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1.
International Journal of Environmental Research and Public Health ; 19(24), 2022.
Article in English | CAB Abstracts | ID: covidwho-2200249

ABSTRACT

HFMD is a viral-mediated infectious illness of increasing public health importance. This study aimed to develop a forecasting tool utilizing climatic predictors and internet search queries for informing preventive strategies in Sabah, Malaysia. HFMD case data from the Sabah State Health Department, climatic predictors from the Malaysia Meteorological Department, and Google search trends from the Google trends platform between the years 2010-2018 were utilized. Cross-correlations were estimated in building a seasonal auto-regressive moving average (SARIMA) model with external regressors, directed by measuring the model fit. The selected variables were then validated using test data utilizing validation metrics such as the mean average percentage error (MAPE). Google search trends evinced moderate positive correlations to the HFMD cases (r0-6 weeks: 0.47-0.56), with temperature revealing weaker positive correlations (r0-3 weeks: 0.17-0.22), with the association being most intense at 0-1 weeks. The SARIMA model, with regressors of mean temperature at lag 0 and Google search trends at lag 1, was the best-performing model. It provided the most stable predictions across the four-week period and produced the most accurate predictions two weeks in advance (RMSE = 18.77, MAPE = 0.242). Trajectorial forecasting oscillations of the model are stable up to four weeks in advance, with accuracy being the highest two weeks prior, suggesting its possible usefulness in outbreak preparedness.

2.
PLoS Global Public Health ; 2(11), 2022.
Article in English | CAB Abstracts | ID: covidwho-2196839

ABSTRACT

Governments all throughout the world have been negotiating about human destiny for decades, but without people. There is a significant chance that the future COP27, which will be hosted by Egypt in November 2022, will be just like the other COPs, in which enthusiasm and ambition are quickly overshadowed by the strength and influence of short-term interests and corporate avarice. Since the COVID-19 pandemic gave us a "sneak preview" of the harmful effects that shocks and stressors brought on by crises like the climate emergency could have on people, many people were hoping that last year's COP26 in Glasgow would be a turning point for climate action. However, the earlier pledge to "phase out" coal-based power in major economies was not included in the COP26 final declaration. The lengthy history of colonialism around the world must be explicitly acknowledged in the climate negotiations in addition to placing a strong emphasis on everyone's health and wellbeing. For the first time, the most recent assessment of the United Nations Intergovernmental Panel on Climate Change (UN IPCC) emphasized the crucial part historical colonialism played in accelerating current anthropogenic climate change. Only extraction from people and the Earth is valued in the colonial capitalist world order humans currently live in. The world's Indigenous Peoples, who were victims of colonization, are now being exploited and pillaged while still fighting the climatic disaster on the ground. Even in the bargaining chambers, where the powerful's interests are prioritized and Indigenous peoples are underrepresented, the colonial legacy persists. However, young people are inventively channeling their angst and fear into initiative and action. For instance, young movements from the frontlines of the climate crisis, like Tuvali, are making the stories of their struggle and survival apparent to the influential through campaigning and awareness raising. The People's Health Hearing, a global forum for testimonies about how extractive industries are wreaking havoc on health and how communities are fending off oppressive systems of pollution, is one of the forums that a number of us are organizing. People with credentials in health are working with health systems and professional associations to influence policy change and take action on climate change by using the strength of health evidence and their voices.

3.
4th International Conference on Computer Science and Technologies in Education, CSTE 2022 ; : 27-30, 2022.
Article in English | Scopus | ID: covidwho-2191701

ABSTRACT

In early 2020, COVID-19 appeared and widely spread worldwide. It affected all vital sectors, including commercial activities and education. Most governments decided to temporarily close educational institutions, including schools and universities. Developed countries with adequate learning-management systems moved to the online teaching mode. Hence, the sudden transition from the traditional to online teaching mode has impacted learning outcomes. The ultimate goal of this paper is to develop a method for evaluating the experience of teaching online during epidemics. More precisely, it assesses the teaching of programming language courses in the computer science and engineering college at the University of Hail. It statistically measures the courses' learning outcomes in the online mode compared to the traditional mode. Perhaps surprisingly, the difference was not significant, which shed light on the positive side of the crisis. According to the obtained results, the experience of teaching online during an epidemic has led us to investigate the opportunities of using online teaching, especially for programming language courses. This highlighted opportunities for using online platforms as supportive teaching tools or even merging them with traditional teaching approaches at times when attending classes on campus is impossible. Finally, to ensure best practices, the author recommended some guidelines to follow. © 2022 IEEE.

4.
Environmental Research ; 221:115282, 2023.
Article in English | ScienceDirect | ID: covidwho-2178501

ABSTRACT

To inhibit the COVID-19 (Coronavirus disease 2019) outbreak, unprecedented nationwide lockdowns were implemented in China in early 2020, resulting in a marked reduction of anthropogenic emissions. However, reasons for the insignificant improvement in air quality in megacities of northeast China, including Shenyang, Changchun, Jilin, Harbin, and Daqing, were scarcely reported. We assessed the influences of meteorological conditions and changes in emissions on air quality in the five megacities during the COVID-19 lockdown (February 2020) using the WRF-CMAQ model. Modeling results indicated that meteorology contributed a 14.7% increment in Air Quality Index (AQI) averaged over the five megacities, thus, the local unfavorable meteorology was one of the causes to yield little improved air quality. In terms of emission changes, the increase in residential emissions (+15%) accompanied by declining industry emissions (−15%) and transportation (−90%) emissions resulted in a slight AQI decrease of 3.1%, demonstrating the decrease in emissions associated with the lockdown were largely offset by the increment in residential emissions. Also, residential emissions contributed 42.3% to PM2.5 concentration on average based on the Integrated Source Apportionment tool. These results demonstrated the key role residential emissions played in determining air quality. The findings of this study provide a scenario that helps make appropriate emission mitigation measures for improving air quality in this part of China.

5.
Obstetrics and Gynaecology Forum ; 32(3):1-3, 2022.
Article in English | CAB Abstracts | ID: covidwho-2169800

ABSTRACT

It can be argued that there are three colliding pandemics that are currently affecting the planet and its people: COVID-19, global inequities and climate change. Regrettably, these are all the result of human action or inaction and are preventable. The United Nations Conference of the Parties (COP26), held in November 2021 in Glasgow, addressed some of these issues.1 Prince Charles called this meeting the 'last chance saloon to save the planet.' The main objective of COP26 was to reduce global heating and limit global warming to the target maximum temperature of 1.5-degree Celsius above pre-industrial levels. According to the National Aeronautics and Space Administration (NASA), since the late 19th century, the earth surface temperature rose by 1.18 degrees Celsius, caused by increased carbon dioxide and other emissions into the atmosphere, with the years 2016 and 2020 being tied as the warmest years on record.2 However, many, including a group of scientists called 'Scientist Rebellion' were not convinced that COP26 would make any difference to the warming of the planet.3 President of COP26, Alok Sharma admitted that the objective of the conference was not reached but remained cautiously optimistic: "We can now say with credibility that we have kept 1.5 degrees alive. But its pulse is weak and it will only survive if we keep our promises and translate commitments into rapid action".

6.
Agricultural Economics and Rural Development ; 19(1):89-100, 2022.
Article in English | CAB Abstracts | ID: covidwho-2168599

ABSTRACT

One of the key challenges in the coming years is to produce enough safe and nutritious food for the future generations without exceeding the planetary reserves even more. In circular agriculture, waste is seen as a raw material to produce new valuable products, including crops, food, feed and energy. Another characteristic of the concept is the need to reduce the consumption of resources and discharges into the environment. This article analyzes the concept of circular agriculture as well as the necessary government policies for implementing this concept as the development paradigm. It is highly recommended for governments to promote circular agriculture, especially in the post COVID-19 period, as means to improve different objectives, including better environmental conditions, climate change mitigation, public health, etc. It is also recommended to support and facilitate the development of circular economy principles as well as to implement best practices from existing initiatives around the world.

7.
Atmospheric Chemistry and Physics ; 23(2):877-894, 2023.
Article in English | ProQuest Central | ID: covidwho-2202606

ABSTRACT

The national and global restrictions in response to the COVID-19 pandemic led to a sudden, albeit temporary, emission reduction of many greenhouse gases (GHGs) and anthropogenic aerosols, whose near-term climate impact were previously found to be negligible when focusing on global- and/or annual-mean scales. Our study aims to investigate the monthly scale coupled climate-and-circulation response to regional, COVID-19-related aerosol emission reductions, using the output from 10 Earth system models participating in the Covid model intercomparison project (CovidMIP). We focus on January–February and March–May 2020, which represent the seasons of largest emission changes in sulfate (SO2) and black carbon (BC). During January–February (JF), a marked decrease in aerosol emissions over eastern China, the main emission region, resulted in a lower aerosol burden, leading to an increase in surface downwelling radiation and ensuing surface warming. Regional sea-level pressure and circulation adjustments drive a precipitation increase over the Maritime Continent, embedded in a negative Pacific Decadal Oscillation (PDO)- and/or El Niño–Southern Oscillation (ENSO)-like response over the Pacific, in turn associated with a northwestward displacement and zonal shrinking of the Indo-Pacific Walker cell. Remote climate anomalies across the Northern Hemisphere, including a weakening of the Siberian High and Aleutian Low, as well as anomalous temperature patterns in the northern mid-latitudes, arise primarily as a result of stationary Rossby wave trains generated over East Asia. The anomalous climate pattern and driving dynamical mechanism reverse polarity between JF and MAM (March–May) 2020, which is shown to be consistent with an underlying shift of the dominant region of SO2 emission reduction from eastern China in JF to India in MAM. Our findings highlight the prominent role of large-scale dynamical adjustments in generating a hemispheric-wide aerosol climate imprint even on short timescales, which are largely consistent with longer-term (decadal) trends. Furthermore, our analysis shows the sensitivity of the climate response to the geographical location of the aerosol emission region, even after relatively small, but abrupt, emission changes. Scientific advances in understanding the climate impact of regional aerosol perturbations, especially the rapidly evolving emissions over China and India, are critically needed to reduce current uncertainties in near-future climate projections and to develop scientifically informed hazard mitigation and adaptation policies.

8.
Journal of Cleaner Production ; 369(64), 2022.
Article in English | CAB Abstracts | ID: covidwho-2159207

ABSTRACT

From an economic point of view, the tourism sector is one of the most important in the world with religious tourism, such as pilgrimages, being a growth area. Tourism activities also make a significant contribution to CO2 emissions (roughly 8% of the world's carbon emissions). In this framework, the main objective of this research is to develop an integrated sustainable model by assessing the impact of pilgrimages to the Camino Lebaniego (Lebaniego Way) in the Cantabrian region, which is one of the most popular routes in northern Spain. To do this, it is necessary to quantify the environmental impacts of this activity since this is a key element in establishing appropriate and effective environmental management programmes. This study uses the Life Cycle Assessment (LCA) method, focused on the Carbon Footprint (CF) impact category, to assess the greenhouse gas (GHG) emissions of this activity considering 'a pilgrim who completes the route in three days' as the selected functional unit (FU). In addition, the sub-sectors of accommodation, food and beverages, and waste management are taken into account. Following this route generated a total of 13.69 kg CO2 eq./FU, of which accommodation and the services offered there contributed almost 71.47%, food was 17.08%, and waste management 11.45%. The evening meal and propane consumption were the hotspots in the hostel, accounting for almost 74% of the total impact, so alternatives were proposed to reduce the impacts associated with these. In terms of transport, it was found that for the same destination, it was better to use a car rather than a plane, because the associated CO2 emissions were lower. Finally, these aspects are discussed and improvement measures for reducing GHG emissions are proposed, involving the introduction of good practices and environmental commitments from the pilgrims themselves, as well as enterprises and local communities. Ecolabels and environmental certifications should become a key tool for sending this signal to the market as should the use of public transport to the destination, among other actions. Ultimately, religious and nature tourism seems to be on the upturn, and it is likely that pilgrimage routes could be the next post-COVID travel trend.

9.
IOP Conference Series : Earth and Environmental Science ; 2022.
Article in English | CAB Abstracts | ID: covidwho-2156474

ABSTRACT

This issue contains 70 papers that were presented at a conference with the theme, "Landscape Dynamics and Sustainable Development Post Covid-19 Pandemic." The papers cover topics on landscape inventory and mapping;human impact on landscape;disaster management;food security;gender and demographic bonus;climate adaptation and mitigation;sustainable cities and community resilience;and clean water and sanitation.

10.
Revue forestière française ; 72(6):491-503, 2020.
Article in French | CAB Abstracts | ID: covidwho-2155985

ABSTRACT

The economic impact of the worldwide Covid health crisis and the faster decline of forests have led to a 14% decrease of the turnover of wood from publicly owned forests Wood prices decreased by 10% on average, and by 17% for spruce, with more wood infested by bark beetles than in 2019 Beech, fir, Scots pine and even oak suffered from this third hot year in a row, with severe drought in summer All sales by submission have been done using an upgradable online selling tool since January 2020 In addition, supply contracts are increasing steadily, and represent 35% of the volumes.

11.
Science of The Total Environment ; 862:160767, 2023.
Article in English | ScienceDirect | ID: covidwho-2150571

ABSTRACT

The COVID-19 epidemic has exerted significant impacts on human health, social and economic activities, air quality and atmospheric chemistry, and potentially on climate change. In this study, an online coupled regional climate–chemistry–aerosol model (RIEMS-Chem) was applied to explore the direct, indirect, and feedback effects of anthropogenic aerosols on radiation, boundary layer meteorology, and fine particulate matter during the COVID-19 lockdown period from 23 January to 8 April 2020 over China. Model performance was validated against a variety of observations for meteorological variables, PM2.5 and its chemical components, aerosol optical properties, as well as shortwave radiation flux, which demonstrated that RIEMS-Chem was able to reproduce the spatial distribution and temporal variation of the above variables reasonably well. During the study period, direct radiative effect (DRE) of anthropogenic aerosols was stronger than indirect radiative effect (IRE) in most regions north of the Yangtze River, whereas IRE dominated over DRE in the Yangtze River regions and South China. In North China, DRE induced larger changes in meteorology and PM2.5 than those induced by IRE, whereas in South China, the changes by IRE were remarkably larger than those by DRE. Emission reduction alone during the COVID-19 lockdown reduced PM2.5 concentration by approximately 32 % on average over East China. As a result, DRE at the surface was weakened by 15 %, whereas IRE changed little over East China, leading to a decrease in total radiative effect (TRE) by approximately 7 % in terms of domain average. The DRE-induced changes in meteorology and PM2.5 were weakened due to emission reduction, whereas the IRE-induced changes were almost the same between the cases with and without emission reductions. By aerosol radiative and feedback effects, the COVID-19 emission reductions resulted in 0.06 °C and 0.04 °C surface warming, 1.6 and 4.0 μg m−3 PM2.5 decrease, 0.4 and 1.3 mm precipitation increase during the lockdown period in 2020 in terms of domain average over North China and South China, respectively, whereas the lockdown caused negligible changes on average over East Asia.

12.
Frontiers in Climate ; 4(September), 2022.
Article in English | CAB Abstracts | ID: covidwho-2162986

ABSTRACT

This perspective article argues that anticipatory research into possible "emergency" response measures such as solar geoengineering will increase knowledge, and thus confidence, in any future decisions to either deploy or reject these technologies. Similarities between COVID and climate can reveal some perspective on the benefits of anticipatory vaccine research for anticipatory for solar geoengineering research. Although we deeply hope governments will aggressively reduce emissions and scale up adaptation efforts in time to avoid the worst climate impacts, we argue that the benefits of anticipatory solar geoengineer research currently outweigh the risks of not moving research forward.

13.
Nanjing Xinxi Gongcheng Daxue Xuebao ; 14(5):516-526, 2022.
Article in Chinese | ProQuest Central | ID: covidwho-2145402

ABSTRACT

Small and medium-sized service enterprises were particularly vulnerable during COVID-19. To help them survive the pandemic, local government introduced series of support scheme, such as the vouchers jointly granted by government and small and medium-sized service enterprises. This paper constructs a tripartite evolutionary game model involving local government, small and medium-sized service enterprises,and consumers, to study the influencing factors of paid subsidies, government credibility, and voucher deduction amount on the strategies of each stakeholder.The results show that the low subsidy and the paid characteristic of consumer vouchers have a great impact on the government credibility, which will prompt government to choose paid support for enterprises;the enterprises are inclined to choose positive self-help strategy due to higher paid subsidies and less deduction for consumption vouchers;that the vouchers hardly influence the actual consumption amount, and the more deductions of consumption vouchers by enterprises of positive self-help strategy, will motivate consumers to choose voucher consumption.Ít can be concluded that a differentiated support scheme combined with precise delivery of consumption vouchers can promote economic recovery.

14.
Atmospheric Chemistry and Physics ; 22(22):15135-15151, 2022.
Article in English | ProQuest Central | ID: covidwho-2144700

ABSTRACT

Sulfur compounds in the upper troposphere and lower stratosphere (UTLS) impact the atmosphere radiation budget, either directly as particles or indirectly as precursor gas for new particle formation. In situ measurements in the UTLS are rare but are important to better understand the impact of the sulfur budget on climate. The BLUESKY mission in May and June 2020 explored an unprecedented situation. (1) The UTLS experienced extraordinary dry conditions in spring 2020 over Europe, in comparison to previous years, and (2) the first lockdown of the COVID-19 pandemic caused major emission reductions from industry, ground, and airborne transportation. With the two research aircraft HALO and Falcon, 20 flights were conducted over central Europe and the North Atlantic to investigate the atmospheric composition with respect to trace gases, aerosol, and clouds. Here, we focus on measurements of sulfur dioxide (SO2) and particulate sulfate (SO42-) in the altitude range of 8 to 14.5 km which show unexpectedly enhanced mixing ratios of SO2 in the upper troposphere and of SO42- in the lowermost stratosphere. In the UT, we find SO2 mixing ratios of (0.07±0.01) ppb, caused by the remaining air traffic, and reduced SO2 sinks due to low OH and low cloud fractions and to a minor extent by uplift from boundary layer sources. Particulate sulfate showed elevated mixing ratios of up to 0.33 ppb in the LS. We suggest that the eruption of the volcano Raikoke in June 2019, which emitted about 1 Tg SO2 into the stratosphere in northern midlatitudes, caused these enhancements, in addition to Siberian and Canadian wildfires and other minor volcanic eruptions. Our measurements can help to test models and lead to new insights in the distribution of sulfur compounds in the UTLS, their sources, and sinks. Moreover, these results can contribute to improving simulations of the radiation budget in the UTLS with respect to sulfur effects.

15.
Atmospheric and Climate Sciences ; 11(2):302-323, 2021.
Article in English | CAB Abstracts | ID: covidwho-2144305

ABSTRACT

The coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), dates back to December 29, 2019, in Wuhan, China. It quickly spreads like wildfire to all continents in the following months. In Guinea, the first case of COVID-19 and death were all reported respectively on March 12 and April 16, 2020. Since then, several studies have found a relationship between certain environmental conditions such as the meteorological factors to have the potential of contributing to the spread of the virus. Thus, this study aims at examining the extent to which observed meteorological factors might have contributed to the spread of the coronavirus disease 2019 (COVID-19) cases in Conakry, from March 1 to May 31, 2020. Meteorological factors such as temperature (Tmin, Tmean and Tmax) and relative humidity (RHmin, RHmean and RHmax) were analyzed together with the data on the COVID-19. The dynamic of the COVID-19 in Guinea was analyzed along with that of some west African countries. The analysis on the dynamic of the COVID-19 pandemic in West Africa indicated Guinea as one of the most affected countries by the pandemic after Nigeria and Ghana. The study found that in general an increase in the temperature is linked to a decline in the COVID-19 number of cases and deaths, while an increase in the humidity is positively correlated to the number of cases and deaths. Nevertheless, from this study it was also observed that low temperature, mild diurnal temperature and high humidity are likely to favor its transmission. The study therefore, recommends that habitations and hospital rooms should be kept in relatively low humidity and relatively higher temperature to minimize the spread of the (SARS-CoV-2).

16.
Environmental Research Letters ; 17(12):123001, 2022.
Article in English | ProQuest Central | ID: covidwho-2134662

ABSTRACT

Since 2013, China has taken a series of actions to relieve serious PM2.5 pollution. As a result, the annual PM2.5 concentration decreased by more than 50% from 2013 to 2021. However, ozone pollution has become more pronounced, especially in the North China Plain. Here, we review the impacts of anthropogenic emissions, meteorology, and atmospheric processes on ambient PM2.5 loading and components and O3 pollution in China. The reported influence of interannual meteorological changes on PM2.5 and O3 pollution during 2013–2019 ranged from 10%–20% and 20%–40%, respectively. During the same period, the anthropogenic emissions of NOx, SO2, primary PM2.5, NMVOC and NH3 are estimated to decrease by 38%, 51%, 35%, 11% and 17%, respectively. Such emission reduction is the main cause for the decrease in PM2.5 concentration across China. However, the imbalanced reductions in various precursors also result in the variation in nitrate gas-particle partitioning and hence an increase in the nitrate fraction in PM2.5. The increase of ozone concentration and the enhancement of atmospheric oxidation capacity can also have substantial impact on the secondary components of PM2.5, which partly explained the growth of organic aerosols during haze events and the COVID-19 shutdown period. The uneven reduction in NOx and NMVOC is suggested to be the most important reason for the rapid O3 increase after 2013. In addition, the decrease in PM2.5 may also have affected O3 formation via radiation effects and heterogeneous reactions. Moreover, climate change is expected to influence both anthropogenic emissions and atmospheric processes. However, the extent and pathways of the PM2.5-O3 interplay and how it will be impacted by the changing emission and atmospheric conditions making the synergetic control of PM2.5 and O3 difficult. Further research on the interaction of PM2.5 and O3 is needed to provide basis for a scientifically-grounded and effective co-control strategy.

17.
International Journal of Global Warming ; 28(4):311-324, 2022.
Article in English | ProQuest Central | ID: covidwho-2126943

ABSTRACT

It is analysed that the urban disaster with pandemic and its related consequences are associated with the global warming induced by the carbon-emitted fossil fuels. In 'urban disaster', the result is shown as a stepwise form in which the effectiveness of urban disaster increases. In addition, 'energy-mix' and 'energy' decrease in their effectiveness, although 'traffic, communication, etc.', 'health, quarantine, etc.', and 'resilience' increase in their effectiveness. This means that three variables, 'traffic, communication, etc.', 'health, quarantine, etc.', and 'resilience', affect the 'energy-mix' and 'energy' as the feedback algorithm. It is analysed for urban disasters with ecological pandemic situations where the social distancing is very important in the urban places due to the higher population density than the rural areas. In this work, the prospects of pandemic society incorporated with the climate change mitigating by energy-mix policy are investigated.

18.
Atmospheric Chemistry and Physics ; 22(22):14455-14466, 2022.
Article in English | ProQuest Central | ID: covidwho-2118990

ABSTRACT

Shanghai, one of China's most important economic centres, imposed a citywide lockdown in April and May 2022 to contain a resurgence in cases of the coronavirus disease in 2019. Compared with the 2020 lockdown, the 2022 lockdown occurred in a warm season and lasted much longer, thereby serving as a relevant real-world test of the response of ambient ozone (O3) concentrations to emission reductions in a high-O3 season. In this study, we analysed surface observations of O3 and nitrogen dioxide (NO2) concentrations and satellite-retrieved tropospheric NO2 and formaldehyde (HCHO) column concentrations in the first 5 months of 2022 with comparisons to the year 2021. During the 2-month 2022 lockdown, the maximum daily 8 h average (MDA8) O3 concentrations at 1 or more of the city's 19 sites exceeded China's air quality standard of 160 µgm-3 21 times, with the highest value being 200 µgm-3. The city-average MDA8 O3 concentration increased by 13 % in April–May 2022 year-on-year, despite sharp declines in NO2 surface and column concentrations (both by 49 %) and a 19 % decrease in the HCHO column concentration. These results show that the reductions in O3 precursors and other pollutants during the 2022 lockdown did not prevent ground-level O3 pollution. An analysis of meteorological data indicates that there were only small changes in the meteorological conditions, and there was little transport of O3 from the high-O3 inland regions during the 2022 lockdown, neither of which can account for the increased and high concentrations of O3 that were observed during this period. The mean HCHO/NO2 ratio in April–May increased from 1.11 in 2021 to 1.68 in 2022, and the correlation between surface O3 and NO2 concentrations changed from negative in 2021 to positive in 2022. These results indicate that the high O3 concentrations in 2022 were mainly due to large reductions in the emissions of NOx and that the decrease in the concentrations of volatile organic compounds (VOCs) could not overcome the NO titration effect. During the 2022 lockdown, Shanghai's urban centre remained VOC-sensitive despite drastic reductions in road transportation (73 %–85 %) and industrial activities (∼60 %), whereas its semi-rural areas transitioned from VOC-limited to VOC–NOx-co-limited regimes. Our findings suggest that future emission reductions similar to those that occurred during the lockdown, such as those that will result from electrifying transportation, will not be sufficient to eliminate O3 pollution in urban areas of Shanghai and possibly other VOC-limited metropoles without the imposition of additional VOC controls or more substantial decreases in NOx emissions.

19.
Atmospheric Chemistry and Physics ; 22(21):14243-14252, 2022.
Article in English | ProQuest Central | ID: covidwho-2110593

ABSTRACT

Compared with 2019, measurements of the global growth rate of background (marine air) atmospheric methane rose by 5.3 ppb yr-1 in 2020, reaching 15.0 ppb yr-1. Global atmospheric chemistry models have previously shown that reductions in nitrogen oxide (NOx) emissions reduce levels of the hydroxyl radical (OH) and lengthen the methane lifetime. Acting in the opposite sense, reductions in carbon monoxide (CO) and non-methane volatile organic compound (NMVOC) emissions increase OH and shorten methane's lifetime. Using estimates of NOx, CO, and NMVOC emission reductions associated with COVID-19 lockdowns around the world in 2020 as well as model-derived regional and aviation sensitivities of methane to these emissions, we find that NOx emission reductions led to a 4.8 (3.8 to 5.8) ppb yr-1 increase in the global methane growth rate. Reductions in CO and NMVOC emissions partly counteracted this, changing (reducing) the methane growth rate by -1.4 (-1.1 to -1.7) ppb yr-1 (CO) and -0.5 (-0.1 to -0.9) ppb yr-1 (NMVOC), yielding a net increase of 2.9 (1.7 to 4.0) ppb yr-1. Uncertainties refer to ±1 standard deviation model ranges in sensitivities. Whilst changes in anthropogenic emissions related to COVID-19 lockdowns are probably not the only important factor that influenced methane during 2020, these results indicate that they have had a large impact and that the net effect of NOx, CO, and NMVOC emission changes can explain over half of the observed 2020 methane changes. Large uncertainties remain in both emission changes during the lockdowns and methane's response to them;nevertheless, this analysis suggests that further research into how the atmospheric composition changed over the lockdown periods will help us to interpret past methane changes and to constrain future methane projections.

20.
Journal of Korean Society for Atmospheric Environment ; 38(4):610-623, 2022.
Article in English | Web of Science | ID: covidwho-2100249

ABSTRACT

Since 2019, Korean Ministry of Environment has implemented the 1st -3rd PM2.5 Seasonal Management Plans(SMP) to reduce PM2.5 concentration during high PM2.5 concentration period. In this study, we quantitatively evaluated the major drivers(meteorology, foreign emissions, and domestic emissions) of which changes led to change of PM2.5 concen-trations in South Korea during the PM2.5 SMP periods(S1, Dec. 2019-Mar. 2020;S2, Dec. 2020-Mar. 2021;S3, Dec. 2021-Mar. 2022) based on observational data and Community Multiscale Air Quality(CMAQ) simulation results. The nation-wide period mean PM2.5 concentration in S1, S2, and S3 decreased by 8.7, 9.1, and 10.1 mu g/m3 compared to that during Dec. 2018-Mar. 2019. Results show that anthropogenic emission reductions in Northeast Asia decreased the PM2.5 concentration by 5.9, 5.5, and 8.8 mu g/m3 respectively during S1-S3. Note that the effect of the regional emission reduction includes not only domestic emission reduction but also reductions in foreign emission impact. The combined impact of meteorology and foreign emission changes explained 65%, 61% of the total PM2.5 decreases over South Korea and the Seoul Metropolitan Area(SMA) respectively during the S1-S3. Consequently, domestic emission reductions including governmental air quality management plans(i.e., the PM2.5 SMP) and socioeconomic changes(i.e., COVID-19 outbreak) led to PM2.5 concentration decrease in South Korea by 35% during the periods. Among seventeen provinces in South Korea, the impacts of domestic emission reduction on the PM2.5 concentration decreases were as high as 39% and 56% in the SMA and Chungnam where the major emission sources such as transportation, power generation facilities, and industrial complex locate and where the PM2.5 SMP measures were probably penetrated. It implies that the effects of domestic emission controls were meaningful to lower PM2.5concentrations during the periods.

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