scholarly journals Controls of Global-Mean Precipitation Increases in Global Warming GCM Experiments

2008 ◽  
Vol 21 (23) ◽  
pp. 6141-6155 ◽  
Author(s):  
Graeme L. Stephens ◽  
Todd D. Ellis
Keyword(s):  
Climate Change ◽  
Carbon Dioxide ◽  
Global Warming ◽  
Water Vapor ◽  
Energy Balance ◽  
Energy Loss ◽  
Radiative Heating ◽  
Global Changes ◽  
Clear Sky ◽  
Global Precipitation

Abstract This paper examines the controls on global precipitation that are evident in the transient experiments conducted using coupled climate models collected for the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4). The change in precipitation, water vapor, clouds, and radiative heating of the atmosphere evident in the 1% increase in carbon dioxide until doubled (1pctto2x) scenario is examined. As noted in other studies, the ensemble-mean changes in water vapor as carbon dioxide is doubled occur at a rate similar to that predicted by the Clausius–Clapeyron relationship. The ratio of global changes in precipitation to global changes in water vapor offers some insight on how readily increased water vapor is converted into precipitation in modeled climate change. This ratio ɛ is introduced in this paper as a gross indicator of the global precipitation efficiency under global warming. The main findings of this paper are threefold. First, increases in the global precipitation track increase atmospheric radiative energy loss and the ratio of precipitation sensitivity to water vapor sensitivity is primarily determined by changes to this atmospheric column energy loss. A reference limit to this ratio is introduced as the rate at which the emission of radiation from the clear-sky atmosphere increases as water vapor increases. It is shown that the derived efficiency based on the simple ratio of precipitation to water vapor sensitivities of models in fact closely matches the sensitivity derived from simple energy balance arguments involving changes to water vapor emission alone. Second, although the rate of increase of clear-sky emission is the dominant factor in the change to the energy balance of the atmosphere, there are two important and offsetting processes that contribute to ɛ in the model simulations studied: One involves a negative feedback through cloud radiative heating that acts to reduce the efficiency; the other is the global reduction in sensible heating that counteracts the effects of the cloud feedback and increases the efficiency. These counteracting feedbacks only apply on the global scale. Third, the negative cloud radiative heating feedback occurs through reductions of cloud amount in the middle troposphere, defined as the layer between 680 and 440 hPa, and by slight global cloud decreases in the lower troposphere. These changes act in a manner to expose the warmer atmosphere below to high clouds, thus resulting in a net warming of the atmospheric column by clouds and a negative feedback on the precipitation.

scholarly journals Climate Change and Refrigerants: Thermodynamic Properties of Low-GWP Fluids for Domestic Applications and Binary Systems for Low-Temperature Options

2020 ◽  
Vol 10 (6) ◽  
pp. 2014 ◽  
Author(s):  
Mariano Pierantozzi ◽  
Sebastiano Tomassetti ◽  
Giovanni Di Nicola
Keyword(s):  
Climate Change ◽  
Carbon Dioxide ◽  
Global Warming ◽  
Low Temperature ◽  
Thermodynamic Properties ◽  
Experimental Research ◽  
Binary Systems ◽  
Research Activity ◽  
Greenhouse Gasses ◽  
Low Global Warming Potential

The most commonly used refrigerants are potent greenhouse gasses that can contribute to climate change. Hydro-Fluoro-Olefins are low Global Warming Potential fluids. A summary of our experimental research activity on the thermodynamic properties of two environmentally friendly Hydro-Fluoro-Olefins, namely R1234yf and R1234ze(E), is reported. In particular, the measurements were performed with an isochoric apparatus and the apparatus specifically built to reach temperatures down to about 100 K. The data elaboration confirms the validity of the choice and that R1234yf and R1234ze(E) can be adopted in many domestic applications. Moreover, considering the reduction of the flammability issues of R1234yf and R1234ze(E), the properties of binary systems containing these fluids and carbon dioxide were analyzed. The presented mixtures could be very interesting for low-temperature applications such as cascade cycles.

scholarly journals Role of Landfill Cover in Reducing Methane Emission

2013 ◽  
Vol 39 (3) ◽  
pp. 115-126 ◽  
Author(s):  
Yucheng Cao ◽  
Ewelina Staszewska
Keyword(s):  
Climate Change ◽  
Carbon Dioxide ◽  
Global Warming ◽  
Methane Oxidation ◽  
Landfill Gas ◽  
Oxidation Potential ◽  
Landfill Cover ◽  
High Fraction ◽  
Engineered Landfill

Abstract Uncontrolled emissions of landfill gas may contribute significantly to climate change, since its composition represents a high fraction of methane, a greenhouse gas with 100- year global warming potential 25 times that of carbon dioxide. Landfill cover could create favourable conditions for methanotrophy (microbial methane oxidation), an activity of using bacteria to oxidize methane to carbon dioxide. This paper presents a brief review of methanotrophic activities in landfill cover. Emphasis is given to the effects of cover materials, environmental conditions and landfill vegetation on the methane oxidation potential, and to their underlying effect mechanisms. Methanotrophs communities and methane oxidation kinetics are also discussed. Results from the overview suggest that well-engineered landfill cover can substantially increase its potential for reducing emissions of methane produced in landfill to the atmosphere.

scholarly journals True Science for Government Leaders and Educators: The Main Cause of Global Warming

2020 ◽  
Vol 7 (7) ◽  
pp. 106-114
Author(s):  
J. Marvin Herndon
Keyword(s):  
Climate Change ◽  
Carbon Dioxide ◽  
Global Warming ◽  
World War Ii ◽  
Radiant Heat ◽  
Geographic Area ◽  
Atmospheric Temperature ◽  
Lower Atmosphere ◽  
Particulate Pollution ◽  
Real Science

Government leaders and educators ought to be able to rely on scientists to tell the truth about climate change, but science has been tainted by politics. Real science, unlike politics, is all about telling the truth, truth that is securely anchored to the properties of matter and radiation. The current, high-profile, politically-driven, climate-change debate centers on two disparate ideas, namely, either global warming is caused by carbon dioxide or is not occurring at all. Neither is correct. Evidence from World War II indicates that particulate pollution, not carbon dioxide, is the cause of global warming. The difference between daily high and nightly low temperature data, tracked over time over a large geographic area, provide evidence that global warming is in fact occurring, which is independent of carbon dioxide. Particles in the lower atmosphere (troposphere) are heated by solar radiation and by radiant heat from the Earth, and transfer that heat to atmospheric gases by molecular collisions. The resultant heating increases atmospheric temperature, and reduces the temperature difference relative to air near the surface, which reduces atmospheric convection, and concomitantly reduces convective heat transport from the surface. This is the mechanism whereby particulate pollution causes global warming.

Carbon Dioxide Adsorbent Preparation by Coating Amine-Functionalized Pectin onto Zeolites

2019 ◽  
Vol 801 ◽  
pp. 179-184
Author(s):  
John Andrew Kane P. Jovellana ◽  
B. Pajarito
Keyword(s):  
Climate Change ◽  
Carbon Dioxide ◽  
Global Warming ◽  
Surface Area ◽  
Carbon Dioxide Capture ◽  
Amine Functionalization ◽  
Amine Functionalized ◽  
Adsorption Capacities ◽  
First Time

Increasing carbon dioxide (CO2) levels in the atmosphere caused by excessive greenhouse gas emissions is strongly associated to global warming and climate change. This study aims to prove the feasibility of using pectin as the backbone for amine functionalization with application as coating on zeolites for carbon dioxide capture. Characterization of the solutions using FTIR and of the adsorbents using SEM demonstrated the successful modification of pectin using NH3 and TETA as alternative amine-functionalized coating for adsorbent. It has been reported for the first time that the polysaccharide pectin can be aminated and modified for CO2 capture upon coated on substrates such as zeolites. The adsorption capacities at 5% breakthrough of the adsorbents coated with the modified pectin are 2.24 mmol/CO2 g adsorbent and 2.28 mmol/CO2 g adsorbent, when coated with NH3-modified and TETA-modified pectin, respectively. It is recommended for further study to synthesize substrates with higher surface area, and optimize the formulations of the pectin modification.

Reaction Kinetics of Fe2O3 and BaCO3 to Prepare Ba2Fe2O5

2014 ◽  
Vol 33 (4) ◽  
pp. 319-323 ◽  
Author(s):  
Jun-Hao Liu ◽  
Guo-Hua Zhang ◽  
Kuo-Chih Chou
Keyword(s):  
Climate Change ◽  
Carbon Dioxide ◽  
Activation Energy ◽  
Global Warming ◽  
Reaction Kinetics ◽  
Isothermal Condition ◽  
Product Layer ◽  
Thermo Gravimetric ◽  
Thermo Gravimetric Analyzer ◽  
Kinetics Of

AbstractCarbon dioxide is a greenhouse gas and substantially affects the global warming and climate change, so study on the adsorption of carbon dioxide is very urgent. As a new CO2 captor, Ba2Fe2O5 was prepared by the solid state reaction of Fe2O3 with BaCO3, following formula Fe2O3 + 2BaCO3 = Ba2Fe2O5 + 2CO2. The reaction kinetics in isothermal condition was investigated by using the method of thermo-gravimetric analyzer (TGA). It was found that the reaction of Fe2O3 with BaCO3 was controlled by the diffusion step in the product layer, and the kinetics process could be described by the RPP model (Real Physical Picture) with the apparent activation energy extracted to be 161.122 kJ/mol.

Attributing the negative scaling of extreme precipitation with temperature over India to cloud radiative cooling during the monsoon season

2021 ◽  
Author(s):  
Sarosh Alam Ghausi ◽  
Axel Kleidon ◽  
Subimal Ghosh
Keyword(s):  
Global Warming ◽  
Energy Balance ◽  
Extreme Precipitation ◽  
Radiative Forcing ◽  
Monsoon Season ◽  
Maximum Power ◽  
Radiative Cooling ◽  
Tropical Regions ◽  
Clear Sky ◽  
Surface Temperatures

<p>Extreme precipitation is expected to increase at the rate of 7% per degree rise in temperature as suggested by the Clausius-Clapeyron equation (also known as CC scaling). Observations however, show deviations from the CC rate, with mostly negative precipitation - temperature scaling in warm tropical regions. Here we explain the negative precipitation scaling in the tropics with the cloud radiative effect on surface temperatures. Temperatures are shaped by the surface energy balance, which is affected by clouds, and hence temperatures are not independent of precipitation. We used observations from India and found negative scaling rates over most regions as extreme precipitation scaling tends to breakdown at temperatures of about 23◦to 25◦C. We show that these negative scaling rates arise from the radiative cooling of clouds associated with precipitation events which is predominant in India during the summer monsoon season. To test our hypothesis, we used an energy balance model constrained by assumption that convective exchange within atmosphere works at its thermodynamic limit of maximum power. Using the NASA-CERES radiation product, we calculated surface temperatures for “All sky” and “Clear sky” conditions to include/exclude the effect of cloud radiative forcing. Our results show a diametric change in precipitation scaling after removing the cooling effect of clouds on surface temperatures. Negative precipitation scaling (-4% /◦C) was found when using “All sky” conditions, but these come close to the CC rate (7% to 9% /◦C) when estimated using temperatures derived from “Clear sky” conditions. The breakdown in extreme precipitation scaling at high temperatures also disappeared forthe “Clear sky” temperatures. This implies that the breakdown in scaling may not relate to changes in aridity or the lack of moisture, but rather to the associated changes in cloud cover. Negative scaling rates derived from observations are thus likely to misrepresent the response of extreme precipitation to global warming in tropical regions. Our findings suggest that an intensification of precipitation extremes at CC rate with global warming is consistent with observations.</p><p>Keywords: Extreme Precipitation, CC scaling, Maximum Power, Indian Mon-soon</p>

scholarly journals Combat the Global Warming by Generating Renewable Sources of Energy

2019 ◽  
pp. 1-4
Author(s):  
PN Darde Mish ◽  
Keyword(s):  
Carbon Dioxide ◽  
Global Warming ◽  
Water Vapor ◽  
Greenhouse Gases ◽  
Temperature Increase ◽  
Renewable Sources ◽  
Average Temperature ◽  
Renewable Sources Of Energy

Global warming is the increase in average temperature of thetheearth’s surface air and oceans. Most of the observed temperature increase is caused by increased concentration of greenhouse gases. Major gases are water vapor (36-70%), carbon dioxide (9-26 %), Methane (4- 9 %) and Ozone (3- 7 %).

scholarly journals Estimation of Biogas Generated in Two Landfills in South-Central Ecuador

Atmosphere ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1365
Author(s):  
Paulina Poma ◽  
Marco Usca ◽  
María Polanco ◽  
Theofilos Toulkeridis ◽  
Carlos Mestanza-Ramón
Keyword(s):  
Climate Change ◽  
Carbon Dioxide ◽  
Mathematical Model ◽  
Organic Matter ◽  
Global Warming ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Electrical Energy ◽  
South Central ◽  
Carbon Dioxide Co2

The landfill is a final disposal technique to confine municipal solid waste (MSW), where organic matter is degraded generating leachate and biogas composed of methane gases (CH4), carbon dioxide (CO2) and other gases that contribute to global warming. The objective of the current research was to estimate the amount of biogas generated through the LandGEM 3.03 mathematical model to determine the amount of electrical energy generated and the number of homes that would be supplied with electrical energy from 2021 to 2144. As a result of the application, it was estimated that in the Pichacay landfill, the highest point of biogas generation in 2053 would be 76,982,177 (m3/year) that would generate 81,226,339.36 (kWh/year), and would supply 5083 homes with electricity. Similarly, in the Las Iguanas landfill, the highest point would be 693,975,228 (m3/year) of biogas that produces 73,223,5296.7 (kWh/year) and would supply electricity to 45,825 homes. Of the performed gas analyses in the Pichacay landfill in 2020, an average of 51.49% CH4, 40.35% CO2, 1.75% O2 and 17.8% H2S was presented, while in the Las Iguanas landfill, for 2020 and 2021, we obtained an average of 51.88/CH4, 36.62% CO2, 1.01% O2 and 187.58 ppm H2S. Finally, the biogas generated by being harnessed minimizes the impacts related to global warming and climate change and would contribute electricity to the nearby communities.

scholarly journals CAMBIAMENTI CLIMATICI: EVIDENZE SCIENTIFICHE, RISCHI ED OPPORTUNITÀ DI MITIGAZIONE

2020 ◽  
Author(s):  
Filippo Giorgi
Keyword(s):  
Climate Change ◽  
Carbon Dioxide ◽  
Global Warming ◽  
Scientific Community ◽  
Fossil Fuels ◽  
Agricultural Practices ◽  
Climatic Changes ◽  
Anthropogenic Emissions ◽  
Climate Scenarios ◽  
Main Model

This contribution presents the various pieces of evidence which bring the scientific community to conclude that global warming is happening and it is mostly due to anthropogenic emissions of greenhouse gases, mainly carbon dioxide and methane, deriving from the use of fossil fuels and some intensive agricultural practices. The main climatic changes associated with global warming are then discussed, along with the main model-derived future climate scenarios and the impacts that climate change can have on different socioeconomic sectors. Finally, the response policies to global warming are described, and in particular the concepts of adaptation and mitigaziotn (reduction of greenhouse gas emissions).

scholarly journals The analysis of the relationship between CO2 level and economic growth

2021 ◽  
pp. 17-23
Author(s):  
Szira Zoltán ◽  
Bárdos Kinga Ilona ◽  
Alghamdi Hani ◽  
Enkhjav Tumentsetseg ◽  
Erika Varga
Keyword(s):  
Climate Change ◽  
Carbon Dioxide ◽  
Global Warming ◽  
Human Activities ◽  
Carbon Dioxide Emissions ◽  
Industrial Revolution ◽  
Carbon Dioxide Emission ◽  
The Impact ◽  
The Relationship

2019 was Earth's second warmest year since 1850. In 2019 the global mean temperature was cooler than in 2016, but warmer than any other year explicitly measured. Consequently, 2016 is still the warmest year in historical observation history. Year-to-year rankings are likely to reflect natural fluctuations in the short term, but the overall pattern remains consistent with a long-term global warming trend. This would be predicted from global warming caused by greenhouse gases, temperature increase across the globe is broadly spread, impacting almost all areas of land and oceans. Climate change" and "global warming" are often used interchangeably but are of distinct significance. Global warming is the long-term heating of the Earth's climate system observed since the pre-industrial period as a result of human activities, mainly the combustion of fossil fuel, which raises the heat-trapping greenhouse gas levels in the Earth's air. The term is often used interchangeably with the term climate change, as the latter applies to warming caused both humanly and naturally, and the impact it has on our planet. This is most generally calculated as the average increase in global surface temperature on Earth. Carbon dioxide emission is one of the main reasons for global warming. Since the Industrial Revolution, human sources of carbon dioxide emissions have been growing. Human activities such as the burning of oil, coal and gas, as well as deforestation are the primary cause of the increased carbon dioxide concentrations in the atmosphere. In our research, let’s examine the relationship between the amount of carbon dioxide emissions and the GDP/capita in developed and developing countries.

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