High-speed rail -- greener than cars or planes?

Even after accounting for the possibility of more fuel-efficient planes and cars, high-speed rail powered by electricity can be the greenest transport option available.

That’s the conclusion of researchers Arpad Horvath and Mikhail Chester, who compared the sustainability of California’s proposed high-speed rail project to other forms of transportation. However, Horvath — from the University of California, Berkeley — and Chester — from Arizona State University — emphasized that high-speed rail remains just one element among many that the state would need to meet its greenhouse gas reduction goals.

“(T)his is not the answer to the state’s greenhouse gas goals,” Chester said. “This is a tiny piece of the puzzle.”

Horvath and Chester found that a high-speed train carrying an average of 80 to 180 passengers over its lifetime would equal — in terms of emissions per passenger-kilometer traveled — a 35-mile-per-gallon sedan carrying 2.2 people. Compared to a typical airplane carrying 116 passengers, the high-speed rail equivalent would be a train carrying 130 to 280 passengers.

“There are tradeoffs,” Chester said. “Depending on ridership, sometimes high-speed rail is better with greenhouse gas emissions and beats out cars and planes. For respiratory impacts, cars are typically the worst offenders, followed by high-speed rail and then airplanes. Overall, what we’re showing is that the trains are looking pretty good.”

California lawmakers recently authorized $4.7 billion in state funds for the rail project, which freed up an additional $3.3 billion in federal funding. The proposed 768-mile system would link Sacramento, San Francisco, Los Angeles and San Diego with trains traveling up to 220 miles per hour.

Legislation signed by Gov. Jerry Brown in July will enable the first stages of construction for the rail system to begin in 2013.