Greenhouse gases warming

Carbon dioxide and other greenhouse gases warm the atmosphere by trapping heat near the surface of the Earth. 

Table 6.3. Life-cycle impacts from production by fermentation of agricultural waste, as yet poorly quantified. Transportation impacts include greenhouse gas warming, air pollution and traffic accidents, assuming current vehicles such as diesel trucks. See caption to Table 6.1 (with use of Sorensen, 2004c).

Fig. 7. Estimates of greenhouse-gas contributions to global warming in the 1980s. Percentages of total contributions are CO2, 49 CH, 18 CFC-11 and...

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... 

Natural gas will continue to be substituted for oil and coal as primary energy source in order to reduce emissions of noxious combustion products particulates (soot), unburned hydrocarbons, dioxins, sulfur and nitrogen oxides (sources of acid rain and snow), and toxic carbon monoxide, as well as carbon dioxide, which is believed to be the chief greenhouse gas responsible for global warming. Policy implemented to curtail carbon emissions based on the perceived threat could dramatically accelerate the switch to natural gas. 

Since nitrous oxide, NjO, is a designated "greenhouse" gas, and may contribute to depletion of the ozone layer, its removal from emissions to atmosphere is desirable [1]. However, there are several reports that NjO can be formed at low selectivity as an undesirable by-product of NO+CO conversions during the initial warm-up-from-cold periods in three-way-catalytic (TWC) converters or components thereof [1-3]. TWC s commonly contain Rhodium and Ceria and although N,0 dissociation over RhjO, has been extensively studied [4], the following are among mechanistic possibilities as yet... 

Global Warming and increased Climatic Variability due to Greenhouse Gas (GHG) Accumulation in the Atmosphere and Increased Radiation due to Ozone Depletion by Chlorofluorocarbons (CFC). 

Mankind s impact on the global climate and whether pollution from modern energy use is indeed warming the Earth have become important issues for national and international policy makers. Political pressure and public sentiment are based on complex data sets that, alone, cannot tell the whole story. The ultimate question is whether our climate is becoming warmer because of the slow build-up in atmospheric greenhouse gas concentrations (1). The answer is not clear, because much of what we know about global climate change is inferred from historical evidence of uncertain quality. 

Each greenhouse gas differs in its ability to absorb heat in the atmosphere. HFCs and PFCs are the most heat-absorbent. Methane traps over 21 times more heat per molecule than carbon dioxide, and nitrous oxide absorbs 270 times more heat per molecule than carbon dioxide. Often, estimates of greenhouse gas emissions are presented in units of millions of metric tons of carbon equivalents (MMTCE), which weighs each gas by its GWP value, that is, Global Warming Potential. 

Over the last centuries, climate change has been raised as a very important issue all over the world. The change in climate results from an increase in the earth s average atmospheric temperature, which is usually referred to as global warming. It may be due to both natural and human causes, especially greenhouse gas (GHG) emissions. 

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