Greenhouse gas emissions are the largest contributor to the U. S., according to an official government website. Earlier versions of GHG emissions from a typical U. S.
passenger vehicle were reported to be around one fifth of EU emissions. In the near future, the United States is likely to commit to the long-term goal of reducing greenhouse gas emissions by 60 to 80 percent. But before reaching that conclusion, it's worth taking a closer look at how much transport contributes to greenhouse gas emissions and what forces are already working to reduce transportation emissions. This simple example shows how the categories in which emissions are reported have a great influence on the perception of each economic sector.
The distribution of emissions from the electric power industry drastically changes the respective contribution of the other sectors, with the exception of transport, where an almost negligible amount of rail transport contributes a small amount of electricity to the mix.Transportation is “consumed by the other sectors, as is electricity,” but the accounting method simply groups passenger cars, light trucks, SUVs, commercial trucks, domestic aviation, military aircraft, commercial and recreational vessels, and emissions from all other modes motorized transport. What is much more important than the relative amount of greenhouse gas emissions from this sector is the utility provided by passenger cars and light trucks and the opportunities ahead to reduce the greenhouse gas intensity of personal motorized transport and , at the same time, maximizing utility.Recent data shows that this is exactly what has happened in recent years, even without plans to reduce greenhouse gas emissions. Since 1990, fossil fuel consumption in the U. S.
UU. It has grown at an average rate of 1 percent per year, lower than the average annual rate of population growth (1.1 percent), electricity consumption (1.9 percent) and GDP (3.0 percent). The growing market share of alternative vehicles such as hybrids and electric engines as well as different types of fuels such as ethanol and biodiesel require full life cycle analysis including production and disposal processes (in the case of batteries) in order to make meaningful comparisons with fossil fuels possible. A related effect is that the transport sector may become more similar to the industrial sector in which energy-intensive production processes are increasingly “out of country” under pressure from national environmental regulations.The analysis of mass transport lifecycle, particularly rail transit, is equally revealing.
When greenhouse gas emissions associated with underlying infrastructure required for rail transit are included in lifetime operating emissions, new rail systems are unlikely to compare favorably with the average passenger car.Of these three factors that contribute to greenhouse gas emissions from vehicles, miles traveled (VMT) vehicle is the most complicated and controversial in many respects. Strictly speaking, VMT for the U. The fleet of vehicles is not measured but estimated from traffic counts, odometer sample readings, household surveys and other references.Of these three factors it could be said that VMT has the closest relationship with real utility (mobility) derived from vehicle use and the most distant relationship with greenhouse gas emissions. Estimates derived from travel demand models are a very poor basis for estimating greenhouse gas emissions although regional planning agencies often use them for this purpose.Legislators should not despair if reducing CO2 emissions from transport sector is more expensive in short term than reducing greenhouse gas emissions in other sectors of economy.
Personal transportation is responsible for relatively small part of U. Greenhouse gas emissions and provides value that consumers rightly attach high priority: mobility.In long term consumer preferences will undoubtedly change as availability of new efficient vehicle technologies and fuels increases. The current volume of regulatory activity in U. The Department of Transportation is typical of what has been seen in last two administrations.
Public pension funds could invest in public-private partnerships that produce more transportation projects in new and abandoned areas in United States.State legislators should start thinking about permanent replacement for gas tax such as mileage-based user rates. Transportation is today largest source of greenhouse gases that heat planet in United States and most of those emissions come from driving in our cities and suburbs.Despite fact that United States has reduced carbon dioxide emissions from its power grid largely by shifting from coal power to cleaner natural gas transportation emissions have remained stubbornly high. Most of those emissions nearly 60 percent come from country's 250 million passenger cars S U V s and vans according to Environmental Protection Agency Cargo trucks contribute additional 23 percent.The vast majority of these emissions come from driving National fuel economy standards implemented under Obama administration have helped moderate increase in automotive emissions because rules require cars and trucks to use less gasoline per mile traveled.But even as vehicles have become more efficient Americans driven by strong economy and low gas prices have been driving more miles and buying more S U V s and vans.
