scholarly journals Higher Abundance of Sediment Methanogens and Methanotrophs Do Not Predict the Atmospheric Methane and Carbon Dioxide Flows in Eutrophic Tropical Freshwater Reservoirs

2021 ◽  
Vol 12 ◽  
Author(s):  
Gabrielle Maria Fonseca Pierangeli ◽  
Mercia Regina Domingues ◽  
Tatiane Araujo de Jesus ◽  
Lúcia Helena Gomes Coelho ◽  
Werner Siegfried Hanisch ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Global Warming ◽  
Anthropogenic Pollution ◽  
Total Carbon ◽  
Anthropogenic Sources ◽  
Atmospheric Methane ◽  
Global Warming Impact ◽  
Carbon Decomposition ◽  
Untreated Sewage ◽  
Gaseous Flows

Freshwater reservoirs emit greenhouse gases (GHGs) such as methane (CH4) and carbon dioxide (CO2), contributing to global warming, mainly when impacted by untreated sewage and other anthropogenic sources. These gases can be produced by microbial organic carbon decomposition, but little is known about the microbiota and its participation in GHG production and consumption in these environments. In this paper we analyzed the sediment microbiota of three eutrophic tropical urban freshwater reservoirs, in different seasons and evaluated the correlations between microorganisms and the atmospheric CH4 and CO2 flows, also correlating them to limnological variables. Our results showed that deeper water columns promote high methanogen abundance, with predominance of acetoclastic Methanosaeta spp. and hydrogenotrophs Methanoregula spp. and Methanolinea spp. The aerobic methanotrophic community was affected by dissolved total carbon (DTC) and was dominated by Crenothrix spp. However, both relative abundance of the total methanogenic and aerobic methanotrophic communities in sediments were uncoupled to CH4 and CO2 flows. Network based approach showed that fermentative microbiota, including Leptolinea spp. and Longilinea spp., which produces substrates for methanogenesis, influence CH4 flows and was favored by anthropogenic pollution, such as untreated sewage loads. Additionally, less polluted conditions favored probable anaerobic methanotrophs such as Candidatus Bathyarchaeota, Sva0485, NC10, and MBG-D/DHVEG-1, which promoted lower gaseous flows, confirming the importance of sanitation improvement to reduce these flows in tropical urban freshwater reservoirs and their local and global warming impact.

A Study on Methane Emissions and Its Mitigation Strategies in Present Scenario

2016 ◽  
Vol 8 (02) ◽  
pp. 87-92 ◽  
Author(s):  
Virendra Kumar ◽  
Swati SachdevSanjeev Kumar ◽  
Sanjeev Kumar
Keyword(s):  
Carbon Dioxide ◽  
Organic Matter ◽  
Global Warming ◽  
Methane Emission ◽  
Energy Production ◽  
Fossil Fuels ◽  
Mitigation Strategies ◽  
Anthropogenic Sources ◽  
Negative Effects ◽  
Methane Generation

Methane is an important gas of earth's environment. It emits from various naturally as well as anthropogenic sources and responsible for maintaining earth's global temperature favorable for humans and other organisms to live. In recent years many activities of human development led to generation of a large volume of methane which has exhibited catastrophic effect on humans as well as animal lives on earth. Methane poses high global warming potential and has been found second most abounded gas in the environment responsible for global warming of earth after carbon dioxide which is well documented in gigantic body of literature. Methane emission is projected to reach 254 Gg/ year by the year 2025. The sources of methane generation are scattered in nature that includes marshes, paddy crops, landfills and natural anaerobic decomposition of the organic matter present in the environment and digestion in ruminants as well handling and use of fossil fuels. The versatile sources of methane generation are uncontrolled and tough to be tamed. However, its emissions and negative effects could be reduced by effectively and efficiently managing its sources of emission and utilizing generated volume for energy production. This study emphasize on the harmful as well as beneficial aspects of the methane, its utilization and strategies to control emission from various sources.

scholarly journals Shipborne measurements of methane and carbon dioxide in the Middle East and Mediterranean areas and contribution from oil and gas emissions

2021 ◽  
Author(s):  
Jean-Daniel Paris ◽  
Aurélie Riandet ◽  
Efstratios Bourtsoukidis ◽  
Marc Delmotte ◽  
Antoine Berchet ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Middle East ◽  
Red Sea ◽  
Oil And Gas ◽  
Arabian Gulf ◽  
Isomeric Ratio ◽  
Anthropogenic Sources ◽  
Lagrangian Model ◽  
Atmospheric Methane ◽  
Mixing Ratios

Abstract. The increase of atmospheric methane (CH4) and carbon dioxide (CO2), two main anthropogenic greenhouse gases, is largely driven by fossil sources. Sources and sinks remain insufficiently characterised in the Mediterranean and Middle East areas, where very few in situ measurements area available. We investigated the atmospheric distribution of CH4 and CO2 in the region through shipborne measurement in July and August 2017. High mixing ratios were observed over the Suez Canal, Red Sea and Arabian Gulf, while generally lower mixing ratios were observed over the Gulfs of Aden and Oman. We probe the origin of CO2 and CH4 excess mixing ratio by using correlations with light alkanes and through the use of a Lagrangian model coupled to two different emission inventories of anthropogenic sources. We find that the CO2 and especially the CH4 enhancements are mainly linked to nearby oil and gas (O&G) activities over the Arabian Gulf, and a mixture of other sources over the Red Sea. The isomeric ratio of pentane is shown to be a useful indicator of the O&G component of atmospheric CH4 at the regional level. Upstream emissions linked to oil in the Northern Arabian Gulf seem to be underestimated while gas-related emissions in the Southern Gulf are overestimated in our simulations. Our results highlight the need for improvement of inventories in the area to better characterize the changes in magnitude and the complex distribution of the O&G sources in the Middle East.

scholarly journals Quality of Peri-Urban Soil Developed from Ore-Bearing Carbonates: Heavy Metal Levels and Source Apportionment Assessed Using Pollution Indices

Minerals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1140
Author(s):  
Katarzyna Sutkowska ◽  
Leslaw Teper ◽  
Tomasz Czech ◽  
Tomasz Hulok ◽  
Michał Olszak ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Contamination Factor ◽  
Anthropogenic Pollution ◽  
Pollution Load Index ◽  
Total Carbon ◽  
Anthropogenic Sources ◽  
Pollution Indices ◽  
Geochemical Background ◽  
Ore Bodies ◽  
Metal Levels

Pollution indices are used to assess the influence of the bedrock as a natural source of heavy-metal (HM), and anthropogenic pollution from ore mining in soils developed from ore-bearing carbonates. The research was conducted in two areas differing in geological setting and type of land use in the Upper Silesia Industrial Region, Southern Poland. Physical properties such as pH, total sulfur, total carbon and total organic carbon values, as well as total Zn, Pb, and Cd contents (ICP-OES) for 39 topsoil samples were measured. Contamination factor (Cf), degree of contamination (Cdeg), pollution load index (PLI) and geoaccumulation index (Igeo), were used to determine the deterioration of topsoil due to HM pollution. The HM content exceeded geochemical background levels by 2.5–18.1 times. Very high to moderate topsoil contamination was determined. In a shallow historical mining zone, the relative influence of particular HM was found to be in the order of Pb > Cd > Zn and, in a deep mining zone, Zn > Cd > Pb. In the topsoil developed over shallow ore bodies, the HM content was mainly (60%) due to naturally occurring HM. In the area of deeply buried ore bodies, 90% of the HM load was related to anthropogenic sources. Zn, Pb and Cd vertical distributions and the patterns of topsoil pollution differ in terms of types of mined ores, mining methods and times elapsed since mining ceased. Pollution indices are an efficient tool for distinguishing soil anthropogenic pollution and geogenic contamination.

scholarly journals Shipborne measurements of methane and carbon dioxide in the Middle East and Mediterranean areas and the contribution from oil and gas emissions

2021 ◽  
Vol 21 (16) ◽  
pp. 12443-12462
Author(s):  
Jean-Daniel Paris ◽  
Aurélie Riandet ◽  
Efstratios Bourtsoukidis ◽  
Marc Delmotte ◽  
Antoine Berchet ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Middle East ◽  
Red Sea ◽  
Oil And Gas ◽  
Arabian Gulf ◽  
Isomeric Ratio ◽  
Anthropogenic Sources ◽  
Lagrangian Model ◽  
Atmospheric Methane ◽  
Mixing Ratios

Abstract. The increase of atmospheric methane (CH4) and carbon dioxide (CO2), two of the main anthropogenic greenhouse gases, is largely driven by fossil sources. Sources and sinks remain insufficiently characterized in the Mediterranean and Middle East areas, where very few in situ measurements are available. We measured the atmospheric mixing ratios of CH4 and CO2 by ship in the region in July and August 2017. High mixing ratios were observed over the Suez Canal, Red Sea and Arabian Gulf, while generally lower mixing ratios were observed over the Gulf of Aden and Gulf of Oman. We probe the origin of the CO2 and CH4 excess mixing ratio by using correlations with light alkanes and through the use of a Lagrangian model coupled to two different emission inventories of anthropogenic sources. We find that the CO2 and especially the CH4 enhancements are mainly linked to nearby oil and gas (OG) activities over the Arabian Gulf and a mixture of other sources over the Red Sea. The isomeric ratio of pentane is shown to be a useful indicator of the OG component of atmospheric CH4 at the regional level. Upstream emissions linked to oil in the northern Arabian Gulf seem to be underestimated, while gas-related emissions in the southern Gulf are overestimated in our simulations. Our results highlight the need for improvement of inventories in the area to better characterize the changes in magnitude and the complex distribution of the OG sources in the Middle East.

GLOBAL WARMING IMPACT ON URMIA LAKE VULNERABILITY AND HAZARD

2017 ◽  
Author(s):  
Homayoun Khoshravan ◽  
Homayoun Khoshravan
Keyword(s):  
Global Warming ◽  
Salt Marshes ◽  
Satellite Images ◽  
Field Research ◽  
Urmia Lake ◽  
Mud Volcanoes ◽  
Seismic Profiles ◽  
Global Warming Impact ◽  
Morphological Behavior ◽  
Different Parts

The main goal of the research is to analyze the global warming impact on Urmia lake vulnerabiliy and hazard. By the study of topographic maps, satellite images and field research, the various types of coasts were identified: mud flats, salt marshes, sandy or cliffed coasts, and islands. Moreover the interpretation of seismic profiles, has led to recognize so important morphological features in the lake bed, such as: erosive channels, colos, mud volcanoes, the raised sandy masses and under water mounts. The main results illustrate the variable morphological behavior of Urmia Lake in different parts of the lake.

Impact of Dursban and Abate on Microbial Numbers and Some Chemical Properties of Standing Ponds

1975 ◽  
Vol 10 (1) ◽  
pp. 33-41 ◽  
Author(s):  
J. Butcher ◽  
M. Boyer ◽  
CD. Fowle
Keyword(s):  
Carbon Dioxide ◽  
Active Ingredient ◽  
Algal Blooms ◽  
Chemical Properties ◽  
Total Carbon ◽  
Dissolved Carbon ◽  
Photosynthetic Productivity ◽  
Dissolved Carbon Dioxide ◽  
Microbial Numbers

Abstract Eleven small ponds, lined with polyethylene, were used to assess the consequences of applications of *DursbanR at 0.004, 0.030, 0.100 and 1.000 ppm and AbateR at 0.025 and 0.100 ppm active ingredient. The treated ponds showed a more pronounced long-term increase in pH and dissolved oxygen and decreasing total and dissolved carbon dioxide in comparison with untreated ponds. Algal blooms were of longer duration in treated ponds than in controls. Total photosynthetic productivity was higher in treated ponds but bacterial numbers did not change significantly. Photosynthetic productivity was estimated by following the changes in total carbon dioxide.

scholarly journals Czech Building Stock: Renovation Wave Scenarios and Potential for CO2 Savings until 2050

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2455
Author(s):  
Antonín Lupíšek ◽  
Tomáš Trubačík ◽  
Petr Holub
Keyword(s):  
Climate Change ◽  
Carbon Dioxide ◽  
Carbon Dioxide Emissions ◽  
Climate Change Mitigation ◽  
Emission Factors ◽  
Anthropogenic Sources ◽  
Building Stock ◽  
National Debate ◽  
Energy Consumptions ◽  
Change Mitigation

One of the major anthropogenic sources of greenhouse gases is the operation of building stock. Improving its energy efficiency has the potential to significantly contribute to achieving climate change mitigation targets. The purpose of this study was to roughly estimate such potential for the operation of the national building stock of Czechia to steer the national debate on the development of related national plans. The estimation is based on a simplified energy model of the Czech building stock that consists of sub-models of residential and nonresidential building stocks, for which their future energy consumptions, shares of energy carriers and sources, and emission factors were modeled in four scenarios. Uncertainties from the approximation of the emission factors were investigated in a sensitivity analysis. The results showed that the operation of the Czech building stock in 2016 totaled 36.9 Mt CO2, which represented 34.6% of the total national carbon dioxide emissions. The four building stock scenarios could produce reductions in the carbon dioxide emissions of between 28% and 93% by 2050, when also considering on-side production from photovoltaics. The implementation of the most ambitious scenario would represent a drop in national CO2 yearly emissions by 43.2% by 2050 (compared to 2016).

scholarly journals Estimating Causal Effects When the Treatment Affects All Subjects Simultaneously: An Application

2021 ◽  
Vol 5 (2) ◽  
pp. 22
Author(s):  
Chiara Binelli
Keyword(s):  
Machine Learning ◽  
Carbon Dioxide ◽  
Global Warming ◽  
Carbon Dioxide Emissions ◽  
Control Group ◽  
Sources Of Information ◽  
Average Global Temperature ◽  
Causal Impact ◽  
The Impact ◽  
Robust Evidence

Several important questions cannot be answered with the standard toolkit of causal inference since all subjects are treated for a given period and thus there is no control group. One example of this type of questions is the impact of carbon dioxide emissions on global warming. In this paper, we address this question using a machine learning method, which allows estimating causal impacts in settings when a randomized experiment is not feasible. We discuss the conditions under which this method can identify a causal impact, and we find that carbon dioxide emissions are responsible for an increase in average global temperature of about 0.3 degrees Celsius between 1961 and 2011. We offer two main contributions. First, we provide one additional application of Machine Learning to answer causal questions of policy relevance. Second, by applying a methodology that relies on few directly testable assumptions and is easy to replicate, we provide robust evidence of the man-made nature of global warming, which could reduce incentives to turn to biased sources of information that fuels climate change skepticism.

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