Vedantham, Anu
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Publication Aircraft Emissions: Current Inventories and Future Scenarios(1999) Baughcum, S. L; Begin, J. J; Franco, F.; Greene, D. L; Lee, D. S; McLaren, M.-L.; Mortlock, A. K; Newton, P. J; Schmitt, A.; Sutkus, D. J; Vedantham, Anu; Wuebbles, D. JThree-dimensional (latitude, longitude, altitude) global inventories of civil and military aircraft fuel burned and emissions have been developed for the United States National Aeronautics and Space Administration (NASA) for the years 1976, 1984, and 1992, and by the European Abatement of Nuisances Caused by Air Transport (ANCAT)/European Commission (EC) Working Group and the Deutsches Zentrum für Luft- und Raumfahrt (DLR) for 1991/92. For 1992, the results of the inventory calculations are in good agreement, with total fuel used by aviation calculated to be 129.3 Tg (DLR), 131.2 Tg (ANCAT), and 139.4 Tg (NASA). Total emissions of NOx (as N02) in 1992 were calculated to range from 1.7 Tg (NASA) to 1.8 Tg (ANCAT and DLR). Forecasts of air travel demand and technology developed by NASA and ANCAT for 2015 have been used to create three-dimensional (3-D) data sets of fuel burn and NOx emissions for purposes of modeling the near-term effects of aircraft. The NASA 2015 forecast results in a global fuel burn of 309 Tg, with a NOx emission of 4.1 Tg (as N02); the global emission index, EI(NOx) (g NOx/kg fuel), is 13.4. In contrast, the ANCAT 2015 forecast results in lower values-a global fuel burn of 287 Tg, an emission of 3.5 Tg of NOx and a global emission index of 12.3. The differences arise from the distribution of air travel demand and technology assumptions.Publication Aviation and the Global Atmosphere: A Special Report of IPCC Working Groups I and III(1999) Vedantham, AnuThis report assesses the effects of aircraft on climate and atmospheric ozone and is the first IPCC report for a specific industrial subsector. It was prepared by IPCC in collaboration with the Scientific Assessment Panel to the Montreal Protocol on Substances that Deplete the Ozone Layer, in response to a request by the International Civil Aviation Organization (ICAO) because of the potential impact of aviation emissions. These are the predominant anthropogenic emissions deposited directly into the upper troposphere and lower stratosphere. Aviation has experienced rapid expansion as the world economy has grown. Passenger traffic (expressed as revenue passenger kilometers) has grown since 1960 at nearly 9% per year, 2.4 times the average Gross Domestic Product (GDP) growth rate. Freight traffic, approximately 80% of which is carried by passenger airplanes, has also grown over the same time period. The rate of growth of passenger traffic has slowed to about 5% in 1997 as the industry is maturing. Total aviation emissions have increased, because increased demand for air transport has outpaced the reductions in specific emissions from the continuing improvements in technology and operational procedures. Passenger traffic, assuming unconstrained demand, is projected to grow at rates in excess of GDP for the period assessed in this report.Publication A Special Report of Working Groups I and III of the Intergovernmental Panel on Climate Change(1999-04-12) Vedantham, AnuThis report assesses the effects of aircraft on climate and atmospheric ozone and is the first IPCC report for a specific industrial subsector. It was prepared by IPCC in collaboration with the Scientific Assessment Panel to the Montreal Protocol on Substances that Deplete the Ozone Layer, in response to a request by the International Civil Aviation Organization (ICAO) because of the potential impact of aviation emissions. These are the predominant anthropogenic emissions deposited directly into the upper troposphere and lower stratosphere. Aviation has experienced rapid expansion as the world economy has grown. Passenger traffic (expressed as revenue passenger kilometers) has grown since 1960 at nearly 9% per year, 2.4 times the average Gross Domestic Product (GDP) growth rate. Freight traffic, approximately 80% of which is carried by passenger airplanes, has also grown over the same time period. The rate of growth of passenger traffic has slowed to about 5% in 1997 as the industry is maturing. Total aviation emissions have increased, because increased demand for air transport has outpaced the reductions in specific emissions3 from the continuing improvements in technology and operational procedures. Passenger traffic, assuming unconstrained demand, is projected to grow at rates in excess of GDP for the period assessed in this report. The effects of current aviation and of a range of unconstrained growth projections for aviation (which include passenger, freight, and military) are examined in this report, including the possible effects of a fleet of second generation, commercial supersonic aircraft. The report also describes current aircraft technology, operating procedures, and options for mitigating aviation's future impact on the global atmosphere. The report does not consider the local environmental effects of aircraft engine emissions or any of the indirect environmental effects of aviation operations such as energy usage by ground transportation at airports.Publication Networking for K-12 Education: The Federal Perspective(1995-01-14) Vedantham, Anu; Breeden, LauraThis article explains the need for quality educational technology in our schools, and notes the contributions of existing technology in improving education. It describes the potential that telecommunications network technology holds for revitalizing American education. It outlines the major federal programs that provide policy guidance and funding assistance for educational institutions to access and contribute to the evolving National Information Infrastructure (NII), and summarizes federal activities to date. In particular it describes the relevant experiences of the first year of the Telecommunications and Information Infrastructure Assistance Program (TIIAP) which is part of the National Telecommunications and Information Administration (NTIA) at the Department of Commerce. Contact information for all federal programs is provided as well.Publication Aircraft Emissions and the Global Atmosphere(1994) Vedantham, Anu; Oppenheimer, MichaelEmissions from airplanes and their potential global effects on the atmosphere have become the subject of intensive study by scientists, and are now drawing the interest of governments. Global fuel consumption has risen much faster for aviation than for other energy-use sectors. Concerns have focused on the contribution of nitrogen oxides (NOx), carbon dioxide (C02), water vapor (H20) and other engine effluents to the buildup of the atmosphere's greenhouse effect. Future aircraft emissions also may affect the stratosphere's ozone layer. This report describes an effort to develop long-term scenarios for emissions from aviation in order to provide a basis for assessing their potential environmental impact throughout the 21st century. Carbon dioxide and nitrogen oxides from the current and projected subsonic aircraft fleets are the main focus of this study. The scenarios in this report were produced by a model that builds on technological and operational assumptions made by industry and government for the period through 2015. It is important to state from the outset what this report is not about. It is not a detailed examination of the environmental effects of aviation. It is not an assessment of the potential for technological or operational changes that could reduce emissions from expected levels. It does not set forth a comprehensive and detailed policy prescription for limiting emissions from aviation. This report does not analyze the potential emissions of a vastly expanded fleet of supersonic aircraft, such as the proposed High-Speed Civil Transport (HSCT), although its possible environmental impacts are discussed briefly.Publication Inner City Networking: Models and Opportunities(1995-04-01) Sparrow, Judith; Vedantham, AnuInformation technologies are fast becoming an essential part of most sectors of the American economy. Today, more than half of the nation's work force uses computers on the job. Having begun as internal systems in large corporations and universities, computer networks have been embraced by small businesses, individuals, and the non-profit sector. Community organizations have been able to use the new technologies in innovative ways to meet some of the social challenges present in today's inner cities. In the process of adopting these technologies, community organizations have changed the ways they are used and perceived, integrating them into their work in creative and non-traditional ways.Publication Telecommunications in Zimbabwe(1990-11-01) Vedantham, AnuTelecommunications in many African countries is several years, perhaps decades, behind the state of the art in developed countries. In 1982, nine out of ten people in the United States owned a telephone line; in Africa, only five out of 100 did. Often, telecommunications investments are put on a lower priority at national planning levels in favor of other technologies such as electrification; advances in telecommunications are not often seen as a crucial factor in economic development. However,as the world becomes increasingly dependent on telecommunications for international economic trade and information transfer, the need for modem telecommunications capability becomes more urgent.Publication Long-term scenarios for aviation: Demand and emissions of CO2 and NOx(1998-07-01) Vedantham, Anu; Oppenheimer, MichaelThis study presents a dynamical systems model for long-term scenarios of demand in the aviation sector and resultant emissions of CO2 and NOx. We analyze the dynamics of demand growth for aviation, particularly in the emerging markets of developing nations. A model for subsonic aviation emissions is presented that reflects the consequences of industry forecasts for improvement in aviation fuel efficiency and emissions indices as well as projections of global economic and population growth over the next century. (Emissions of commercial supersonic aircraft are not modeled here.) The model incorporates a dynamical system of logistic growth towards a time-dependent capacity level. Using the long-term model, we present a set of projections of demand for aviation services, fossil fuel use, and emissions of carbon dioxide (C02) and nitrogen oxides (NOx through the year 2100; previous forecasts have not extended past 2040. We briefly discuss expectations for the distribution of NOx emissions over altitude and latitude.