Transportation is one of several major sectors that contribute to climate change. Globally, the sector's roughly 25% share of man-made carbon dioxide (CO2) emissions is similar to its share of energy consumption. Because liquid fuels are so well suited for powering cars, trucks, boats and aircraft, transportation is uniquely reliant on oil, which is the best natural resource for producing liquid fuels.
This National Research Council (NRC) report assesses the potential to achieve twin goals of reducing petroleum use and cutting greenhouse gas (GHG) emissions from U.S. cars and light trucks to 80 percent below the 2005 level by 2050.
ABSTRACT. Improving the fuel efficiency of automobiles (cars and light trucks) is an important means of addressing transportation oil demand and greenhouse gas (GHG) emissions. This report examines the efficiency attainable through evolutionary changes in U.S. automobiles that have fueling characteristics as well as performance, size and other attributes similar to those of today. The analysis combines results from previous engineering studies of powertrain efficiency and load reduction with new examinations of rates of technology change and cost reduction.
With the backing of 13 car companies, the United Auto Workers and other parties, the Obama Administration announced the biggest step forward on auto efficiency in over a generation. The new Corporate Average Fuel Economy (CAFE) regulations just finalized target the greenhouse gas emissions equivalent of 54.5 mpg by model year 2025, double the efficiency of this year's vehicle fleet.
The climate benefits of biofuels such as ethanol and biodiesel have been debated for many years. Attempts to compare these fuels with one another and fossil-derived fuels such as gasoline and diesel confront many uncertainties, not all of which can be resolved through further data analysis. By scrutinizing the greatest sources of uncertainty and grounding analysis in the areas of high certainty such as combustion chemistry and the terrestrial carbon cycle, this paper sheds light on this challenging subject and points the way toward new strategies for addressing CO2 emissions from transportation fuels.
Autonomous "robot" vehicles that can drive themselves hold great promise for transforming transportation systems across the world. Part of their appeal is the potential to greatly improve energy efficiency and reduce emissions. Not so fast, notes Bradley Berman in a critical piece on ReadWriteDrive, where he quotes Energy Institute research professor John DeCicco's admonition that technology "doesn't save us from ourselves."
Since 2005, the United States has embarked on a steady expansion of renewable fuels such as ethanol and biodiesel, widely touted as a win-win proposition for energy security and the environment. However, the promised breakthroughs in biofuel technology have greatly lagged the rapid ramp-up of production mandated by Congress while adverse side effects of the policy have become ever more clear.