author(s):  
Mustapa S.I ◽  
Bekhet H.A

The rapid urbanisation and economic growth has led to unprecedented increase in CO2 emissions, which led to a vital global issue due partly to the rise in demand from the transport sector. In the years ahead, the transport services demand is likely to increase further, which lead to intensification in CO2 emissions as well. The transportation sector in Malaysia contributes for about 28% of total CO2 emissions, of which 85% of it goes to road transportation mode. This has led to a great interest in how the CO2 emissions in this sector can effectively be reduced. Using a multiple regression model and datasets from 1990 to 2015, this study aimed to examine factors that influence the CO2 emissions in Malaysia. Key factors of CO2 emissions, i.e., fuel consumption (FC), distance travel (DT), fuel efficiency (FE), and fuel price (FP) were investigated for the road transport sector. The findings demonstrated that the impact of factors on CO2 emissions were varies in each technology vehicles. These findings not only contributes to enhancing the current literature, but also provide insights for policy maker in Malaysia to design policy instruments for road transport sector.


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