Dynamic simulation of airborne pollutant concentrations associated with the effect of climate change in Batu Muda region, Malaysia

2021 ◽  
Author(s):  
Cedric Lemuel Lee ◽  
Wong Yong Jie ◽  
Senthil Kumar Arumugasamy
Keyword(s):  
Climate Change ◽  
Dynamic Simulation ◽  
Pollutant Concentrations ◽  
Airborne Pollutant

scholarly journals Changes in Air Quality during the First-Level Response to the Covid-19 Pandemic in Shanghai Municipality, China

2020 ◽  
Vol 12 (21) ◽  
pp. 8887 ◽  
Author(s):  
Yang Bai ◽  
Yi Zhou ◽  
Juha M. Alatalo ◽  
Alice C. Hughes
Keyword(s):  
Air Quality ◽  
Human Activities ◽  
Central Government ◽  
Negative Impact ◽  
Living Environment ◽  
Low Carbon ◽  
Pollutant Concentrations ◽  
Airborne Pollutant ◽  
Urban Population Growth ◽  
Shanghai Municipality

Ongoing rapid urban population growth world-wide has led to serious environmental problems that affect ecosystems and also lower the security and happiness of urban residents about their living environment. The most frequently reported negative impact is a deterioration in urban air quality. In this study, we performed a comprehensive assessment of the effects of the city lockdown policy in response to Covid-19 on air quality in Shanghai Municipality, China, and sought to identify a balance point between human activities and improving air quality. The first-level response (FLR) by Shanghai to control the spread of Covid-19 was to launch a lockdown, which remained in place from 24 January to 23 March, 2020. We compared airborne pollutant concentrations in different regions (downtown, suburbs) of Shanghai city in three periods (Pre-FLR, During-FLR, and Post-FLR) and in the corresponding periods in the previous year. The results showed that air quality improved significantly During-FLR compared with Pre-FLR, with the concentrations of PM2.5, PM10, SO2, NO2, and CO all decreasing significantly. The concentrations of all pollutants except O3 also decreased significantly compared with the same period in the previous year. There were also some differences in pollutant concentrations between the downtown region and the suburbs of Shanghai. However, we found that the concentrations of pollutants rebounded gradually when the restrictions on human activities ended after two months of lockdown. This study provides empirical evidence of the important effect of limiting human activities on air quality. For sustainable and clean future urban management in Shanghai and beyond, central government policy regulations requiring a low-carbon lifestyle and cleaner production in industries should be established.

scholarly journals Mid-21st century air quality at the urban scale under the influence of changed climate and emissions: case studies for Paris and Stockholm

2015 ◽  
Vol 15 (19) ◽  
pp. 27041-27085
Author(s):  
K. Markakis ◽  
M. Valari ◽  
M. Engardt ◽  
G. Lacressonnière ◽  
R. Vautard ◽  
...  
Keyword(s):  
Climate Change ◽  
Urban Areas ◽  
Large Scale ◽  
Regional Scale ◽  
Influential Factor ◽  
Daily Average ◽  
Pollutant Concentrations ◽  
Emission Projections ◽  
The Impact ◽  
The City

Abstract. Ozone, PM10 and PM2.5 concentrations over Paris, France and Stockholm, Sweden were modeled at 4 and 1 \\unit{km} horizontal resolutions respectively for the present and 2050 periods employing decade-long simulations. We account for large-scale global climate change (RCP-4.5) and fine resolution bottom-up emission projections developed by local experts and quantify their impact on future pollutant concentrations. Moreover, we identify biases related to the implementation of regional scale emission projections over the study areas by comparing modeled pollutant concentrations between the fine and coarse scale simulations. We show that over urban areas with major regional contribution (e.g., the city of Stockholm) the bias due to coarse emission inventory may be significant and lead to policy misclassification. Our results stress the need to better understand the mechanism of bias propagation across the modeling scales in order to design more successful local-scale strategies. We find that the impact of climate change is spatially homogeneous in both regions, implying strong regional influence. The climate benefit for ozone (daily average and maximum) is up to −5 % for Paris and −2 % for Stockholm city. The joined climate benefit on PM2.5 and PM10 in Paris is between −10 and −5 % while for Stockholm we observe mixed trends up to 3 % depending on season and size class. In Stockholm, emission mitigation leads to concentration reductions up to 15 % for daily average and maximum ozone and 20 % for PM and through a sensitivity analysis we show that this response is entirely due to changes in emissions at the regional scale. On the contrary, over the city of Paris (VOC-limited photochemical regime), local mitigation of NOx emissions increases future ozone concentrations due to ozone titration inhibition. This competing trend between the respective roles of emission and climate change, results in an increase in 2050 daily average ozone by 2.5 % in Paris. Climate and not emission change appears to be the most influential factor for maximum ozone concentration over the city of Paris, which may be particularly interesting in a health impact perspective.

scholarly journals The role of climate and emission changes in future air quality over southern Canada and northern Mexico

2008 ◽  
Vol 8 (14) ◽  
pp. 3973-3983 ◽  
Author(s):  
E. Tagaris ◽  
K.-J. Liao ◽  
K. Manomaiphiboon ◽  
S. He ◽  
J.-H. Woo ◽  
...  
Keyword(s):  
Climate Change ◽  
Air Quality ◽  
Global Climate Change ◽  
Global Climate ◽  
Western Canada ◽  
Eastern Canada ◽  
Northern Mexico ◽  
Pollutant Concentrations ◽  
Future Emissions ◽  
Pm2.5 Concentration

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.

scholarly journals Climate Change Impacts on Sediment Quality of Subalpine Reservoirs: Implications on Management

2017 ◽  
Author(s):  
Laura Marziali ◽  
Gianni Tartari ◽  
Franco Salerno ◽  
Lucia Valsecchi ◽  
Clara Bravi ◽  
...  
Keyword(s):  
Climate Change ◽  
Sediment Quality ◽  
Climate Change Impacts ◽  
Change Scenario ◽  
Rainfall Erosivity ◽  
Change Models ◽  
Sediment Loads ◽  
Pollutant Concentrations ◽  
Sediment Flow

Reservoirs are characterized by accumulation of sediments where micropollutants may concentrate, with potential toxic effects on downstream river ecosystems. However, sediment management such as flushing is needed to maintain storage capacity. Climate change is expected to increase sediment loads, but potential effects on their quality are scarcely known. In this context, sediment contamination by trace elements (As, Cd, Cr, Cu, Hg, Ni, Pb, Zn) and organics (PAHs, PCBs, C>12) was analyzed in 20 reservoirs located in Italian Central Alps. A strong As and a moderate Cd, Hg and Pb enrichment was emphasized by Igeo, with potential ecotoxicological risk according to PEC quotients. Siltation, granulometry, total organic carbon (TOC) and altitude resulted as the main drivers governing pollutant concentrations in sediments. According to climate change models, expected increase of rainfall erosivity will enhance soil erosion and consequently the sediment flow to reservoirs, potentially increasing coarse grain fractions and thus potentially diluting pollutants. Conversely, increased weathering may enhance metal fluxes to reservoirs. Increased vegetation cover will potentially result in higher TOC concentrations, which may contrast contaminant bioavailability and thus toxicity. Our results may provide elements for a proper management of contaminated sediments in a climate change scenario aiming at preserving water quality and ecosystem functioning.

scholarly journals Mejoras de eficiencia energética en calefacción. Potencial de intervención en edificio escolar existente del área Metropolitana de San Juan, Argentina

2021 ◽  
Vol 11 (1) ◽  
pp. 20-31
Author(s):  
María Guillermina Ré ◽  
◽  
María Pía Mazzocco ◽  
Celina Filippín
Keyword(s):  
Climate Change ◽  
Energy Efficiency ◽  
Energy Consumption ◽  
Dynamic Simulation ◽  
Energy Savings ◽  
San Juan ◽  
School Buildings ◽  
Constant Growth ◽  
Efficiency Indicators ◽  
Significant Opportunity

Climate change, the constant growth of energy consumption, and the high levels of emissions recorded by the energy sector, require the implementation of concrete solutions. Building rehabilitation offers a significant opportunity to contribute in this regard. The purpose of this work is to analyze the potential for intervention in a school building from the “Programa Nacional 700 Escuela” (National 700 Schools Program). The improvements in energy efficiency are evaluated through a dynamic simulation and indicators are calculated regarding the annual energy consumption for heating. The values for the reference building are 74.5 kWh/m2 year and 158 kWh/student. With the rehabilitation proposals, energy savings could be achieved of between 39.7% and 60%. The R-Mean alternative appears as the most convenient one as it achieves energy benefits of 47%, with lower investment costs. The energy efficiency indicators for said set of improvements are 39.2 kWh/m2 year and 83.1 kWh/student. The results achieved can serve as reference for the rehabilitation of 71 school buildings built in the province of San Juan between 2004 and 2015, which belong to a construction typology with a similarity of materials of their envelope and functional configuration.

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