Gas greenhouse

There are five major greenhouse gases that occur naturally water vapor, carbon dioxide, ozone, methane, and nitrous oxide. Human activity has in- 

Gas 1994 Mixing ratio Radiative forcing (W/m2) Atmospheric residence time (year) Rate of increase 

FIGURE 4-43 Increase in the mixing ratio of carbon dioxide in Earth s atmosphere as measured since March 1958 at the Mauna Loa Observatory (data from Keeling and Whorf, 1998). 

As shown in Fig. 4-42, carbon dioxide (C02) absorbs the second largest amount of long-wave infrared radiation in the atmosphere (about 32% Mann and Lazier, 1996). Over Earth s history, the predominant natural source of CO2 in the atmosphere has been volcanic eruptions, and the vast majority of that C02 is now stored in ocean sediments and rocks derived from those sediments (Mann and Lazier, 1996). If Earth did not have oceans, the concentration of C02 in Earth s atmosphere would be far higher than it is currently. 

Storage, source, or sink of carbon dioxide Magnitude (GtC/year)c 

In the earth s atmosphere, gases such as CO2, CH4, and N2O are called greenhouse gases, because they are nearly transparent to visible sunlight, but they absorb infrared (IR) radiation. In essence, they warm the atmosphere by slowing the release of heat into space. (The analogy with a real greenhouse isn t perfect, but it comes close.) 

On average, every person in the world is responsible for just over a ton of CO2 emissions each year. Most of this is due to the burning of fossil fuels in power plants and vehicles. According to some estimates, to prevent dangerous climate change while allowing for some increase in population, that number must be reduced to about 0.3 tons per person per year. 

When sunlight strikes the earth s surface, some of it is reflected toward space as infrared radiation (heat). Many chemical compounds found in the earth s atmosphere allow sunlight to enter the atmosphere freely, while certain gases and vapors absorb this infrared radiation and trap the heat in the atmosphere (these are 

A sink is a reservoir that uptakes a chemical element or compound from another part of its cycle. For example, soil and trees tend to act as natural sinks for carbon, as billions of tons of carbon each year in the form of CO2 are absorbed by oceans, soils, and trees. The EU-15 countries had agreed to cut, by 2012, 8% of the 1990 values, but the data collected in late 2006 by the European Commission predict that the values will be only 0.6% below the base year levels by 2010. Worse still, Austria, Belgium, Denmark, Ireland, Italy, Portugal, and Spain may even exceed their individual limits. 

The concentration of greenhouse gases in the atmosphere keeps changing dynamically due to several reactions and processes, such as (Archer, 2005 Caldeira and Wickett, 2005) 

condensation and precipitation of water vapor from the atmosphere, 

oxidation of methane by hydroxyl radical and water vapor, 

As we saw in Chapter 26, Earth s atmosphere is composed of a mixture of gases—mostly Nj, Oj, and Ar—with a variable amount of water vapor and only trace amounts of all other gases. It is the water vapor and some of the trace gases that are able to absorb infrared radiation. Because these gases are the source of Earth s greenhouse effect, they are called greenhouse gases. 

Each greenhouse gas has a different capacity for absorbing infrared radiation and absorbs it at different infrared wavelengths. The net effect of a particular gas is the product of its infrared absorbing capability times the gas s atmospheric concentration. The concentrations 

Seeing the unexpectedly rapid increase of emissions in Asia, in November 2007, the UN panel revised its prediction saying that a rise of 6°C (11°F) could be reached by as early as 2030 and, as a result, one quarter of the world s species could be eliminated. Yet, as of today, we are still using the atmosphere as a free garbage dump for our emissions. 

I hope that this book will convince the reader that the orderly transition to a clean and inexhaustible solar-hydrogen economy has to start now and that it must be completed by the end of this century. 

Water vapor, carbon dioxide (82% of our emissions), methane (9%), nitrous oxide (5%), and aerosols (2%) are all greenhouse gases. Also, ozone blocks 

In addition to C02, methane comes from landfills, coal mines, oil and gas operations, and agriculture. Nitrous oxide (NO) is emitted from burning fossil fuels and through the use of certain fertilizers or industrial processes. In terms of its effect on the climate, the most important greenhouse gas is C02. 

Our planet was created in such a way that plants will consume C02, while animals generate it. The concentration of C02 in the atmosphere reflects the balance between plant and animal life on the planet. Prior to the industrial age, the movement ( flux ) of carbon between the atmosphere, the land, and the oceans were kept in balance by nature s photosynthesis. In the last centuries, this balance has been upset not only by overpopulation and deforestation, but also by lifestyle changes—resulting in increased per capita energy consumption. 

such as water vapor, carbon dioxide, tropospheric ozone, nitrous oxide, methane, and chloroflurocarbons (CFCs), are largely transparent to solar radiation 

The shore is part of a larger zone referred to as the coast, the entire area that is affected by the sea. The coast includes the familiar sand and surf, as well as mud flats, tide pools, and marshes. The coast begins at the point where waves start breaking as they roll in toward the shore, and it extends to the farthest reaches of waves and tides on land. In some localities, the distance between the first breaking waves and the highest tides is just a matter of meters in others, it encompasses miles. 

No other part of the Earth is more dynamic than the coast. Some of the changes it experiences are both quick and extreme, like those caused by a storm. Others, such as its gentle reshaping by wind and waves, occur so slowly that they can only be observed over decades. Yet, when viewed over eons, these slow changes are as significant as those carried out by the most severe storms. 

Throughout the Earth s history, the locations and characteristics of coasts correspond to the amount of water in the oceans. Although unnoticeable in a single human lifetime, the volume of the world s oceans has varied dramatically over the life of the Earth. Two of the primary factors that determine ocean volume are the amount of ice in the ocean and the size of the ocean basin. 

Ice plays a role in ocean volume because freezing effectively removes water from the ocean, causing water levels to drop and the coasdines to widen. During each major ice age, the ocean contained less water than it does at the present time. When so much water disappeared into ice, continents were wider and shorelines extended far past their present-day borders. 

The container that holds the oceans water is called the ocean basin. As the rest of the Earth s crust, the basin is made of movable plates that can shift positions, much like a bowl 

In this chapter the mechanism by which global warming could arise is explained and the nature and sources of the chemicals which are responsible for the effect are analyzed. The principal attention will be paid to the Asian inputs to global warming though emissions of various GHG. 

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Chlorofluorocarbons (CFCs). Prior to 1978 most aerosol products contained chlorofluorocarbon propeUants. Since that time, the use of chlorinated fluorocarbons for aerosols has been seriously curtailed. These compounds have been impHcated in the depeletion of the ozone (qv) layer and are considered to be greenhouse gases (see Airpollution Atmospheric modeling). 

M. A. DeLuchi, "Emissions of Greenhouse Gases from the Use of Gasoline, Methanol, and Other Alternative Transportation Puels," ia W. Kohl, ed.. Methanol as an yiltemativeFuel Choice yin yissessment, ]oim. Hopkias Poreiga PoHcy lastitute, Washiagtoa, D.C., 1990, pp. 167—199. 

The aim of this work is to analyse processes for determination and removal (or reducing) greenhouse gases (GHG NO, SO, and CO) from air and make the comparative study of GHG emission and with production of electricity. Among various analytical methods green analytical techniques were analysed and tested for GHC determination. 

E. A. Davidson, in Production and Consumption of Greenhouse Gases Methane, Nitrogen Oxides, and Halomethanes, ed. J. E. Rogers and W. B. Whitman, American Society for Microbiology, Washington, 1991, p. 219. 

Fantechi, R., and Ghazi, A. (eds.), "Carbon Dioxide and Other Greenhouse Gases Climatic and Associated Impacts." Kluwer Academic Publishers, Boston, 1989. 

Fenner (11) has pointed out that short-lifetime constituents of the atmosphere such as nitrogen oxides, carbon monoxide, and nonmethane hydrocarbons may also play roles related to global warming because of their chemical relations to the longer-lived greenhouse gases. Also, SO, with a very short life interacts with ozone and other constituents to be converted to particulate sulfate, which has effects on cloud droplet formation. 

Wolf, G. T., and Frosch, R, A., Impact of alternative fuels on vehicle emissions of greenhouse gases, j. Air Waste Manage. Assoc. 41(12) 1172-1176 (December 1991). 

But for power station applications, the thermal efficiency is not the only measure of the performance of a plant. While a new type of plant may involve some reduction in running costs due to improved thermal efficiency, it may also involve additional capital costs. The cost of electricity produced is the crucial criterion within the overall economics, and this depends not only on the thermal efficiency and capital costs, but also on the price of fuel, operational and maintenance costs, and the taxes imposed. Yet another factor, which has recently become important, is the production by gas turbine plants of greenhouse gases (mainly carbon dioxide) which contribute to global warming. Many countries are now considering the imposition of a special tax on the amount of CO2 produced by a power plant, and this may adversely affect the economics. So consideration of a new plant in future will involve not only the factors listed above but also the amount of CO2 produced per unit of electricity together with the extra taxes that may have to be paid. 

Finally, there are also pollutants that do not cause direct health impacts hut that may have the potential to cause harm indirectly, through their actions on the overall ecology, or as they function as precursor chemicals that lead to the production of other harmful chemicals. The major indirect-action pollutants include volatile organic carbon (VOC) compounds that act as precursors to more harmful species chemicals called halocarbons and chemicals called greenhouse gases. 

Cofiring biomass has environmental benefits in addition to lowering greenhouse gases. Since biomass has little or no sulfur, sulfur dioxide (SOj) emissions are less when biomass fuels are used. In the United States, power plants have allowable sulfur dioxide levels for each gigawatt of power produced. If they produce less than the allowable amount of sulfur dioxide, they receive credits with which they can trade on the open market. The price for these sulfur dioxide credits is about 70 to 200 per ton. 

One of the main benefits from future use of biofuels would be the reduction of greenhouse gases compared to the use of fossil fuels. Carbon dioxide, a greenhouse gas that contributes to global warming, is released into the air from combustion. Twenty-four percent of worldwide energy-related carbon emissions in 1997 were from the United States. Carbon... 

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