Carbon dioxide global emissions

At present, roughly 80% of the current global energy needs comes from fossil fuels. Besides, oil is used as a raw material for the production of several chemical products. Ethanol (C2H5OH), a natural product obtained from biomass, is, on the one hand, a renewable source of energy that would be an important factor for near-zero carbon dioxide (C02) emissions, on the other hand, it is the basis for a C2 chemistry, that is, a raw material for the production of different chemical products [19,21,137-147], Besides, ethanol is accessible, can be easily transported, biodegradable, has low toxicity, and can be transformed by catalytic reactions [137],... 

In developing the analyses, the committee made quantitative estimates of some of the impacts believed to be most important, but it was not able to examine all of the possible impacts. The environmental impacts examined are associated with potential global climate change caused by carbon dioxide (C02) emissions from light-duty vehicles under the various technology pathways (see Table 5-2 in Chapter 5). The committee does not attempt to estimate any impacts on... 

Perhaps the biggest environmental challenge for ironmaking processes into the twenty-first century involves responding to the concerns about global warming. Ironmaking processes require the use of carbon-based reductants, and ultimately result in the emission of carbon dioxide. 

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... 

Transportation is also the emissions leader. About 75 percent of carbon dioxide emissions and 45 percent of nitrogen oxide emissions come from the transportation sector. If rising levels of CO, are found to be responsible for global warming, and measures are put in place to severely curtail CO, emissions, the measures will have the greatest impact on the transportation sector. 

Power plant emissions result from the comhustion of fossil fuels such as coal, gas, and oil. These emissions include sulfur dioxide (SO,), nitrogen oxides (NO.,), particulate matter, and hazardous air pollutants, all of which are subject to environmental regulations. Another emission is carbon dioxide (CO,), suspected of being responsible for global warming. 

Concerns about global climate change have led to extensive research and high-level international debates about the need for targets and timetables to reduce carbon dioxide emissions. Some policymakers believe that current uncertainties in how to approach the issue do notjustify an all-out effort to reduce carbon dioxide emission, while others feel that this is a crisis needing immediate attention. 

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. 

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