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1.
Environ Monit Assess ; 192(10): 665, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-33001326

RESUMO

With economic development and the acceleration of urbanization, China's energy demand has gradually increased and brought a lot of energy-related CO2 emissions. Energy-related CO2 emissions are affected by a variety of factors. Quantifying the correlation between energy-related CO2 and driving factors and constructing the driving factor system are conducive to predict the future energy-related CO2 emissions and analyze the impact of driving factors. In this paper, the improved grey relational analysis (IGRA) was proposed to screen the influencing factors of energy-related CO2 emissions considering the sample difference, and the factor analysis (FA) was used to reduce dimensionality of the influencing factors. Then, a carbon dioxide emission forecasting model based on the bacterial foraging optimization algorithm (BFO) and the least square support vector machine (LSSVM) was proposed. Empirical analysis results of Hebei show that the LSSVM optimized BFO significantly improves the accuracy of energy-related CO2 emissions forecasting, and IGRA-FA-BFOLSSVM model is significantly better than BP, PSOBP, SVM, and LSSVM models. The mean absolute percentage error (MAPE) of the proposed model is 0.374%. The forecasting results of the supplementary case show that the model has better generalization ability. In addition, education and technological progress have proven to be important drivers of energy-related CO2 emissions. Simultaneously, the research results can also offer more breakthrough points for policy makers to control carbon emissions.


Assuntos
Dióxido de Carbono/análise , Monitoramento Ambiental , China , Desenvolvimento Econômico , Análise Fatorial
2.
Nat Commun ; 11(1): 5172, 2020 10 14.
Artigo em Inglês | MEDLINE | ID: mdl-33057164

RESUMO

The COVID-19 pandemic is impacting human activities, and in turn energy use and carbon dioxide (CO2) emissions. Here we present daily estimates of country-level CO2 emissions for different sectors based on near-real-time activity data. The key result is an abrupt 8.8% decrease in global CO2 emissions (-1551 Mt CO2) in the first half of 2020 compared to the same period in 2019. The magnitude of this decrease is larger than during previous economic downturns or World War II. The timing of emissions decreases corresponds to lockdown measures in each country. By July 1st, the pandemic's effects on global emissions diminished as lockdown restrictions relaxed and some economic activities restarted, especially in China and several European countries, but substantial differences persist between countries, with continuing emission declines in the U.S. where coronavirus cases are still increasing substantially.


Assuntos
Poluentes Atmosféricos/análise , Dióxido de Carbono/análise , Infecções por Coronavirus/epidemiologia , Pneumonia Viral/epidemiologia , Poluentes Atmosféricos/economia , Betacoronavirus , Dióxido de Carbono/economia , Infecções por Coronavirus/economia , Infecções por Coronavirus/prevenção & controle , Monitoramento Ambiental , Combustíveis Fósseis/análise , Combustíveis Fósseis/economia , Humanos , Indústrias/economia , Dióxido de Nitrogênio/análise , Dióxido de Nitrogênio/economia , Pandemias/economia , Pandemias/prevenção & controle , Pneumonia Viral/economia , Pneumonia Viral/prevenção & controle
3.
J Environ Qual ; 49(5): 1081-1091, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33016440

RESUMO

Terrestrial ecosystems, both natural ecosystems and agroecosystems, generate greenhouse gases (GHGs). The chamber method is the most common method to quantify GHG fluxes from soil-plant systems and to better understand factors affecting their generation and mitigation. The objective of this study was to review and synthesize literature on chamber designs (non-flow-through, non-steady-state chamber) and associated factors that affect GHG nitrous oxide (N2 O) flux measurement when using chamber methods. Chamber design requires consideration of many facets that include materials, insulation, sealing, venting, depth of placement, and the need to maintain plant growth and activity. Final designs should be tailored, and bench tested, in order to meet the nuances of the experimental objectives and the ecosystem under study while reducing potential artifacts. Good insulation, to prevent temperature fluctuations and pressure changes, and a high-quality seal between base and chamber are essential. Elimination of pressure differentials between headspace and atmosphere through venting should be performed, and designs now exist to eliminate Venturi effects of earlier tube-type vent designs. The use of fans within the chamber headspace increases measurement precision but may alter the flux. To establish best practice recommendations when using fans, further data are required, particularly in systems containing tall plants, to systematically evaluate the effects that fan speed, position, and mixing rate have on soil gas flux.


Assuntos
Ecossistema , Metano/análise , Dióxido de Carbono/análise , Monitoramento Ambiental , Óxido Nitroso/análise
4.
J Environ Qual ; 49(5): 1421-1434, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33016444

RESUMO

Land application of biochar reportedly provides many benefits, including reduced risk of nutrient transport, greenhouse gas (GHG) emission mitigation, and increased soil C storage, but additional field validation is needed. We evaluated the effectiveness of biochar in controlling the lability of nutrients in agricultural land. This study was designed to evaluate the impacts of biochar co-applied with various N and P sources on GHG fluxes from a subtropical grassland. Nutrients (inorganic fertilizer and aerobically digested Class B biosolids) were surface applied at a rate of 160 kg plant available N ha-1  yr-1 with or without biochar (applied at 20 Mg ha-1 ). Greenhouse gas (CO2 , CH4 , and N2 O) fluxes were assessed using static chambers and varied significantly, both temporally and with treatments. Greenhouse gas fluxes ranged from 1,247 to 23,160, -0.7 to 42, and -1.4 to 376 mg m-2 d-1 for CO2 , N2 O, and CH4 , respectively. Results of the 3-yr field study demonstrated strong seasonal variability associated with GHG emissions. Nutrient source had no effect on soil CO2 and CH4 emissions, but annual and cumulative (3-yr) N2 O emissions increased with biosolids (8 kg N2 O ha-1  yr-1 ) compared with inorganic fertilizer (5 kg N2 O ha-1  yr-1 ) application. Data suggested that environmental conditions played a more important role on GHG fluxes than nutrient additions. Biochar reduced CO2 emissions modestly (<9%) but had no effects on N2 O and CH4 emissions.


Assuntos
Gases de Efeito Estufa , Dióxido de Carbono/análise , Carvão Vegetal , Pradaria , Metano/análise , Óxido Nitroso/análise , Nutrientes , Solo
5.
Emerg Med Clin North Am ; 38(4): 755-769, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32981615

RESUMO

There are approximately 350,000 out-of-hospital cardiac arrests and 200,000 in-hospital cardiac arrests annually in the United States, with survival rates of approximately 5% to 10% and 24%, respectively. The critical factors that have an impact on cardiac arrest survival include prompt recognition and activation of prehospital care, early cardiopulmonary resuscitation, and rapid defibrillation. Advanced life support protocols are continually refined to optimize intracardiac arrest management and improve survival with favorable neurologic outcome. This article focuses on current treatment recommendations for adult nontraumatic cardiac arrest, with emphasis on the latest evidence and controversies regarding intracardiac arrest management.


Assuntos
Reanimação Cardiopulmonar/métodos , Parada Cardíaca/terapia , Manuseio das Vias Aéreas , Antiarrítmicos/administração & dosagem , Pressão Sanguínea , Dióxido de Carbono/análise , Diástole , Ecocardiografia , Cardioversão Elétrica , Serviço Hospitalar de Emergência , Epinefrina/administração & dosagem , Humanos , Hipotermia Induzida , Infusões Intraósseas , Infusões Intravenosas , Monitorização Fisiológica , Sistemas Automatizados de Assistência Junto ao Leito , Guias de Prática Clínica como Assunto , Vasoconstritores/administração & dosagem
6.
J Environ Manage ; 273: 110979, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32889312

RESUMO

Reducing inequality, eradicating poverty and achieving a carbon-neutral society are recognized as important components of the United Nations' Sustainable Development Goals. In this study, we focus on carbon and energy inequality between and within ten Latin American and Caribbean (LAC) countries. Detailed carbon and energy footprint were estimated by combining the consumption profiles (2014) in ten LAC countries with environmental extended multi-regional input-output (MRIO) analysis. Our results show significant inequality of regional total and per capita carbon and energy footprint across the studied LAC countries in 2014. The top 10% income category was responsible for 29.1% and 26.3% of the regional total carbon and energy footprint, and their per capita carbon and energy footprint were 12.2 and 7.5 times of the bottom 10% earners in that region. The average carbon footprint of studied LAC countries varied between 0.53 and 2.21 t CO2e/cap (ton of CO2 equivalent, per capita), and the energy footprint ranged from 0.38 to 1.76 t SOE/cap (ton of Standard Oil Equivalent, per capita). The huge difference in total and per capita carbon emissions and energy consumption of different income groups suggests notable differences in climate change responsibility, and supports policies for achieving sustainable consumption in terms of carbon tax, renewable energy subsidy, and decarbonizing the consumption structure in different LAC countries.


Assuntos
Pegada de Carbono , Carbono , Dióxido de Carbono/análise , Região do Caribe , América Latina , Fatores Socioeconômicos
7.
Sci Total Environ ; 740: 140057, 2020 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-32927541

RESUMO

Existing related researches have focused on the linear relationship between population aging and carbon emissions, which easily lead to partial understanding of the effect of population aging on carbon emissions. In order to more comprehension of the effect of population aging on carbon emissions, this study explores the nonlinear relationship between population aging and carbon emission through empirical analysis of ten selected provinces in China from 2000 to 2016 using the panel threshold model. In the proposed panel threshold model, carbon emission is set as the explained variable, population aging is set as the core explanatory variable, the levels of population aging and trade openness are set as threshold variables, the levels of economic development, energy consumption structure, industrial structure, and technological innovation are set as the controlling variables, respectively. The results show that population aging has a threshold effect on curbing carbon emission. The levels of population aging and trade openness are two key factors that affect the relationship between population aging and carbon emission. Whether the level of popultion aging is lower or higher than the threshold value of 0.12937, the population aging has a negative coefficient on carbon emissions. Moreover, the higher the level of population aging, the greater the offsetting effect of population aging on carbon emission. When the level of trade openness is below the threshold value of 0.30990, the effect of population aging on carbon emission is negligible. When the level of trade openness is higher than the threshold value of 0.30990, the offesetting effect of population aging on carbon emission begins to appear. In other words, population aging has an offsetting effect on carbon emission when trade openness is in relatively high level, whereas the offsetting effect disappears when trade openness is lower than threshold value.


Assuntos
Dióxido de Carbono/análise , Carbono , China , Desenvolvimento Econômico
8.
Sci Total Environ ; 740: 140403, 2020 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-32927559

RESUMO

Waste amendments, such as steel slag and biochar, have been reported as a strategy for improving soil fertility, crop productivity, and carbon (C) sequestration in agricultural lands. However, information regarding the subsequent effects of steel slag and biochar on C cycling and the underlying microbial mechanisms in paddy soils remains limited. Hence, this study aimed to examine the effect of these waste amendments (applied in 2015-2017) on total soil CO2 emissions, total and active soil organic C (SOC) contents, and microbial communities in the early and late seasons in a subtropical paddy field. The results showed that despite the exogenous C input from these waste amendments (steel slag, biochar and slag + biochar), they significantly (P < 0.05) decreased total CO2 emissions (e.g., by 41.9-59.6% at the early season), compared to the control soil. These amendments also significantly (P < 0.001) increased soil salinity and pH. The increased soil pH had a negative effect (r = -0.37, P < 0.05) on microbial biomass C (MBC). The biochar and slag + biochar treatments (cf. control) significantly (P < 0.001) increased SOC contents in the both seasons. The amendments altered the soil microbial community structure that associated with soil C cycling: (1) all three amendments increased the relative abundance of Agromyces and Streptomyces, which was associated with higher soil pH (cf. control); and (2) biochar and slag + biochar treatments caused a higher relative abundance of Sphingomonas, which was supported by high SOC contents under those amendments. Overall, this study demonstrated that the steel slag and biochar amendments altered microbial community composition due to changes in key soil properties, such as salinity, pH and SOC contents, with implications for increasing soil C stocks while mitigating CO2 emissions in the paddy field.


Assuntos
Oryza , Solo , Dióxido de Carbono/análise , Carvão Vegetal , Microbiologia do Solo , Aço
9.
J Environ Manage ; 263: 110390, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32883476

RESUMO

Quantifying the economic benefits and environmental costs brought about by trade can help reveal the environmental inequalities behind regional trade. There have been many studies on the accounting of greenhouse gas emissions and pollutants embodied in regional trade, but there are insufficient studies analyzing the imbalance between the economic benefits and environmental costs embodied in trade. Electricity-related carbon emissions are the main contributor to global warming, explaining more than 40% of carbon emissions both globally and in China. This study uses the network approach and multiregional input-output (MRIO) model to quantify the electricity-related carbon emissions and value added embodied in China's interprovincial trade from 2007 to 2012 and also applies the regional environmental inequality (REI) index to measure the imbalance of electricity-related carbon emissions and economic benefits embodied in such trade. The results show that 20-80% of the electricity-related carbon emissions and 15-70% of the value added of a province's final demand are outsourced to other provinces. The major directions of the net value added and electricity-related carbon emissions embodied in China's interprovincial trade were from north to south and from the center to the east. Unequal bilateral interprovincial trade mainly occurred between inland provinces and developed provinces, and western provinces (such as Guizhou, Gansu, and Ningxia) suffered economic and environmental losses from interprovincial trade. This study can promote understanding of the distribution impacts of domestic trade on environmental costs and economic benefits and provide a reference for China's cross-provincial carbon emission mitigation policies.


Assuntos
Dióxido de Carbono/análise , Carbono , China , Eletricidade , Fatores Socioeconômicos
10.
J Environ Manage ; 275: 111221, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32956918

RESUMO

Accurately assessing the effectiveness of industrial carbon emission reduction in each province and optimizing the emission reduction path have important practical significance for China's Nationally Determined Contribution (NDC) emission reduction achievement targets. This study first evaluates the industry's emission reduction effects across 30 provinces of China. Then, the emission reduction paths of "lagging regions," which fail to meet the 2030 industrial carbon emission reduction target, are optimized based on the two-dimensional perspective of carbon emission efficiency and emission reduction cost. This study found that (1) China has exceeded its 2020 industrial carbon emission reduction target. There are 9 potential "lagging regions" that failed to meet their 2020 targets, (2) if the current emission reduction rate is maintained, China is capable of exceeding its 2030 industrial carbon emission reduction target, but there are still 11 "lagging regions," (3) there are clear differences in carbon emission efficiency and shadow price among the "lagging regions," and (4) under the premise of ensuring feasibility and fairness, the three provinces of Liaoning, Guangxi, and Shaanxi can set strict emission reduction targets, while other "lagging regions" can set flexible targets.


Assuntos
Carbono , Indústrias , Carbono/análise , Dióxido de Carbono/análise , China , Custos e Análise de Custo
11.
Waste Manag ; 118: 55-61, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32889234

RESUMO

The occurrence of elevated temperatures within landfills is a challenging issue for landfill operators to detect and correct. Little is known regarding the causes of elevated temperatures (ETs) or the number of landfills currently operating under such conditions. Therefore, the goal of this research was to determine which landfills within Florida have been impacted by ETs, and to develop a more complete understanding of the factors that may lead to these landfills becoming elevated temperature landfills (ETLFs). Historical landfill gas wellhead data, waste deposition reports, and landfill site geometry were collected for 27 landfill cells through the Florida Department of Environmental Protection electronic document management system, OCULUS database and from landfill operators and owners. These data were evaluated to quantify the characteristics that result in landfills having 'elevated' temperatures. Gas data included landfill gas temperatures and methane, carbon dioxide, and balance gas content. Furthermore, landfill maps were created in ArcGIS to observe spatial distribution of ETs in landfills over time. Upon analysis of the landfill gas wellhead data, it was discovered that 74% of studied landfill cells had ET readings; regulatory limits specify a maximum allowable gas temperature of 55 °C (131 °F). It was discovered that 37% of landfill cells contained MSW ash; of these cells, 90% of them are considered ETLFs. ETLF cells are on-average double the site area and approximately 6 m deeper than the average non-ETLF cell. Furthermore, results suggest that heat propagation in most landfills is limited; however, heat propagation is possible if gas wells are turned off for an extended time period.


Assuntos
Eliminação de Resíduos , Instalações de Eliminação de Resíduos , Dióxido de Carbono/análise , Florida , Metano , Temperatura
12.
PLoS One ; 15(8): e0235465, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32790686

RESUMO

As carbon dioxide (CO2) levels increase, coral reefs and other marine systems will be affected by the joint stressors of ocean acidification (OA) and warming. The effects of these two stressors on coral physiology are relatively well studied, but their impact on biotic interactions between corals are poorly understood. While coral-coral interactions are less common on modern reefs, it is important to document the nature of these interactions to better inform restoration strategies in the face of climate change. Using a mesocosm study, we evaluated whether the combined effects of ocean acidification and warming alter the competitive interactions between the common coral Porites astreoides and two other mounding corals (Montastraea cavernosa or Orbicella faveolata) common in the Caribbean. After 7 days of direct contact, P. astreoides suppressed the photosynthetic potential of M. cavernosa by 100% in areas of contact under both present (~28.5°C and ~400 µatm pCO2) and predicted future (~30.0°C and ~1000 µatm pCO2) conditions. In contrast, under present conditions M. cavernosa reduced the photosynthetic potential of P. astreoides by only 38% in areas of contact, while under future conditions reduction was 100%. A similar pattern occurred between P. astreoides and O. faveolata at day 7 post contact, but by day 14, each coral had reduced the photosynthetic potential of the other by 100% at the point of contact, and O. faveolata was generating larger lesions on P. astreoides than the reverse. In the absence of competition, OA and warming did not affect the photosynthetic potential of any coral. These results suggest that OA and warming can alter the severity of initial coral-coral interactions, with potential cascading effects due to corals serving as foundation species on coral reefs.


Assuntos
Antozoários/fisiologia , Biodiversidade , Mudança Climática , Animais , Antozoários/metabolismo , Dióxido de Carbono/análise , Fotossíntese , Água do Mar/química
13.
Nature ; 584(7820): 227-233, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32788734

RESUMO

Anthropogenic global surface warming is proportional to cumulative carbon emissions1-3; this relationship is partly determined by the uptake and storage of heat and carbon by the ocean4. The rates and patterns of ocean heat and carbon storage are influenced by ocean transport, such as mixing and large-scale circulation5-10. However, existing climate models do not accurately capture the observed patterns of ocean warming, with a large spread in their projections of ocean circulation and ocean heat uptake8,11. Additionally, assessing the influence of ocean circulation changes (specifically, the redistribution of heat by resolved advection) on patterns of observed and simulated ocean warming remains a challenge. Here we establish a linear relationship between the heat and carbon uptake of the ocean in response to anthropogenic emissions. This relationship is determined mainly by intrinsic parameters of the Earth system-namely, the ocean carbon buffer capacity, the radiative forcing of carbon dioxide and the carbon inventory of the ocean. We use this relationship to reveal the effect of changes in ocean circulation from carbon dioxide forcing on patterns of ocean warming in both observations and global Earth system models from the Fifth Coupled Model Intercomparison Project (CMIP5). We show that historical patterns of ocean warming are shaped by ocean heat redistribution, which CMIP5 models simulate poorly. However, we find that projected patterns of heat storage are primarily dictated by the pre-industrial ocean circulation (and small changes in unresolved ocean processes)-that is, by the patterns of added heat owing to ocean uptake of excess atmospheric heat rather than ocean warming by circulation changes. Climate models show more skill in simulating ocean heat storage by the pre-industrial circulation compared to heat redistribution, indicating that warming patterns of the ocean may become more predictable as the climate warms.


Assuntos
Dióxido de Carbono/análise , Aquecimento Global , Temperatura Alta , Oceanos e Mares , Água do Mar/análise , Água do Mar/química , Movimentos da Água , Atmosfera/química , Atividades Humanas
14.
Nature ; 584(7820): 234-237, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32788738

RESUMO

Tropical soils contain one-third of the carbon stored in soils globally1, so destabilization of soil organic matter caused by the warming predicted for tropical regions this century2 could accelerate climate change by releasing additional carbon dioxide (CO2) to the atmosphere3-6. Theory predicts that warming should cause only modest carbon loss from tropical soils relative to those at higher latitudes5,7, but there have been no warming experiments in tropical forests to test this8. Here we show that in situ experimental warming of a lowland tropical forest soil on Barro Colorado Island, Panama, caused an unexpectedly large increase in soil CO2 emissions. Two years of warming of the whole soil profile by four degrees Celsius increased CO2 emissions by 55 per cent compared to soils at ambient temperature. The additional CO2 originated from heterotrophic rather than autotrophic sources, and equated to a loss of 8.2 ± 4.2 (one standard error) tonnes of carbon per hectare per year from the breakdown of soil organic matter. During this time, we detected no acclimation of respiration rates, no thermal compensation or change in the temperature sensitivity of enzyme activities, and no change in microbial carbon-use efficiency. These results demonstrate that soil carbon in tropical forests is highly sensitive to warming, creating a potentially substantial positive feedback to climate change.


Assuntos
Ciclo do Carbono , Dióxido de Carbono/análise , Florestas , Aquecimento Global , Solo/química , Clima Tropical , Retroalimentação , Ilhas , Panamá , Fatores de Tempo , Água/análise
15.
Sci Total Environ ; 747: 141214, 2020 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-32795794

RESUMO

Coastal marshes have a significant capacity to sequester carbon; however, sea-level rise (SLR) is expected to result in prolonged flooding and saltwater intrusion in coastal regions. To explore the effects of SLR projections on net CO2 uptake in coastal marshes, we conducted a "double-check" investigation, including the eddy covariance (EC) measurements of the CO2 fluxes in subtropical coastal marshes along inundation and salinity gradients, in combination with a mesocosm experiment for analyzing CO2 flux components under waterlogging and increased salinity conditions. During the same measurement periods, the net ecosystem CO2 exchange (NEEEC based on the EC dataset) in an oligohaline marsh was higher than that in a low-elevation mesohaline marsh, whereas the NEEEC was lower than that in a high-elevation freshwater marsh. The declines in NEEEC between the marshes could be attributed to a greater decrease in gross primary production relative to ecosystem respiration. Waterlogging slightly increased the NEEms (NEE based on the mesocosms) because of inhibited soil respiration and slight changes in plant photosynthesis and shoot respiration. However, the NEEms measured during the drainage period decreased significantly due to the stimulated soil respiration. The NEEms decreased with increasing salinity (except under mild salinity), and waterlogging exacerbated the adverse impacts of salinity. The amplificatory effect of decreases in both leaf photosynthesis and growth under hydrological stresses contributed more to reduce the NEEms than to respiratory effluxes. Both waterlogging and increased salinity reduced the root biomass, soil microbial biomass, and activities of assayed soil enzymes (except for cellulase under waterlogging conditions), leading to limited soil respiration. The declines in plant growth, photosynthesis, and soil respiration could also be attributed to the decrease in soil nutrients under waterlogging and increased salinity conditions. We propose that the coupling of SLR-driven hydrological effects lowers the capacity of CO2 uptake in subtropical coastal marshes.


Assuntos
Dióxido de Carbono , Áreas Alagadas , Dióxido de Carbono/análise , Ecossistema , Elevação do Nível do Mar , Solo
16.
Sci Total Environ ; 747: 141380, 2020 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-32795802

RESUMO

Silicate fertilizer application in croplands is effective in mitigating soil methane (CH4) emissions and increasing rice yield. However, the effects of silicate fertilizer on soil greenhouse gas (GHG) emissions in Moso bamboo forests, and the underlying mechanisms are poorly understood. In the present study, a two-year field experiment was conducted to investigate the effect of silicate fertilizer rates (0 (CK), 0.225 and 1.125 Mg ha-1) on soil GHG emissions in a Moso bamboo forest. The results showed that silicate fertilizer application significantly reduced soil CO2 and N2O emissions, and increased soil CH4 uptakes. Compared to the CK treatments, the cumulative soil CO2 emission fluxes decreased by 29.6% and 32.5%, and the cumulative soil N2O emission fluxes decrease by 41.9% and 48.3%, the CH4 uptake fluxes increased by 13.5% and 32.4% in the 0.225 and 1.125 Mg ha-1 treatments, respectively. The soil GHG emissions were significantly positively related to soil temperature (P < 0.05), but negatively related to soil moisture; however, this relationship was not observed between CH4 uptake fluxes and moisture in CK treatment. Soil CO2 emission and CH4 uptake were significantly positively related with water-soluble organic C (WSOC) and microbial biomass C (MBC) concentrations in all treatments (P < 0.05). Soil N2O emissions were significantly positively related to MBC, NH4+-N, NO3--N, and microbial biomass N (MBN) concentrations in all treatments (P < 0.05), but not with WSOC concentration. Structural equation modeling showed that application of silicate fertilizer directly reduced soil GHG emission by decreasing the labile C and N pools, and indirectly by influencing the soil physicochemical properties. Our findings suggest that silicate fertilizer can be an effective tool in combatting climate change by reducing soil GHG emissions in Moso bamboo forests.


Assuntos
Fertilizantes , Gases de Efeito Estufa , Dióxido de Carbono/análise , Florestas , Metano/análise , Nitrogênio/análise , Óxido Nitroso/análise , Silicatos , Solo
17.
Sci Total Environ ; 747: 141515, 2020 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-32795805

RESUMO

In this paper, we extend the debate on environmental quality in sub-Saharan Africa (SSA) by examining the nexus between financial development and environmental quality. While doing this, we also investigate the technology effect of financial development on environmental quality and the direction of causality between financial development and environmental quality. Unlike prior studies, we use a novel composite index of financial development. We rely on a panel dataset of 35 SSA countries for the period 1985-2014. Through the augmented mean group estimator, we offer the following findings. First, financial development is a positive (negative) driver of environmental quality (CO2 emissions). Second, financial development has an unfavourable technology effect on environmental quality. Lastly, lower environmental quality is associated with increase in population, affluence and technology. We also find, via the Dumitrescu-Hurlin panel causality test, that there is a bidirectional causal relationship between financial development and CO2 emissions. We document the policy implications in the concluding section.


Assuntos
Dióxido de Carbono , Desenvolvimento Econômico , África ao Sul do Saara , Dióxido de Carbono/análise , Tecnologia
18.
PLoS One ; 15(8): e0237597, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32853232

RESUMO

Several factors influence the environmental performance simultaneously but ethnic fractionalization, political freedom, financial development and institutional quality have a substantial impact to explain the environmental performance across economies. This study focuses to explore that how environmental performance is affected by these economic, political and social indicators by using the annual data of 163 developed and developing countries covering the time period of 1996-2016.The data is collected from World Development Indicators, World Governance Indicators, Freedom House and Cline Centre. The stationarity of variables is analyzed through LLC, IPS and ADF Fisher Chi-square test. Before applying panel ARDL approach to find out the long run relationship among variables, order of integration is determined through Pedroni's cointegration test. The findings of study highlight that ethnic diversity; institutional quality and political freedom play a significant role to decrease CO2emissions while energy consumption, GDP growth and financial development are increasing the environmental degradation. Ethnic diversity is a source of creative and innovative approaches about problem solving of environmental degradation. Political freedom allows people to participate in decision making that posits much compliance with environmental agreements. The foreign direct investment is attracted by good quality institutions which cause to advent of more environment friendly technology along with attractions for further innovations that may helpful to reduce CO2 emissions. Contrary, GDP growth, financial development and energy consumption enhance the industrialization and urbanization leading to increase the level of CO2 emissions. It is suggested for policy makers that cohesion among different ethnic groups; improving institutional quality; providing political freedom to people and inclusive financial sector will acknowledge the less pollutant environment.


Assuntos
Dióxido de Carbono/análise , Desenvolvimento Econômico , Desenvolvimento Industrial , Meio Social , Urbanização , Humanos
19.
J Neurol Sci ; 417: 117078, 2020 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-32768718

RESUMO

BACKGROUND AND AIM: COVID-19 pandemic has resulted in an unprecedented increased usage of Personal protective equipment (PPE) by healthcare-workers. PPE usage causes headache in majority of users. We evaluated changes in cerebral hemodynamics among healthcare-workers using PPE. METHODS: Frontline healthcare-workers donning PPE at our tertiary center were included. Demographics, co-morbidities and blood-pressure were recorded. Transcranial Doppler (TCD) monitoring of middle cerebral artery was performed with 2-MHz probe. Mean flow velocity (MFV) and pulsatility index (PI) were recorded at baseline, after donning N95 respirator-mask, and after donning powered air-purifying respirator (PAPR), when indicated. End-tidal carbon-dioxide (ET-CO2) pressure was recorded for participants donning PAPR in addition to the N95 respirator-mask. RESULTS: A total of 154 healthcare-workers (mean age 29 ± 12 years, 67% women) were included. Migraine was the commonest co-morbidity in 38 (25%) individuals while 123 (80%) developed de-novo headache due to N95 mask. Donning of N95 respirator-mask resulted in significant increase in MFV (4.4 ± 10.4 cm/s, p < 0.001) and decrease in PI (0.13 ± 0.12; p < 0.001) while ET-CO2 increased by 3.1 ± 1.2 mmHg (p < 0.001). TCD monitoring in 24 (16%) participants donning PAPR and N95 respirator mask together showed normalization of PI, accompanied by normalization of ET-CO2 values within 5-min. Combined use of N95 respirator-mask and PAPR was more comfortable as compared to N95 respirator-mask alone. CONCLUSION: Use of N95 respirator-mask results in significant alterations in cerebral hemodynamics. However, these effects are mitigated by the use of additional PAPR. We recommend the use of PAPR together with the N95 mask for healthcare-workers doing longer duties in the hospital wards.


Assuntos
Betacoronavirus , Pessoal de Saúde , Máscaras/efeitos adversos , Doenças Profissionais/prevenção & controle , Pandemias , Dispositivos de Proteção Respiratória , Adulto , Velocidade do Fluxo Sanguíneo , Dióxido de Carbono/análise , Circulação Cerebrovascular , Infecções por Coronavirus/prevenção & controle , Estudos Transversais , Feminino , Cefaleia/etiologia , Hemodinâmica , Humanos , Masculino , Artéria Cerebral Média/diagnóstico por imagem , Artéria Cerebral Média/fisiopatologia , Doenças Profissionais/etiologia , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Fluxo Pulsátil , Ultrassonografia Doppler Transcraniana , Adulto Jovem
20.
Environ Monit Assess ; 192(9): 592, 2020 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-32821960

RESUMO

The Pars Special Economic Energy Zone (PSEEZ) is one of the largest gas reserves in the world. To reduce the CO2 emission from the area in line with the international climate commitments, two groups of scenario have been developed: the first is using the ecosystem services of mangrove forests, and the second is technology development for oil and gas industries. For the first scenario, the carbon sequestrated by the trees was calculated using the allometric equation, and the carbon of sediments was determined by using the Walkley-Black method. For the second scenario, CO2 emitted from the PSEEZ was calculated by using the Iranian Petroleum Ministry Guidelines. CO2 emission from the PSEEZ was 0.030 Gt year-1. The maximum CO2 sequestered by mangrove scenarios was 0.12% of the PSEEZ emissions, while the flaring elimination technology reduces 36% of the PSEEZ emissions. Generally, the scenario of using oil and gas industry technologies is more effective.


Assuntos
Dióxido de Carbono/análise , Ecossistema , Monitoramento Ambiental , Irã (Geográfico) , Áreas Alagadas
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