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1.
Geoscientific Model Development ; 16(11):3313-3334, 2023.
Article in English | ProQuest Central | ID: covidwho-20245068

ABSTRACT

Using climate-optimized flight trajectories is one essential measure to reduce aviation's climate impact. Detailed knowledge of temporal and spatial climate sensitivity for aviation emissions in the atmosphere is required to realize such a climate mitigation measure. The algorithmic Climate Change Functions (aCCFs) represent the basis for such purposes. This paper presents the first version of the Algorithmic Climate Change Function submodel (ACCF 1.0) within the European Centre HAMburg general circulation model (ECHAM) and Modular Earth Submodel System (MESSy) Atmospheric Chemistry (EMAC) model framework. In the ACCF 1.0, we implement a set of aCCFs (version 1.0) to estimate the average temperature response over 20 years (ATR20) resulting from aviation CO2 emissions and non-CO2 impacts, such as NOx emissions (via ozone production and methane destruction), water vapour emissions, and contrail cirrus. While the aCCF concept has been introduced in previous research, here, we publish a consistent set of aCCF formulas in terms of fuel scenario, metric, and efficacy for the first time. In particular, this paper elaborates on contrail aCCF development, which has not been published before. ACCF 1.0 uses the simulated atmospheric conditions at the emission location as input to calculate the ATR20 per unit of fuel burned, per NOx emitted, or per flown kilometre.In this research, we perform quality checks of the ACCF 1.0 outputs in two aspects. Firstly, we compare climatological values calculated by ACCF 1.0 to previous studies. The comparison confirms that in the Northern Hemisphere between 150–300 hPa altitude (flight corridor), the vertical and latitudinal structure of NOx-induced ozone and H2O effects are well represented by the ACCF model output. The NOx-induced methane effects increase towards lower altitudes and higher latitudes, which behaves differently from the existing literature. For contrail cirrus, the climatological pattern of the ACCF model output corresponds with the literature, except that contrail-cirrus aCCF generates values at low altitudes near polar regions, which is caused by the conditions set up for contrail formation. Secondly, we evaluate the reduction of NOx-induced ozone effects through trajectory optimization, employing the tagging chemistry approach (contribution approach to tag species according to their emission categories and to inherit these tags to other species during the subsequent chemical reactions). The simulation results show that climate-optimized trajectories reduce the radiative forcing contribution from aviation NOx-induced ozone compared to cost-optimized trajectories. Finally, we couple the ACCF 1.0 to the air traffic simulation submodel AirTraf version 2.0 and demonstrate the variability of the flight trajectories when the efficacy of individual effects is considered. Based on the 1 d simulation results of a subset of European flights, the total ATR20 of the climate-optimized flights is significantly lower (roughly 50 % less) than that of the cost-optimized flights, with the most considerable contribution from contrail cirrus. The CO2 contribution observed in this study is low compared with the non-CO2 effects, which requires further diagnosis.

2.
Atmospheric Chemistry and Physics ; 23(11):6127-6144, 2023.
Article in English | ProQuest Central | ID: covidwho-20232936

ABSTRACT

According to the United States Environmental Protection Agency (US EPA), emissions from oil and gas infrastructure contribute 30 % of all anthropogenic methane (CH4) emissions in the US. Studies in the last decade have shown emissions from this sector to be substantially larger than bottom-up assessments, including the EPA inventory, highlighting both the increased importance of methane emissions from the oil and gas sector in terms of their overall climatological impact and the need for independent monitoring of these emissions. In this study we present continuous monitoring of regional methane emissions from two oil and gas basins using tower-based observing networks. Continuous methane measurements were taken at four tower sites in the northeastern Marcellus basin from May 2015 through December 2016 and five tower sites in the Delaware basin in the western Permian from March 2020 through April 2022. These measurements, an atmospheric transport model, and prior emission fields are combined using an atmospheric inversion to estimate monthly methane emissions in the two regions. This study finds the mean overall emission rate from the Delaware basin during the measurement period to be 146–210 Mg CH4 h-1 (energy-normalized loss rate of 1.1 %–1.5 %, gas-normalized rate of 2.5 %–3.5 %). Strong temporal variability in the emissions was present, with the lowest emission rates occurring during the onset of the COVID-19 pandemic. Additionally, a synthetic model–data experiment performed using the Delaware tower network shows that the presence of intermittent sources is not a significant source of uncertainty in monthly quantification of the mean emission rate. In the Marcellus, this study finds the overall mean emission rate to be 19–28 Mg CH4 h-1 (gas-normalized loss rate of 0.30 %–0.45 %), with relative consistency in the emission rate over time. These totals align with aircraft top-down estimates from the same time periods. In both basins, the tower network was able to constrain monthly flux estimates within ±20 % uncertainty in the Delaware and ±24 % uncertainty in the Marcellus. The results from this study demonstrate the ability to monitor emissions continuously and detect changes in the emissions field, even in a basin with relatively low emissions and complex background conditions.

3.
American Journal of Gastroenterology ; 117(10 Supplement 2):S2164-S2165, 2022.
Article in English | EMBASE | ID: covidwho-2323899

ABSTRACT

Introduction: Lactulose is a non-absorbable disaccharide which acts in the large bowel, and is commonly used in the treatment of hepatic encephalopathy. We present an interesting case of altered mental status due to hepatic encephalopathy successfully managed with lactulose in a patient with history of total colectomy. Case Description/Methods: A 67-year-old male with non-alcoholic cirrhosis and inflammatory bowel disease (IBD) post total proctocolectomy with a continent ileostomy known as a Kock-pouch (K-pouch) presented to the hospital with flu like symptoms and altered mental status. He was subsequently found to be positive for COVID-19. At the time of initial evaluation, the patient was obtunded with an elevated ammonia level of 91 umol/L. Colorectal surgery was consulted as the patient was not able to empty his K-pouch. Recently, he complained of inability to catheterize and with bleeding from the stoma. Initial catheterization with a Water's tube yielded 400 cc of effluent. Nasogastric tube was placed through which he was receiving lactulose 30 mg q8 hours. The patient's mental status improved within 24 hours. The patient ultimately underwent flexible pouchoscopy with endoscopic dilation and placement of a 22 French mushroom catheter for decompression of the K-pouch. Discussion(s): Lactulose is a non-absorbable disaccharide composed of galactose and fructose. The small intestine does not have the enzymes required to breakdown lactulose so it reaches the large bowel in its original form. In the large bowel, it is metabolized by colonic bacteria into monosaccharides and then to volatile fatty acids, hydrogen and methane. Lactulose decreases both the production and absorption of ammonia mainly through the presence of gut bacteria. The question arises as to how lactulose decreased ammonia levels in this patient without a large bowel. One proposed mechanism is the translocation of bacteria normally found in the large bowel to the small intestine. Small Intestinal Bacterial Overgrowth (SIBO), is a condition causing an increased number of bacteria in the small intestine. Patients with IBD and structural abnormalities are at increased risk of developing SIBO. Lactulose is commonly used in the diagnosis through the administration of lactulose and subsequent measurements of hydrogen and methane gas in expired air. This condition, in our patient with history of ulcerative colitis and colectomy, is a proposed mechanism of the efficacy of lactulose in the treatment of hepatic encephalopathy.

4.
Energy Sources Part a-Recovery Utilization and Environmental Effects ; 45(2):5063-5080, 2023.
Article in English | Web of Science | ID: covidwho-2327267

ABSTRACT

The COVID-19 pandemic has created a new type of waste (surgical mask waste "WMs") that presents a major challenge now and in the future, given the strong possibilities of similar epidemics to reoccur. In order to find an effective industrial solution to the millions of WMs produced daily, this research aims to develop a new eco-friendly strategy to convert WMs into H-2-CH4-rich syngas, carbon nanoparticles (CNPs), and benzene-rich tar using an updraft gasifier system. The experiments started with the preparation of WM granules using shredding followed by granulation processes. Subsequently, the granules were processed in a lab-scale reactor with a capacity of 0.9-1 kg/h and consisted of a continuous WM feed system, a gasifier, a sampling system for syngas and tar, a ceramic filtration unit for separating the CNPs against the synthesis gas, and a burner. The gasification experiments were performed in ambient air with different air-fuel equivalence ratios (ER: 0.21, 0.25, and 0.29) and temperatures (700 degrees C, 800 degrees C, and 900 degrees C) to determine the optimal conditions that yield the maximum amount of H-2-CH4-rich syngas and CNPs with less impurities. The chemical composition and morphology of the obtained gasification products (syngas, tar, and CNPs) were observed using GC-FID, FTIR, and SEM. The results showed that the maximum production of syngas (4.29 +/- 0.16 kg/h with HHV of 3804 kJ/kg) and CNPs (0.14 +/- 0.011 kg/h) accompanied by a moderate tar rate (0.123 +/- 0.009 kg/h with HHV of 41,139.88 kJ/kg) could be obtained at 900 degrees C and ER = 0.29, while the highest H-2 (16.93 +/- 1.7 vol.%) and CH4 (10.44 +/- 0.85 vol.%) contents in syngas product were synthesized at 900 degrees C and ER = 0.19. Benzene and toluene were the major GC-FID compounds in the formulated tar product with abundance up to 25.6% and 11%, respectively. Meanwhile, gasification conditions of 900 degrees C and ER = 0.24 allowed the best morphology to be formulated for spherical-shaped CNPs with a diameter of less than 200 nm.

5.
Environ Sci Pollut Res Int ; 30(29): 74386-74397, 2023 Jun.
Article in English | MEDLINE | ID: covidwho-2326985

ABSTRACT

In the context of the COVID-19 pandemic, antiviral drugs (AVDs) were heavily excreted into wastewater and subsequently enriched in sewage sludge due to their widespread use. The potential ecological risks of AVDs have attracted increasing attention, but information on the effects of AVDs on sludge anaerobic digestion (AD) is limited. In this study, two typical AVDs (lamivudine and ritonavir) were selected to investigate the responses of AD to AVDs by biochemical methane potential tests. The results indicated that the effects of AVDs on methane production from sludge AD were dose- and type-dependent. The increased ritonavir concentration (0.05-50 mg/kg TS) contributed to an 11.27-49.43% increase in methane production compared with the control. However, methane production was significantly decreased at high lamivudine doses (50 mg/kg TS). Correspondingly, bacteria related to acidification were affected when exposed to lamivudine and ritonavir. Acetoclastic and hydrotropic methanogens were inhibited at a high lamivudine dose, while ritonavir enriched methylotrophic and hydrotropic methanogens. Based on the analysis of intermediate metabolites, the inhibition of lamivudine and the promotion of ritonavir on acidification and methanation were confirmed. In addition, the existence of AVDs could affect sludge properties. Sludge solubilization was inhibited when exposed to lamivudine and enhanced by ritonavir, perhaps caused by their different structures and physicochemical properties. Moreover, lamivudine and ritonavir could be partially degraded by AD, but 50.2-68.8% of AVDs remained in digested sludge, implying environmental risks.


Subject(s)
COVID-19 , Sewage , Humans , Sewage/chemistry , Anaerobiosis , Biofuels , Waste Disposal, Fluid/methods , Antiviral Agents/pharmacology , Ritonavir , Lamivudine/metabolism , Pandemics , Methane/metabolism , Bioreactors
6.
Tydskrif Vir Geesteswetenskappe ; 62(4):623-646, 2022.
Article in English | Web of Science | ID: covidwho-2308287

ABSTRACT

The Covid-19 pandemic has had a devastating socio-economic effect on the country, including the death of more than 102 000 people, many of whom were the breadwinners of their families. This could not have happened at a worse time, since the economy of the country was in a recession even before the pandemic. The situation is exacerbated by the highest level of unemployment in the world, widespread nepotism and corruption, the plundering of state coffers and the favouring of the business interests of BRICS partners by government officials over those of South Africans. The government's commitment to prioritising their BRICS partners' business interests over those of the South African people contributes to food insecurity in South Africa. This includes the export of coal from mines in Mpumalanga to China and India, while nothing is done to rehabilitate the region, which was once known for its agriculture. The government handed over to the Chinese company SAEMB the Musina-Makhado Special Economic Zone, where four opencast mines, a 3 300 MW power station and an iron smelting plant will be developed. This development, however, requires the government to build a dam that will harvest 60% of the annual runoff of the Limpopo River, which in turn will have a devastating effect on farmers and communities downriver in South Africa, Zimbabwe and Mozambique who irrigate their crops with water from the Limpopo River. The same kowtowing of the South African government to its BRICS partners can be seen in the reluctance with which the government responds to the plundering of our marine resources by Chinese fishing boats and abalone smugglers. The unfair competition imposed on local chicken farmers by distributers of dumped chicken, mainly from Brazil, with the approval of government, caused the closure of several South African chicken farms and the resulting loss of tens of thousands of jobs along the supply chain. The reluctance of the government to take sides in the Russia-Ukraine war is partly linked to the fact that South Africa imports fertilizer and wheat from Russia. South Africa, a water-scarce country, is more vulnerable than many other countries to the effects of global climate change. The abnormal rain pattern, that is characterised by severe droughts in certain regions and heavy rainstorms and floods in others, has a devastating impact on the already economically struggling South African community. Abroad, attempts are made to ensure that mean temperatures do not exceed the pre-industrial level mark by more than 1,5 degrees C. South Africa, however, heats up twice as fast as many other countries, and has already exceeded the pre-industrial era level by more than 2 degrees C;it will continue to get warmer and drier, causing most of the country to become desertified by 2050. A third of South African rivers do not reach the sea anymore because of over ion of water from rivers;similarly, there is extensive ion of groundwater. Together farming and forestry account for 70% of water use in South Africa. This over ion of water, worsened by the heat and aridification resulting from climate change, led to the degradation of most wetland and estuarine ecosystems and the drying and burning of irreplaceable peatlands. These political, socioeconomic and environmental calamities create the worst possible scenario for food security in South Africa. Already one in four people in Africa suffers from food insecurity and this number will rapidly rise in the wake of global climate change, which will result in the loss of two thirds of arable land by 2025. South Africa is nearing socioeconomic collapse. This, in conjunction with continuing droughts, storms and rising temperatures associated with global climate change, will lead to food insecurity, starvation and anarchy. The effect of global climate change will make it progressively more difficult to produce enough food for the South African population. It is imperative that South Africans consider alternative methods of food production, including water use. Entomophagy is widely practiced throughout the world, but is especially prevalent in South America, the Far East and Africa, where approximately 2 billion people use 1 900 species of insects as food. The nutritional value of insects is unsurpassed and, in some respects, even more nutritious than meat. The larvae of the black soldier fly (BSF) Hermetia illucens are a source of high-quality proteins and unsaturated fats that are used worldwide as animal feed. Insects are a source of minerals such as iron, calcium, copper, zinc and magnesium and high levels of vitamin A, B 2 and C. The ecological and socioeconomic benefits of using BSF larvae instead of grain as feed for fish, chickens and pigs are enormous. BSF larvae can be bred almost for free by feeding it a wide variety of organic waste, including rotten vegetables and fruit, manure and even carcases that would have ended up in rubbish dumps and would have contributed to the methane and carbon dioxide pollution emanating from such dumps. The water use of BSF is negligible, because the water in the organic waste that would have been discarded in waste dumps is sufficient to sustain them. BSF affords the subsistence and small-scale farmer the opportunity to raise chickens at a lower input cost than ever before. The conversion of feed to food in insects is far greater than that of chickens, pigs or cattle. In the case of the house cricket (Acheta domestica) the conversion rate of feed to food is twice as effective as that of chickens, four times as effective as pigs and twelve times greater than that of cattle. Compared to conventional farming, this implies that with insects far more exceptionally nutritious food can be produced in a smaller area, with little water and no poison or fertilizer whatsoever, while waste and the associated methane gas are removed from the environment at the same time. A few South African companies have already seen the potential of insects as food and feed. Even though insect farming is still in its infancy, it is already generating jobs and new socioeconomic opportunities in South Africa. Insect farming, especially BSF farming, will in the near future probably grow in popularity all over the world as an affordable, healthy, ecologically sustainable alternative food source that will, directly or indirectly, be consumed by humans. BSF afford the environmentally conscious homesteader who wants to produce livestock such as chickens, fish, or pigs in a sustainable manner an unsurpassed environmentally friendly alternative. BSF will also give the desperate, impoverished and starving population of the future an alternative free source of feed that will offer them economic prospects and food security.

7.
Atmospheric Chemistry and Physics ; 23(8):4863-4880, 2023.
Article in English | ProQuest Central | ID: covidwho-2298817

ABSTRACT

The global atmospheric methane growth rates reported by NOAA for 2020 and 2021 are the largest since systematic measurements began in 1983. To explore the underlying reasons for these anomalous growth rates, we use newly available methane data from the Japanese Greenhouse gases Observing SATellite (GOSAT) to estimate methane surface emissions. Relative to baseline values in 2019, we find that a significant global increase in methane emissions of 27.0 ± 11.3 and 20.8 ± 11.4 Tg is needed to reproduce observed atmospheric methane in 2020 and 2021, respectively, assuming fixed climatological values for OH. We see the largest annual increases in methane emissions during 2020 over Eastern Africa (14 ± 3 Tg), tropical Asia (3 ± 4 Tg), tropical South America (5 ± 4 Tg), and temperate Eurasia (3 ± 3 Tg), and the largest reductions are observed over China (-6 ± 3 Tg) and India (-2 ± 3 Tg). We find comparable emission changes in 2021, relative to 2019, except for tropical and temperate South America where emissions increased by 9 ± 4 and 4 ± 3 Tg, respectively, and for temperate North America where emissions increased by 5 ± 2 Tg. The elevated contributions we saw in 2020 over the western half of Africa (-5 ± 3 Tg) are substantially reduced in 2021, compared to our 2019 baseline. We find statistically significant positive correlations between anomalies of tropical methane emissions and groundwater, consistent with recent studies that have highlighted a growing role for microbial sources over the tropics. Emission reductions over India and China are expected in 2020 due to the Covid-19 lockdown but continued in 2021, which we do not currently understand. To investigate the role of reduced OH concentrations during the Covid-19 lockdown in 2020 on the elevated atmospheric methane growth in 2020–2021, we extended our inversion state vector to include monthly scaling factors for OH concentrations over six latitude bands. During 2020, we find that tropospheric OH is reduced by 1.4 ± 1.7 % relative to the corresponding 2019 baseline value. The corresponding revised global growth of a posteriori methane emissions in 2020 decreased by 34 % to 17.9 ± 13.2 Tg, relative to the a posteriori value that we inferred using fixed climatological OH values, consistent with sensitivity tests using the OH climatology inversion using reduced values for OH. The counter statement is that 66 % of the global increase in atmospheric methane during 2020 was due to increased emissions, particularly from tropical regions. Regional flux differences between the joint methane–OH inversion and the OH climatology inversion in 2020 are typically much smaller than 10 %. We find that OH is reduced by a much smaller amount during 2021 than in 2020, representing about 10 % of the growth of atmospheric methane in that year. Therefore, we conclude that most of the observed increase in atmospheric methane during 2020 and 2021 is due to increased emissions, with a significant contribution from reduced levels of OH.

8.
Bulletin of the American Meteorological Society ; 104(3):623-630, 2023.
Article in English | ProQuest Central | ID: covidwho-2298113

ABSTRACT

Presentations spanned a range of applications: the public health impacts of poor air quality and environmental justice;greenhouse gas measuring, monitoring, reporting, and verification (GHG MMRV);stratospheric ozone monitoring;and various applications of satellite observations to improve models, including data assimilation in global Earth system models. The combination of methane (CH4), carbon dioxide (CO2), carbon monoxide (CO), and NO2 retrievals can improve confidence in emissions inventories and model performance, and together these data products would be of use in future air quality management tools. The ability to retrieve additional trace gases (e.g., ethane, isoprene, and ammonia) in the thermal IR along with those measured in the UV–Vis–NIR region would be extremely useful for air quality applications, including source apportionment analysis (e.g., for oil/natural gas extraction, biogenic, and agricultural sources). Ground-level ozone is one of six criteria pollutants for which the EPA sets National Ambient Air Quality Standards (NAAQS) to protect against human health and welfare effects.

9.
Environmental Progress and Sustainable Energy ; 2023.
Article in English | Scopus | ID: covidwho-2296646

ABSTRACT

A bold, visionary, transforming, systemic, holistic, integrated, caring, inclusive, equitable, sustainable, and resilient paradigm for fast transitions toward a clean energy and decarbonized future is imperative and urgently needed. Business as usual and silo approaches are not viable with the changes that are occurring. These changes are linked and interacting systems of physical, natural, health, social, economic, finance, governance, and institution. The effects and impacts are dire, existential, and pervasive. The 2021 IPCC Report Physical Science Basis: Summary for Policymakers, in clear language stated "it is unequivocal that human influence has warmed the atmosphere, oceans and land”. The scientific communities in the US, Europe, Asia and other regions all subscribe to this situation. Well documented global empirical evidence is also confirming the profound systems and systemic transformations that are occurring. Business, industry, and the general public, in particular youths, worldwide are all increasingly demanding actions – that transcend words of what needs to be done to deeds of how and now. In the US, the 2022 Inflation Reduction Act, would allocate US 370 billion for combating climate change and clean energy production. The IRA is the largest climate spending package ever. President Biden has called for 100% clean electricity by 2035 and pledged to cut carbon emissions by 50%–52% below 2005 levels by the end of this decade, doubling the previous target. A decarbonized future was endorsed by Leaders at the 2021 G-7 Carbis, UK Summit. There is growing realization that the global climate change crisis requires strengthened and expanded global cooperation with new, innovative and non-bureaucratic mechanisms for collaboration. The 2021 IPCC Report summarized that global surface temperature will continue to increase until at least the mid- century under all emissions' scenarios considered. "Global warming of 1.5 and 2°C will be exceeded during the 21st century unless deep reductions in CO2 and other greenhouse gas emissions occur in the coming decades.” The UNEP and IEA contends reducing anthropogenic methane emissions will help mitigate climate change and is a cost-effective proposition. The release of methane and micro-organisms from melting of permafrost needs to be better studied and understood., The confluence of increased heat, humidity, fine particulates air pollution, water contaminants and the COVID pandemic, will exacerbate health burdens. This will have serious consequences for human wellbeing, and cascading into national and global security. With climate change, therapeutics and vaccines will not work. The article provides a brief overview of the unprecedented climate related hurricanes, storms, floods and wildfires disasters occurring in all regions of the world. It highlights of some of the key effects, impacts and consequences with current policies and practices with regard to the energy-climate conundrum. There is an imperative to change course toward a decarbonized future. A number of systemic expeditious interventions are delineated. These include actions by all on:. The* fundamental need to change behavior;*afforestation, reforestation, rehabilitation of wetlands, mangroves, wastelands and coral reefs to restore ecosystem functions which would also create significant number of employment and livelihoods' opportunities;*retrofitting existing structures to be more energy efficient, incorporate increasing renewable energy, sustainability and resiliency criteria, – to "build back better” and provide jobs;*the life cycle of food and agriculture practices need to be systemically examined to reduce adverse impacts on climate, Energy, environment and health. There are difficulties and challenges. The commensurate opportunities and benefits of a decarbonized paradigm include clean and safe jobs;healthy quality of life;and a sustained and resilient future for current and future generations. © 2023 American Institute of Chemical Engineers.

10.
Fermentation ; 9(2):131, 2023.
Article in English | ProQuest Central | ID: covidwho-2250109

ABSTRACT

In Greece biomass is often being disposed of uncontrollably, resulting in significant environmental impacts. The aim of this study is the single-stage anaerobic co-digestion assessment, valorizing Northern and Southern Greece mixtures, resulting from previous literature reviews, experimental designs, and biochemical methane potential (BMP) assays. Regarding the methane yield maximization, in Northern Greece, the most suitable mixture was 10% corn silage, 80% cattle manure, and 10% malt;while in Southern Greece it was 10% corn silage, 57% cattle manure, 23% orange peels, and 10% olive pomace for fall/winter season. The hydraulic retention time (HRT) was set at 20 d and an initial organic loading rate (OLR) of 2 g COD/(L·d) was applied, with a view to gradually increase it. However, volatile fatty acids accumulation was observed, which led to OLR reduction to 1.5 g COD/(L·d) for both experiments. The Northern Greece reactor operated successfully for OLR 1.5–5 g COD/(L·d), while further increase led to system failure. On the other hand, the reactor of the Southern Greece mixture operated successfully at OLR 1.5–2 g COD/(L·d), but further operation indicated inadequacy, probably due to inhibitor (such as limonene) accumulation. Mixtures consisting of corn silage, cattle manure, and malt can be successfully valorized at high OLR. However, further investigation for mixtures with orange peels is suggested due to the presence of inhibitors.

11.
Environmental Research Communications ; 5(2), 2023.
Article in English | Scopus | ID: covidwho-2284079

ABSTRACT

In the summer of 2020, the AVIRIS-NG airborne imaging spectrometer surveyed California's Southern San Joaquin Valley and the South Bay (Los Angeles County) to identify anthropogenic methane (CH4) point source plumes, estimate emission rates, and attribute sources to both facilities and emission sectors. These flights were designed to revisit regions previously surveyed by the 2016-2017 California Methane Survey and to assess the socioeconomic responses of COVID-19 on emissions across multiple sectors. For regions flown by both the California Methane Survey and the California COVID campaigns, total CH4 point source emissions from the energy and oil & natural gas sectors were 34.8% lower during the summer 2020 flights, however, emission trends varied across sector. For the energy sector, there was a 28.2% decrease driven by reductions in refinery emissions consistent with a drop in production, which was offset in part with increases from powerplants. For the oil & natural gas sector, CH4 emissions declined 34.2% and significant variability was observed at the oilfield scale. Emissions declined for all but the Buena Vista and Cymric fields with an observed positive relationship between production and emissions. In addition to characterizing the short-term impact of COVID-19 on CH4 emissions, this study demonstrates the broader potential of remote sensing with sufficient sensitivity, spatial resolution, and spatio-temporal completeness to quantify changes in CH4 emissions at the scale of key sectors and facilities. © 2023 The Author(s). Published by IOP Publishing Ltd.

12.
Energies ; 16(3), 2023.
Article in English | Scopus | ID: covidwho-2249447

ABSTRACT

The energy sector is in the spotlight today for its contribution to global warming and its dependence on global geopolitics. Even though many countries have reduced their use of coal, the COVID-19 crisis, the drop in temperatures in Central Asia, and the war between Russia and Ukraine have shown that coal continues to play an important role in this sector today. As long as we continue to depend energetically on coal, it is necessary to create the basis for the successful extraction and industrial use of coal mine methane (CMM), for example, as an unconventional energy resource. Early degassing technology is a technique that allows for the extraction of the methane contained within the coal seams. The application of this technology would reduce emissions, improve mine safety, and even increase their profitability. However, this technology has been understudied and is still not implemented on a large scale today. Moreover, mines with this technology generally burn the extracted methane in flares, losing a potential unconventional fuel. This study, therefore, presents different scenarios of the use of coalbed methane (CBM), with the aim of generating an impact on pollutant emissions from coal mines. To this end, a model has been designed to evaluate the economic efficiency of degasification. In addition, an emissions analysis was carried out. The results showed that the use of this technology has a negative impact on the economy of mines, which can be completely reversed with the use of CBM as fuel. Furthermore, it is observed that degasification, in addition to reducing the number of accidents in coal mining, reduces emissions by 30–40%. © 2023 by the authors.

13.
Adv Sci (Weinh) ; 10(10): e2206120, 2023 04.
Article in English | MEDLINE | ID: covidwho-2264801

ABSTRACT

Microplastic (MP) pollution is one of the greatest threats to marine ecosystems. Cold seeps are characterized by methane-rich fluid seepage fueling one of the richest ecosystems on the seafloor, and there are approximately more than 900 cold seeps globally. While the long-term evolution of MPs in cold seeps remains unclear. Here, how MPs have been deposited in the Haima cold seep since the invention of plastics is demonstrated. It is found that the burial rates of MPs in the non-seepage areas significantly increased since the massive global use of plastics in the 1930s, nevertheless, the burial rates and abundance of MPs in the methane seepage areas are much lower than the non-seepage area of the cold seep, suggesting the degradation potential of MPs in cold seeps. More MP-degrading microorganism populations and functional genes are discovered in methane seepage areas to support this discovery. It is further investigated that the upwelling fluid seepage facilitated the fragmentation and degradation behaviors of MPs. Risk assessment indicated that long-term transport and transformation of MPs in the deeper sediments can reduce the potential environmental and ecological risks. The findings illuminated the need to determine fundamental strategies for sustainable marine plastic pollution mitigation in the natural deep-sea environments.


Subject(s)
Ecosystem , Geologic Sediments , Plastics , Microplastics , Methane/metabolism
14.
Chemosphere ; 311, 2023.
Article in English | Scopus | ID: covidwho-2246826

ABSTRACT

Energy crisis and increasing rigorous management standards pose significant challenges for solid waste management worldwide. Several emerging diseases such as COVID-19 aggravated the already complex solid waste management crisis, especially sewage sludge and food waste streams, because of the increasingly large production year by year. As mature waste disposal technologies, landfills, incineration, composting, and some other methods are widespread for solid wastes management. This paper reviews recent advances in key sewage sludge disposal technologies. These include incineration, anaerobic digestion, and valuable products oriented-conversion. Food waste disposal technologies comprised of thermal treatment, fermentation, value-added product conversion, and composting have also been described. The hot topic and dominant research foci of each area are summarized, simultaneously compared with conventional technologies in terms of organic matter degradation or conversion performance, energy generation, and renewable resources production. Future perspectives of each technology that include issues not well understood and predicted challenges are discussed with a positive effect on the full-scale implementation of the discussed disposal methods. © 2022 Elsevier Ltd

15.
The International Archives of Photogrammetry, Remote Sensing and Spatial Information Sciences ; XLVIII-4/W6-2022:273-278, 2023.
Article in English | ProQuest Central | ID: covidwho-2233748

ABSTRACT

The Malaysian government implemented the Movement Control Order (MCO) from March 18 to May 13, 2020, in an effort to curb the coronavirus disease outbreak that had spread throughout the nation. Utilizing data from GOSAT, GOSAT-2, OCO-2, OCO-3, and TROPOMI, the total column-averaged dry-air mole fraction of carbon dioxide and methane (referred as XCO2 and XCH4) is employed to examine the patterns of both gases throughout the MCO as well as from the same period the prior and following year. The Inverse Distance Weighting (IDW) interpolation method is utilized in mapping the XCO2 and XCH4 for the industrial areas in Peninsular Malaysia. The results revealed that even MCO is implemented, the XCO2 and XCH4 in the industrial areas are increasing year by year. By using satellites data, the XCO2 and XCH4 from large areas can be monitored continuously.

16.
NeuroQuantology ; 20(15):2648-2662, 2022.
Article in English | EMBASE | ID: covidwho-2203997

ABSTRACT

The carbon emission, nitrous oxide emission and methane emission are the major components of air pollution. The largest carbon emitting countries in the world were China, United States, India followed by Iron, Saudi Arabia, South Korea, Canada, Mexico, Indonesia, Brazil, South Africa and Turkey. China alone emitted 9839 metric tonnes in 2017. The share of the above emission was 27.2 percentage in the carbon emission of world countries. United states were the second important country in emitting the carbon which accounted for 14.6 percentage in the total world countries emission. India emitted 2467 metric tonnes of carbon emission which accounted for 6.8 percentage in the total emission. China emitted double the emissions of United States and India. The top fifteen countries collectively such as China, United States, India, Iron, Saudi Arabia, South Korea, Canada, Mexico, Indonesia, Brazil, South Africa and Turkey emitted 72 percentage of carbon emissions the rest of the 180 countries in the world emitted nearly 28 percentage of the total global emission. It is close to the emissions of China. The nitrous oxide emission is yet another component of greenhouse gas. In 2018, the largest nitrous oxide emission was observed in the coal fixed power plants in South Africa, Germany and India and in coal burning industrial clusters in India. In India, the largest nitrous oxide emissions were observed at Delhi, Uttar Pradesh and in Odisha. The third important component of air pollution was PM10. The top countries emitting particulate matter were China, Spain, India, Chad, Mali, Nepal, Mexico, Israel, Uganda, Thailand and Turkey.Methane was the next important component of air pollution. Methane would stay about for about 9 years in the atmosphere. Therefore, methane had identified as the target for greenhouse gas emission. In this backdrop, an attempt was made to compare the air pollution among the world countries. The findings of the study showed that Bangladesh was the high air polluting country among the least developed countries. Among the developed countries, the problem of air pollution was predominant in United States. India was the highest air polluted countries among the developing countries. The estimated t value reveals that the carbon emission was significantly higher in developing countries than in less developed countries and between least developed and developed countries. Copyright © 2022, Anka Publishers. All rights reserved.

17.
Eksperimental'naya i Klinicheskaya Gastroenterologiya ; 203(7):131-144, 2022.
Article in Russian | Scopus | ID: covidwho-2164643

ABSTRACT

Purpose of the work: to study liver elasticity indicators, hydrogen and methane levels in exhaled air, and their associations with clinical and biochemical parameters for patients who underwent COVID-19. Materials and methods. We examined 30 patients (mean age 51.8±2.91) who underwent COVID-19 (confirmed by SARSCoV-2 RNA test or SARS-CoV-2 antigen) 12-16 weeks after the onset of the first symptoms, of which 11 were diagnosed with pneumonia. 19 people (mean age 47.1±3.09) who did not have COVID-19 made up the comparison group. The patients underwent a clinical and biochemical study, the degree of liver fibrosis was determined (FibroScan® 502 Echosens, France), the levels of hydrogen (H2) and methane (CH4) in the exhaled air were measured (baseline and after taking lactulose solution) (GastroCheck Gastrolyzer, Bedfont Scientific Ltd., England). Results. Past COVID-19 infection was directly correlated with age (r=0.331, p=0.022), male gender (r=0.324, p=0.025), and presence of liver fibrosis (r=0.291, p=0.044). COVID-19 survivors were more likely to have liver fibrosis (p<0.001) and higher liver elasticity in kPa (p=0.018) with overweight and obesity (63.3%) and elevated body mass index (p= 0.03) compared with the control group. The presence of liver fibrosis was associated with moderate pneumonia (p<0.001). Among those who had COVID-19, there were significantly more non-producers of methane (p=0.02), fewer people with an average level of methane in exhaled air (p=0.016). In COVID-19 convalescents, bacterial overgrowth syndrome (BOS) was detected less frequently than in controls (p=0.04), but signs of delayed intestinal transit were more often recorded (p<0.05). The presence of liver fibrosis in survivors of COVID-19 is associated with BOS detection (23.3% vs. 5.2%, p<0.001), which probably contributes to the pathogenesis of liver damage. Hydrogen levels at 120 min and methane at 60 min after ingestion of lactulose solution distinguished between COVID-19 convalescents and COVID-19 survivors with an AUC of 0.683 and 0.660, respectively. The associations of the levels of gases in the exhaled air with clinical and biochemical parameters were revealed: the presence of overweight and obesity showed inverse associations with the level of methane production (r= -0.342, p<0.05), its concentration after taking lactulose at various time intervals, and also the basic level of hydrogen (r= -0.313, p<0.05);the degree of obesity was also inversely correlated with the level of methane emission (r= -0.368, p=0.038). Direct links were established between indicators of liver elasticity in kPa and the level of hydrogen production (r=0.275, p<0.05). Conclusions. Obtained indirect signs of pronounced changes in the intestinal microbiome, which obviously contribute to a more severe course of COVID-19, the development of liver fibrosis, so the impact on the intestinal microflora can be considered as a potential target in the treatment of patients with COVID-19. © 2022 Kola Science Centre of the Russian Academy of Sciences. All rights reserved.

18.
Insects and food security in South Africa in the light of climate change. ; 62(4):623-646, 2022.
Article in English | Academic Search Complete | ID: covidwho-2155916

ABSTRACT

The Covid-19 pandemic has had a devastating socio-economic effect on the country, including the death of more than 102 000 people, many of whom were the breadwinners of their families. This could not have happened at a worse time, since the economy of the country was in a recession even before the pandemic. The situation is exacerbated by the highest level of unemployment in the world, widespread nepotism and corruption, the plundering of state coffers and the favouring of the business interests of BRICS partners by government officials over those of South Africans. The government's commitment to prioritising their BRICS partners' business interests over those of the South African people contributes to food insecurity in South Africa. This includes the export of coal from mines in Mpumalanga to China and India, while nothing is done to rehabilitate the region, which was once known for its agriculture. The government handed over to the Chinese company SAEMB the Musina-Makhado Special Economic Zone, where four opencast mines, a 3 300 MW power station and an iron smelting plant will be developed. This development, however, requires the government to build a dam that will harvest 60% of the annual runoff of the Limpopo River, which in turn will have a devastating effect on farmers and communities downriver in South Africa, Zimbabwe and Mozambique who irrigate their crops with water from the Limpopo River. The same kowtowing of the South African government to its BRICS partners can be seen in the reluctance with which the government responds to the plundering of our marine resources by Chinese fishing boats and abalone smugglers. The unfair competition imposed on local chicken farmers by distributers of dumped chicken, mainly from Brazil, with the approval of government, caused the closure of several South African chicken farms and the resulting loss of tens of thousands of jobs along the supply chain. The reluctance of the government to take sides in the Russia-Ukraine war is partly linked to the fact that South Africa imports fertilizer and wheat from Russia. South Africa, a water-scarce country, is more vulnerable than many other countries to the effects of global climate change. The abnormal rain pattern, that is characterised by severe droughts in certain regions and heavy rainstorms and floods in others, has a devastating impact on the already economically struggling South African community. Abroad, attempts are made to ensure that mean temperatures do not exceed the pre-industrial level mark by more than 1,5 °C. South Africa, however, heats up twice as fast as many other countries, and has already exceeded the pre-industrial era level by more than 2 °C;it will continue to get warmer and drier, causing most of the country to become desertified by 2050. A third of South African rivers do not reach the sea anymore because of over ion of water from rivers;similarly, there is extensive ion of groundwater. Together farming and forestry account for 70% of water use in South Africa. This over ion of water, worsened by the heat and aridification resulting from climate change, led to the degradation of most wetland and estuarine ecosystems and the drying and burning of irreplaceable peatlands. These political, socioeconomic and environmental calamities create the worst possible scenario for food security in South Africa. Already one in four people in Africa suffers from food insecurity and this number will rapidly rise in the wake of global climate change, which will result in the loss of two thirds of arable land by 2025. South Africa is nearing socioeconomic collapse. This, in conjunction with continuing droughts, storms and rising temperatures associated with global climate change, will lead to food insecurity, starvation and anarchy. The effect of global climate change will make it progressively more difficult to produce enough food for the South African population. It is imperative that South Africans consider alternative methods of food production, including water use. Entomophagy is widel practiced throughout the world, but is especially prevalent in South America, the Far East and Africa, where approximately 2 billion people use 1 900 species of insects as food. The nutritional value of insects is unsurpassed and, in some respects, even more nutritious than meat. The larvae of the black soldier fly (BSF) Hermetia illucens are a source of high-quality proteins and unsaturated fats that are used worldwide as animal feed. Insects are a source of minerals such as iron, calcium, copper, zinc and magnesium and high levels of vitamin A, B2 and C. The ecological and socioeconomic benefits of using BSF larvae instead of grain as feed for fish, chickens and pigs are enormous. BSF larvae can be bred almost for free by feeding it a wide variety of organic waste, including rotten vegetables and fruit, manure and even carcases that would have ended up in rubbish dumps and would have contributed to the methane and carbon dioxide pollution emanating from such dumps. The water use of BSF is negligible, because the water in the organic waste that would have been discarded in waste dumps is sufficient to sustain them. BSF affords the subsistence and small-scale farmer the opportunity to raise chickens at a lower input cost than ever before. The conversion of feed to food in insects is far greater than that of chickens, pigs or cattle. In the case of the house cricket (Acheta domestica) the conversion rate of feed to food is twice as effective as that of chickens, four times as effective as pigs and twelve times greater than that of cattle. Compared to conventional farming, this implies that with insects far more exceptionally nutritious food can be produced in a smaller area, with little water and no poison or fertilizer whatsoever, while waste and the associated methane gas are removed from the environment at the same time. A few South African companies have already seen the potential of insects as food and feed. Even though insect farming is still in its infancy, it is already generating jobs and new socioeconomic opportunities in South Africa. Insect farming, especially BSF farming, will in the near future probably grow in popularity all over the world as an affordable, healthy, ecologically sustainable alternative food source that will, directly or indirectly, be consumed by humans. BSF afford the environmentally conscious homesteader who wants to produce livestock such as chickens, fish, or pigs in a sustainable manner an unsurpassed environmentally friendly alternative. BSF will also give the desperate, impoverished and starving population of the future an alternative free source of feed that will offer them economic prospects and food security. [ FROM AUTHOR]

19.
Atmospheric Chemistry and Physics ; 22(17):11203-11215, 2022.
Article in English | ProQuest Central | ID: covidwho-2025099

ABSTRACT

We use satellite methane observations from the Tropospheric Monitoring Instrument (TROPOMI), for May 2018 to February 2020, to quantify methane emissions from individual oil and natural gas (O/G) basins in the US and Canada using a high-resolution (∼25 km) atmospheric inverse analysis. Our satellite-derived emission estimates show good consistency with in situ field measurements (R=0.96) in 14 O/G basins distributed across the US and Canada. Aggregating our results to the national scale, we obtain O/G-related methane emission estimates of12.6±2.1 Tg a-1 for the US and 2.2±0.6 Tg a-1 for Canada, 80 % and 40 %, respectively, higher than the national inventories reported to the United Nations. About 70 % of the discrepancy in the US Environmental Protection Agency (EPA) inventory can be attributed to five O/G basins, the Permian, Haynesville, Anadarko, Eagle Ford, and Barnett basins, which in total account for 40 % of US emissions. We show more generally that our TROPOMI inversion framework can quantify methane emissions exceeding 0.2–0.5 Tg a-1 from individual O/G basins, thus providing an effective tool for monitoring methane emissions from large O/G basins globally.

20.
Natural Gas Industry ; 42(7):1-6, 2022.
Article in Chinese | Scopus | ID: covidwho-2024390

ABSTRACT

Natural gas will play more and more important role in the sustainable low-carbon development mode characterized by low energy consumption, low pollution and low emission. It has been and will continue to be the focus of attention. The 28th World Gas Conference (WGC2022) was held on May 23-27, 2022 in Daegu, South Korea. The conference summarized the progress of world natural gas in the past four years, analyzed and judged the future development trend, and reached seven consensuses: (1) Natural gas is not only a transitional fuel, but also a basic fuel for future development. (2) Supply and demand value chain of natural gas has high flexibility and adaptability, and supply diversification has become a development advantage. (3) With the effect of the rapid increase of oil and gas price, the reversal of natural gas to coal has intensified the rapid growth of global carbon emissions. (4) Structural tension is emerging in the global LNG market, and the number of long-term agreement contracts will show an increasing trend. (5) The coordinated development of natural gas and hydrogen will accelerate the arrival of the low-carbon era. (6) Methane monitoring and leakage measurement technology in the natural gas industry will become the next important innovation. (7) Governments of various countries have continuously raised the minimum level of underground gas storage, and successively issued incentive policies to increase gas reserves and production. Based on the experience, the following suggestions are put forward for the development of China's natural gas: (1) Continue to highlight the important position of the natural gas industry, increase exploration and development, and improve supply capacity and voice;(2) To adapt to the new setup of international natural gas supply caused by the COVID-19 and the conflict between Russia and Ukraine, and to formulate overall strategies for natural gas import and export trade;(3) Attach importance to LNG business, scientifically arrange the construction of LNG import supporting facilities, and take the initiative to cooperate with natural gas resource countries;(4) The whole industrial chain of natural gas and hydrogen business should be planned and deployed together, and hydrogen and natural gas infrastructure construction should be linked up effectively;(5) Increase policy support, strengthen infrastructure construction such as underground gas storage and LNG terminal, reserve more energy to develop confidence, and build a strong defense line for energy security. © 2022 Natural Gas Industry Journal Agency. All rights reserved.

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