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Students of public policy sometimes envision an idealized policy process where competent data collection and incisive analysis on both sides of a debate lead to reasoned judgments and sound decisions. Unfortunately, numbers that prove decisive in policy debates are not always carefully developed, credibly documented, or correct. This paper presents four widely cited examples of numbers in the energy field that are either misleading or wrong. It explores the origins of these numbers, how they missed the mark, and how they have been misused by both analysts and the media. In addition, it describes and uses a three-stage analytical process for evaluating such statistics that involves defining terms and boundaries, assessing underlying data, and critically analyzing arguments. [ABSTRACT FROM AUTHOR]

This paper explores how long-term energy forecasts are created and why they are useful. It focuses on forecasts of energy use in the United States for the year 2000 but considers only long-term predictions, i.e., those covering two or more decades. The motivation is current interest in global warming forecasts, some of which run beyond a century. The basic observation is that forecasters in the 1950–1980 period underestimated the importance of unmodeled surprises. A key example is the failure to foresee the ability of the United States economy to respond to the oil embargos of the 1970s by increasing efficiency. Not only were most forecasts of that period systematically high, but forecasters systematically underestimated uncertainties. Long-term energy forecasts must make assumptions about both technologies and social systems. At their most successful, they influence how people act by showing the consequences of not acting. They are useful when they provide insights to energy planners, influence the perceptions of the public and the energy policy community, capture current understanding of underlying physical and economic principles, or highlight key emerging social or economic trends. It is true that at best we see dimly into the future, but those who acknowledge their duty to posterity will feel impelled to use their foresight upon what facts and guiding principles we do possess. Though many data are at present wanting or doubtful, our conclusions may be rendered so far probable as to lead to further inquiries… (), p. 4. [ABSTRACT FROM AUTHOR]

The interdependency of aircraft technological systems, the global reach of the aviation transport industry, and the uncertainty surrounding potential atmospheric effects have made defining the relationship between aviation and environmental impact an arduous task. Air travel continues to experience the fastest growth of all modes of transport, and although the energy intensity of the aviation transport system continues to decline, fuel use and total emissions have steadily risen. This trend, which represents a conflict between growth and environmental impact, has motivated the aircraft manufacturing and airline industries, the scientific community, and governmental bodies to consider what pace of emissions reduction is acceptable. This paper analyzes the historical influence of aircraft performance on cost to examine the potential pace of future efficiency improvements and emissions reduction. Technological and operational influences on aircraft energy intensity are quantified and correlated with direct operating cost and aircraft price using analytical and statistical models built upon historical data for US airlines. The energy intensity reduction potential and economic characteristics of future aircraft are also projected, through extrapolations of historical trends in aircraft technology and operations. [ABSTRACT FROM AUTHOR]

Energy conservation in Chinese residential buildings merits attention in part due to China's large population, increased standard of living, and high volume of construction. This paper focuses on three major themes: issues exerting an upward pressure on residential energy use, policy for promoting energy conservation, and technical opportunities to decrease energy use and increase comfort. An increase in total floor area, increasing electric appliance ownership, and an increase in demand for heating and cooling characterize the residential sector. Space heating remains the dominant energy end-use. Relatively new buildings in cold regions of China, while a marked improvement over earlier construction, still suffer from inadequate insulation, leaky windows, and lack of attention to construction quality. Energy-conservation standards have addressed these issues in part, but further effort is needed to ensure code compliance. A survey of prospective homeowners shows that energy-efficient housing would best be promoted by marketing the combined benefits of natural lighting and ventilation, better quality, and savings in heating and air-conditioning energy costs, rather than only promoting a dwelling as “environmentally friendly” or offering reduced heating bills. Reviewed technologies concentrate on reductions in heating and cooling energy through improved site layout, building design, building envelope materials, ventilation, and alternative cooling equipment. [ABSTRACT FROM AUTHOR]