Think twice about 'green' transport, say scientists
Jun 7 07:45 PM US/Eastern
http://www.breitbart.com/article.php?id ... _article=1
...taking public transport may not be as green as you automatically think, says a new US study.
Its authors point out an array of factors that are often unknown to the public.
These are hidden or displaced emissions that ramp up the simple "tailpipe" tally, which is based on how much carbon is spewed out by the fossil fuels used to make a trip.
Environmental engineers Mikhail Chester and Arpad Horvath at the University of California at Davis say that when these costs are included, a more complex and challenging picture emerges.
In some circumstances, for instance, it could be more eco-friendly to drive into a city -- even in an SUV, the bete noire of green groups -- rather than take a suburban train. It depends on seat occupancy and the underlying carbon cost of the mode of transport...
..."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.
"Must not listen to deniers!! Taking away Americans freedom of movement most necessary."
