Transport and the environment - AbsoluteAstronomy.com

The environmental impact of transport
Transport
Transport or transportation is the movement of people, cattle, animals and goods from one location to another. Modes of transport include air, rail, road, water, cable, pipeline, and space. The field can be divided into infrastructure, vehicles, and operations...

is significant because it is a major user of energy, and burns most of the world's petroleum

Petroleum

Petroleum or crude oil is a naturally occurring, flammable liquid consisting of a complex mixture of hydrocarbons of various molecular weights and other liquid organic compounds, that are found in geologic formations beneath the Earth's surface. Petroleum is recovered mostly through oil drilling...

. This creates air pollution

Air pollution

Air pollution is the introduction of chemicals, particulate matter, or biological materials that cause harm or discomfort to humans or other living organisms, or cause damage to the natural environment or built environment, into the atmosphere....

, including nitrous oxide

Nitrous oxide

Nitrous oxide, commonly known as laughing gas or sweet air, is a chemical compound with the formula . It is an oxide of nitrogen. At room temperature, it is a colorless non-flammable gas, with a slightly sweet odor and taste. It is used in surgery and dentistry for its anesthetic and analgesic...

s and particulates, and is a significant contributor to global warming

Global warming

Global warming refers to the rising average temperature of Earth's atmosphere and oceans and its projected continuation. In the last 100 years, Earth's average surface temperature increased by about with about two thirds of the increase occurring over just the last three decades...

through emission of carbon dioxide

Carbon dioxide

Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...

, for which transport is the fastest-growing emission sector. By subsector, road transport is the largest contributor to global warming.

Environmental regulations in developed countries have reduced the individual vehicles emission; however, this has been offset by an increase in the number of vehicles, and more use of each vehicle. Some pathways to reduced the carbon emissions of road vehicles considerably have been studied. Energy use and emissions vary largely between modes, causing environmentalists

Environmentalism

Environmentalism is a broad philosophy, ideology and social movement regarding concerns for environmental conservation and improvement of the health of the environment, particularly as the measure for this health seeks to incorporate the concerns of non-human elements...

to call for a transition from air and road to rail and human-powered transport, and increase transport electrification and energy efficiency

Efficient energy use

Efficient energy use, sometimes simply called energy efficiency, is the goal of efforts to reduce the amount of energy required to provide products and services. For example, insulating a home allows a building to use less heating and cooling energy to achieve and maintain a comfortable temperature...

.

Other environmental impacts of transport systems include traffic congestion

Traffic congestion

Traffic congestion is a condition on road networks that occurs as use increases, and is characterized by slower speeds, longer trip times, and increased vehicular queueing. The most common example is the physical use of roads by vehicles. When traffic demand is great enough that the interaction...

and automobile-oriented urban sprawl

Urban sprawl

Urban sprawl, also known as suburban sprawl, is a multifaceted concept, which includes the spreading outwards of a city and its suburbs to its outskirts to low-density and auto-dependent development on rural land, high segregation of uses Urban sprawl, also known as suburban sprawl, is a...

, which can consume natural habitat and agricultural lands. By reducing transportation emissions globally, it is predicted that there will be significant positive effects on Earth's air quality, acid rain

Acid rain

Acid rain is a rain or any other form of precipitation that is unusually acidic, meaning that it possesses elevated levels of hydrogen ions . It can have harmful effects on plants, aquatic animals, and infrastructure. Acid rain is caused by emissions of carbon dioxide, sulfur dioxide and nitrogen...

, smog

Smog

Smog is a type of air pollution; the word "smog" is a portmanteau of smoke and fog. Modern smog is a type of air pollution derived from vehicular emission from internal combustion engines and industrial fumes that react in the atmosphere with sunlight to form secondary pollutants that also combine...

and climate change.

The health impact of transport emissions is also of concern. A recent survey of the studies on the effect of traffic emissions on pregnancy outcomes has linked exposure to emissions to adverse effects on gestational duration and possibly also intrauterine growth.

Aviation

Longer flights are more efficient, so emissions vary based on length of flight. CO2 emissions from air travel range from .24 kg CO2 per passenger mile for short flights down to .18 kg CO2 per passenger mile for long flights. However, researchers have been raising concern about the globally increasing hypermobility

Hypermobility (travel)

The term hypermobility in regard to travelers arose around 1980 and is a concept that has increased in useage since the early 1990s: Damette ; Hepworth and Ducatel ; Whitelegg ; Lowe ; van der Stoep ; Shields ; Cox ; Adams ; Khisty and Zeitler ; Gössling et al. ; and Mander & Randles...

of society, involving frequent and often long distance air travel and the resulting environmental and climate impacts. This threatens to overcome gains made in the efficiency of aircraft and their operations. Climate scientist Kevin Anderson raised concern about the growing effect of air transport on the climate in a paper[13] and a presentation[14] in 2008. He has pointed out that even at a reduced annual rate of increase in UK passenger air travel and with the government's targeted emissions reductions in other energy use sectors, by 2030 aviation would be causing 70% of the UK's allowable CO2 emissions.

Cars

Unleaded gasoline has 8.87 kg of CO2 per gallon. The average fuel economy for cars sold in the US 2005 was about 25.2 MPG giving around 350gCO2/mile. The Department of Transportation's MOBILE 6.2 model, used by regional governments to model air quality, uses a fleet average (all cars, old and new) of 20.3 mpg giving around 440gCO2/mile.

Buses

On average, inner city commuting buses emit .3 kg of CO2 per passenger mile, and long distance (>20 mi) bus trips emit .08 kg of CO2 per passenger mile. Road and transportation conditions vary, so some carbon calculations add 10% to the total distance of the trip to account for potential traffic jams, detours, and pit-stops that may arise.

Rail

On average, commuter rail and subway trains emit .16 kg of CO2 per passenger mile, and long distance (>20 mi) trains emit .19 kg of CO2 per passenger mile. Some carbon calculations add 10% to the total trip distance to account for detours, stop-overs, and other issues that may arise.

Shipping

The fleet emission average for delivery vans, trucks and big rigs is 10.17 kg CO2 per gallon of diesel consumed. Delivery vans and trucks average about 7.8 mpg while big rigs average about 5.3 mpg.

Shipping Emissions Factors:
- Air cargo - .8063 kg of CO2 per Ton-Mile
- Truck - 0.1693 kg of CO2 per Ton-Mile
- Train - 0.1048 kg of CO2 per Ton-Mile
- Sea freight - 0.0403 kg of CO2 per Ton-Mile
- Zeppelin - 0.0887 kg of CO2 per Ton-Mile

Mitigation of environmental impact

Road-Rail Parallel Layout

Road-Rail Parallel Layout is a design option to reduce the environmental impact of new transportation routes by locating railway tracks alongside a highway

Highway

A highway is any public road. In American English, the term is common and almost always designates major roads. In British English, the term designates any road open to the public. Any interconnected set of highways can be variously referred to as a "highway system", a "highway network", or a...

.
In 1984 the Paris

Paris

Paris is the capital and largest city in France, situated on the river Seine, in northern France, at the heart of the Île-de-France region...

—Lyon

Lyon

Lyon , is a city in east-central France in the Rhône-Alpes region, situated between Paris and Marseille. Lyon is located at from Paris, from Marseille, from Geneva, from Turin, and from Barcelona. The residents of the city are called Lyonnais....

high-speed rail route in France had about 14% parallel layout with the highway, and in 2002 70% parallel layout was achieved with the Cologne–Frankfurt high-speed rail line.

Australia

The environmental impact of transport in Australia is considerable. Australia subsidizes fossil fuel energy, keeping prices artificially low and raising greenhouse gas emissions due to the increased use of fossil fuels as a result of the subsidies. The Australian Energy Regulator and state agencies such as the New South Wales' Independent Pricing and Regulatory Tribunal set and regulate electricity prices, thereby lowering production and consumer cost.