Wednesday, April 09, 2008

Green Fight: Planes vs. Trains and the Surprise Heavyweight

For the past couple of years, air travel has been cast as the lead villain in the climate change drama that's unfolded. But according to a piece at the NY Times today, jet manufacturers are starting to turn that around.

But not entirely because they're interested in saving the planet. It's mostly a money issue. "Jet fuel is now the largest expense for most airlines, and for American carriers each penny increase in price per gallon costs nearly $200 million a year."

To lower the impact of fuel prices on airlines, the Times' piece notes three key innovations. First, jet engines are being designed to consume less fuel and weight less. Second, lighter, sturdier composites are replacing the aluminum that makes up most of a plane. And finally, hydraulic systems are being switched out for more efficient electric motors.

These innovations should take to the air in 2013. In the meantime, should you feel guilty every time you step on a plane? Not necessarily.

According to charts
available at the Sightline institute (a sustainability think tank in Seattle), cars still pollute more than planes. That's based on a calculation of CO2 pounds-per-passenger-mile. On the chart, trains are the most efficient, per passenger mile. But what if the train's not full?

On
the latest Guardian Science Weekly podcast, environmental journalist Fred Pearce wonders how green trains are, since every time he's on one, it's not full. In fact, in a blog posting of his from last summer, he looks at this issue and notes one UK rail operator, National Express, typically only runs half-full. He runs a couple calculations in the piece and finds one trip through the English countryside probably cost as much in emissions as a plane trip to Hong Kong.

In researching this issue, I happened across
a surprising fact at the Guardian. The carbon emissions of planes and trains are dwarfed by another form of non-automobile transportation: boats. Global shipping cranks 200 million tons of carbon into the atmosphere each year. That's about five percent of the total global output. Air transport only accounts for 2 percent. What's worse, as global trade increases, pollution from shipping may increase as much as 75 percent (reaching a total of 350 million tons by 2020, reports BP Marine).

Another fact to consider.
According to the Little Green Data Book (a joint Development Economics Data Group and Environment Department of the World Bank project), transportation is a distant second (3,386 metric tons) to the leading cause of CO2 emissions: electricity and heat (6,243 metric tons). So if you really want to reduce your carbon footprint, turn down your thermostat and shut down your electronics (like TVs, stereos and computers) instead of putting them on standby (this is responsible for millions of tons of CO2 each year).

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I started pound360 to channel my obsession with vitamins, running and the five senses. Eventually, I got bored focusing on all that stuff, so I came back from a one month hiatus in May of 2007 (one year after launching Pound360) and broadened my mumblings here to include all science.