‘…In fact, they add 63 percent to the “tailpipe” emissions of a car, 31 percent to those of a plane, and 55 percent to those of a train.
And another big variable that may be overlooked in green thinking is seat occupancy.
A saloon (sedan) car or even an 4×4 that is fully occupied may be responsible for less greenhouse gas per kilometer travelled per person than a suburban train that is a quarter full, the researchers calculate.
“Government policy has historically relied on energy and emission analysis of automobiles, buses, trains and aircraft at their tailpipe, ignoring vehicle production and maintenance, infrastructure provision and fuel production requirements to support these modes,” they say.
So getting a complete view of the ultimate environmental cost of the type of transport, over its entire lifespan, should help decision-makers to make smarter investments.
For travelling distances up to, say, 1,000 kilometres (600 miles), “we can ask questions as to whether it’s better to invest in a long-distance railway, improving the air corridor or boosting car occupancy,” said Chester.
The paper appears in Environmental Research Letters, a publication of Britain’s Institute of Physics.
The calculations are based on US technology and lifestyles.
It used 2005 models of the Toyota Camry saloon, Chevrolet Trailblazer SUV and Ford F-150 to calibrate automobile performance; the light transit systems in the San Francisco Bay Area and Boston as the models for the metro and commuter lines; and the Embraer 145, Boeing 737 and Boeing 747 as the benchmarks for short-, medium- and long-haul aircraft….”